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Sample records for solar coatings designed

  1. Solar selective absorption coatings

    DOEpatents

    Mahoney, Alan R.; Reed, Scott T.; Ashley, Carol S.; Martinez, F. Edward

    2003-10-14

    A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron structure designed to efficiently absorb solar radiation, while retaining low thermal emissivity for infrared thermal radiation. A sol-gel layer protects the structured metallic overlayer from mechanical, thermal, and environmental degradation. Processes for producing such solar selective absorption coatings are also disclosed.

  2. Solar selective absorption coatings

    DOEpatents

    Mahoney, Alan R.; Reed, Scott T.; Ashley, Carol S.; Martinez, F. Edward

    2004-08-31

    A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron structure designed to efficiently absorb solar radiation, while retaining low thermal emissivity for infrared thermal radiation. A sol-gel layer protects the structured metallic overlayer from mechanical, thermal, and environmental degradation. Processes for producing such solar selective absorption coatings are also disclosed.

  3. Optimization of antireflection coating design for multijunction solar cells and concentrator systems

    NASA Astrophysics Data System (ADS)

    Valdivia, Christopher E.; Desfonds, Eric; Masson, Denis; Fafard, Simon; Carlson, Andrew; Cook, John; Hall, Trevor J.; Hinzer, Karin

    2008-06-01

    Photovoltaic solar cells are a route towards local, environmentally benign, sustainable and affordable energy solutions. Antireflection coatings are necessary to input a high percentage of available light for photovoltaic conversion, and therefore have been widely exploited for silicon solar cells. Multi-junction III-V semiconductor solar cells have achieved the highest efficiencies of any photovoltaic technology, yielding up to 40% in the laboratory and 37% in commercial devices under varying levels of concentrated light. These devices benefit from a wide absorption spectrum (300- 1800 nm), but this also introduces significant challenges for antireflection coating design. Each sub-cell junction is electrically connected in series, limiting the overall device photocurrent by the lowest current-producing junction. Therefore, antireflection coating optimization must maximize the current from the limiting sub-cells at the expense of the others. Solar concentration, necessary for economical terrestrial deployment of multi-junction solar cells, introduces an angular-dependent irradiance spectrum. Antireflection coatings are optimized for both direct normal incidence in air and angular incidence in an Opel Mk-I concentrator, resulting in as little as 1-2% loss in photocurrent as compared to an ideal zero-reflectance solar cell, showing a similar performance to antireflection coatings on silicon solar cells. A transparent conductive oxide layer has also been considered to replace the metallic-grid front electrode and for inclusion as part of a multi-layer antireflection coating. Optimization of the solar cell, antireflection coating, and concentrator system should be considered simultaneously to enable overall optimal device performance.

  4. Design of broadband multilayer dichroic coating for a high-efficiency solar energy harvesting system.

    PubMed

    Jiachen, Wang; Lee, Sang Bae; Lee, Kwanil

    2015-05-20

    We report on the design and performance of a broadband dichroic coating for a solar energy conversion system. As a spectral beam splitter, the coating facilitates a hybrid system that combines a photovoltaic cell with a thermal collector. When positioned at a 45° angle with respect to incident light, the coating provides high reflectance in the 40-1100 nm and high transmission in the 1200-2000 nm ranges for a photovoltaic cell and a thermal collector, respectively. Numerical simulations show that our design leads to a sharp transition between the reflection and transmission bands, low ripples in both bands, and slight polarization dependence.

  5. Optical interference coatings design contest 2010: solar absorber and Fabry-Perot etalon.

    PubMed

    Hendrix, Karen; Oliver, James

    2011-03-20

    Two design problems were posed: a high-temperature solar-selective coating, and a near to mid-infrared Fabry-Perot etalon. A total of 50 submissions were received, 42 for problem A and eight for problem B. The submissions were created through a wide spectrum of design approaches and optimization strategies. Michael Trubetskov and Fabien Lemarchand won the first contest by submitting the design with the highest overall merit function, and the fewest layer/thinnest solar-selective design, respectively. Michael Trubetskov also won the second contest by submitting the thinnest Fabry-Perot etalon design, with a free spectral range standard deviation of 0. Vladimir Pervak and Bill Southwell received second-place finishes. The submitted designs are described and evaluated.

  6. Design of coated standing nanowire array solar cell performing beyond the planar efficiency limits

    NASA Astrophysics Data System (ADS)

    Zeng, Yang; Ye, Qinghao; Shen, Wenzhong

    2016-05-01

    The single standing nanowire (SNW) solar cells have been proven to perform beyond the planar efficiency limits in both open-circuit voltage and internal quantum efficiency due to the built-in concentration and the shifting of the absorption front. However, the expandability of these nano-scale units to a macro-scale photovoltaic device remains unsolved. The main difficulty lies in the simultaneous preservation of an effective built-in concentration in each unit cell and a broadband high absorption capability of their array. Here, we have provided a detailed theoretical guideline for realizing a macro-scale solar cell that performs furthest beyond the planar limits. The key lies in a complementary design between the light-trapping of the single SNWs and that of the photonic crystal slab formed by the array. By tuning the hybrid HE modes of the SNWs through the thickness of a coaxial dielectric coating, the optimized coated SNW array can sustain an absorption rate over 97.5% for a period as large as 425 nm, which, together with the inherited carrier extraction advantage, leads to a cell efficiency increment of 30% over the planar limit. This work has demonstrated the viability of a large-size solar cell that performs beyond the planar limits.

  7. Design of coated standing nanowire array solar cell performing beyond the planar efficiency limits

    SciTech Connect

    Zeng, Yang; Ye, Qinghao; Shen, Wenzhong

    2016-05-28

    The single standing nanowire (SNW) solar cells have been proven to perform beyond the planar efficiency limits in both open-circuit voltage and internal quantum efficiency due to the built-in concentration and the shifting of the absorption front. However, the expandability of these nano-scale units to a macro-scale photovoltaic device remains unsolved. The main difficulty lies in the simultaneous preservation of an effective built-in concentration in each unit cell and a broadband high absorption capability of their array. Here, we have provided a detailed theoretical guideline for realizing a macro-scale solar cell that performs furthest beyond the planar limits. The key lies in a complementary design between the light-trapping of the single SNWs and that of the photonic crystal slab formed by the array. By tuning the hybrid HE modes of the SNWs through the thickness of a coaxial dielectric coating, the optimized coated SNW array can sustain an absorption rate over 97.5% for a period as large as 425 nm, which, together with the inherited carrier extraction advantage, leads to a cell efficiency increment of 30% over the planar limit. This work has demonstrated the viability of a large-size solar cell that performs beyond the planar limits.

  8. New design graded refractive index antireflection coatings for silicon solar cells

    NASA Astrophysics Data System (ADS)

    Xiong, Chao; Xu, Weilong; Zhao, Yu; Xiao, Jin; Zhu, Xifang

    2017-07-01

    Reflectance spectrum of nanoporous silicon dioxide (SiO2) double layer was calculated by using the matrix method. The results were compared with the corresponding spectrum of silicon oxynitride (SiOxNy)-porous silicon (PS) double layer which deposited on nanostructured black silicon coatings. The nanoporous silicon dioxide (SiO2) double layer deposited on nanostructure black silicon antireflection coating presents a lower reflectance in a broad range of solar spectrum. This research outcome may find a wide application in solar cell industry.

  9. Selective coating for solar collectors

    SciTech Connect

    Schardein, D.J.

    1983-03-15

    A selective solar coating for solar collectors is disclosed. The coating is characterized by its high absorptance and low emittance. The coating comprises an organic compound or substance having a high molecular weight and a high carbon content, such as a petroleum, vegetable or animal oil, fat or wax, which is pyrolyzed to produce a carbon black pigmented varnish.

  10. The design of broad band anti-reflection coatings for solar cell applications

    NASA Astrophysics Data System (ADS)

    Siva Rama Krishna, Angirekula; Sabat, Samrat Lagnajeet; Ghanashyam Krishna, Mamidipudi

    2017-01-01

    The design of broadband anti-reflection coatings (ARCs) for solar cell applications using multiobjective differential evolutionary (MODE) algorithms is reported. The effect of thickness and refractive index contrast within the layers of the ARC on the bandwidth of reflectance is investigated in detail. In the case of the hybrid plasmonic ARC structures the effect of size, shape and filling fraction of silver (Ag) nanoparticles on the reflectance is studied. Bandwidth is defined as the spectral region of wavelengths over which the reflectance is below 2%. Single, two and three layers ARCs (consisting of MgF2, Al2O3, Si3N4, TiO2 and ZnS or combinations of these materials) were simulated for performance evaluation on an a-Si photovoltaic cell. It is observed that the three layer ARC consisting of MgF2/Si3N4/TiO2(ZnTe) of 81/42/36 nm thicknesses, respectively, exhibited a weighted reflectance of 1.9% with a bandwidth of 450 nm over the wavelength range of 300-900 nm. The ARC bandwidth could be further improved by embedding randomly distributed Ag nanoparticles of size between 100 and 120 nm on a two layer ARC consisting of Al2O3/TiO2 with thickness of 42 nm and 56 nm respectively. This plasmon-dielectric hybrid ARC design exhibited a weighted reflectance of 0.6% with a bandwidth of 560 nm over the wavelength range of 300-900 nm.

  11. Electrocurtain coating process for coating solar mirrors

    SciTech Connect

    Kabagambe, Benjamin; Boyd, Donald W.; Buchanan, Michael J.; Kelly, Patrick; Kutilek, Luke A.; McCamy, James W.; McPheron, Douglas A.; Orosz, Gary R.; Limbacher, Raymond D.

    2013-10-15

    An electrically conductive protective coating or film is provided over the surface of a reflective coating of a solar mirror by flowing or directing a cation containing liquid and an anion containing liquid onto the conductive surface. The cation and the anion containing liquids are spaced from, and preferably out of contact with one another on the surface of the reflective coating as an electric current is moved through the anion containing liquid, the conductive surface between the liquids and the cation containing liquid to coat the conductive surface with the electrically conductive coating.

  12. Solar Selective Coatings for High Temperature Applications

    NASA Technical Reports Server (NTRS)

    Jaworske, Donald A.; Shumway, Dean A.

    2003-01-01

    Solar selective coatings are envisioned for use on minisatellites, for applications where solar energy is to be used to power heat engines or to provide thermal energy for remote regions in the interior of the spacecraft. These coatings are designed to have the combined properties of high solar absorptance and low infrared emittance. The coatings must be durable at elevated temperatures. For thermal bus applications, the temperature during operation is likely to be near 100 C. For heat engine applications. the temperature is expected to be much greater. The objective of this work was to screen candidate solar selective coatings for their high temperature durability. Candidate solar selective coatings were composed of molecular mixtures of metal and dielectric, including: nickel and aluminum oxide, titanium and aluminum oxide, and platinum and aluminum oxide. To identify high temperature durability, the solar absorptance and infrared emittance of the candidate coatings were evaluated initially, and after heating to temperatures in the range of 400 C to 700 C. The titanium and aluminum oxide molecular mixture was found to be the most durable.

  13. Innovative multilayer coated optics for Solar Physics

    NASA Astrophysics Data System (ADS)

    Meltchakov, Evgueni; Auchere, Frederic; Delmotte, Franck; De Rossi, Sebastien; Mercier, Raymond; Zhang, Xueyan

    Development of multilayer coated optics with specific spectral characteristics and enhanced temporal, thermal and radiation stability requires an innovative approach to the design of reflecting multilayers and optimization of the coating process. Here we report on the progress in design, calculations and fabrication of reflecting multilayer coatings for solar imaging in the extreme ultra-violet (EUV) range. We will present recent results of characterization of new tri-component periodic multilayer structures containing aluminum as a low absorbing material within the spectral range from 17 to 40 nm. The EUV peak reflectance of these coatings (for instance, the Al/Mo/SiC multilayers) reaches 56% at 17.4 nm and 42% at 30 nm, highest reported up to now for these wavelengths. We have studied the temporal and thermal stability of structural and optical parameters of Al-based multilayer coatings as well as the resistivity of the coatings to high-energy and high-dose proton irradiation. A special attention will be drawn to specific bi-periodic systems with enhanced selectivity, which possess two efficient reflection bands and attenuate some unwanted emission lines in the EUV range. Experimental results show that such multilayer coatings are good candidates for the EUV imaging telescopes of Solar Orbiter and future solar missions.

  14. High temperature solar selective coatings

    DOEpatents

    Kennedy, Cheryl E

    2014-11-25

    Improved solar collectors (40) comprising glass tubing (42) attached to bellows (44) by airtight seals (56) enclose solar absorber tubes (50) inside an annular evacuated space (54. The exterior surfaces of the solar absorber tubes (50) are coated with improved solar selective coatings {48} which provide higher absorbance, lower emittance and resistance to atmospheric oxidation at elevated temperatures. The coatings are multilayered structures comprising solar absorbent layers (26) applied to the meta surface of the absorber tubes (50), typically stainless steel, topped with antireflective Savers (28) comprising at least two layers 30, 32) of refractory metal or metalloid oxides (such as titania and silica) with substantially differing indices of refraction in adjacent layers. Optionally, at least one layer of a noble metal such as platinum can be included between some of the layers. The absorbent layers cars include cermet materials comprising particles of metal compounds is a matrix, which can contain oxides of refractory metals or metalloids such as silicon. Reflective layers within the coating layers can comprise refractory metal silicides and related compounds characterized by the formulas TiSi. Ti.sub.3SiC.sub.2, TiAlSi, TiAN and similar compounds for Zr and Hf. The titania can be characterized by the formulas TiO.sub.2, Ti.sub.3O.sub.5. TiOx or TiO.sub.xN.sub.1-x with x 0 to 1. The silica can be at least one of SiO.sub.2, SiO.sub.2x or SiO.sub.2xN.sub.1-x with x=0 to 1.

  15. Design and demonstration of a system for the deposition of atomic-oxygen durable coatings for reflective solar dynamic power system concentrators

    NASA Technical Reports Server (NTRS)

    Mcclure, Donald J.

    1988-01-01

    A system for the vacuum deposition of atomic-oxygen durable coatings for reflective solar dynamic power systems (SDPS) concentrators was designed and demonstrated. The design issues pertinent to SDPS were developed by the Government Aerospace Systems Division of the Harris Corporation and are described in NASA-CR-179489. Both design and demonstration phases have been completed. At the time of this report the deposition system was ready for coating of facets for SDPS concentrators. The materials issue relevant to the coating work were not entirely resolved. These issues can only be resolved when substrates which are comparable to those which will be used in flight hardware are available. The substrates available during the contract period were deficient in the areas of surface roughness and contamination. These issues are discussed more thoroughly in the body of the report.

  16. Absorptive coating for aluminum solar panels

    NASA Technical Reports Server (NTRS)

    Desmet, D.; Jason, A.; Parr, A.

    1979-01-01

    Method for coating forming coating of copper oxide from copper component of sheet aluminum/copper alloy provides strong durable solar heat collector panels. Copper oxide coating has solar absorption characteristics similar to black chrome and is much simpler and less costly to produce.

  17. Absorptive coating for aluminum solar panels

    NASA Technical Reports Server (NTRS)

    Desmet, D.; Jason, A.; Parr, A.

    1979-01-01

    Method for coating forming coating of copper oxide from copper component of sheet aluminum/copper alloy provides strong durable solar heat collector panels. Copper oxide coating has solar absorption characteristics similar to black chrome and is much simpler and less costly to produce.

  18. Solar Design Workbook

    SciTech Connect

    Franta, G.; Baylin, F.; Crowther, R.; Dubin, F.; Grace, A., Griffith, J.W.; Holtz, M.; Kutscher, C.; Nordham, D.; Selkowitz, S.; Villecco, M.

    1981-06-01

    This Solar Design Workbook presents solar building design applications for commercial buildir^s. The book is divided into four sections. The first section describes the variety of solar applications in buildings including conservation aspects, solar fundamentals, passive systems, active systems, daylighting, and other solar options. Solar system design evaluation techniques including considerations for building energy requirements, passive systems, active systems, and economics are presented in Section II. The third section attempts to assist the designer in the building design process for energy conservation and solar applications including options and considerations for pre-design, design, and post-design phases. The information required for the solar design proee^ has not been fully developed at this time. Therefore, Section III is incomplete, but an overview of the considerations with some of the design proces elements is presented. Section IV illustrates ease studies that utilize solar applications in the building design.

  19. Solar Control design package

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Information used in the evaluation of design of Solar Control's solar heating and cooling system controller and the Solarstat is given. Some of the information includes system performance specifications, design data brochures, and detailed design drawings.

  20. The optimization of solar blind UV high reflectance coatings

    NASA Astrophysics Data System (ADS)

    Zhang, Hailiang; Jia, HongHui; Yang, Jiankun; Chang, Shengli; Ying, Hongwei

    2007-11-01

    Ultraviolet (UV) communication is a new kind of communication method by realizing non line-of-sight transmission of information, which overcomes disadvantages of line-of sight communication in other free space optical communication, such as non-UV laser communication. It will have a bright prospect of application. At present, there are more and more studies on UV communication technology at home and abroad. As for the UV communication system of our studies, we have researched deeply on one of the key technologies of UV communication that is UV high reflectance coatings. Based on the traditional theories and arithmetic of design for quarter-wavelength multilayer high reflectance coatings, the Needle method is improved greatly for the coating design, thus a kind of solar blind UV high reflectance coatings is designed. Results of calculation shows that this solar blind UV high-reflecting coating's reflectance is more than 97% at the range of wavelength λ=250~280nm and the coating's reflectance is smaller than 3% at the range of wavelength λ>300nm. Compared with Al coating and quarter- wavelength high reflective multi-layers coating, the coating is more suitable to be used in the atmosphere UV communication system, so the communication distance and the sensitivity of receiving system can be improved greatly. This solar blind UV high-reflecting coating can also be used in other UV optical technology and application, such as UV image, UV reconnaissance.

  1. Solar Absorptance of Cermet Coatings Evaluated

    NASA Technical Reports Server (NTRS)

    Jaworske, Donald A.

    2004-01-01

    Cermet coatings, molecular mixtures of metal and ceramic, are being considered for the heat inlet surface of solar Stirling convertors. In this application, the key role of the cermet coating is to absorb as much of the incident solar energy as possible. To achieve this objective, the cermet coating has a high solar absorptance value. Cermet coatings are manufactured utilizing sputter deposition, and many different metal and ceramic combinations can be created. The ability to mix metal and ceramic at the atomic level offers the opportunity to tailor the composition, and hence, the optical properties of these coatings. The NASA Glenn Research Center has prepared and characterized a wide variety of cermet coatings utilizing different metals deposited in an aluminum oxide ceramic matrix. In addition, the atomic oxygen durability of these coatings has been evaluated.

  2. Antisoiling Coatings for Solar-Energy Devices

    NASA Technical Reports Server (NTRS)

    Cuddihy, E. F.; Willis, P.

    1986-01-01

    Fluorocarbons resist formation of adherent deposits. Promising coating materials reduce soiling of solar photovoltaic modules and possibly solar thermal collectors. Contaminating layers of various degrees of adherence form on surfaces of devices, partially blocking incident solar energy, reducing output power. Loose soil deposits during dry periods but washed off by rain. New coatings help prevent formation of more-adherent, chemically and physically bonded layers rain alone cannot wash away.

  3. Antisoiling Coatings for Solar-Energy Devices

    NASA Technical Reports Server (NTRS)

    Cuddihy, E. F.; Willis, P.

    1986-01-01

    Fluorocarbons resist formation of adherent deposits. Promising coating materials reduce soiling of solar photovoltaic modules and possibly solar thermal collectors. Contaminating layers of various degrees of adherence form on surfaces of devices, partially blocking incident solar energy, reducing output power. Loose soil deposits during dry periods but washed off by rain. New coatings help prevent formation of more-adherent, chemically and physically bonded layers rain alone cannot wash away.

  4. Design of a three-layer antireflection coating for high efficiency indium phosphide solar cells using a chemical oxide as first layer

    NASA Technical Reports Server (NTRS)

    Moulot, Jacques; Faur, M.; Faur, M.; Goradia, C.; Goradia, M.; Bailey, S.

    1995-01-01

    It is well known that the behavior of III-V compound based solar cells is largely controlled by their surface, since the majority of light generated carriers (63% for GaAs and 79% for InP) are created within 0.2 mu m of the surface of the illuminated cell. Consequently, the always observed high surface recombination velocity (SRV) on these cells is a serious limiting factor for their high efficiency performance, especially for those with p-n junction made by either thermal diffusion or ion implantation. A good surface passivation layer, ideally a grown oxide as opposed to a deposited one, will cause a significant reduction in the SRV without adding interface problems, thus improving the performance of III-V compound based solar cells. Another significant benefit to the overall performance of the solar cells can be achieved by a substantial reduction of their large surface optical reflection by the use of a well designed antireflection (AR) coating. In this paper, we demonstrate the effectiveness of using a chemically grown thermally and chemically stable oxide, not only for surface passivation but also as an integral part of a 3-layer AR coating for thermally diffused p+n InP solar cells. A phosphorus-rich interfacial oxide, In(PO3)3, is grown at the surface of the p+ emitter using an etchant based on HNO3, o-H3PO4 and H2O2. This oxide has the unique properties of passivating the surface as well as serving as an efficient antireflective layer yielding a measured record high AMO open-circuit voltage of 890.3 mV on a thermally diffused InP(Cd,S) solar cell. Unlike conventional single layer AR coatings such as ZnS, Sb2O3, SiO or double layer AR coatings such as ZnS/MgF2 deposited by e-beam or resistive evaporation, this oxide preserves the stoichiometry of the InP surface. We show that it is possible to design a three-layer AR coating for a thermally diffused InP solar cell using the In(PO3)3 grown oxide as the first layer and Al2O3 and MgF2 as the second and third

  5. Design of a three-layer antireflection coating for high efficiency indium phosphide solar cells using a chemical oxide as first layer

    NASA Technical Reports Server (NTRS)

    Moulot, Jacques; Faur, M.; Faur, M.; Goradia, C.; Goradia, M.; Bailey, S.

    1995-01-01

    It is well known that the behavior of III-V compound based solar cells is largely controlled by their surface, since the majority of light generated carriers (63% for GaAs and 79% for InP) are created within 0.2 mu m of the surface of the illuminated cell. Consequently, the always observed high surface recombination velocity (SRV) on these cells is a serious limiting factor for their high efficiency performance, especially for those with p-n junction made by either thermal diffusion or ion implantation. A good surface passivation layer, ideally a grown oxide as opposed to a deposited one, will cause a significant reduction in the SRV without adding interface problems, thus improving the performance of III-V compound based solar cells. Another significant benefit to the overall performance of the solar cells can be achieved by a substantial reduction of their large surface optical reflection by the use of a well designed antireflection (AR) coating. In this paper, we demonstrate the effectiveness of using a chemically grown thermally and chemically stable oxide, not only for surface passivation but also as an integral part of a 3-layer AR coating for thermally diffused p+n InP solar cells. A phosphorus-rich interfacial oxide, In(PO3)3, is grown at the surface of the p+ emitter using an etchant based on HNO3, o-H3PO4 and H2O2. This oxide has the unique properties of passivating the surface as well as serving as an efficient antireflective layer yielding a measured record high AMO open-circuit voltage of 890.3 mV on a thermally diffused InP(Cd,S) solar cell. Unlike conventional single layer AR coatings such as ZnS, Sb2O3, SiO or double layer AR coatings such as ZnS/MgF2 deposited by e-beam or resistive evaporation, this oxide preserves the stoichiometry of the InP surface. We show that it is possible to design a three-layer AR coating for a thermally diffused InP solar cell using the In(PO3)3 grown oxide as the first layer and Al2O3 and MgF2 as the second and third

  6. Design of a Three-Layer Antireflection Coating for High Efficiency Indium Phosphide Solar Cells Using a Chemical Oxide as First Layer

    NASA Technical Reports Server (NTRS)

    Moulot, Jacques; Faur, Mircea; Faur, Maria; Goradia, Chandra; Goradia, Manju; Bailey, Sheila

    1995-01-01

    It is well known that the behavior of III-V compound based solar cells is largely controlled by their surface, since the majority of light generated carriers (63% for GaAs and 79% for InP) are created within 0.2 microns of the illuminated surface of the cell. Consequently, the always observed high surface recombination velocity (SRV) on these cells is a serious limiting factor for their high efficiency performance, especially for those with the p-n junction made by either thermal diffusion or ion implantation. A good surface passivation layer, ideally, a grown oxide as opposed to a deposited one, will cause a significant reduction in the SRV without adding interface problems, thus improving the performance of III-V compound based solar cells. Another significant benefit to the overall performance of the solar cells can be achieved by a substantial reduction of their large surface optical reflection by the use of a well designed antireflection (AR) coating. In this paper, we demonstrate the effectiveness of using a chemically grown, thermally and chemically stable oxide, not only for surface passivation but also as an integral part of a 3- layer AR coating for thermally diffused p(+)n InP solar cells. A phosphorus-rich interfacial oxide, In(PO3)3, is grown at the surface of the p(+) emitter using an etchant based on HNO3, o-H3PO4 and H2O2. This oxide has the unique properties of passivating the surface as well as serving as a fairly efficient antireflective layer yielding a measured record high AM0, 25 C, open-circuit voltage of 890.3 mV on a thermally diffused InP(Cd,S) solar cell. Unlike conventional single layer AR coatings such as ZnS, Sb2O3, SiO or double layer AR coatings such as ZnS/MgF2 deposited by e-beam or resistive evaporation, this oxide preserves the stoichiometry of the InP surface. We show that it is possible to design a three-layer AR coating for a thermally diffused InP solar cell using the In(PO3)3 grown oxide as the first layer and Al2O3, MgF2 or

  7. Design of a Three-Layer Antireflection Coating for High Efficiency Indium Phosphide Solar Cells Using a Chemical Oxide as First Layer

    NASA Technical Reports Server (NTRS)

    Moulot, Jacques; Faur, Mircea; Faur, Maria; Goradia, Chandra; Goradia, Manju; Bailey, Sheila

    1995-01-01

    It is well known that the behavior of III-V compound based solar cells is largely controlled by their surface, since the majority of light generated carriers (63% for GaAs and 79% for InP) are created within 0.2 microns of the illuminated surface of the cell. Consequently, the always observed high surface recombination velocity (SRV) on these cells is a serious limiting factor for their high efficiency performance, especially for those with the p-n junction made by either thermal diffusion or ion implantation. A good surface passivation layer, ideally, a grown oxide as opposed to a deposited one, will cause a significant reduction in the SRV without adding interface problems, thus improving the performance of III-V compound based solar cells. Another significant benefit to the overall performance of the solar cells can be achieved by a substantial reduction of their large surface optical reflection by the use of a well designed antireflection (AR) coating. In this paper, we demonstrate the effectiveness of using a chemically grown, thermally and chemically stable oxide, not only for surface passivation but also as an integral part of a 3- layer AR coating for thermally diffused p(+)n InP solar cells. A phosphorus-rich interfacial oxide, In(PO3)3, is grown at the surface of the p(+) emitter using an etchant based on HNO3, o-H3PO4 and H2O2. This oxide has the unique properties of passivating the surface as well as serving as a fairly efficient antireflective layer yielding a measured record high AM0, 25 C, open-circuit voltage of 890.3 mV on a thermally diffused InP(Cd,S) solar cell. Unlike conventional single layer AR coatings such as ZnS, Sb2O3, SiO or double layer AR coatings such as ZnS/MgF2 deposited by e-beam or resistive evaporation, this oxide preserves the stoichiometry of the InP surface. We show that it is possible to design a three-layer AR coating for a thermally diffused InP solar cell using the In(PO3)3 grown oxide as the first layer and Al2O3, MgF2 or

  8. Accelerated life testing of solar absorber coatings

    NASA Astrophysics Data System (ADS)

    Carlsson, Bo; Moeller, K.; Frei, Ulrich; Koehl, Michael

    1994-09-01

    Results from a comprehensive case study on accelerated life testing of some selective solar collector absorber coatings for DHW systems are reviewed. The study was conducted within Task X `Solar Materials Research and Development' of the IEA Solar Heating and Cooling Program from 1987 to 1992 and is unique due to its quantitative and systematic approach for durability assessment. The work of case study involved the development of both experimental and theoretical tools to aid the assessment of service life or absorber coatings. This entailed performance analysis, failure analysis, microclimate characterization, environmental resistance testing and life date analysis. Predicted in-service degradation of coatings from accelerated life testing was found to be in fairly good agreement both qualitatively and quantitatively with what was actually observed on coatings installed and tested for three years in solar collectors working under typical DHW conditions.

  9. Development and experimental study for hydrogen production from the thermochemical two-step water splitting cycles with a CeO2 coated new foam device design using solar furnace system

    NASA Astrophysics Data System (ADS)

    Cho, Hyun seok; Kodama, Tatsuya; Gokon, Nobuyuki; Kim, Jong kyu; Lee, Sang nam; Kang, Yong heack

    2017-06-01

    A solar reactor containing a CeO2-coated reactive foam device for producing hydrogen via a thermochemical two-step water splitting cycle was proposed and experimentally tested. Modeling of the optical properties of the 40 kWth KIER (Korea Institute of Energy Research) solar furnace was performed to design and prepare the optimized foam matrix shape and the new solar reactor. Solar demonstration of the solar reactor was accomplished in the KIER 40 kWth solar furnace and hydrogen was produced successfully during the water decomposition step. The conical shape foam device was suggested and tested the temperature gradients and hydrogen productivity. Finally, five cyclic test was conducted with the conical shape CeO2-coated foam device, the total hydrogen production was 1394.32 Ncm3 during the five cycles and the average hydrogen production per cycle was 278.86 Ncm3.

  10. Optimization of solar-selective paint coatings

    NASA Astrophysics Data System (ADS)

    McChesney, M. A.; Zimmer, P. B.; Lin, R. J. H.

    1982-06-01

    The objective was the development of low-cost, high-performance, solar-selective paint coatings for solar flat-plate collector (FPC) use and passive thermal wall application. Thickness-sensitive selective paint coating development was intended to demonstrate large scale producibility. Thickness-insensitive selective paint (TISP) coating development was intended to develop and optimize the coating for passive solar systems and FPC applications. Low-cost, high-performance TSSP coatings and processes were developed to demonstrate large-scale producibility and meet all program goals. Dip, spray, roll, laminating and gravure processes were investigated and used to produce final samples. High-speed gravure coating was selected as the most promising process for solar foil fabrication. Development and optimization of TISP coatings was not completely successful. A variation in reflective metal pigment was suspected of being the primary problem, although other variables may have contributed. Consistent repeating of optical properties of these coatings achieved on the previous program was not achieved.

  11. Survey of coatings for solar collectors

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. E.

    1975-01-01

    Optimum solar selective properties of black chrome require some tailoring of current and time for plating solution being used. Black zinc is produced from high zinc electroplate by subsequent conversion with chromate dip. Measurements have also been made of reflectance of previously known solar selective coatings of black copper and electroplated black nickel.

  12. Solar versus seismic design

    SciTech Connect

    Reitherman, R.K.

    1980-01-01

    There are several recurring seismic problems induced by passive solar design trends. The structural significance of the amount and distribution of mass, asymmetry, fluid-filled container dynamics, setbacks, atria, and buried buildings is briefly explained. It is intended to assist the solar designer in developing a better conceptual understanding of these issues from a practical viewpoint, especially during the preliminary design phase.

  13. Inexpensive Antireflection Coating for Solar Cells

    NASA Technical Reports Server (NTRS)

    Tracy, C. E.; Kern, W.; Vibronek, R. D.

    1982-01-01

    Continuous method for applying antireflection coating to solar cells increases efficiency of devices by preventing energy from being reflected away, but adds little to manufacturing cost. Method consists of spraying solution on cells or glass collector plates, drying sprayed layer, and curing it. Solution is formulated to spread evenly over surfaces.

  14. TRANSPARENT COATINGS FOR SOLAR CELLS RESEARCH

    SciTech Connect

    Glatkowski, P. J.; Landis, D. A.

    2013-04-16

    Todays solar cells are fabricated using metal oxide based transparent conductive coatings (TCC) or metal wires with optoelectronic performance exceeding that currently possible with Carbon Nanotube (CNT) based TCCs. The motivation for replacing current TCC is their inherent brittleness, high deposition cost, and high deposition temperatures; leading to reduced performance on thin substrates. With improved processing, application and characterization techniques Nanofiber and/or CNT based TCCs can overcome these shortcomings while offering the ability to be applied in atmospheric conditions using low cost coating processes At todays level of development, CNT based TCC are nearing commercial use in touch screens, some types of information displays (i.e. electronic paper), and certain military applications. However, the resistivity and transparency requirements for use in current commercial solar cells are more stringent than in many of these applications. Therefore, significant research on fundamental nanotube composition, dispersion and deposition are required to reach the required performance commanded by photovoltaic devices. The objective of this project was to research and develop transparent conductive coatings based on novel nanomaterial composite coatings, which comprise nanotubes, nanofibers, and other nanostructured materials along with binder materials. One objective was to show that these new nanomaterials perform at an electrical resistivity and optical transparency suitable for use in solar cells and other energy-related applications. A second objective was to generate new structures and chemistries with improved resistivity and transparency performance. The materials also included the binders and surface treatments that facilitate the utility of the electrically conductive portion of these composites in solar photovoltaic devices. Performance enhancement venues included: CNT purification and metallic tube separation techniques, chemical doping, CNT

  15. Protective coatings and sealants for solar applications

    SciTech Connect

    Wischmann, K. B.; Gonzales, M. H.

    1980-09-01

    An aging study has been completed which evaluated a number of polymeric materials for potential use as (1) protective coatings for back surfaces of mirrors and (2) solar heliostat edge seals. These investigations were conducted in an artificial weathering chamber that accelerated thermal cycling. The primary mirror failure mode was observed to be silver corrosion resulting from moisture exposure. To increase mirror longevity in current heliostat designs, intimate bonding at all the composite interfaces is essential to minimize moisture pathways to the silvered surface. If any voids or delaminations are present, mirror degradation will eventually occur. Delaminations can also occur as the result of mechanical stresses brought about by mismatches in the various materials coefficients of thermal expansion. If good bonding cannot be achieved or mechanical stresses avoided, then improved moisture barriers must be designed to assure mirror longevity. With good adhesion, a KRATON rubber was found to exhibit superior back surface mirror protection (12 months in environmental chamber with no corrosion). An ultraviolet stabilized butyl rubber appeared to be the best edge seal. All heliostats edge sealed with silicones showed silver corrosion which indicated either poor bonding or moisture permeation.

  16. Advanced Solar Panel Designs

    NASA Technical Reports Server (NTRS)

    Ralph, E. L.; Linder, E. B.

    1995-01-01

    Solar panel designs that utilize new high-efficiency solar cells and lightweight rigid panel technologies are described. The resulting designs increase the specific power (W/kg) achievable in the near-term and are well suited to meet the demands of higher performance small satellites (smallsats). Advanced solar panel designs have been developed and demonstrated on two NASA SBIR contracts at Applied Solar. The first used 19% efficient, large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells with a lightweight rigid graphite epoxy isogrid substrate configuration. A 1,445 sq cm coupon was fabricated and tested to demonstrate 60 W/kg with a high potential of achieving 80 W/kg. The second panel design used new 22% efficiency, dual-junction GaInP2/GaAs/Ge solar cells combined with a lightweight aluminum core/graphite fiber mesh facesheet substrate. A 1,445 sq cm coupon was fabricated and tested to demonstrate 105 W/kg with the potential of achieving 115 W/kg.

  17. SOLAR EFFECTS ON BUILDING DESIGN.

    ERIC Educational Resources Information Center

    Building Research Inst., Inc., Washington, DC.

    A REPORT OF A PROGRAM HELD AS PART OF THE BUILDING RESEARCH INSTITUTE 1962 SPRING CONFERENCE ON THE SOLAR EFFECTS ON BUILDING DESIGN. TOPICS DISCUSSED ARE--(1) SOLAR ENERGY DATA APPLICABLE TO BUILDING DESIGN, (2) THERMAL EFFECTS OF SOLAR RADIATION ON MAN, (3) SOLAR EFFECTS ON ARCHITECTURE, (4) SOLAR EFFECTS ON BUILDING COSTS, (5) SELECTION OF…

  18. Reflective coatings for solar applications

    SciTech Connect

    Jorgensen, G.

    1993-05-01

    Many applications of solar energy require large mirrors to provide high levels of concentrated sunlight. The success of such conversion systems hinges on the optical durability and economic viability of the reflector materials. A major effort at the National Renewable Energy Laboratory (NREL) has been to improve the existing reflector materials technology and to identify candidates that retain optical performance and durability criteria and offer potential for reduced cost. To attain the goals, it is desirable to maintain and increase the involvement of industrial organizations in reflective materials R D related to the conversion of solar resources to useful energy. Toward this end, NREL has recently initiated several collaborative efforts with industry to develop advanced reflector materials.

  19. Reflective coatings for solar applications

    SciTech Connect

    Jorgensen, G.

    1993-05-01

    Many applications of solar energy require large mirrors to provide high levels of concentrated sunlight. The success of such conversion systems hinges on the optical durability and economic viability of the reflector materials. A major effort at the National Renewable Energy Laboratory (NREL) has been to improve the existing reflector materials technology and to identify candidates that retain optical performance and durability criteria and offer potential for reduced cost. To attain the goals, it is desirable to maintain and increase the involvement of industrial organizations in reflective materials R&D related to the conversion of solar resources to useful energy. Toward this end, NREL has recently initiated several collaborative efforts with industry to develop advanced reflector materials.

  20. Progress to Develop an Advanced Solar-Selective Coating

    SciTech Connect

    Kennedy, C. E.

    2008-03-01

    The progress to develop a durable advanced solar-selective coating will be described. Experimental work has focused on modeling high-temperature, solar-selective coatings; depositing the individual layers and modeled coatings; measuring the optical, thermal, morphology, and compositional properties and using the data to validate the modeled and deposited properties; re-optimizing the coating; and testing the coating performance and durability.

  1. Control of miscibility and aggregation via the material design and coating process for high-performance polymer blend solar cells.

    PubMed

    Zhou, Erjun; Cong, Junzi; Hashimoto, Kazuhito; Tajima, Keisuke

    2013-12-23

    A power conversion efficiency of 3.6% for an all-polymer solar cell, which is the highest ever reported, is achieved by introducing a conjugated side chain into a p-type polymer to improve the miscibility of the polymer blend and by adding small amounts of 1,8-diiodooctane to increase the aggregation of n-type polymer. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Solar Energy: Solar System Design Fundamentals.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on solar system design fundamentals is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy…

  3. High temperature solar selective absorber coating deposited by laser cladding

    NASA Astrophysics Data System (ADS)

    Pang, Xuming

    2017-09-01

    In order to prepare high temperature stability cermets solar selective absorbing coating, single- layer Ni/Mo–TiC cermets coatings were firstly deposited on stainless steel substrate using laser cladding method and surface coating method. The result shows that the performance of the laser cladding coating is far superior to the coating fabricated by the surface coating method with thermal emittance decreased from 44.6% to 5.5%. Furthermore, the spectrally selective coating fabricated by laser cladding shows the excellent thermal stability. The solar absorptance and thermal emittance of the coating are 80.7% and 6.0% at 600 °C, 80% and 5.5% at room temperature, respectively. This result indicates that TiC-based cermets are more propitious solar selective absorber materials. More importantly, laser cladding, as a representative of new techniques, could be applied to the field of the solar selective absorber coating.

  4. Advanced solar panel designs

    NASA Technical Reports Server (NTRS)

    Ralph, E. L.; Linder, E. B.

    1996-01-01

    Solar panel designs that utilize new high-efficiency solar cells and lightweight rigid panel technologies are described. The resulting designs increase the specific power (W/kg) achievable in the near-term and are well suited to meet the demands of higher performance small satellites (smallsats). Advanced solar panel designs have been developed and demonstrated on two NASA SBIR contracts at Applied Solar. The first used 19% efficient, large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells with a lightweight rigid graphite epoxy isogrid substrate configuration. A 1,445 cm(exp 2) coupon was fabricated and tested to demonstrate 60 W/kg with a high potential of achieving 80 W/kg. The second panel design used new 22% efficiency, dual junction GaInP2/GaAs/Ge solar cells combined with a lightweight aluminum core/graphite fiber mesh facesheet substrate. A 1,445 cm(exp 2) coupon was fabricated and tested to demonstrate 105 W/kg with the potential of achieving 115 W/kg. This paper will address the construction details for the GaAs/isogrid and dual-junction GaAs/carbon mesh panel configurations. These are ultimately sized to provide 75 Watts and 119 Watts respectively for smallsats or may be used as modular building blocks for larger systems. GaAs/isogrid and dual-junction GaAs/carbon mesh coupons have been fabricated and tested to successfully demonstrate critical performance parameters and results are also provided here.

  5. Advanced solar panel designs

    NASA Technical Reports Server (NTRS)

    Ralph, E. L.; Linder, E.

    1995-01-01

    This paper describes solar cell panel designs that utilize new hgih efficiency solar cells along with lightweight rigid panel technology. The resulting designs push the W/kg and W/sq m parameters to new high levels. These new designs are well suited to meet the demand for higher performance small satellites. This paper reports on progress made on two SBIR Phase 1 contracts. One panel design involved the use of large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells of 19% efficiency combined with a lightweight rigid graphite fiber epoxy isogrid substrate configuration. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power level of 60 W/kg with a potential of reaching 80 W/kg. The second panel design involved the use of newly developed high efficiency (22%) dual junction GaInP2/GaAs/Ge solar cells combined with an advanced lightweight rigid substrate using aluminum honeycomb core with high strength graphite fiber mesh facesheets. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power of 105 W/kg and 230 W/sq m. This paper will address the construction details of the panels and an a analysis of the component weights. A strawman array design suitable for a typical small-sat mission is described for each of the two panel design technologies being studied. Benefits in respect to weight reduction, area reduction, and system cost reduction are analyzed and compared to conventional arrays.

  6. Advanced solar panel designs

    NASA Astrophysics Data System (ADS)

    Ralph, E. L.; Linder, E.

    1995-10-01

    This paper describes solar cell panel designs that utilize new hgih efficiency solar cells along with lightweight rigid panel technology. The resulting designs push the W/kg and W/sq m parameters to new high levels. These new designs are well suited to meet the demand for higher performance small satellites. This paper reports on progress made on two SBIR Phase 1 contracts. One panel design involved the use of large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells of 19% efficiency combined with a lightweight rigid graphite fiber epoxy isogrid substrate configuration. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power level of 60 W/kg with a potential of reaching 80 W/kg. The second panel design involved the use of newly developed high efficiency (22%) dual junction GaInP2/GaAs/Ge solar cells combined with an advanced lightweight rigid substrate using aluminum honeycomb core with high strength graphite fiber mesh facesheets. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power of 105 W/kg and 230 W/sq m. This paper will address the construction details of the panels and an a analysis of the component weights. A strawman array design suitable for a typical small-sat mission is described for each of the two panel design technologies being studied. Benefits in respect to weight reduction, area reduction, and system cost reduction are analyzed and compared to conventional arrays.

  7. Advanced solar panel designs

    NASA Technical Reports Server (NTRS)

    Ralph, E. L.; Linder, E.

    1995-01-01

    This paper describes solar cell panel designs that utilize new hgih efficiency solar cells along with lightweight rigid panel technology. The resulting designs push the W/kg and W/sq m parameters to new high levels. These new designs are well suited to meet the demand for higher performance small satellites. This paper reports on progress made on two SBIR Phase 1 contracts. One panel design involved the use of large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells of 19% efficiency combined with a lightweight rigid graphite fiber epoxy isogrid substrate configuration. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power level of 60 W/kg with a potential of reaching 80 W/kg. The second panel design involved the use of newly developed high efficiency (22%) dual junction GaInP2/GaAs/Ge solar cells combined with an advanced lightweight rigid substrate using aluminum honeycomb core with high strength graphite fiber mesh facesheets. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power of 105 W/kg and 230 W/sq m. This paper will address the construction details of the panels and an a analysis of the component weights. A strawman array design suitable for a typical small-sat mission is described for each of the two panel design technologies being studied. Benefits in respect to weight reduction, area reduction, and system cost reduction are analyzed and compared to conventional arrays.

  8. Coating Processes Boost Performance of Solar Cells

    NASA Technical Reports Server (NTRS)

    2012-01-01

    NASA currently has spacecraft orbiting Mercury (MESSENGER), imaging the asteroid Vesta (Dawn), roaming the red plains of Mars (the Opportunity rover), and providing a laboratory for humans to advance scientific research in space (the International Space Station, or ISS). The heart of the technology that powers those missions and many others can be held in the palm of your hand - the solar cell. Solar, or photovoltaic (PV), cells are what make up the panels and arrays that draw on the Sun s light to generate electricity for everything from the Hubble Space Telescope s imaging equipment to the life support systems for the ISS. To enable NASA spacecraft to utilize the Sun s energy for exploring destinations as distant as Jupiter, the Agency has invested significant research into improving solar cell design and efficiency. Glenn Research Center has been a national leader in advancing PV technology. The Center s Photovoltaic and Power Technologies Branch has conducted numerous experiments aimed at developing lighter, more efficient solar cells that are less expensive to manufacture. Initiatives like the Forward Technology Solar Cell Experiments I and II in which PV cells developed by NASA and private industry were mounted outside the ISS have tested how various solar technologies perform in the harsh conditions of space. While NASA seeks to improve solar cells for space applications, the results are returning to Earth to benefit the solar energy industry.

  9. High durability solar absorptive coating and methods for making same

    DOEpatents

    Hall, Aaron C.; Adams, David P.

    2016-11-22

    The present invention relates to solar absorptive coatings including a ceramic material. In particular, the coatings of the invention are laser-treated to further enhance the solar absorptivity of the material. Methods of making and using such materials are also described.

  10. Engineering coatings: Design and application. Second edition

    SciTech Connect

    Grainger, S.; Blunt, J.

    1999-07-01

    This is a guidebook for coating selection and the means of application for specific circumstances. Mechanisms of wear and corrosion are discussed in detail to assist in the analysis of component failures and newly designed parts. Coverage includes coating finishing, quality assurance, health and safety issues and other useful reference information for designers and surface engineers who use or select coatings.

  11. Advances in Concentrating Solar Power Collectors: Mirrors and Solar Selective Coatings

    SciTech Connect

    Kenendy, C. E.

    2007-10-10

    The intention is to explore the feasibility of depositing the coating by lower-cost methods and to perform a rigorous cost analysis after a viable high-temperature solar-selective coating is demonstrated by e-beam.

  12. Suppressing lossy-film-induced angular mismatches between reflectance and transmittance extrema: optimum optical designs of interlayers and AR coating for maximum transmittance into active layers of CIGS solar cells.

    PubMed

    Chang, Yin-Jung

    2014-01-13

    The investigation of optimum optical designs of interlayers and antireflection (AR) coating for achieving maximum average transmittance (T(ave)) into the CuIn(1-x)Ga(x)Se2 (CIGS) absorber of a typical CIGS solar cell through the suppression of lossy-film-induced angular mismatches is described. Simulated-annealing algorithm incorporated with rigorous electromagnetic transmission-line network approach is applied with criteria of minimum average reflectance (R(ave)) from the cell surface or maximum T(ave) into the CIGS absorber. In the presence of one MgF2 coating, difference in R(ave) associated with optimum designs based upon the two distinct criteria is only 0.3% under broadband and nearly omnidirectional incidence; however, their corresponding T(ave) values could be up to 14.34% apart. Significant T(ave) improvements associated with the maximum-T(ave)-based design are found mainly in the mid to longer wavelengths and are attributed to the largest suppression of lossy-film-induced angular mismatches over the entire CIGS absorption spectrum. Maximum-T(ave)-based designs with a MgF2 coating optimized under extreme deficiency of angular information is shown, as opposed to their minimum-R(ave)-based counterparts, to be highly robust to omnidirectional incidence.

  13. Sol-gel-derived AR coatings for solar receivers

    NASA Astrophysics Data System (ADS)

    Ashley, C. S.; Reed, S. T.

    1984-09-01

    A process for applying sol-gel antireflection (AR) coatings to solar receiver envelopes is investigated. The process consists of applying a porous film which is subsequently etched to achieve the optimum AR effect. The result is a single-layer interference film with a reflectance minimum at 550 nm. The solar transmittance of coated tubes is typically increased to 0.05 to 0.97, as compared with 0.91 for uncoated tubes. Coated tubes showed no significant decrease in solar transmittance after 16 weeks of operation in a parabolic trough collector system. Recommendations are included for process improvement before industrial scale-up.

  14. New solar selective coating based on carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Abendroth, Thomas; Leupolt, Beate; Mäder, Gerrit; Härtel, Paul; Grählert, Wulf; Althues, Holger; Kaskel, Stefan; Beyer, Eckhard

    2016-05-01

    Carbon nanotubes (CNTs) can be applied to assemble a new type of solar selective coating system for solar thermal applications. In this work the predominant absorption processes occurring by interaction with π-plasmon and Van Hove singularities (VHS) were investigated by UV-VIS-NIR spectroscopy and ellipsometry. Not only optical properties for as deposited SWCNT thin films itself, but also the potential for systematic tailoring will be presented. Besides low cost technologies required, the adjustability of optical properties, as well as their thermal stability render CNT based solar selective coatings as promising alternative to commercially available coating systems.

  15. Enhanced light trapping in solar cells using snow globe coating

    PubMed Central

    Basch, Angelika; Beck, Fiona; Söderström, Thomas; Varlamov, Sergey; Catchpole, Kylie R

    2012-01-01

    A novel method, snow globe coating, is found to show significant enhancement of the short circuit current JSC (35%) when applied as a scattering back reflector for polycrystalline silicon thin-film solar cells. The coating is formed from high refractive index titania particles without containing binder and gives close to 100% reflectance for wavelengths above 400 nm. Snow globe coating is a physicochemical coating method executable in pH neutral media. The mild conditions of this process make this method applicable to many different types of solar cells. Copyright © 2012 John Wiley & Sons, Ltd. PMID:26300618

  16. Durability of Solar Selective Coatings in a Simulated Space Environment

    NASA Technical Reports Server (NTRS)

    Jaworske, Donald A.; Lyons, Valerie (Technical Monitor)

    2002-01-01

    Solar selective coatings are being considered for heat engine and thermal switching applications on minisatellites. Such coatings must have the combined properties of high solar absorptance and low infrared emittance. High solar absorptance is needed to collect solar energy as efficiently as possible while low infrared emittance is needed to minimize radiant energy loss at operating temperature. These properties are achieved in sputter deposited thin films through the use of molecular mixtures of metal and dielectric. Solar selective coatings having a solar absorptance to infrared emittance ratio of 9 have been successfully deposited using a mixture of nickel and aluminum oxide. The space environment, however, presents some challenges for the use of materials on the exterior of spacecraft, including durability to atomic oxygen and vacuum ultraviolet radiation. To address these concerns, several candidate solar selective coatings were exposed to atomic oxygen in a plasma asher and to ultraviolet radiation in a vacuum facility equipped with calibrated deuterium lamps. The optical properties of the coatings were monitored as a function of time to evaluate their performance over long term exposure to the simulated space environment. Several coatings were found to be durable to both the atomic oxygen and the vacuum ultraviolet environments.

  17. Particulate and solar radiation stable coating for spacecraft

    NASA Technical Reports Server (NTRS)

    Slemp, W. S. (Inventor)

    1977-01-01

    A laminate thermal control coating for spacecraft comprising a layer of solar radiation stable film, a layer of particulate radiation stable film applied to the upper surface of the solar radiation stable film, and a layer of reflecting material applied to the lower surface of the solar radiation stable film was described. The coating experiences no increase in solar radiation absorptance (the proportion of radiant energy absorbed) upon exposure to particulate or solar radiation as the particulate radiation is substantially absorbed in the particulate radiation stable layer and the solar radiation partially absorbed by the particulate radiation stable layer is transmitted by the solar radiation stable film to the reflecting material which reflects it back through the laminate and into space.

  18. Optical interference coatings design contest 2004.

    PubMed

    Tilsch, Markus; Hendrix, Karen; Verly, Pierre

    2006-03-01

    A manufacturable, broadband, broad-angle antireflection (AR) coating for the visible (13 designs submitted) and a minimum-shift immersed short-pass filter (12 designs submitted) were the subjects of the design contest held in conjunction with the 2004 Optical Interference Coatings topical meeting of the Optical Society of America. Under the specified constraints, the broadband, broad-angle AR coating could be made more than 65 nm wide. The statistical stability of manufacturing simulations is discussed. The short-pass filter could operate up to a +/- 5.5 degree angular range. The submitted designs are described and evaluated.

  19. Solar selective coatings based on nickel oxide obtained via spray pyrolysis.

    PubMed

    Voinea, Mihaela; Ienei, Elena; Bogatu, Cristina; Duta, Anca

    2009-07-01

    The paper presents the optimization process for obtaining NiO thin layers on copper substrate for solar absorber coatings, using an inexpensive and up-scalable technique: spray pyrolysis deposition (SPD). Efficient selective coatings must present a high absorption coefficient of the incident solar irradiation, and low emission of heat. The solar selective coatings design involves tailoring the surface properties for superior optical properties. The deposition parameters were varied for maximizing the solar absorbance and minimizing the thermal emittance. The film morphology was controlled using copolymers of the maleic anhydride as additives into the precursors' solution. The structural and surface properties of the films were investigated by X-ray diffraction and atomic force microscopy, respectively. The Cu/CuO(x)/NiO solar absorber shows good values for the solar absorptance (alpha(s) = 0.95) and thermal emittance (epsilon(T) = 0.05) compared with the ones obtained by other methods employed in literature and new additives are recommended in tailoring the surface of solar selective coatings.

  20. Optimized solar module design

    NASA Technical Reports Server (NTRS)

    Santala, T.; Sabol, R.; Carbajal, B. G.

    1978-01-01

    The minimum cost per unit of power output from flat plate solar modules can most likely be achieved through efficient packaging of higher efficiency solar cells. This paper outlines a module optimization method which is broadly applicable, and illustrates the potential results achievable from a specific high efficiency tandem junction (TJ) cell. A mathematical model is used to assess the impact of various factors influencing the encapsulated cell and packing efficiency. The optimization of the packing efficiency is demonstrated. The effect of encapsulated cell and packing efficiency on the module add-on cost is shown in a nomograph form.

  1. Solar Selective Coatings Developed for Space Power Applications

    NASA Technical Reports Server (NTRS)

    Jaworske, Donald A.

    2002-01-01

    A solar collector having the combined properties of high solar absorptance, low infrared emittance, and high thermal conductivity is envisioned for space power applications on minisatellites. A high solar absorptance is needed to collect as much of the incident solar radiation as possible and a low infrared emittance is needed to minimize radiant energy losses. A lightweight material having a high thermal conductivity is needed to transport the absorbed energy to where it is needed. Such a solar collector may be used with a low temperature-differential heat engine to provide electric power to the minisatellite components or as a source of thermal energy for a thermal bus that would heat remote regions of the spacecraft. The key to such a collector is the use of cermet coatings. Cermet coatings are composed of molecular islands of metal embedded in a three-dimensional matrix of dielectric. Recent research on molecular mixtures of aluminum and aluminum oxide at the NASA Glenn Research Center has yielded cermet coatings with a solar absorptance a of 0.797 and an infrared emittance epsilon of 0.131, yielding an alpha/epsilon ratio of 6. Although additional work is needed to further increase the alpha/epsilon ratio, these coatings are attractive owing to their potential durability in the space environment. The aluminum oxide surface should provide substantial protection from the atomic oxygen found in low Earth orbit. To help minimize emittance, these coatings are deposited on a smooth surface. The selected surface is aluminum that has been diamond turned to a mirror finish. Cermet coatings are manufactured by sputter deposition. To achieve the desired variable composition, Glenn's researchers implemented a novel approach using a cylindrical target composed of aluminum and aluminum oxide. Rotating the cylinder during the deposition process yields a coating of variable composition. A photograph of the custom-made aluminum and aluminum oxide cylindrical target installed

  2. Novel Passivating/Antireflective Coatings for Space Solar Cells

    NASA Technical Reports Server (NTRS)

    Faur, Mircea; Faur, Maria; Bailey, S. G.; Flood, D. J.; Faur, H. M.; Mateescu, C. G.; Alterovitz, S. A.; Scheiman, D.; Jenkins, P. P.; Brinker, D. J.

    2005-01-01

    We are developing a novel process to grow passivating/antireflective (AR) coatings for terrestrial and space solar cells. Our approach involves a Room Temperature Wet Chemical Growth (RTWCG) process, which was pioneered, and is under development at SPECMAT, Inc., under a Reimbursable Space Act Agreement with NASA Glenn Research Center. The RTWCG passivating/AR coatings with graded index of refraction are applied in one easy step on finished (bare) cells. The RTWCG coatings grown on planar, textured and porous Si, as well as on poly-Si, CuInSe2, and III-V substrates, show excellent uniformity irrespective of surface topography, crystal orientation, size and shape. In this paper we present some preliminary results of the RTWCG coatings on Si and III-V substrates that show very good potential for use as a passivation/AR coating for space solar cell applications. Compared to coatings grown using conventional techniques, the RTWCG coatings have the potential to reduce reflection losses and improve current collection near the illuminated surface of space solar cells, while reducing the fabrication costs.

  3. Wet-chemistry based selective coatings for concentrating solar power

    NASA Astrophysics Data System (ADS)

    Maimon, Eran; Kribus, Abraham; Flitsanov, Yuri; Shkolnik, Oleg; Feuermann, Daniel; Zwicker, Camille; Larush, Liraz; Mandler, Daniel; Magdassi, Shlomo

    2013-09-01

    Spectrally selective coatings are common in low and medium temperature solar applications from solar water heating collectors to parabolic trough absorber tubes. They are also an essential element for high efficiency in higher temperature Concentrating Solar Power (CSP) systems. Selective coatings for CSP are usually prepared using advanced expensive methods such as sputtering and vapor deposition. In this work, coatings were prepared using low-cost wet-chemistry methods. Solutions based on Alumina and Silica sol gel were prepared and then dispersed with black spinel pigments. The black dispersions were applied by spray/roll coating methods on stainless steel plates. The spectral emissivity of sample coatings was measured in the temperature range between 200 and 500°C, while the spectral absorptivity was measured at room temperature and 500°C. Emissivity at wavelengths of 0.4-1.7 μm was evaluated indirectly using multiple measurements of directional reflectivity. Emissivity at wavelengths 2-14 μm was measured directly using a broadband IR camera that acquires the radiation emitted from the sample, and a range of spectral filters. Emissivity measurement results for a range of coated samples will be presented, and the impact of coating thickness, pigment loading, and surface preparation will be discussed.

  4. Preliminary design package for solar collector and solar pump

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A solar-operated pump using an existing solar collector, for use on solar heating and cooling and hot water systems is described. Preliminary design criteria of the collector and solar-powered pump is given including: design drawings, verification plans, and hazard analysis.

  5. New Challenges in Optical Coating Design

    NASA Astrophysics Data System (ADS)

    Stenzel, Olaf

    Modern mathematical algorithms allow to theoretically generate thin film designs that fit nearly any reasonable specification. Nevertheless, as practice has shown, the gap between calculated and technologically achievable characteristics may be significant, so that the search for qualitatively new design and production tools is still in progress and represents one of the most complex challenges in thin optical coating theory and technology today. Such new design challenges include the incorporation of gradient index layers into classical designs, the design of rugate filters, or novel filter concepts that are based on resonant grating waveguide structures. Moreover, the development of novel composite coating materials is expected to facilitate the optimisation of future designs.

  6. Enhanced photocurrent in crystalline silicon solar cells by hybrid plasmonic antireflection coatings

    NASA Astrophysics Data System (ADS)

    Fahim, Narges F.; Ouyang, Zi; Jia, Baohua; Zhang, Yinan; Shi, Zhengrong; Gu, Min

    2012-12-01

    Photocurrent enhancement induced by plasmonic light trapping is of great interest for photovoltaics. We design and demonstrate hybrid plasmonic antireflection coatings as an efficient light trapping strategy for broadband absorption and photocurrent enhancement in crystalline silicon solar cells. Gold nanoparticles of size ranging from 15 to 150 nm are embedded in standard SiNx antireflection coatings with a thickness of 90 nm. Through optimizing the location of tailored nanoparticles within the SiNx layer, both light scattering enhancement and near-field light concentration can be harnessed. A maximum increase of 6.3% in photocurrent is achieved for textured multi-crystalline Si solar cells with the optimum configuration.

  7. Passive solar design handbook. Volume 3: Passive solar design analysis

    NASA Astrophysics Data System (ADS)

    Jones, R. W.; Bascomb, J. D.; Kosiewicz, C. E.; Lazarus, G. S.; McFarland, R. D.; Wray, W. O.

    1982-07-01

    Simple analytical methods concerning the design of passive solar heating systems are presented with an emphasis on the average annual heating energy consumption. Key terminology and methods are reviewed. The solar load ratio (SLR) is defined, and its relationship to analysis methods is reviewed. The annual calculation, or Load Collector Ratio (LCR) method, is outlined. Sensitivity data are discussed. Information is presented on balancing conservation and passive solar strategies in building design. Detailed analysis data are presented for direct gain and sunspace systems, and details of the systems are described. Key design parameters are discussed in terms of their impact on annual heating performance of the building. These are the sensitivity data. The SLR correlations for the respective system types are described. The monthly calculation, or SLR method, based on the SLR correlations, is reviewed. Performance data are given for 9 direct gain systems and 15 water wall and 42 Trombe wall systems.

  8. Solar water heater design package

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Package describes commercial domestic-hot-water heater with roof or rack mounted solar collectors. System is adjustable to pre-existing gas or electric hot-water house units. Design package includes drawings, description of automatic control logic, evaluation measurements, possible design variations, list of materials and installation tools, and trouble-shooting guide and manual.

  9. Solar water heater design package

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Package describes commercial domestic-hot-water heater with roof or rack mounted solar collectors. System is adjustable to pre-existing gas or electric hot-water house units. Design package includes drawings, description of automatic control logic, evaluation measurements, possible design variations, list of materials and installation tools, and trouble-shooting guide and manual.

  10. Advanced Antireflection Coatings for High-Performance Solar Energy Applications

    NASA Technical Reports Server (NTRS)

    Pan, Noren

    2015-01-01

    Phase II objectives: Develop and refine antireflection coatings incorporating lanthanum titanate as an intermediate refractive index material; Investigate wet/dry thermal oxidation of aluminum containing semiconductor compounds as a means of forming a more transparent window layer with equal or better optical properties than its unoxidized form; Develop a fabrication process that allows integration of the oxidized window layer and maintains the necessary electrical properties for contacting the solar cell; Conduct an experimental demonstration of the best candidates for improved antireflection coatings.

  11. Solar Power System Design for the Solar Probe+ Mission

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Schmitz, Paul C.; Kinnison, James; Fraeman, Martin; Roufberg, Lew; Vernon, Steve; Wirzburger, Melissa

    2008-01-01

    Solar Probe+ is an ambitious mission proposed to the solar corona, designed to make a perihelion approach of 9 solar radii from the surface of the sun. The high temperature, high solar flux environment makes this mission a significant challenge for power system design. This paper summarizes the power system conceptual design for the solar probe mission. Power supplies considered included nuclear, solar thermoelectric generation, solar dynamic generation using Stirling engines, and solar photovoltaic generation. The solar probe mission ranges from a starting distance from the sun of 1 AU, to a minimum distance of about 9.5 solar radii, or 0.044 AU, from the center of the sun. During the mission, the solar intensity ranges from one to about 510 times AM0. This requires power systems that can operate over nearly three orders of magnitude of incident intensity.

  12. Transparent, Conductive Coatings Developed for Arc-Proof Solar Arrays

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Transparent, conductive thin-film coatings have many potential applications where a surface must be able to dissipate electrical charges without sacrificing its optical properties. Such applications include automotive and aircraft windows, heat mirrors, optoelectronic devices, gas sensors, and solar cell array surfaces for space applications. Many spacecraft missions require that solar cell array surfaces dissipate charges in order to avoid damage such as electronic upsets, formation of pinholes in the protective coatings on solar array blankets, and contamination due to deposition of sputtered products. In tests at the NASA Lewis Research Center, mixed thin-films of sputter-deposited indium tin oxide (ITO) and magnesium fluoride (MgF2) that could be tailored to the desired sheet resistivity, showed transmittance values of greater than 90 percent. The samples evaluated were composed of mixed, thin-film ITO/MgF2 coatings, with a nominal thickness of 650 angstroms, deposited onto glass substrates. Preliminary results indicated that these coatings were durable to vacuum ultraviolet radiation and atomic oxygen. These coatings show promise for use on solar array surfaces in polar low-Earth-orbit environments, where a sheet resistivity of less than 10(exp 8)/square is required, and in geosynchronous orbit environments, where a resistivity of less than 10(exp 9)/square is required.

  13. Transparent, Conductive Coatings Developed for Arc-Proof Solar Arrays

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Transparent, conductive thin-film coatings have many potential applications where a surface must be able to dissipate electrical charges without sacrificing its optical properties. Such applications include automotive and aircraft windows, heat mirrors, optoelectronic devices, gas sensors, and solar cell array surfaces for space applications. Many spacecraft missions require that solar cell array surfaces dissipate charges in order to avoid damage such as electronic upsets, formation of pinholes in the protective coatings on solar array blankets, and contamination due to deposition of sputtered products. In tests at the NASA Lewis Research Center, mixed thin-films of sputter-deposited indium tin oxide (ITO) and magnesium fluoride (MgF2) that could be tailored to the desired sheet resistivity, showed transmittance values of greater than 90 percent. The samples evaluated were composed of mixed, thin-film ITO/MgF2 coatings, with a nominal thickness of 650 angstroms, deposited onto glass substrates. Preliminary results indicated that these coatings were durable to vacuum ultraviolet radiation and atomic oxygen. These coatings show promise for use on solar array surfaces in polar low-Earth-orbit environments, where a sheet resistivity of less than 10(exp 8)/square is required, and in geosynchronous orbit environments, where a resistivity of less than 10(exp 9)/square is required.

  14. Evaluation of glass resin coatings for solar cell applications

    NASA Technical Reports Server (NTRS)

    Field, M. B.

    1978-01-01

    Using a variety of non-vacuum deposition techniques coatings were implemented on silicon solar cells and arrays of cells interconnected on Kapton substrates. The coatings provide both antireflection optical matching and environmental protection. Reflectance minima near 2% was achieved at a single wavelength in the visible. Reflectance averaging below 5% across the useful collection range was demonstrated. The coatings and methods of deposition were: (1) Ta2O5 spun, dipped or sprayed; (2) Ta2O5.SiO2 spun, dipped or sprayed; (3) GR908 (SiO2) spun, dipped, or sprayed. Total coating thickness were in the range of 18 microns to 25 microns. The coatings and processes are compatible with single cells or cells mounted on Kapton substrates.

  15. Glass frits coated with silver nanoparticles for silicon solar cells

    NASA Astrophysics Data System (ADS)

    Li, Yingfen; Gan, Weiping; Zhou, Jian; Li, Biyuan

    2015-06-01

    Glass frits coated with silver nanoparticles were prepared by electroless plating. Gum Arabic (GA) was used as the activating agent of glass frits without the assistance of stannous chloride or palladium chloride. The silver-coated glass frits prepared with different GA dosages were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA). The characterization results indicated that silver-coated glass frits had the structures of both glass and silver. Spherical silver nanoparticles were distributed on the glass frits evenly. The density and particle size of silver nanoparticles on the glass frits can be controlled by adjusting the GA dosage. The silver-coated glass frits were applied to silver pastes to act as both the densification promoter and silver crystallite formation aid in the silver electrodes. The prepared silver-coated glass frits can improve the photovoltaic performances of solar cells.

  16. Testing of a new solar coating for solar water heating applications

    SciTech Connect

    AlShamaileh, Ehab

    2010-09-15

    A novel and affordable solar selective coating exhibiting higher solar absorption efficiency compared to the commercial black paint coating used in most ordinary solar water heating systems (SWHSs) has been developed. The coating is fabricated by embedding a metallic particle composed of a nickel-aluminium (NiAl) alloy into the black paint. The optical behaviour of several percentages of the NiAl alloy in the coating is studied using UV-Vis and IR spectroscopies. The chemical composition of the coating was characterized using XRD and thermo-gravimetric analysis (TGA) for both the black and alloy-containing paint. The results allowed deducing that the optimum composition to consider for further testing was 6% NiAl alloy by mass. The applicability of the coating in a real thermosyphonic SWHS was evaluated throughout the year, spanning both hot and cold seasons. It is found that the new coating shows better performance compared to the untreated black paint by an average of 5 C over a period of 1 year. The corrosion resistance of the coating was investigated using electrochemical polarization and weight-loss measurements in the corrosive medium of 3% NaCl in 0.50 M HCl. Higher inhibition efficiency of corrosion was found for the alloy-containing paint compared to the untreated paint by more than 12%. Finally, Scanning Electron Microscopy (SEM) was used to explore the morphology of the modified coating surface, and compared to the untreated surface. (author)

  17. Final Technical Report CONDUCTIVE COATINGS FOR SOLAR CELLS USING CARBON NANOTUBES

    SciTech Connect

    Paul J Glatkowski; Jorma Peltola; Christopher Weeks; Mike Trottier; David Britz

    2007-09-30

    US Department of Energy (DOE) awarded a grant for Eikos Inc. to investigate the feasibility of developing and utilizing Transparent Conducting Coatings (TCCs) based on carbon nanotubes (CNT) for solar cell applications. Conventional solar cells today employ metal oxide based TCCs with both Electrical Resistivity (R) and Optical Transparency (T), commonly referred to as optoelectronic (RT) performance significantly higher than with those possible with CNT based TCCs available today. Transparent metal oxide based coatings are also inherently brittle requiring high temperature in vacuum processing and are thus expensive to manufacture. One such material is indium tin oxide (ITO). Global demand for indium has recently increased rapidly while supply has diminished causing substantial spikes in raw material cost and availability. In contrast, the raw material, carbon, needed for CNT fabrication is abundantly available. Transparent Conducting Coatings based on CNTs can overcome not only cost and availability constraints while also offering the ability to be applied by existing, low cost process technologies under ambient conditions. Processes thus can readily be designed both for rigid and flexible PV technology platforms based on mature spray or dip coatings for silicon based solar cells and continuous roll to roll coating processes for polymer solar applications.

  18. Advanced optical coating technology used in the development of concentrator arrays for solar space power applications

    NASA Astrophysics Data System (ADS)

    Fulton, Michael L.; O'Neill, Mark J.

    2006-08-01

    Since 1990 thin film optical coatings have taken a prominent role in the development of highly efficient solar power concentrators for future space applications. During the initial development of this coating technology, the Boeing High Technology Center explored various ways of protecting ENTECH's DC93-500 silicone Fresnel lenses from the harsh space environment. ENTECH's mini-dome lenses focused solar energy onto small high-efficiency solar cells for generating electrical power. To protect the silicone lenses from solar UV darkening, one early approach involved a cerium-doped glass cover cemented over the lens. Unfortunately, during launch simulation shock testing the glass lens covers cracked. We next explored the deposition of a UV blocking thin film coating directly to the silicone lens surface. This was a problem of immense proportions analogous to pouring concrete on to the surface of a reservoir filled with "Jell-O." Differential in coefficient of thermal expansion between the DC93-500 silicone and the deposited dielectric optical coating had to be balanced with intrinsic stress of the optical coating materials. Ion Beam Optics' work has culminated, some fifteen years later, in the current coating technology that is being incorporated in the Stretched Lens Array SquareRigger (SLASR). SLASR is designed to replace classic flat panel solar arrays with a lighter, lower cost, and more efficient (30%) concentrator arrays for future space applications. This paper will describe the coating technology and show its performance and benefits for SLASR space power systems. Results from both ground tests and space flight tests will be presented.

  19. Silicon solar cells with Al2O3 antireflection coating

    NASA Astrophysics Data System (ADS)

    Dobrzański, Leszek A.; Szindler, Marek; Drygała, Aleksandra; Szindler, Magdalena M.

    2014-09-01

    The paper presents the possibility of using Al2O3 antireflection coatings deposited by atomic layer deposition ALD. The ALD method is based on alternate pulsing of the precursor gases and vapors onto the substrate surface and then chemisorption or surface reaction of the precursors. The reactor is purged with an inert gas between the precursor pulses. The Al2O3 thin film in structure of the finished solar cells can play the role of both antireflection and passivation layer which will simplify the process. For this research 50×50 mm monocrystalline silicon solar cells with one bus bar have been used. The metallic contacts were prepared by screen printing method and Al2O3 antireflection coating by ALD method. Results and their analysis allow to conclude that the Al2O3 antireflection coating deposited by ALD has a significant impact on the optoelectronic properties of the silicon solar cell. For about 80 nm of Al2O3 the best results were obtained in the wavelength range of 400 to 800 nm reducing the reflection to less than 1%. The difference in the solar cells efficiency between with and without antireflection coating was 5.28%. The LBIC scan measurements may indicate a positive influence of the thin film Al2O3 on the bulk passivation of the silicon.

  20. Silicon solar cells with Al2O3 antireflection coating

    NASA Astrophysics Data System (ADS)

    Dobrzański, Leszek; Szindler, Marek; Drygała, Aleksandra; Szindler, Magdalena

    2014-09-01

    The paper presents the possibility of using Al2O3 antireflection coatings deposited by atomic layer deposition ALD. The ALD method is based on alternate pulsing of the precursor gases and vapors onto the substrate surface and then chemisorption or surface reaction of the precursors. The reactor is purged with an inert gas between the precursor pulses. The Al2O3 thin film in structure of the finished solar cells can play the role of both antireflection and passivation layer which will simplify the process. For this research 50×50 mm monocrystalline silicon solar cells with one bus bar have been used. The metallic contacts were prepared by screen printing method and Al2O3 antireflection coating by ALD method. Results and their analysis allow to conclude that the Al2O3 antireflection coating deposited by ALD has a significant impact on the optoelectronic properties of the silicon solar cell. For about 80 nm of Al2O3 the best results were obtained in the wavelength range of 400 to 800 nm reducing the reflection to less than 1%. The difference in the solar cells efficiency between with and without antireflection coating was 5.28%. The LBIC scan measurements may indicate a positive influence of the thin film Al2O3 on the bulk passivation of the silicon.

  1. Solar absorption characteristics of several coatings and surface finishes. [for solar energy collectors

    NASA Technical Reports Server (NTRS)

    Lowery, J. R.

    1977-01-01

    Solar absorption characteristics are established for several films potentially favorable for use as receiving surfaces in solar energy collectors. Included in the investigation were chemically produced black films, black electrodeposits, and anodized coatings. It was found that black nickel exhibited the best combination of selective optical properties of any of the coatings studied. A serious drawback to black nickel was its high susceptibility to degradation in the presence of high moisture environments. Electroplated black chrome generally exhibited high solar absorptivities, but the emissivity varied considerably and was also relatively high under some conditions. The black chrome had the greatest moisture resistance of any of the coatings tested. Black oxide coatings on copper and steel substrates showed the best combination of selective optical properties of any of the chemical conversion films studied.

  2. Technics: Solar Design. Insolutions.

    ERIC Educational Resources Information Center

    Watson, Donald

    1979-01-01

    Some quantitative methods are illustrated that might be used to select design elements that are appropriate year-round and matched to the annual climate profile, and, in addition, to apportion architectural and mechanical strategies so that they complement one another. (Author/MLF)

  3. Automated solar collector installation design

    DOEpatents

    Wayne, Gary; Frumkin, Alexander; Zaydman, Michael; Lehman, Scott; Brenner, Jules

    2014-08-26

    Embodiments may include systems and methods to create and edit a representation of a worksite, to create various data objects, to classify such objects as various types of pre-defined "features" with attendant properties and layout constraints. As part of or in addition to classification, an embodiment may include systems and methods to create, associate, and edit intrinsic and extrinsic properties to these objects. A design engine may apply of design rules to the features described above to generate one or more solar collectors installation design alternatives, including generation of on-screen and/or paper representations of the physical layout or arrangement of the one or more design alternatives.

  4. Durability testing of antireflection coatings for solar applications

    NASA Astrophysics Data System (ADS)

    Jorgensen, Gary J.; Brunold, Stefan; Koehl, Michael; Nostell, Per; Oversloot, Henk; Roos, Arne

    1999-10-01

    Antireflection (AR) coatings can be incorporated into highly transmitting glazings that, depending upon their cost, performance, and durability of optical properties, can be economically viable in solar collectors, agricultural greenhouses, and PV systems. A number of AR-coated glazings have been prepared under the auspices of the International Energy Agency Working Group on Durability of Materials for Solar Thermal Collectors. The AR coatings are of two types, including (1) various sol-gels applied to glass and (2) an embossed treatment of sheet acrylic. Typically, for unweathered glazings, a 4 - 5% increase in solar-weighted transmittance has been achieved. For AR-coated glass, reflectance values as low as 0.5% - 0.7% at selected wavelengths (680 - 720 nm) were obtained. To determine the durability of the hemispherical transmittance, several collaborating countries are testing these materials both outdoors and in accelerated weathering chambers. All materials exposed outdoors are affixed to mini-collector boxes to simulate flat-plate collector conditions. Results for candidate AR coatings weathered at geographically disperse outdoor test sites exhibit changes in spectral transmittance primarily in the high visible range (600 - 700 nm). Accelerated testing at measured levels of simulated solar irradiance, and at different constant levels of temperature and relative humidity have been performed in different countries. Parallel testing with different levels of laboratory-controlled relevant stress factors permits the time-dependent performance of these materials to be compared with measured results from in-service outdoor exposure conditions. Coating adhesion and performance loss resulting from dirt and dust retention are also discussed.

  5. Durability testing of antireflection coatings for solar applications

    SciTech Connect

    Jorgensen, G.; Brunold, S.; Koehl, M.; Nostell, P.; Roos, A.; Oversloot, H.

    2000-01-05

    Antireflection (AR) coatings can be incorporated into highly transmitting glazings that, depending on their cost, performance, and durability of optical properties, can be economically viable in solar collectors, agricultural greenhouses, and PV systems. A number of AR-coated glazings have been prepared under the auspices of the International Energy Agency (IEA) Working Group on Durability of Materials for Solar Thermal Collectors. The AR coatings are of two types, including (1) various sol-gels applied to glass and (2) an embossed treatment of sheet acrylic. Typically, for unweathered glazings, a 4%--5% increase in solar-weighted transmittance has been achieved. For AR-coated glass, reflectance values as low as 0.5%--0.7% at selected wavelengths (680--720 nm) were obtained. To determine the durability of the hemispherical transmittance, several collaborating countries are testing these materials both outdoors and in accelerated weathering chambers. All materials exposed outdoors are affixed to mini-collector boxes to simulate flat-plate collector conditions. Results for candidate AR coatings weathered at geographically disperse outdoor test sites exhibit changes in spectral transmittance primarily in the high visible range (600--700 nm). Accelerated testing at measured levels of simulated solar irradiance and at different constant levels of temperature and relative humidity have been performed in different countries. Parallel testing with different levels of laboratory-controlled relevant stress factors permits the time-dependent performance of these materials to be compared with measured results from in-service outdoor exposure conditions. Coating adhesion and performance loss resulting from dirt and dust retention are also discussed.

  6. Nanowire-based multifunctional antireflection coatings for solar cells.

    PubMed

    Hiralal, Pritesh; Chien, Chihtao; Lal, Niraj N; Abeygunasekara, Waranatha; Kumar, Abhishek; Butt, Haider; Zhou, Hang; Unalan, Husnu Emrah; Baumberg, Jeremy J; Amaratunga, Gehan A J

    2014-11-06

    Organic (P3HT/PCBM) solar cells are coated with ZnO nanowires as antireflection coatings and show up to 36% enhancement in efficiency. The improvement is ascribed to an effective refractive index which results in Fabry-Perot absorption bands which match the polymer band-gap. The effect is particularly pronounced at high light incidence angles. Simultaneously, the coating is used as a UV-barrier, demonstrating a 50% reduction in the rate of degradation of the polymers under accelerated lifetime testing. The coating also allows the surface of the solar cell to self-clean via two distinct routes. On one hand, photocatalytic degradation of organic material on ZnO is enhanced by the high surface area of the nanowires and quantified by dye degradation measurements. On the other, the surface of the nanowires can be functionalized to tune the water contact angle from superhydrophilic (16°) to superhydrophobic (152°), resulting in self-cleaning via the Lotus effect. The multifunctional ZnO nanowires are grown by a low cost, low temperature hydrothermal method, compatible with process limitations of organic solar cells.

  7. Passivating Window/First Layer AR Coating for Space Solar Cells

    NASA Technical Reports Server (NTRS)

    Faur, Mircea; Faur, Maria; Bailey, S. G.; Flood, D. J.; Brinker, D. J.; Alterovitz, S. A.; Wheeler, D. R.; Matesscu, G.; Goradia, C.; Goradia, M.

    2004-01-01

    Chemically grown oxides, if well designed, offer excellent surface passivation of the emitter surface of space solar cells and can be used as effective passivating window/first layer AR coating. In this paper, we demonstrate the effectiveness of using a simple room temperature wet chemical technique to grow cost effective passivating layers on solar cell front surfaces after the front grid metallization step. These passivating layers can be grown both on planar and porous surfaces. Our results show that these oxide layers: (i) can effectively passivate the from the surface, (ii) can serve as an effective optical window/first layer AR coating, (iii) are chemically, thermally and UV stable, and (iv) have the potential of improving the BOL and especially the EOL efficiency of space solar cells. The potential of using this concept to simplify the III-V based space cell heterostructures while increasing their BOL and EOL efficiency is also discussed.

  8. Investigation of critical surface degradation effects on coatings and solar cells developed in Germany (S1002)

    NASA Technical Reports Server (NTRS)

    Preuss, L.

    1984-01-01

    Various coatings developed in the FRG (i.e., second-surface mirrors with interference filters with and without conductive layers, conductive layers on solar-cell covers, and selective absorber coatings) have been qualified by accelerated tests under simulated space environment conditions. Experiments with coatings and solar cells have shown, however, that the thermo-optical behavior can differ considerably when performed on the ground and in space because of the great difficulty in simulating the space environment realistically. The objective of this experiment is to qualify these coatings under realistic space environment conditions. In addition, the experiment will provide design criteria, techniques, and test methods to insure control of the combined space and spacecraft environment effects, such as contamination, electrical conductance, and optical degradation, on the coatings. Data to be measured include the temperature of the samples, the electrical resistance of the conductive layers of the samples, the short circuit current of the solar-cell modules, and the deposition of contaminants on the samples (using quartz crystal microbalances (QCM's)).

  9. Development and Testing of High-Temperature Solar Selective Coatings

    SciTech Connect

    Kennedy, C.; Price, H.

    2005-01-01

    The Solar Energy Technologies Program is working to reduce the cost of parabolic trough solar power technology. System studies show that increasing the operating temperature of the solar field from 390 to >450 C will result in improved performance and cost reductions. This requires the development of new more-efficient selective coatings that have both high solar absorptance (>0.96) and low thermal emittance (<0.07) and are thermally stable above 450 C, ideally in air. Potential selective coatings were modeled, identified for laboratory prototyping, and manufactured at NREL. Optimization of the samples and high-temperature durability testing will be performed. Development of spectrally selective materials depends on reliable characterization of their optical properties. Protocols for testing the thermal/optical properties of selective coatings were developed and a round-robin experiment was conducted to verify and document the reflectance and high-temperature emittance measurements. The development, performance, and durability of these materials and future work will be described.

  10. Absorption to reflection transition in selective solar coatings.

    PubMed

    Olson, Kyle D; Talghader, Joseph J

    2012-07-02

    The optimum transition wavelength between high absorption and low emissivity for selective solar absorbers has been calculated in several prior treatises for an ideal system, where the emissivity is exactly zero in the infrared. However, no real coating can achieve such a low emissivity across the entire infrared with simultaneously high absorption in the visible. An emissivity of even a few percent radically changes the optimum wavelength separating the high and low absorption spectral bands. This behavior is described and calculated for AM0 and AM1.5 solar spectra with an infrared emissivity varying between 0 and 5%. With an emissivity of 5%, solar concentration of 10 times the AM1.5 spectrum the optimum transition wavelength is found to be 1.28 µm and have a 957K equilibrium temperature. To demonstrate typical absorptions in optimized solar selective coatings, a four-layer sputtered Mo and SiO₂ coating with absorption of 5% across the infrared is described experimentally and theoretically.

  11. Multi-source/component spray coating for polymer solar cells.

    PubMed

    Chen, Li-Min; Hong, Ziruo; Kwan, Wei Lek; Lu, Cheng-Hsueh; Lai, Yi-Feng; Lei, Bao; Liu, Chuan-Pu; Yang, Yang

    2010-08-24

    A multi-source/component spray coating process to fabricate the photoactive layers in polymer solar cells is demonstrated. Well-defined domains consisting of polymer:fullerene heterojunctions are constructed in ambient conditions using an alternating spray deposition method. This approach preserves the integrity of the layer morphology while forming an interpenetrating donor (D)/acceptor (A) network to facilitate charge transport. The formation of multi-component films without the prerequisite of a common solvent overcomes the limitations in conventional solution processes for polymer solar cells and enables us to process a wide spectrum of materials. Polymer solar cells based on poly(3-hexylthiophene):[6,6]-phenyl C(61) butyric acid methyl ester spray-coated using this alternating deposition method deliver a power conversion efficiency of 2.8%, which is comparable to their blend solution counterparts. More importantly, this approach offers the versatility to independently select the optimal solvents for the donor and acceptor materials that will deliver well-ordered nanodomains. This method also allows the direct stacking of multiple photoactive polymers with controllable absorption in a tandem structure even without an interconnecting junction layer. The introduction of multiple photoactive materials through multisource/component spray coating offers structural flexibility and tenability of the photoresponse for future polymer solar cell applications.

  12. Interior design for passive solar homes

    NASA Astrophysics Data System (ADS)

    Breen, J. C.

    1981-07-01

    The increasing emphasis on refinement of passive solar systems brought recognition to interior design as an integral part of passive solar architecture. Interior design can be used as a finetuning tool minimizing many of the problems associated with passive solar energy use in residential buildings. In addition, treatment of interior space in solar model homes may be a prime factor in determining sales success. A new style of interior design is evolving in response to changes in building from incorporating passive solar design features. The psychology behind passive solar architecture is reflected in interiors, and selection of interior components increasingly depends on the functional suitably of various interior elements.

  13. Interior design for passive solar homes

    SciTech Connect

    Breen, J. C.

    1981-07-01

    The increasing emphasis on refinement of passive solar systems has brought recognition to interior design as an integral part of passive solar architecture. Interior design can be used as a finetuning tool minimizing many of the problems associated with passive solar energy use in residential buildings. In addition, treatment of interior space in solar model homes may be a prime factor in determining sales success. A new style of interior design is evolving in response to changes in building form incorporating passive solar design features. The psychology behind passive solar architecture is reflected in interiors, and selection of interior components increasingly depends on the functional suitability of various interior elements.

  14. Optimized Selective Coatings for Solar Collectors

    NASA Technical Reports Server (NTRS)

    Mcdonald, G.; Curtis, H. B.

    1967-01-01

    The spectral reflectance properties of black nickel electroplated over stainless steel and of black copper produced by oxidation of copper sheet were measured for various plating times of black nickel and for various lengths of time of oxidation of the copper sheet, and compared to black chrome over nickel and to converted zinc. It was determined that there was an optimum time for both plating of black nickel and for the oxidation of copper black. At this time the solar selective properties show high absorptance in the solar spectrum and low emittance in the infrared. The conditions are compared for production of optimum optical properties for black nickel, black copper, black chrome, and two black zinc conversions which at the same conditions had absorptances of 0.84, 0.90, 0.95, 0.84, and 0.92, respectively, and emittances of 0.18, 0.08, 0.09, 0.10, and 0.08, respectively.

  15. Silver nanoparticles-coated glass frits for silicon solar cells

    NASA Astrophysics Data System (ADS)

    Li, Yingfen; Gan, Weiping; Li, Biyuan

    2016-04-01

    Silver nanoparticles-coated glass frit composite powders for silicon solar cells were prepared by electroless plating. Silver colloids were used as the activating agent of glass frits. The products were characterized by X-ray diffraction, scanning electron microscopy, and differential scanning calorimetry. The characterization results indicated that silver nanoparticles with the melting temperature of 838 °C were uniformly deposited on glass frit surface. The particle size of silver nanoparticles could be controlled by adjusting the [Ag(NH3)2]NO3 concentration. The as-prepared composite powders were applied in the front side metallization of silicon solar cells. Compared with those based on pure glass frits, the solar cells containing the composite powders had the denser silver electrodes and the better silver-silicon ohmic contacts. Furthermore, the photovoltaic performances of solar cells were improved after the electroless plating.

  16. Design of starch coated seed cotton dryers

    USDA-ARS?s Scientific Manuscript database

    A model was developed for the design and analysis of a high temperature tunnel dryer, primarily used with a new cotton ginning product, EASIflo ® cottonseed (starch-coated cottonseed). This form of cottonseed has emerged as a viable, value-added product for the cotton ginning industry. Currently, li...

  17. Performance of antireflecting coating-AlGaAs window layer coupling for terrestrial concentrator GaAs solar cells

    SciTech Connect

    Valle, C.A. del; Alcaraz, M.F.

    1997-09-01

    In this paper, the authors present the performance of optical coating systems coupled with AlGaAs window layers over GaAs solar cells. Single, double, and triple antireflecting coatings and window layers with constant and graded aluminum content are considered. Comparison between constant and graded window layers is established. To better represent reality, practical factors such as absorption of materials even for antireflecting coatings and the oxidation at window layer surface due to its high aluminum content are also included in the calculations. The design criteria to determine the optimum thickness of each layer is the achievement of maximum photogenerated current density. For this purpose and to account for terrestrial concentrators GaAs solar cells, the inclusion of direct terrestrial solar spectrum together with the internal spectral response of the device are taken into account. Finally, the best antireflecting coating/AlGaAs window layer couplings for different cases are presented.

  18. Solar dynamic power module design

    NASA Technical Reports Server (NTRS)

    Secunde, Richard R.; Labus, Thomas L.; Lovely, Ronald G.

    1989-01-01

    Studies have shown that use of solar dynamic (SD) power for the growth eras of the Space Station Freedom program will result in life cycle cost savings when compared to power supplied by photovoltaic sources. In the SD power module, a concentrator collects and focuses solar energy into a heat receiver which has integral thermal energy storage. A power conversion unit (PCU) based on the closed Brayton thermodynamic cycle removes thermal energy from the receiver and converts that energy to electrical energy. Since the closed Brayton cycle is a single phase gas cycle, the conversion hardware (heat exchangers, turbine, compressor, etc.) can be designed for operation in low earth orbit, and tested with confidence in test facilities on earth before launch into space. The concentrator subassemblies will be aligned and the receiver/PCU/radiator combination completely assembled and charged with gas and cooling liquid on earth before launch to, and assembly on orbit.

  19. Comparison under a simulated sun of two black-nickel-coated flat-plate solar collectors with a nonselective black-paint-coated collector

    NASA Technical Reports Server (NTRS)

    Simon, F. F.

    1975-01-01

    A performance evaluation was made of two, black nickel coated, flat plate solar collectors. Collector performance was determined under a simulated sun for a wide range of inlet temperatures, including the temperature required for solar powered absorption air conditioning. For a basis of comparison a performance test was made on a traditional, two glass, nonselective, black paint coated, flat plate collector. Performance curves and performance parameters are presented to point out the importance of the design variables which determine an efficient collector. A black nickel coated collector was found to be a good performer at the conditions expected for solar powered absorption air conditioning. This collector attained a thermal efficiency of 50 percent at an inlet temperature of 366 K (200 F) and an incident flux of 946 watts/sq m (300 Btu/hr-sq ft).

  20. Chemical vapor deposited silica coatings for solar mirror protection

    NASA Technical Reports Server (NTRS)

    Gulino, Daniel A.; Dever, Therese M.; Banholzer, William F.

    1988-01-01

    A variety of techniques is available to apply protective coatings to oxidation susceptible spacecraft components, and each has associated advantages and disadvantages. Film applications by means of chemical vapor deposition (CVD) has the advantage of being able to be applied conformally to objects of irregular shape. For this reason, a study was made of the oxygen plasma durability of thin film (less than 5000 A) silicon dioxide coatings applied by CVD. In these experiments, such coatings were applied to silver mirrors, which are strongly subject to oxidation, and which are proposed for use on the space station solar dynamic power system. Results indicate that such coatings can provide adequate protection without affecting the reflectance of the mirror. Scanning electron micrographs indicated that oxidation of the silver layer did occur at stress crack locations, but this did not affect the measured solar reflectances. Oxidation of the silver did not proceed beyond the immediate location of the crack. Such stress cracks did not occur in thinner silica flims, and hence such films would be desirable for this application.

  1. Chemical vapor deposited silica coatings for solar mirror protection

    NASA Technical Reports Server (NTRS)

    Gulino, Daniel A.; Dever, Therese M.; Banholzer, William F.

    1988-01-01

    A variety of techniques is available to apply protective coatings to oxidation susceptible spacecraft components, and each has associated advantages and disadvantages. Film applications by means of chemical vapor deposition (CVD) has the advantage of being able to be applied conformally to objects of irregular shape. For this reason, a study was made of the oxygen plasma durability of thin film (less than 5000 A) silicon dioxide coatings applied by CVD. In these experiments, such coatings were applied to silver mirrors, which are strongly subject to oxidation, and which are proposed for use on the space station solar dynamic power system. Results indicate that such coatings can provide adequate protection without affecting the reflectance of the mirror. Scanning electron micrographs indicated that oxidation of the silver layer did occur at stress crack locations, but this did not affect the measured solar reflectances. Oxidation of the silver did not proceed beyond the immediate location of the crack. Such stress cracks did not occur in thinner silica films, and hence such films would be desirable for this application.

  2. Subsystem design package for Solar II collector

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The requirements for the design and performance of the Solar 2 Collector Subsystem developed for use in solar heating of single family residences and mobile homes are presented. Installation drawings are included.

  3. Selective coatings for solar-to-thermal energy converters

    NASA Astrophysics Data System (ADS)

    Gukhman, G. A.; Koltun, M. M.

    1984-02-01

    A selective coating proposed for flat plate solar collectors consists of a thick Al2O3 layer with embedded metal particles and on it an infrared reflecting layer of electrically conducting vitreous ceramic material (PbO or In2O3). Both layers are deposited electromatically on collectors made of aluminum or an aluminum alloy. A double layer of 2 to 3 micron thick chromium on 9 to 10 micron thick nickel is effective in preventing oxidation on copper surfaces. Specimens of such coatings were tested in a laboratory humidity chamber and are now tested under the climatic conditions in the Crimea, 750,000 Wh/sq m of solar radiation at a mean-weekly intensity of 700 W/sq m having been accumulated in nine months. The ratio of heat absorbint to total surface area is or = 0.9 and emissivity is or = 0.2 were not degraded by holding in a furnace at 500 C for 50 h. The feasibility of producing multilayer coatings of this type was established on the basis of computer calculations for various combinations of collector material and protective interlayers.

  4. Optical Design of Segmented Hexagon Array Solar Mirror

    NASA Technical Reports Server (NTRS)

    Huegele, Vince

    2000-01-01

    A segmented array of mirrors was designed for a solar concentrator test stand at MSFC for firing solar thermal propulsion engines. The 144 mirrors each have a spherical surface to approximate a parabolic concentrator when combined into the entire 18-foot diameter array. The mirror segments are aluminum hexagons that had the surface diamond turned and quartz coated. The array focuses sunlight reflected from a heliostat to a 4 inch diameter spot containing 10 kw of power at the 15-foot focal point. The derivation of the surface figure for the respective mirror elements is shown. The alignment process of the array is discussed and test results of the system's performance is given.

  5. Optical design of SHASM: segmented hexagon array solar mirror

    NASA Astrophysics Data System (ADS)

    Huegele, Vinson B.

    2000-10-01

    A segmented array of mirrors was designed for a solar concentrator test stand at MSFC for firing solar thermal propulsion engines. The 144 mirrors each have s spherical surface to approximate a parabolic concentrator when combined into the entire 17-foot diameter array. The mirror segments are aluminum hexagons that had the surface diamond turned and quartz coated. The array focuses sunlight reflected from a heliostat to a 4 inch diameter spot containing 8 kilowatts of power at the 15 foot focal point. The derivation of the surface figure for the respective mirror elements is shown. The alignment process of the array is discussed and test results of the system's performance are given.

  6. Solar Water-Heater Design Package

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Information on a solar domestic-hot water heater is contained in 146 page design package. System consists of solar collector, storage tanks, automatic control circuitry and auxiliary heater. Data-acquisition equipment at sites monitors day-by-day performance. Includes performance specifications, schematics, solar-collector drawings and drawings of control parts.

  7. An integrated approach for designing reliable coatings

    SciTech Connect

    Shaffer, E.O. II

    1996-12-31

    In its simplest form, adhesive failure is predicted when some applied energy exceeds a critical property of the joint. The challenge in designing reliability is to establish the details of both the applied energies and the critical performance properties. Complications arise in determining performance properties, which include both adhesive and cohesive strengths, since they are strong functions of processing and environmental conditions. Thus, any test used to measure these must be able to mimic the correct conditions. Another complication that arises is the dependence of the applied debond energies on the mechanical properties of the coating and substrate. The available debond energy is also a function of the geometry and any external loads applied. In this presentation, the author shows how computational mechanics can be used to determine the role of mechanical properties on the applied energy. In doing so, key properties are identified that allow the coating manufacturer to optimize their material for specific applications. Examples are given for several microelectronic applications.

  8. Coating and surface finishing definition for the Solar Orbiter/METIS inverted external occulter

    NASA Astrophysics Data System (ADS)

    Landini, Federico; Romoli, Marco; Vives, Sebastien; Baccani, Cristian; Escolle, Clement; Pancrazzi, Maurizio; Focardi, Mauro; Da Deppo, Vania; Moses, John D.; Fineschi, Silvano

    2014-07-01

    The METIS coronagraph aboard the Solar Orbiter mission will undergo extreme environmental conditions (e.g., a thermal excursion of about 350 degrees throughout the various mission phases), due to the peculiar spacecraft trajectory that will reach a perihelion of 0.28 AUs. METIS is characterized by an innovative design for the occultation system that allows to halve the thermal load inside the instrument while guaranteeing the stray light reduction that is required for a solar coronagraph. The Inverted External Occulter (IEO) concept revolutionizes the classical scheme, by exchanging the usual positions of the entrance aperture (that is now the outermost element of the instrument facing the Sun) with the actual occulter (that is a spherical mirror inside the coronagraph boom). The chosen material for the IEO manufacturing is Titanium, as a trade o_ between light weight, strength and low thermal expansion coefficient. A 2 years long test campaign has been run to define the IEO geometry, and its results are addressed in previous dedicated papers. This work describes the results of a further campaign aimed at defining the IEO surface and edge finishing, the support flange geometry and the Titanium coating. Various edge finishing were installed on a prototype of the instrument occulting system and their performance in stray light reduction were compared. The support flange geometry was designed in order to reduce the overall weight, to control the thermal load and to accentuate its stray light suppression performance. The coating is a particularly delicate issue. A black coating is necessary in order to assess the stray light issues, typically critical for visible coronagraphs. Black coating of Titanium is not a standard process, thus several space qualified black coatings were experimented on Titanium and characterized. The impact of the IEO coatings was evaluated, the reflectivity and the BRDFs were measured and are addressed in the paper.

  9. Laser processing of solar cells with anti-reflective coating

    SciTech Connect

    Harley, Gabriel; Smith, David D.; Dennis, Tim; Waldhauer, Ann; Kim, Taeseok; Cousins, Peter John

    2016-02-16

    Contact holes of solar cells are formed by laser ablation to accommodate various solar cell designs. Use of a laser to form the contact holes is facilitated by replacing films formed on the diffusion regions with a film that has substantially uniform thickness. Contact holes may be formed to deep diffusion regions to increase the laser ablation process margins. The laser configuration may be tailored to form contact holes through dielectric films of varying thicknesses.

  10. DESIGN DATA STUDY FOR COATED COLUMBIUM ALLOYS

    DTIC Science & Technology

    ANTIOXIDANTS, * COATINGS , * NIOBIUM ALLOYS, *REFRACTORY COATINGS , *SILICON COATINGS , ALLOYS, ALUMINUM, DEFORMATION, ELASTIC PROPERTIES, HIGH...TEMPERATURE, OXIDATION, PLASTIC PROPERTIES, REENTRY VEHICLES, REFRACTORY MATERIALS, SHEETS, SILICIDES , VACUUM APPARATUS, VAPOR PLATING, ZIRCONIUM ALLOYS

  11. Design of antireflective nanostructures and optical coatings for next-generation multijunction photovoltaic devices.

    PubMed

    Perl, Emmett E; McMahon, William E; Bowers, John E; Friedman, Daniel J

    2014-08-25

    The successful development of multijunction photovoltaic devices with four or more subcells has placed additional importance on the design of high-quality broadband antireflection coatings. Antireflective nanostructures have shown promise for reducing reflection loss compared to the best thin-film interference coatings. However, material constraints make nanostructures difficult to integrate without introducing additional absorption or electrical losses. In this work, we compare the performance of various nanostructure configurations with that of an optimized multilayer antireflection coating. Transmission into a four-junction solar cell is computed for each antireflective design, and the corresponding cell efficiency is calculated. We find that the best performance is achieved with a hybrid configuration that combines nanostructures with a multilayer thin-film optical coating. This approach increases transmitted power into the top subcell by 1.3% over an optimal thin-film coating, corresponding to an increase of approximately 0.8% in the modeled cell efficiency.

  12. Space exploration with a solar sail coated by materials that undergo thermal desorption

    NASA Astrophysics Data System (ADS)

    Kezerashvili, Roman Ya.

    2015-12-01

    For extrasolar space exploration it is suggested to use space environmental effects such as solar radiation heating to accelerate a solar sail coated by materials that undergo thermal desorption at a particular temperature. The developed approach allows the perihelion of the solar sail orbits to be determined based on the temperature requirement for the solar sail materials. Our study shows that the temperature of a solar sail increases as r - 2 / 5 when the heliocentric distance r decreases. The proposed sail has two coats of the materials that undergo desorption at different solar sail temperatures depending on the heliocentric distance. The first desorption occurs at the Earth orbit and provides the thrust needed to propel the solar sail toward the Sun. When the solar sail approaches the Sun, its temperature increases, and the second coat undergoes desorption at the perihelion of the heliocentric escape orbit. This provides a second thrust and boosts the solar sail to its escape velocity.

  13. Space Station Freedom solar array design development

    NASA Technical Reports Server (NTRS)

    Winslow, Cindy; Bilger, Kevin; Baraona, Cosmo

    1989-01-01

    The Space Station Freedom solar array program is required to provide a 75-kW power module that uses eight solar array (SA) wings over a four-year period in low earth orbit (LEO). Each wing will be capable of providing 23.4 kW at the 4-yr design point. The design of flexible-substrate SAs that must survive exposure to the space environment, including atomic oxygen, for an operating life of fifteen years is discussed. The tradeoff study and development areas being investigated include solar cell module size, solar cell weld pads, panel stiffener frames, materials inherently resistant to atomic oxygen, and weight reduction design alternatives.

  14. Space Station Freedom solar array design development

    NASA Technical Reports Server (NTRS)

    Winslow, Cindy; Bilger, Kevin; Baraona, Cosmo

    1989-01-01

    The Space Station Freedom solar array program is required to provide a 75-kW power module that uses eight solar array (SA) wings over a four-year period in low earth orbit (LEO). Each wing will be capable of providing 23.4 kW at the 4-yr design point. The design of flexible-substrate SAs that must survive exposure to the space environment, including atomic oxygen, for an operating life of fifteen years is discussed. The tradeoff study and development areas being investigated include solar cell module size, solar cell weld pads, panel stiffener frames, materials inherently resistant to atomic oxygen, and weight reduction design alternatives.

  15. Reflectivity, polarization properties, and durability of metallic mirror coatings for the European Solar Telescope

    NASA Astrophysics Data System (ADS)

    Feller, A.; Krishnappa, N.; Pleier, O.; Hirzberger, J.; Jobst, P. J.; Schürmann, M.

    2012-09-01

    In the context of the conceptual design study for the European Solar Telescope (EST) we have investigated different metallic mirror coatings in terms of reflectivity, polarization properties and durability. Samples of the following coating types have been studied: bare aluminum, silver with different dielectric layers for protection and UV enhancement, and an aluminum-silver combination. From 2009 to 2011 we have carried out a long-term durability test under realistic observing conditions at the VTT solar telescope of the Observatorio del Teide (Tenerife, Spain), accompanied by repeated reflectivity measurements in the EST spectral working range (0.3 - 20 μm), and by polarization measurements in the visible range. The test results allow us to find the optimum coatings for the different mirrors in the EST beampath and to eventually assess aging effects and re-coating cycles. The results of the polarization measurements are a valuable input for an EST telescope polarization model, helping to meet the stringent requirements on polarimetric accuracy.

  16. NEW HIGHER PERFORMANCE LOW COST SELECTIVE SOLAR RADIATION CONTROL COATINGS

    SciTech Connect

    Timothy Ellison; Buddie Dotter; David Tsu

    2003-10-28

    Energy Conversion Devices, Inc., ECD, has developed a new high-speed low-cost process for depositing high quality dielectric optical coatings--Microwave Plasma Enhanced Chemical Vapor Deposition (MPECVD). This process can deposit SiO{sub x} about 10 times faster than the state-of-the-art conventional technology, magnetron sputtering, at about 1/10th the cost. This process is also being optimized for depositing higher refractive index materials such as Si{sub 3}N{sub 4} and TiO{sub 2}. In this program ECD, in collaboration with Southwall Technologies, Inc. (STI), demonstrated that this process can be used to fabricate high performance low cost Selective Solar Radiation Control (SSRC) films for use in the automotive industry. These coatings were produced on thin (2 mil thick) PET substrates in ECD's pilot roll-to-roll pilot MPECVD deposition machine. Such film can be laminated with PVB in a vehicle's windows. This process can also be used to deposit the films directly onto the glass. Such highly selective films, with a visible transmission (T{sub vis}) of > 70% and a shading coefficient of < 60% can significantly reduce the heat entering a car from solar radiation. Consequently, passenger comfort is increased and the energy needed to operate air conditioning (a/c) systems is reduced; consequently smaller a/c systems can be employed resulting in improved vehicle fuel efficiency.

  17. Concentrating solar collector subsystem: Preliminary design package

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Preliminary design data are presented for a concentrating solar collector including an attitude controller. Provided are schedules, technical status, all documents required for preliminary design, and other program activities.

  18. Design data brochure: Solar hot water system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A design calculation is detailed for a single-family residence housing a family of four in a nonspecific geographical area. The solar water heater system is designed to provide 80 gallons of 140 F hot water per day.

  19. Prototype solar-heating system design package

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Design package for complete residential solar-heating system is given. Includes documents and drawings describing performance design, verification standards, and analysis of system with sufficient information to assemble working system.

  20. Design, fabrication, testing and delivery of a solar collector

    NASA Technical Reports Server (NTRS)

    Sims, W. H.; Ballheim, R. W.; Bartley, S. M.; Smith, G. W.

    1976-01-01

    A two phase program encompassing the redesign and fabrication of a solar collector which is low in cost and aesthetically appealing is described. Phase one work reviewed the current collector design and developed a low-cost design based on specific design/performance/cost requirements. Throughout this phase selected collector component materials were evaluated by testing and by considering cost, installation, maintainability and durability. The resultant collector design was composed of an absorber plate, insulation, frame, cover, desiccant and sealant. In Phase two, three collector prototypes were fabricated and evaluated for both nonthermal and thermal characteristics. Tests included static load tests of covers, burst pressure tests of absorber plates, and tests for optical characteristics of selective absorber plate coatings. The three prototype collectors were shipped to Marshall Space Flight Center for use in their solar heating and cooling test facility.

  1. Design of a Traditional Solar Tracking System

    NASA Astrophysics Data System (ADS)

    Barsoum, Nader; Vasant, Pandian

    2010-06-01

    Solar energy is rapidly advancing as an important means of renewable energy resource. More energy is produced by tracking the solar panel to remain aligned to the sun at a right angle to the rays of light. This paper describes in detail the design and construction of a prototype for solar tracking system with two degrees of freedom, which detects the sunlight using photocells. The control circuit for the solar tracker is based on a PIC16F84A microcontroller (MCU). This is programmed to detect the sunlight through the photocells and then actuate the motor to position the solar panel where it can receive maximum sunlight.

  2. Antireflection nanocomposite thick film coatings with quasi-zero refractive index for solar cells

    NASA Astrophysics Data System (ADS)

    Gadomsky, O. N.; Shchukarev, I. A.; Pereskokov, E. A.

    2016-08-01

    Application of nanostructured composite coatings with a quasi-zero refractive index synthesized using the proposed patented technology provides a 25-30% increase in the efficiency of solar cells as compared to that of analogous solar cells with traditional (e.g., silicon nitride) single-layer interference antireflection coating.

  3. Sun-believable solar paint. A transformative one-step approach for designing nanocrystalline solar cells.

    PubMed

    Genovese, Matthew P; Lightcap, Ian V; Kamat, Prashant V

    2012-01-24

    A transformative approach is required to meet the demand of economically viable solar cell technology. By making use of recent advances in semiconductor nanocrystal research, we have now developed a one-coat solar paint for designing quantum dot solar cells. A binder-free paste consisting of CdS, CdSe, and TiO(2) semiconductor nanoparticles was prepared and applied to conducting glass surface and annealed at 473 K. The photoconversion behavior of these semiconductor film electrodes was evaluated in a photoelectrochemical cell consisting of graphene-Cu(2)S counter electrode and sulfide/polysulfide redox couple. Open-circuit voltage as high as 600 mV and short circuit current of 3.1 mA/cm(2) were obtained with CdS/TiO(2)-CdSe/TiO(2) electrodes. A power conversion efficiency exceeding 1% has been obtained for solar cells constructed using the simple conventional paint brush approach under ambient conditions. Whereas further improvements are necessary to develop strategies for large area, all solid state devices, this initial effort to prepare solar paint offers the advantages of simple design and economically viable next generation solar cells.

  4. Damage Threshold Dependence of Multilayer Laser Mirrors on Coating Design

    DTIC Science & Technology

    1991-06-05

    AD-A239 234 _ _ _ _ _ _ _ _ _ _ _ FOREIGN TECHNOLOGY DIVISION DAMAGE THRESHOLD DEPENDENCE OF M4ULTILAYER LASER MIRRORS ON COATING DESIGN by ’du...MICROFICHE NR: FTD-91-C-000401 DAMAGE THRESHOLD DEPENDENCE OF MULTILAYER LASER MIRRORS ON COATING DESIGN By: Wu Zhouling, Fan Zhengxin English pages: 10...For NTIS~P& DTI-- T,,BI I By t ; DAMAGE THRESHOLD DEPENDENCE OF MULTILAYER LASER MIRRORS ON COATING DESIGN Wu Zhouling and Fan Zhengxin, Shanghai

  5. Optical interference coating design contest 2016: a dispersive mirror and coating uniformity challenge.

    PubMed

    Kruschwitz, Jennifer D T; Pervak, Vladimir; Keck, Jason; Bolshakov, Ilya; Gerig, Zachary; Lemarchand, Fabien; Sato, Kageyuki; Southwell, William; Sugiura, Muneo; Trubetskov, Michael; Yuan, Wenjia

    2017-02-01

    A dispersive mirror and a coating uniformity challenge were the topics of the design contest held in conjunction with the 2016 Optical Interference Coatings topical meeting of The Optical Society (OSA). A total of 18 designers from China, France, Germany, Japan, and the United States submitted 38 total designs for problems A and B. Michael Trubetskov submitted the winning designs for all four design challenges. The design problems and the submitted solutions are described and evaluated.

  6. High temperature performance of high-efficiency, multi-layer solar selective coatings for tower applications

    SciTech Connect

    Gray, M. H.; Tirawat, R.; Kessinger, K. A.; Ndione, P. F.

    2015-05-01

    The roadmap to next-generation concentrating solar power plants anticipates a progression to central towers with operating temperatures in excess of 650°C. These higher temperatures are required to drive higher power-cycle efficiencies, resulting in lower cost energy. However, these conditions also place a greater burden on the materials making up the receiver. Any novel absorber material developed for next-generation receivers must be stable in air, cost effective, and survive thousands of heating and cooling cycles. The collection efficiency of a power tower plant can be increased if the energy absorbed by the receiver is maximized while the heat loss from the receiver to the environment is minimized. Thermal radiation losses can be significant (>7% annual energy loss) with receivers at temperatures above 650°C. We present progress toward highly efficient and durable solar selective absorbers (SSAs) intended for operating temperatures from 650°C to 1000°C. Selective efficiency (ηsel) is defined as the energy retained by the absorber, accounting for both absorptance and emittance, relative to the energy incident on the surface. The low emittance layers of multilayer SSAs are binary compounds of refractory metals whose material properties indicate that coatings formed of these materials should be oxidation resistant in air to 800-1200°C. On this basis, we initially developed a solar selective coating for parabolic troughs. This development has been successfully extended to meet the absorptance and emittance objectives for the more demanding, high temperature regime. We show advancement in coating materials, processing and designs resulting in the initial attainment of target efficiencies ηsel > 0.91 for proposed tower conditions. Additionally, spectral measurements show that these coatings continue to perform at targeted levels after cycling to temperatures of 1000°C in environments of nitrogen and forming gas.

  7. High temperature performance of high-efficiency, multi-layer solar selective coatings for tower applications

    DOE PAGES

    Gray, M. H.; Tirawat, R.; Kessinger, K. A.; ...

    2015-05-01

    The roadmap to next-generation concentrating solar power plants anticipates a progression to central towers with operating temperatures in excess of 650°C. These higher temperatures are required to drive higher power-cycle efficiencies, resulting in lower cost energy. However, these conditions also place a greater burden on the materials making up the receiver. Any novel absorber material developed for next-generation receivers must be stable in air, cost effective, and survive thousands of heating and cooling cycles. The collection efficiency of a power tower plant can be increased if the energy absorbed by the receiver is maximized while the heat loss from themore » receiver to the environment is minimized. Thermal radiation losses can be significant (>7% annual energy loss) with receivers at temperatures above 650°C. We present progress toward highly efficient and durable solar selective absorbers (SSAs) intended for operating temperatures from 650°C to 1000°C. Selective efficiency (ηsel) is defined as the energy retained by the absorber, accounting for both absorptance and emittance, relative to the energy incident on the surface. The low emittance layers of multilayer SSAs are binary compounds of refractory metals whose material properties indicate that coatings formed of these materials should be oxidation resistant in air to 800-1200°C. On this basis, we initially developed a solar selective coating for parabolic troughs. This development has been successfully extended to meet the absorptance and emittance objectives for the more demanding, high temperature regime. We show advancement in coating materials, processing and designs resulting in the initial attainment of target efficiencies ηsel > 0.91 for proposed tower conditions. Additionally, spectral measurements show that these coatings continue to perform at targeted levels after cycling to temperatures of 1000°C in environments of nitrogen and forming gas.« less

  8. Space Station Freedom Solar Array design development

    NASA Technical Reports Server (NTRS)

    Winslow, Cindy; Bilger, Kevin; Baraona, Cosmo R.

    1989-01-01

    The Space Station Freedom Solar Array Program is required to provide a 75 kW power module that uses eight solar array (SA) wings over a four-year period in low Earth orbit (LEO). Each wing will be capable of providing 23.4 kW at the 4-year design point. Lockheed Missles and Space Company, Inc. (LMSC) is providing the flexible substrate SAs that must survive exposure to the space environment, including atomic oxygen, for an operating life of fifteen years. Trade studies and development testing, important for evolving any design to maturity, are presently underway at LMSC on the flexible solar array. The trade study and development areas being investigated include solar cell module size, solar cell weld pads, panel stiffener frames, materials inherently resistant to atomic oxygen, and weight reduction design alternatives.

  9. Double-layer anti-reflection coating containing a nanoporous anodic aluminum oxide layer for GaAs solar cells.

    PubMed

    Yang, Tianshu; Wang, Xiaodong; Liu, Wen; Shi, Yanpeng; Yang, Fuhua

    2013-07-29

    Multilayer anti-reflection (AR) coatings can be used to improve the efficiency of Gallium Arsenide (GaAs) solar cells. We propose an alternate method to obtain optical thin films with specified refractive indices, which is using a self-assembled nanoporous anodic aluminum oxide (AAO) template as an optical thin film whose effective refractive index can be tuned by pore-widening. Different kinds of double-layer AR coatings each containing an AAO layer were designed and investigated by finite difference time domain (FDTD) method. We demonstrate that a λ /4n - λ /4n AR coating consisting of a TiO(2) layer and an AAO layer whose effective refractive index is 1.32 realizes a 96.8% light absorption efficiency of the GaAs solar cell under AM1.5 solar spectrum (400 nm-860 nm). We also have concluded some design principles of the double-layer AR coating containing an AAO layer for GaAs solar cells.

  10. Solar-heating system design package

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Report describes solar heating system composed of warm-air solar collector, logic control unit, and switching and transport unit, that meets government standards for installation in residential dwellings. Text describes system operation and performance specifications complemented by comprehensive set of subcomponent design drawings.

  11. Properties of conductive coatings for thermal control mirrors and solar cell covers

    NASA Technical Reports Server (NTRS)

    Joslin, D. E.; Kan, H. K. A.

    1975-01-01

    Conductive transparent coatings applied to the dielectric surfaces of a spacecraft offer the possibility of distributing charge uniformly over the entire spacecraft surface. Optical and electrical measurements of such a coating as a function of temperature are described. These results are used in considering the impact of a conductive coating on the absorptance of thermal control mirrors and on the transmittance of solar cell cover glass, which can be improved by the application of an antireflection coating.

  12. Method of forming oxide coatings. [for solar collector heating panels

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. E. (Inventor)

    1983-01-01

    This invention is concerned with an improved plating process for covering a substrate with a black metal oxide film. The invention is particularly directed to making a heating panel for a solar collector. A compound is electrodeposited from an aqueous solution containing cobalt metal salts onto a metal substrate. This compound is converted during plating into a black, highly absorbing oxide coating which contains hydrated oxides. This is achieved by the inclusion of an oxidizing agent in the plating bath. The inclusion of an oxidizing agent in the plating bath is contrary to standard electroplating practice. The hydrated oxides are converted to oxides by treatment in a hot bath, such as boiling water. An oxidizing agent may be added to the hot liquid treating bath.

  13. Evaluation of thermal control coatings for use on solar dynamic radiators in low Earth orbit

    NASA Technical Reports Server (NTRS)

    Dever, Joyce A.; Rodriguez, Elvin; Slemp, Wayne S.; Stoyack, Joseph E.

    1991-01-01

    Thermal control coatings with high thermal emittance and low solar absorptance are needed for Space Station Freedom (SSF) solar dynamic power module radiator (SDR) surfaces for efficient heat rejection. Additionally, these coatings must be durable to low earth orbital (LEO) environmental effects of atomic oxygen, ultraviolet radiation and deep thermal cycles which occur as a result of start-up and shut-down of the solar dynamic power system. Eleven candidate coatings were characterized for their solar absorptance and emittance before and after exposure to ultraviolet (UV) radiation (200 to 400 nm), vacuum UV (VUV) radiation (100 to 200 nm) and atomic oxygen. Results indicated that the most durable and best performing coatings were white paint thermal control coatings Z-93, zinc oxide pigment in potassium silicate binder, and YB-71, zinc orthotitanate pigment in potassium silicate binder. Optical micrographs of these materials exposed to the individual environmental effects of atomic oxygen and vacuum thermal cycling showed that no surface cracking occurred.

  14. Evaluation of thermal control coatings for use on solar dynamic radiators in low earth orbit

    NASA Technical Reports Server (NTRS)

    Dever, Joyce A.; Rodriguez, Elvin; Slemp, Wayne S.; Stoyack, Joseph E.

    1991-01-01

    Thermal control coatings with high thermal emittance and low solar absorptance are needed for Space Station Freedom (SSF) solar dynamic power module radiator (SDR) surfaces for efficient heat rejection. Additionally, these coatings must be durable to low earth orbital (LEO) environmental effects of atomic oxygen, ultraviolet radiation and deep thermal cycles which occur as a result of start-up and shut-down of the solar dynamic power system. Eleven candidate coatings were characterized for their solar absorptance and emittance before and after exposure to ultraviolet (UV) radiation (200 to 400 nm), vacuum UV (VUV) radiation (100 to 200 nm) and atomic oxygen. Results indicated that the most durable and best performing coatings were white paint thermal control coatings Z-93, zinc oxide pigment in potassium silicate binder, and YB-71, zinc orthotitanate pigment in potassium silicate binder. Optical micrographs of these materials exposed to the individual environmental effects of atomic oxygen and vacuum thermal cycling showed that no surface cracking occurred.

  15. Evaluation of thermal control coatings for use on solar dynamic radiators in low earth orbit

    NASA Technical Reports Server (NTRS)

    Dever, Joyce A.; Rodriguez, Elvin; Slemp, Wayne S.; Stoyack, Joseph E.

    1991-01-01

    Thermal control coatings with high thermal emittance and low solar absorptance are needed for Space Station Freedom (SSF) solar dynamic power module radiator (SDR) surfaces for efficient heat rejection. Additionally, these coatings must be durable to low earth orbital (LEO) environmental effects of atomic oxygen, ultraviolet radiation and deep thermal cycles which occur as a result of start-up and shut-down of the solar dynamic power system. Eleven candidate coatings were characterized for their solar absorptance and emittance before and after exposure to ultraviolet (UV) radiation (200 to 400 nm), vacuum UV (VUV) radiation (100 to 200 nm) and atomic oxygen. Results indicated that the most durable and best performing coatings were white paint thermal control coatings Z-93, zinc oxide pigment in potassium silicate binder, and YB-71, zinc orthotitanate pigment in potassium silicate binder. Optical micrographs of these materials exposed to the individual environmental effects of atomic oxygen and vacuum thermal cycling showed that no surface cracking occurred.

  16. Design of multilayer antireflection coatings made from co-sputtered and low-refractive-index materials by genetic algorithm.

    PubMed

    Schubert, Martin F; Mont, Frank W; Chhajed, Sameer; Poxson, David J; Kim, Jong Kyu; Schubert, E Fred

    2008-04-14

    Designs of multilayer antireflection coatings made from co-sputtered and low-refractive-index materials are optimized using a genetic algorithm. Co-sputtered and low-refractive-index materials allow the fine-tuning of refractive index, which is required to achieve optimum anti-reflection characteristics. The algorithm minimizes reflection over a wide range of wavelengths and incident angles, and includes material dispersion. Designs of antireflection coatings for silicon-based image sensors and solar cells, as well as triple-junction GaInP/GaAs/Ge solar cells are presented, and are shown to have significant performance advantages over conventional coatings. Nano-porous low-refractive-index layers are found to comprise generally half of the layers in an optimized antireflection coating, which underscores the importance of nano-porous layers for high-performance broadband and omnidirectional antireflection coatings.

  17. Solar cell array design handbook, volume 1

    NASA Technical Reports Server (NTRS)

    Rauschenbach, H. S.

    1976-01-01

    Twelve chapters discuss the following: historical developments, the environment and its effects, solar cells, solar cell filters and covers, solar cell and other electrical interconnections, blocking and shunt diodes, substrates and deployment mechanisms, material properties, design synthesis and optimization, design analysis, procurement, production and cost aspects, evaluation and test, orbital performance, and illustrative design examples. A comprehensive index permits rapid locating of desired topics. The handbook consists of two volumes: Volume 1 is of an expository nature while Volume 2 contains detailed design data in an appendix-like fashion. Volume 2 includes solar cell performance data, applicable unit conversion factors and physical constants, and mechanical, electrical, thermal optical, magnetic, and outgassing material properties. Extensive references are provided.

  18. Design data brochure: Solar hot air heater

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The design, installation, performance, and application of a solar hot air heater for residential, commercial and industrial use is reported. The system has been installed at the Concho Indian School in El Reno, Oklahoma.

  19. Modular solar-heating system - design package

    NASA Technical Reports Server (NTRS)

    Sinton, D. S.

    1979-01-01

    Compilation contains design, performance, and hardware specifications in sufficient detail to fabricate or procure materials and install, operate, and maintain complete modular solar heating and hot water system for single family size dwellings.

  20. Antireflection coating on metallic substrates for solar energy and display applications

    NASA Astrophysics Data System (ADS)

    Hsiao, Wei-Yuan; Tang, Chien-Jen; Lee, Kun-Hsien; Jaing, Cheng-Chung; Kuo, Chien-Cheng; Chen, Hsi-Chao; Chang, Hsing-Hua; Lee, Cheng-Chung

    2010-08-01

    Normally metallic films are required for solar energy and display related coatings. To increase the absorbing efficiency or contrast, it is necessary to apply an antireflection coating (ARC) on the metal substrate. However, the design of a metal substrate is very different from the design of a dielectric substrate, since the optical constant of metallic thin film is very dependent on its thickness and microstructure. In this study, we design and fabricate ARCs on Al substrates using SiO2 and Nb2O5 as the dielectric materials and Nb for the metal films. The ARC successfully deposited on the Al substrate had the following structure: air/SiO2/Nb2O5/Metal/Nb2O5/Al. The measured average reflectance of the ARC is less than 1% in the visible region. We found that it is better to use a highly refractive material than a low refractive material. The thickness of the metallic film can be thicker with the result that it is easier to control and has a lesser total thickness. The total thickness of the ARC is less than 200 nm. We successfully fabricated a solar absorber and OLED device with the ARC structure were successfully fabricated.

  1. Design and testing of AR coatings for MEGARA optics

    NASA Astrophysics Data System (ADS)

    Ortiz, R.; Carrasco, E.; Páez, G.; Pompa, O.; Sanchez-Blanco, E.; Gil de Paz, A.; Gallego, J.; Iglesias-Páramo, J.

    2016-08-01

    We present the antireflection coatings of the optical elements of MEGARA, the new integral field and multi-object spectrograph for the Gran Telescopio Canarias. We describe the methodology for optimizing the solutions. We also present the results of the final deposited coatings. The main optics require broadband coatings in the range from 370 nm to 980 nm for different materials with a mean R<1.3% at specific angles of incidence in each surface. For each material a specific arrangement of thicknesses of the same eight layers were produced and tested. For the spectrograph pupil elements four layer coatings were designed and produced R<0.3%. The design of main optics and pupil elements coatings have been shared between INAOE and CIO. The coating depositions have been performed at CIO in the Integrity 39 Denton Vacuum Deposition System. The main optics final coatings fulfill MEGARA requirements.

  2. Design and fabrication of solar cell modules

    NASA Technical Reports Server (NTRS)

    Shaughnessy, T. P.

    1978-01-01

    A program conducted for design, fabrication and evaluation of twelve silicon solar cell modules is described. The purpose of the program was to develop a module design consistent with the requirements and objectives of JPL specification and to also incorporate elements of new technologies under development to meet LSSA Project goals. Module development emphasized preparation of a technically and economically competitive design based upon utilization of ion implanted solar cells and a glass encapsulation system. The modules fabricated, tested and delivered were of nominal 2 X 2 foot dimensions and 20 watt minimum rating. Basic design, design rationale, performance and results of environmental testing are described.

  3. Interplanetary spacecraft design using solar electric propulsion

    NASA Technical Reports Server (NTRS)

    Duxbury, J. H.; Paul, G. M.

    1974-01-01

    Emphasis of the electric propulsion technology program is now on the application of solar electric propulsion to scientific missions. Candidate planetary, cometary, and geosynchronous missions are being studied. The object of this paper is to describe a basic spacecraft design proposed as the means to accomplish (1) a comet Encke slow flyby, (2) a comet Encke rendezvous, and (3) an out-of-the-ecliptic mission. The discussion includes design differences foreseen for the various missions and indicates those areas where spacecraft design commonality is possible. Particular emphasis is placed on a solar electric propulsion module design which permits an attractive degree of design inheritance from mission to mission.

  4. Enhanced Aluminum Reflecting and Solar-Blind Filter Coatings for the Far-Ultraviolet

    NASA Technical Reports Server (NTRS)

    Del Hoyo, Javier; Quijada, Manuel

    2017-01-01

    The advancement of far-ultraviolet (FUV) coatings is essential to meet the specified throughput requirements of the Large UV/Optical/IR (LUVOIR) Surveyor Observatory which will cover wavelengths down to the 100 nm range. The biggest constraint in the optical thin film coating design is attenuation in the Lyman-Alpha Ultraviolet range of 100-130 nm in which conventionally deposited thin film materials used in this spectral region (e.g. aluminum [Al] protected with Magnesium fluoride [MgF2]) often have high absorption and scatter properties degrading the throughput in an optical system. We investigate the use of optimally deposited aluminum and aluminum tri-fluoride (AlF3) materials for reflecting and solar blind band-pass filter coatings for use in the FUV. Optical characterization of the deposited designs has been performed using UV spectrometry. The optical thin film design and optimal deposition conditions to produce superior reflectance and transmittance using Al and AlF3 are presented.

  5. Solafern solar system design brochure

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A complete residential solar space heating and hot water system is described. Low maintenance, durable, and efficient air heating collectors are used. The collectors have a selective absorber and a tempered glass cover nearly one-quarter of an inch thick with an aluminum frame. The solar energy can be delivered directly to the living area when there is a demand; otherwise, it is stored in the form of hot water. Hot water storage is accomplished through the use of an air-to-water exchanger. The hot water storage is used simultaneously to preheat the domestic hot water, as well as to store energy for space heating.

  6. Solar Effective Envelope Design Advisor (SEEDA)

    NASA Astrophysics Data System (ADS)

    Mahaek, Ekkachai

    The lack of effort by mainstream architects in integrating energy-efficient strategies in architectural designing is due to the complexity in a building's energy conscious concepts and theories, the difficulties to visualize and quantify energy consumption, and the late implementing of energy consumption analysis in the conventional design process. This task would be accomplishing by a building system's engineer where results might be determined only after the basic architectural design has been completed. An effective simple tool and method should then be available to assist architects in building's energy-efficient designing at the beginning of the design. The building's energy consumption is directly and mainly influenced by the relationship of the sun, site, and its building configuration. The solar radiations will first impact on the building's envelope, which will have a direct effect on the amount of energy a building will consume. If an architect can define or map the intensity of solar energy on the site's buildable volume, and use this information to determine the levels of solar insolation, a more energy efficient building form can be proposed. This research hypothesis has shared the fundamental techniques of the Solar Envelope projection by Professor Ralph Knowles [Knowles, 1981] of the University of Southern California. However a different approach is taken by including the influence of regional restrictions and the surrounding buildings' shadows when projecting of solar volumes and solar envelope. The research methodology will discuss the development of a computer-based approach to develop a three-dimensional architectural form based on an insolation map related to the design site. The prototype computer program is referred as the Solar Effective Envelope Design Advisor (SEEDA). The solar insolation volume of the site is determined by integrating three types of computer-generated models include the Buildable Volume model based on design constraints

  7. Design of Aerosol Coating Reactors: Precursor Injection

    PubMed Central

    Buesser, Beat; Pratsinis, Sotiris E.

    2013-01-01

    Particles are coated with thin shells to facilitate their processing and incorporation into liquid or solid matrixes without altering core particle properties (coloristic, magnetic, etc.). Here, computational fluid and particle dynamics are combined to investigate the geometry of an aerosol reactor for continuous coating of freshly-made titanium dioxide core nanoparticles with nanothin silica shells by injection of hexamethyldisiloxane (HMDSO) vapor downstream of TiO2 particle formation. The focus is on the influence of HMDSO vapor jet number and direction in terms of azimuth and inclination jet angles on process temperature and coated particle characteristics (shell thickness and fraction of uncoated particles). Rapid and homogeneous mixing of core particle aerosol and coating precursor vapor facilitates synthesis of core-shell nanoparticles with uniform shell thickness and high coating efficiency (minimal uncoated core and free coating particles). PMID:23658471

  8. Biourbanism: Solar based urban and regional design

    SciTech Connect

    Williams, D.

    1999-07-01

    New neighborhoods for an additional one billion people will need to be constructed on the planet within the next 10 years. If the historic patterns of growth continue--the sprawl, the congestion, the draining of swamps, the loss of agricultural land--the requirement for all basic resources will outstrip the availability. While this is of great concern, it is the destruction of an acceptable quality of life--the sense of place--that will be the most difficult and expensive to change. An essential step to reverse the direction of this undesirable future is changing the design and planning of these communities to work with resident solar energies, regional biology, local renewable resources, and sustainable urban planning and design principles. Design can make a difference. This paper develops the view that the solar approach must include urban and regional design and presents solar-based renewable resources example of the design of regions.

  9. Refractive Secondary Solar Concentrator Being Designed and Developed

    NASA Technical Reports Server (NTRS)

    Macosko, Robert P.; Donovan, Richard M.

    1998-01-01

    As the need for achieving super high temperatures (2000 K and above) in solar heat receivers has developed so has the need for secondary concentrators. These concentrators refocus the already highly concentrated solar energy provided by a primary solar collector, thereby significantly reducing the light entrance aperture of the heat receiver and the resulting infrared radiation heat loss from the receiver cavity. Although a significant amount of research and development has been done on nonimaging hollow reflective concentrators, there has been no other research or development to date on solid, single crystal, refractive concentrators that can operate at temperatures above 2000 K. The NASA Lewis Research Center recently initiated the development of single-crystal, optically clear, refractive secondary concentrators that, combined with a flux extractor, offer a number of significant advantages over the more conventional, hollow, reflective concentrators at elevated temperatures. Such concentrators could potentially provide higher throughput (efficiency), require no special cooling device, block heat receiver material boiloff from the receiver cavity, provide for flux tailoring in the cavity via the extractor, and potentially reduce infrared heat loss via an infrared block coating.The many technical challenges of designing and fabricating high-temperature refractive secondary concentrators and flux extractors include identifying optical materials that can survive the environment (high-temperature, vacuum and/or hydrogen atmosphere), developing coatings for enhanced optical and thermal performance, and developing crystal joining techniques and hardware that can survive launch loads.

  10. Improvement of black nickel coatings. [product development for use in solar collectors

    NASA Technical Reports Server (NTRS)

    Peterson, R. E.; Lin, J. H.

    1976-01-01

    Selectively absorbing black nickel coatings are among the most optically efficient low cost coatings for use on flat plate solar collectors. However, a current Ni-Zn-S-O coating in use is quite susceptible to a humid environment, degrading badly in less than ten days at 38 C (100 F) at 95 percent relative humidity. Therefore, a black nickel formula was developed which can withstand such exposures with no loss of optical efficiency, solar absorption of 0.92 and an infrared emittance (at 100 C) of 1.00 were still present after 14 days of humidity exposure. This compares to a solar absorptance of only 0.72 for the previous formula after a similar time period. The electroplating bath and conditions were changed to obtain the more stable coating configuration. The effect of bath composition, temperature, pH, and plating current density and time on the coating composition, spectral optical properties and durability were investigated systematically.

  11. Structural and optical properties of copper-coated substrates for solar thermal absorbers

    NASA Astrophysics Data System (ADS)

    Pratesi, Stefano; De Lucia, Maurizio; Meucci, Marco; Sani, Elisa

    2016-10-01

    Spectral selectivity, i.e. merging a high absorbance at sunlight wavelengths to a low emittance at the wavelengths of thermal spectrum, is a key characteristics for materials to be used for solar thermal receivers. It is known that spectrally selective absorbers can raise the receiver efficiency for all solar thermal technologies. Tubular sunlight receivers for parabolic trough collector (PTC) systems can be improved by the use of spectrally selective coatings. Their absorbance is increased by deposing black films, while the thermal emittance is minimized by the use of properly-prepared substrates. In this work we describe the intermediate step in the fabrication of black-chrome coated solar absorbers, namely the fabrication and characterization of copper coatings on previously nickel-plated stainless steel substrates. We investigate the copper surface features and optical properties, correlating them to the coating thickness and to the deposition process, in the perspective to assess optimal conditions for solar absorber applications.

  12. Demonstration of transparent solar array module design

    NASA Technical Reports Server (NTRS)

    Pack, G. J.

    1984-01-01

    This report discusses the design, development, fabrication and testing of IR transparent solar array modules. Three modules, consisting of a baseline design using back surface reflector cells, and two modules using gridded back contact, IR transparent cells, were subjected to vacuum thermal balance testing to verify analytical predictions of lower operating emperature and increased efficiency. As a result of this test program, LMSC has verified that a significant degree of IR transparency can be designed into a flexible solar array. Test data correlates with both steady state and transient thermal analysis.

  13. Overview of Passive Solar Design Techniques.

    DTIC Science & Technology

    1982-09-01

    the "market acceptance" of the passive solar designs. In mast cases, a passive system is integrated into the architecture of a building, which...increases discomfort by decreasing the rate of moisture evaporation from the skin. The Bioclimatic Chart developed by V. Olgyay provides a convenient way...outdoors and, therefore, not previously cir- culated through the system. passive solar system: An assembly of natural and architectural components

  14. Gradient SiNO anti-reflective layers in solar selective coatings

    DOEpatents

    Ren, Zhifeng; Cao, Feng; Sun, Tianyi; Chen, Gang

    2017-08-01

    A solar selective coating includes a substrate, a cermet layer having nanoparticles therein deposited on the substrate, and an anti-reflection layer deposited on the cermet layer. The cermet layer and the anti-reflection layer may each be formed of intermediate layers. A method for constructing a solar-selective coating is disclosed and includes preparing a substrate, depositing a cermet layer on the substrate, and depositing an anti-reflection layer on the cermet layer.

  15. Technical applications of solar energy. Project photovoltaic systems and project selective coatings

    NASA Astrophysics Data System (ADS)

    Gindele, K.; Honstetter, K.; Karl, H.; Koehl, M.; Lehner, G.; Mast, M.; Spohn, C.; Wagner, A.

    1983-12-01

    Long time stability of photovoltaic generators, hybrid collectors, and measuring devices for solar cells and solar cell generators were investigated. No aging of electrical features is stated after 6 yr working, while thermal and electrical efficiencies of collectors amount to 70% and 8% respectively. Radiative properties of selective coatings were measured, composition and structure of selective surfaces, vapor deposition methods (e.g., cermet-coatings), and chemical methods (e.g., cooper-oxide) were investigated.

  16. Plasma-enhanced CVD silicon nitride antireflection coatings for solar cells

    NASA Technical Reports Server (NTRS)

    Johnson, C. C.; Wydeven, T.; Donohoe, K.

    1983-01-01

    Multilayer plasma-enhanced chemical vapor deposition (PECVD) silicon nitride antireflection coatings were deposited on space quality silicon solar cells. Preliminary experiments indicated that multilayer coatings decreased the total reflectance of polished silicon from 35 percent to less than 3 percent over the spectral range 0.4-1.0 micron. The solar cell energy conversion efficiency was increased from an average of 8.84 percent to an average of 12.63 percent.

  17. Residential solar-heating system - design brochure

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Design brochure for commercially-available solar-heating system is valuable to architects, engineers, and designers. It contains information on system configuration, system sizing, and mechanical layout. Drawings and specifications of all components and typical installation details are included in appendix.

  18. Design tools for passive solar applications

    SciTech Connect

    Balcomb, J D

    1986-04-01

    Examples of passive solar design tools are given, categorized as either evaluation tools or guidance tools. A trend toward microcomputer-based tools is noted; however, these are usually developed for use by engineers rather than architects. The need for more instructive tools targeted specifically to designers is emphasized.

  19. Application and design of solar photovoltaic system

    NASA Astrophysics Data System (ADS)

    Tianze, Li; Hengwei, Lu; Chuan, Jiang; Luan, Hou; Xia, Zhang

    2011-02-01

    Solar modules, power electronic equipments which include the charge-discharge controller, the inverter, the test instrumentation and the computer monitoring, and the storage battery or the other energy storage and auxiliary generating plant make up of the photovoltaic system which is shown in the thesis. PV system design should follow to meet the load supply requirements, make system low cost, seriously consider the design of software and hardware, and make general software design prior to hardware design in the paper. To take the design of PV system for an example, the paper gives the analysis of the design of system software and system hardware, economic benefit, and basic ideas and steps of the installation and the connection of the system. It elaborates on the information acquisition, the software and hardware design of the system, the evaluation and optimization of the system. Finally, it shows the analysis and prospect of the application of photovoltaic technology in outer space, solar lamps, freeways and communications.

  20. Organic Tandem Solar Cells: Design and Formation

    NASA Astrophysics Data System (ADS)

    Chen, Chun-Chao

    In the past decade, research on organic solar cells has gone through an important development stage leading to major enhancements in power conversion efficiency, from 4% to 9% in single-junction devices. During this period, there are many novel processing techniques and device designs that have been proposed and adapted in organic solar-cell devices. One well-known device architecture that helps maximize the solar cell efficiency is the multi-junction tandem solar-cell design. Given this design, multiple photoactive absorbers as subcells are stacked in a monolithic fashion and assembled via series connection into one complete device, known as the tandem solar cell. Since multiple absorbers with different optical energy bandgaps are being applied in one tandem solar-cell device, the corresponding solar cell efficiency is maximized through expanded absorption spectrum and reduced carrier thermalization loss. In Chapter 3, the architecture of solution-processible, visibly transparent solar cells is introduced. Unlike conventional organic solar-cell devices with opaque electrodes (such as silver, aluminum, gold and etc.), the semi-transparent solar cells rely on highly transparent electrodes and visibly transparent photoactive absorbers. Given these two criteria, we first demonstrated the visibly transparent single-junction solar cells via the polymer absorber with near-infrared absorption and the top electrode based on solution-processible silver nanowire conductor. The highest visible transparency (400 ˜ 700 nm) of 65% was achieved for the complete device structure. More importantly, power conversion efficiency of 4% was also demonstrated. In Chapter 4, we stacked two semi-transparent photoactive absorbers in the tandem architecture in order to realize the semi-transparent tandem solar cells. A noticeable performance improvement from 4% to 7% was observed. More importantly, we modified the interconnecting layers with the incorporation of a thin conjugated

  1. Building Design Guidelines for Solar Energy Technologies

    DOE R&D Accomplishments Database

    Givoni, B.

    1989-01-01

    There are two main objectives to this publication. The first is to find out the communalities in the experience gained in previous studies and in actual applications of solar technologies in buildings, residential as well as nonresidential. The second objective is to review innovative concepts and products which may have an impact on future developments and applications of solar technologies in buildings. The available information and common lessons were collated and presented in a form which, hopefully, is useful for architects and solar engineers, as well as for teachers of "solar architecture" and students in Architectural Schools. The publication is based mainly on the collection and analysis of relevant information. The information included previous studies in which the performance of solar buildings was evaluated, as well as the personal experience of the Author and the research consultants. The state of the art, as indicated by these studies and personal experience, was summarized and has served as basis for the development of the Design Guidelines. In addition to the summary of the state of the art, as was already applied in solar buildings, an account was given of innovative concepts and products. Such innovations have occurred in the areas of thermal storage by Phase Change Materials (PCM) and in glazing with specialized or changeable properties. Interesting concepts were also developed for light transfer, which may enable to transfer sunlight to the core areas of large multi story nonresidential buildings. These innovations may have a significant impact on future developments of solar technologies and their applications in buildings.

  2. Solar Selective Coatings Prepared From Thin-Film Molecular Mixtures and Evaluated

    NASA Technical Reports Server (NTRS)

    Jaworske, Don A.

    2003-01-01

    Thin films composed of molecular mixtures of metal and dielectric are being considered for use as solar selective coatings for a variety of space power applications. By controlling molecular mixing during ion-beam sputter deposition, researchers can tailor the solar selective coatings to have the combined properties of high solar absorptance and low infrared emittance. On orbit, these combined properties simultaneously maximize the amount of solar energy captured by the coating and minimize the amount of thermal energy radiated. The solar selective coatings are envisioned for use on minisatellites, for applications where solar energy is used to power heat engines or to heat remote regions in the interior of the spacecraft. Such systems may be useful for various missions, particularly those to middle Earth orbit. Sunlight must be concentrated by a factor of 100 or more to achieve the desired heat inlet operating temperature. At lower concentration factors, the temperature of the heat inlet surface of the heat engine is too low for efficient operation, and at high concentration factors, cavity type heat receivers become attractive. The an artist's concept of a heat engine, with the annular heat absorbing surface near the focus of the concentrator coated with a solar selective coating is shown. In this artist's concept, the heat absorbing surface powers a small Stirling convertor. The astronaut's gloved hand is provided for scale. Several thin-film molecular mixtures have been prepared and evaluated to date, including mixtures of aluminum and aluminum oxide, nickel and aluminum oxide, titanium and aluminum oxide, and platinum and aluminum oxide. For example, a 2400- Angstrom thick mixture of titanium and aluminum oxide was found to have a solar absorptance of 0.93 and an infrared emittance of 0.06. On the basis of tests performed under flowing nitrogen at temperatures as high as 680 C, the coating appeared to be durable at elevated temperatures. Additional durability

  3. Dip coating process: Silicon sheet growth development for the large-area silicon sheet task of the low-cost silicon solar array project

    NASA Technical Reports Server (NTRS)

    Heaps, J. D.; Maciolek, R. B.; Harrison, W. B.; Wolner, H. A.

    1975-01-01

    The research program to investigate the technical and economic feasibility of producing solar-cell-quality sheet silicon by dip-coating one surface of carbonized ceramic substrates with a thin layer of large-grain polycrystalline silicon is reported. The initial effort concentrated on the design and construction of the experimental dip-coating facility. The design was completed and its experimental features are discussed. Current status of the program is reported, including progress toward solar cell junction diffusion and miscellaneous ceramic substrate procurement.

  4. Design and Characterization of High-strength Bond Coats for Improved Thermal Barrier Coating Durability

    NASA Astrophysics Data System (ADS)

    Jorgensen, David John

    High pressure turbine blades in gas turbine engines rely on thermal barrier coating (TBC) systems for protection from the harsh combustion environment. These coating systems consist of a ceramic topcoat for thermal protection, a thermally grown oxide (TGO) for oxidation passivation, and an intermetallic bond coat to provide compatibility between the substrate and ceramic over-layers while supplying aluminum to sustain Al2O 3 scale growth. As turbine engines are pushed to higher operating temperatures in pursuit of better thermal efficiency, the strength of industry-standard bond coats limits the lifetime of these coating systems. Bond coat creep deformation during thermal cycling leads to a failure mechanism termed rumpling. The interlayer thermal expansion differences, combined with TGO-imposed growth stresses, lead to the development of periodic undulations in the bond coat. The ceramic topcoat has low out-of-plane compliance and thus detaches and spalls from the substrate, resulting in a loss of thermal protection and subsequent degradation of mechanical properties. New creep resistant Ni3Al bond coats were designed with improved high-temperature strength to inhibit this type of premature failure at elevated temperatures. These coatings resist rumpling deformation while maintaining compatibility with the other layers in the system. Characterization methods are developed to quantify rumpling and assess the TGO-bond coat interface toughness of experimental systems. Cyclic oxidation experiments at 1163 °C show that the Ni3Al bond coats do not experience rumpling but have faster oxide growth rates and are quicker to spall TGO than the (Pt,Ni)Al benchmark. However, the Ni 3Al coatings outperformed the benchmark by over threefold in TBC system life due to a higher resistance to rumpling (mechanical degradation) while maintaining adequate oxidation passivation. The Ni3Al coatings eventually grow spinel NiAl2O4 on top of the protective Al2O3 layer, which leads to the

  5. Efficiency improvement of silicon solar cells enabled by ZnO nanowhisker array coating

    PubMed Central

    2012-01-01

    An efficient antireflection coating is critical for the improvement of silicon solar cell performance via increased light coupling. Here, we have grown well-aligned ZnO nanowhisker (NW) arrays on Czochralski silicon solar cells by a seeding-growth two-step process. It is found that the ZnO NWs have a great effect on the macroscopic antireflection effect and, therefore, improves the solar cell performance. The ZnO NW array-coated solar cells display a broadband reflection suppression from 500 to 1,100 nm, and the minimum reflectance smaller than 3% can easily be achieved. By optimizing the time of ZnO NW growth, it has been confirmed that an increase of 3% relatively in the solar cell efficiency can be obtained. These results are quite interesting for the application of ZnO nanostructure in the fabrication of high-efficiency silicon solar cells. PMID:22704578

  6. Opaline backreflector coating in dye-sensitized solar cell.

    PubMed

    Herman, Lia Agustine; Yip, Chan Hoe; Wong, Chee Cheong

    2010-07-01

    Photonic crystals are ordered nanostructures that are designed to manipulate the propagation of light. The periodicity of a photonic crystal can be engineered to be highly reflective at selected wavelengths. In this work, a mono-layer and double-layer colloidal photonic crystal film were self-assembled on a glass substrate to be used as backreflectors in a dye-sensitized solar cell (DSSC). The colloidal photonic crystal film consists of different polystyrene monodispersed particles with sizes between 200 nm and 290 nm. Making use of flow controlled vertical deposition (FCVD) method, opaline films of Bragg's reflection wavelength between 450 nm to 750 nm were achieved. These wavelengths were designed to match the absorption spectrum of the Ruthenium-complex dye used in DSSC. An enhancement in incident photon-to-current conversion efficiency (IPCE) of the opaline backreflector DSSC of about 30% at Bragg's peak wavelength has been achieved.

  7. Thermal design of spacecraft solar arrays using a polyimide foam

    NASA Astrophysics Data System (ADS)

    Bianco, N.; Iasiello, M.; Naso, V.

    2015-11-01

    The design of the Thermal Control System (TCS) of spacecraft solar arrays plays a fundamental role. Indeed, the spacecraft components must operate within a certain range of temperature. If this doesn't occur, their performance is reduced and they may even break. Solar arrays, which are employed to recharge batteries, are directly exposed to the solar heat flux, and they need to be insulated from the earth's surface irradiation. Insulation is currently provided either with a white paint coating or with a Multi Layer Insulation (MLI) system [1]. A configuration based on an open-cell polyimide foam has also been recently proposed [2]. Using polyimide foams in TCSs looks very attractive in terms of costs, weight and assembling. An innovative thermal analysis of the above cited TCS configurations is carried out in this paper, by solving the porous media energy equation, under the assumption of Local Thermal Equilibrium (LTE) between the two phases. Radiation effects through the solar array are also considered by using the Rosseland approximation. Under a stationary daylight condition, temperature profiles are obtained by means of the finite-element based code COMSOL Multiphysics®. Finally, since the weight plays an important role in aerospace applications, weights of the three TCS configurations are compared.

  8. Edge coating apparatus with movable roller applicator for solar cell substrates

    SciTech Connect

    Pavani, Luca; Abas, Emmanuel

    2012-12-04

    A non-contact edge coating apparatus includes an applicator for applying a coating material on an edge of a solar cell substrate and a control system configured to drive the applicator. The control system may drive the applicator along an axis to maintain a distance with an edge of the substrate as the substrate is rotated to have the edge coated with a coating material. The applicator may include a recessed portion into which the edge of the substrate is received for edge coating. For example, the applicator may be a roller with a groove. Coating material may be introduced into the groove for application onto the edge of the substrate. A variety of coating materials may be employed with the apparatus including hot melt ink and UV curable plating resist.

  9. CuO-PANI nanostructure with tunable spectral selectivity for solar selective coating application

    NASA Astrophysics Data System (ADS)

    Cindrella, L.; Prabhu., S.

    2016-08-01

    CuO-PANI nanostructure has been demonstrated as the solar selective absorber coating for the first time. The effortless chemical methods and easily scalable techniques such as precipitation, in-situ polymerization and spray coating were adopted for the fabrication of CuO nanorods and CuO-PANI nanostructures for solar application. The synthesis was carried out without using any template. The morphology and phase structure of fabricated CuO nanorods and CuO-PANI nanostructure coatings were studied by atomic force microscopy, scanning electron microscopy and X-ray diffraction analysis. The energy dispersive X-ray spectra and elemental mapping confirm the presence of the chosen elements in the nanostructure. The solar absorptance (αs), thermal emittance (εt) and selectivity (ξ) of the nanostructure coatings on glass substrate were optimized to 0.94, 0.01 and 94 respectively by changing the polyaniline content on the surface of the CuO nanorods. The efficiency of the solar selective coatings were evaluated. The optimized solar absorber coating of CuO-PANI nanostructure is highly promising for its selective optical properties.

  10. Effects of positive ion implantation into antireflection coating of silicon solar cells

    NASA Technical Reports Server (NTRS)

    Middleton, A. E.; Harpster, J. W.; Collis, W. J.; Kim, C. K.

    1971-01-01

    The state of technological development of Si solar cells for highest obtained efficiency and radiation resistance is summarized. The various theoretical analyses of Si solar cells are reviewed. It is shown that factors controlling blue response are carrier diffusion length, surface recombination, impurity concentration profile in surface region, high level of surface impurity concentration (degeneracy), reflection coefficient of oxide, and absorption coefficient of Si. The theory of ion implantation of charge into the oxide antireflection coating is developed and side effects are discussed. The experimental investigations were directed at determining whether the blue response of Si solar cells could be improved by phosphorus ion charges introduced into the oxide antireflection coating.

  11. Design data brochure for the Owens-Illinois Sunpak (TM) air-cooled solar collector

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Information necessary to evaluate the design and installation of the Owens-Illinois Sunpak TM Air-Cooled Solar Collector is presented. Information includes collector features, fluid flow, thermal performance, installation and system tips. The collector utilizes a highly selective wavelength coating in combination with vacuum insulation, which virtually eliminates conduction and convention losses.

  12. Large area flexible solar array design for Space Shuttle application

    NASA Technical Reports Server (NTRS)

    Souza, C. J.

    1980-01-01

    A large area flexible solar array has been designed for Shuttle power augmentation. The solar array utilizes large area, low cost, weldable solar cells. The paper addresses how the unique requirements of this system are implemented into the design. Economic and reliability issues relating to the optimization of a large area, foldable solar array concomitant to the Shuttle/Orbiter system are reviewed.

  13. Optimization of spray coating for the fabrication of sequentially deposited planar perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Habibi, Mehran; Ahmadian-Yazdi, Mohammad-Reza; Eslamian, Morteza

    2017-04-01

    We use facile coating techniques including spray coating and drop casting to fabricate methylammonium lead iodide perovskite solar cells through a two-step sequential deposition approach. In the first step, for the deposition of the lead iodide, spray coating substitutes for the commonly used lab-scale spin coating, while the operating parameters of the former process are optimized to achieve a fully covered and uniform film of lead iodide. In the second step, to deposit methylammonium iodide atop the lead iodide layer to form methylammonium lead iodide perovskite, dip-coating process is replaced by the touch-free drop casting and scalable pulsed-spray coating. It is found that the performance of the perovskite films and devices made by pulsed-spray coating and drop casting is similar to those prepared by dip coating, while the large-scale production capabilities of such methods beside the low material consumptions of drop casting prove their potential to replace dip coating in large-scale manufacturing of perovskite solar cells. The champion devices fabricated by spray-drop and spin-drop techniques demonstrated power conversion efficiencies of 6.92% and 9.48%, respectively. It is expected that device fabrication in a low-humidity environment using the optimized parameters and optimization of other layers will result in higher efficiencies.

  14. The design of solar tower power plants

    NASA Astrophysics Data System (ADS)

    Gretz, J.

    The conversion of solar energy into electricity in solar thermal tower power plants is examined. Mirrors attached to mobile, sun-following heliostats concentrate solar rays into the opening of a receiver mounted on a tower. In the receiver, the radiant energy is absorbed by a system of pipes filled with a flowing material which is heated and drives a turbogenerator directly or via a heat exchanger. It is shown that the optics involved in this concept preclude the optimization of the pipe material, since the local distribution of rays in the heater of tower power plants varies diurnally and annually. This requires each pipe section to be designed for maximum stress, even though that stress occurs only at brief intervals during the day.

  15. Solar heating system final design package

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The system is composed of a warm air collector, a logic control unit and a universal switching and transport unit. The collector was originally conceived and designed as an integrated roof/wall system and therefore provides a dual function in the structure. The collector serves both as a solar energy conversion system and as a structural weather resistant skin. The control unit provides totally automatic control over the operation of the system. It receives input data from sensor probes in collectors, storage and living space. The logic was designed so as to make maximum use of solar energy and minimize use of conventional energy. The transport and switching unit is a high-efficiency air-handling system equipped with gear motor valves that respond to outputs from the control system. The fan unit was designed for maximum durability and efficiency in operation, and has permanently lubricated ball bearings and excellent air-handling efficiency.

  16. Building design guidelines for solar energy technologies

    SciTech Connect

    Givoni, B.

    1989-01-01

    There are two main objectives to this publication. The first is to find out the communalities in the experience gained in previous studies and in actual applications of solar technologies in buildings, residential as well as nonresidential. The second objective is to review innovative concepts and products which may have an impact on future developments and applications of solar technologies in buildings. The available information and common lessons were collated and presented in a form which, hopefully, is useful for architects and solar engineers, as well as for teachers of solar architecture'' and students in Architectural Schools. The publication is based mainly on the collection and analysis of relevant information. The information included previous studies in which the performance of solar buildings was evaluated, as well as the personal experience of the Author and the research consultants. The state of the art, as indicated by these studies and personal experience, was summarized and has served as basis for the development of the Design Guidelines. In addition to the summary of the state of the art, as was already applied in solar buildings, an account was given of innovative concepts and products. Such innovations have occurred in the areas of thermal storage by Phase Change Materials (PCM) and in glazing with specialized or changeable properties. Interesting concepts were also developed for light transfer, which may enable to transfer sunlight to the core areas of large multi story nonresidential buildings. These innovations may have a significant impact on future developments of solar technologies and their applications in buildings. 15 refs., 19 figs., 3 tabs.

  17. Refinement in black chrome for use as a solar selective coating

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. E.

    1974-01-01

    Black chrome is significant as a solar selective coating because the current extensive use of black chrome in the electroplating industry as a durable decorative finish makes black chrome widely available on a commercial scale and potentially low in cost as a solar selective coating. Black-chrome deposits were modified by underplating with dull nickel or by being plated on rough surfaces. Both of these procedures increased the visible absorptance. There was no change in the infrared reflectance for the dull-nickel - black-chrome combination from that reported for the bright-nickel - black-chrome combination. However, the bright-nickel - black-chrome coating plated on rough surfaces indicated a slight decrease in infrared reflectance. As integrated over the solar spectrum for air mass 2, the reflectance of the dull-nickel - black-chrome coating was 0.077, of the bright-nickel - black-chrome coating plated on a 0.75-micron (30-microinch) surface was 0.070, of the bright-nickel - black-chrome coating plated on a 2.5 micron (100-microinch) surface was 0.064. The corresponding values for the bright-nickel - black-chrome coating on a 0.0125-micron (0.5-microinch) surface, two samples of black nickel, and two samples of Nextrel black paint were 0.132, 0.123, 0.133, and 0.033, respectively.

  18. Preliminary study of a solar selective coating system using black cobalt oxide for high temperature solar collectors

    NASA Technical Reports Server (NTRS)

    Mcdonald, G.

    1980-01-01

    Black cobalt oxide coatings (high solar absorptance layer) were deposited on thin layers of silver or gold (low emittance layer) which had been previously deposited on oxidized (diffusion barrier layer) stainless steel substrates. The reflectance properties of these coatings were measured at various thicknesses of cobalt for integrated values of the solar and infrared spectrum. The values of absorptance and emittance were calculated from the measured reflectance values, before and after exposure in air at 650 C for approximately 1000 hours. Absorptance and emittance were interdependent functions of the weight of cobalt oxide. Also, these cobalt oxide/noble metal/oxide diffusion barrier coatings have absorptances greater than 0.90 and emittances of approximately 0.20 even after about 1000 hours at 650 C.

  19. Experimental and CFD studies on SnO2 coatings over solar cells to increase collector efficiency

    NASA Astrophysics Data System (ADS)

    Vinutha, A.; Anvesh, C. H. Venkata; Babu, R. Art; Sarma, P. N.

    2017-07-01

    Solar radiation is major outcome of renewable energy sources. The low overall efficiency (21%) in solar collectors is mainly due to the reflection of the heat absorbed from the solar cells back to atmospheric air. Experiments are conducted to apply a Nano-coating layer of tin oxide on solar cells (silicon wafers) by a thermal vapour process under high vacuum, followed by annealing with an objective of reducing the reflection. The tests conducted with the Nano-coated solar cells showed that the cell efficiency has increased from 24% without coating to 31% with an optimum coating 400 nm thicknesses has been found. As the coating thickness is increased from zero to 600nm the heat loss due to convection decreased monotonically from 461.4 to 452 W/m2. The CFD analysis provides the temperature distribution in the solar panel and heat transferred to base for effective heat re-utilization.

  20. Design and installation of solar heating and hot water systems

    SciTech Connect

    Williams, J.R.

    1983-01-01

    A no-nonsense explanation of information on the use of solar energy for heating, cooling, and producing hot water. The work is both scholarly and practical. Background of high school algebra is the only mathematics expected. Worked examples but no exercises. Contents: Solar radiation. Heating loads. Design and analysis of flat-place liquid-heating collectors. Flat-plate air-heating collectors. Evacuated solar collectors. Solar hot water systems. Solar ponds. Active solar heating and cooling systems.

  1. Ultraviolet degradation to double anti-reflective coated solar cells

    NASA Technical Reports Server (NTRS)

    Meulenberg, Andrew

    1992-01-01

    Six experiments at COMSAT Labs (since the early '80's) have consistently shown higher UV degradation rates for DAR coated cells when the tests are extended beyond 1000 hours. Results for degradation at 10 years, extrapolated from data at 3000 hours, exceeds 10%. Lesser degradation rates are observed for DAR coated textured cells. Data and models will be presented.

  2. Optical designs for improved solar cell performance

    NASA Astrophysics Data System (ADS)

    Kosten, Emily Dell

    wavelengths. This approach has the potential for very high efficiencies, and excellent annual power production. Using a light-trapping filtered concentrator approach, we design filter elements and find an optimal design. Thus, this thesis explores silicon microwires, angle restriction, and spectral splitting as different optical approaches for improving the cost and efficiency of solar cells.

  3. Levelized cost of energy (LCOE) metric to characterize solar absorber coatings for the CSP industry

    DOE PAGES

    Boubault, Antoine; Ho, Clifford K.; Hall, Aaron; ...

    2015-07-08

    The contribution of each component of a power generation plant to the levelized cost of energy (LCOE) can be estimated and used to increase the power output while reducing system operation and maintenance costs. The LCOE is used in order to quantify solar receiver coating influence on the LCOE of solar power towers. Two new parameters are introduced: the absolute levelized cost of coating (LCOC) and the LCOC efficiency. Depending on the material properties, aging, costs, and temperature, the absolute LCOC enables quantifying the cost-effectiveness of absorber coatings, as well as finding optimal operating conditions. The absolute LCOC is investigatedmore » for different hypothetic coatings and is demonstrated on Pyromark 2500 paint. Results show that absorber coatings yield lower LCOE values in most cases, even at significant costs. Optimal reapplication intervals range from one to five years. At receiver temperatures greater than 700 °C, non-selective coatings are not always worthwhile while durable selective coatings consistently reduce the LCOE—up to 12% of the value obtained for an uncoated receiver. Moreover the absolute LCOC is a powerful tool to characterize and compare different coatings, not only considering their initial efficiencies but also including their durability.« less

  4. Levelized cost of energy (LCOE) metric to characterize solar absorber coatings for the CSP industry

    SciTech Connect

    Boubault, Antoine; Ho, Clifford K.; Hall, Aaron; Lambert, Timothy N.; Ambrosini, Andrea

    2015-07-08

    The contribution of each component of a power generation plant to the levelized cost of energy (LCOE) can be estimated and used to increase the power output while reducing system operation and maintenance costs. The LCOE is used in order to quantify solar receiver coating influence on the LCOE of solar power towers. Two new parameters are introduced: the absolute levelized cost of coating (LCOC) and the LCOC efficiency. Depending on the material properties, aging, costs, and temperature, the absolute LCOC enables quantifying the cost-effectiveness of absorber coatings, as well as finding optimal operating conditions. The absolute LCOC is investigated for different hypothetic coatings and is demonstrated on Pyromark 2500 paint. Results show that absorber coatings yield lower LCOE values in most cases, even at significant costs. Optimal reapplication intervals range from one to five years. At receiver temperatures greater than 700 °C, non-selective coatings are not always worthwhile while durable selective coatings consistently reduce the LCOE—up to 12% of the value obtained for an uncoated receiver. Moreover the absolute LCOC is a powerful tool to characterize and compare different coatings, not only considering their initial efficiencies but also including their durability.

  5. Photocatalytic Coatings for Exploration and Spaceport Design

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This project developed self-cleaning photocatalytic coatings that remove contamination without human intervention. The coatings chemically remove organic contaminants and leave no residue. The photocatalyst will not negatively affect other coating properties, especially corrosion resistance. Titanium dioxide, TiO2, is an extremely popular photocatalyst because of its chemical stability, nontoxicity, and low cost. TiO2 is commonly used in the photocatalytic oxidation of organic matter or pollutants in the gas and liquid phases. However, TiO2 does have some drawbacks. It has limited light absorption because of its large band-gap and suffers from a photonic efficiency of less than 10 percent for organic degradation. Dopants can lower the band-gap and improve efficiency. Since the photocatalytically active form of TiO2 is a nanocrystalline powder, it can be difficult to make a robust coating with enough catalyst loading to be effective. Photocatalysts become active when certain light energy is absorbed. When photons with an energy greater than the band-gap, Eg, (wavelengths shorter than 400 nm) impinge upon the surface of the TiO2, an electron-hole pair is formed. The electron-hole pair oxidizes adsorbed substances either directly or via reactive intermediates that form on the surface, such as hydroxyl radicals (OH) or superoxide ions (O2-). Several factors can influence the band-gap energy of TiO2, two of which are crystal structure and impurities. TiO2 exists as three crystal structures brookite, anatase, and rutile that can be controlled via heat treatment. Anatase is the most photocatalytically active crystal form of TiO2. Doping TiO2 with impurities can alter its band-gap energy, as well as its effectiveness as a catalyst. Depending on their size, dopant atoms can occupy either the substitutional or interstitial lattice positions. Atoms that are relatively large will assume the interstitial positions and create a much greater energy disturbance in the crystal than

  6. Solar energy absorption characteristics and the effects of heat on the optical properties of several coatings

    NASA Technical Reports Server (NTRS)

    Lowery, J. R.

    1981-01-01

    The solar energy absorption characteristics of several high temperature coatings were determined and effects of heat on these coatings were evaluated. Included in the investigation were an electroplated alloy of black chrome and vanadium, electroplated black chrome, and chemically colored 316 stainless steel. Each of the coatings possessed good selective solar energy absorption properties at laboratory ambient temperature. Measured at a temperature of 700 K (800 F), the emittances of black chrome, black chrome vanadium, and colored stainless steel were 0.11, 0.61, and 0.15, respectively. Black chrome and black chrome vanadium did not degrade optically in the presence of high heat (811 K (1000 F)). Chemically colored stainless steel showed slight optical degradation when exposed to moderately high heat (616 K (650 F)0, but showed more severe degradation at exposure temperatures beyond this level. Each of the coatings showed good corrosion resistance to a salt spray environment.

  7. Production and characterization of large-area sputtered selective solar absorber coatings

    NASA Astrophysics Data System (ADS)

    Graf, Wolfgang; Koehl, Michael; Wittwer, Volker

    1992-11-01

    Most of the commercially available selective solar absorber coatings are produced by electroplating. Often the reproducibility or the durability of their optical properties is not very satisfying. Good reproducibility can be achieved by sputtering, the technique for the production of low-(epsilon) coatings for windows. The suitability of this kind of deposition technique for flat-plate solar absorber coatings based on the principle of ceramic/metal composites was investigated for different material combinations, and prototype collectors were manufactured. The optical characterization of the coatings is based on spectral measurements of the near-normal/hemispherical and the angle-dependent reflectance in the wavelength-range 0.38 micrometers - 17 micrometers . The durability assessment was carried out by temperature tests in ovens and climatic chambers.

  8. Moth eye antireflection coated GaInP/GaAs/GaInNAs solar cell

    NASA Astrophysics Data System (ADS)

    Aho, Arto; Tommila, Juha; Tukiainen, Antti; Polojärvi, Ville; Niemi, Tapio; Guina, Mircea

    2014-09-01

    The performance of a GaInP/GaAs/GaInNAs solar cell incorporating AlInP moth eye antireflection coating is reported and compared with the performance of a similar cell comprising TiO2/SiO2 antireflection coating. The moth eye coating exhibits an average reflectance of only 2% within the spectral range from 400 nm to 1600 nm. EQE measurements revealed absorption-related losses in the AlInP moth eye coating at wavelengths below 510 nm. Short wavelength absorption decreases the current generation in the top GaInP junction by 10%. Despite the absorption losses, the moth eye patterned GaInP/GaAs/GaInNAs solar cell exhibited higher current generation under AM1.5G real sun illumination.

  9. Knowledge-based optical coatings design and manufacturing

    NASA Astrophysics Data System (ADS)

    Guenther, Karl H.; Gonzalez, Avelino J.; Yoo, Hoi J.

    1990-12-01

    The theory of thin film optics is well developed for the spectral analysis of a given optical coating. The inverse synthesis - designing an optical coating for a certain spectral performance - is more complicated. Usually a multitude of theoretical designs is feasible because most design problems are over-determined with the number of layers possible with three variables each (n, k, t). The expertise of a good thin film designer comes in at this point with a mostly intuitive selection of certain designs based on previous experience and current manufacturing capabilities. Manufacturing a designed coating poses yet another subset of multiple solutions, as thin if in deposition technology has evolved over the years with a vast variety of different processes. The abundance of published literature may often be more confusing than helpful to the practicing thin film engineer, even if he has time and opportunity to read it. The choice of the right process is also severely limited by the given manufacturing hardware and cost considerations which may not easily allow for the adaption of a new manufacturing approach, even if it promises to be better technically (it ought to be also cheaper). On the user end of the thin film coating business, the typical optical designer or engineer who needs an optical coating may have limited or no knowledge at all about the theoretical and manufacturing criteria for the optimum selection of what he needs. This can be sensed frequently by overly tight tolerances and requirements for optical performance which sometimes stretch the limits of mother nature. We introduce here a know1edge-based system (KBS) intended to assist expert designers and manufacturers in their task of maximizing results and minimizing errors, trial runs, and unproductive time. It will help the experts to manipulate parameters which are largely determined through heuristic reasoning by employing artificial intelligence techniques. In a later state, the KBS will include a

  10. A handbook for solar central receiver design

    SciTech Connect

    Falcone, P.K.

    1986-12-01

    This Handbook describes central receiver technology for solar thermal power plants. It contains a description and assessment of the major components in a central receiver system configured for utility scale production of electricity using Rankine-cycle steam turbines. It also describes procedures to size and optimize a plant and discussed examples from recent system analyses. Information concerning site selection criteria, cost estimation, construction, and operation and maintenance is also included, which should enable readers to perform design analyses for specific applications.

  11. Rapid Mapping of AR Coating Thickness on Si Solar Cells Using GT-FabScan 6000

    SciTech Connect

    Sopori, B.; Amieva, J.; Butterfield, B.; Li, C.

    2005-02-01

    A new technique for rapid mapping of the thickness of an antireflection (AR) coating on a solar cell is described. A filtered, reflectance (intensity) image of the AR-coated wafer is generated by a CCD camera mounted on a GTFabScan. This image is converted into a thickness image using a transformation relating local AR thickness to the local intensity in the image plane. The thickness map is generated in <100 ms.

  12. Design of a solar tracking interactive kiosk

    NASA Astrophysics Data System (ADS)

    Greene, Nathaniel R.; Brunskill, Jeffrey C.

    2017-01-01

    A two-axis solar tracker and its interactive kiosk were designed by an interdisciplinary team of students and faculty. The objective was to develop a publicly accessible kiosk that would facilitate the study of energy usage and production on campus. Tracking is accomplished by an open-loop algorithm, microcontroller, and ham radio rotator. Solar panel output is monitored in real time and displayed to the public with lights and digits that can be read by the casual passersby. While maximum power point tracking is the most accurate means of quantifying the output power of a photovoltaic panel, simplicity and design constraints dictated the use of short-circuit current as a proxy for power. A touchscreen display allows kiosk visitors to compare two solar panels, an automatic tracker that faces the sun, and an identical panel whose elevation and azimuth can be controlled with a virtual joystick. This project was a capstone experience for students in physics/engineering, computer science, and instructional technology. We discuss technical challenges and design choices, as well as the educational goals of the kiosk.

  13. Residential Solar Design Review: A Manual on Community Architectural Controls and Solar Energy Use.

    ERIC Educational Resources Information Center

    Jaffe, Martin; Erley, Duncan

    Presented are architectural design issues associated with solar energy use, and procedures for design review committees to consider in examining residential solar installation in light of existing aesthetic goals for their communities. Recommended design review criteria include the type of solar system being used and the ways in which the system…

  14. Progress Toward Developing a Durable High-Temperature Solar Selective Coating (Poster)

    SciTech Connect

    Kennedy, C.; Price, H. W.

    2007-03-01

    Increasing the operating temperature of parabolic trough solar fields from 400 C to >450 C will increase their efficiency and reduce the cost of electricity. Current coatings do not have the stability and performance necessary to move to higher operating temperatures. The objective is to develop new, more efficient selective coatings with both high solar absoprtance ({alpha} > 0.96) and low thermal emittance ({var_epsilon} < 0.07) that are thermally stable above 450 C, ideally in air, with improved durability and manufacturability, and reduced cost.

  15. Properties of Plasma Enhanced Chemical Vapor Deposition Barrier Coatings and Encapsulated Polymer Solar Cells

    NASA Astrophysics Data System (ADS)

    Qi, Lei; Zhang, Chunmei; Chen, Qiang

    2014-01-01

    In this paper, we report silicon oxide coatings deposited by plasma enhanced chemical vapor deposition technology (PECVD) on 125 μm polyethyleneterephthalate (PET) surfaces for the purpose of the shelf lifetime extension of sealed polymer solar cells. After optimization of the processing parameters, we achieved a water vapor transmission rate (WVTR) of ca. 10-3 g/m2/day with the oxygen transmission rate (OTR) less than 0.05 cc/m2/day, and succeeded in extending the shelf lifetime to about 400 h in encapsulated solar cells. And then the chemical structure of coatings related to the properties of encapsulated cell was investigated in detail.

  16. Sputtered solar absorber coatings with high-spectral selectivity and good durability

    NASA Astrophysics Data System (ADS)

    Graf, Wolfgang; Brucker, Franz; Koehl, Michael; Troescher, Thomas; Wittwer, Volker; Blessing, Rolf; Herlitze, Lothar

    1995-08-01

    Sputtering is a well established coating technology for glass panes. This technology is also interesting for the production of selective solar absorber coatings because the environmental impact is much less than for electroplating. There are already several sputtered absorber coatings for evacuated tubular collectors existing on the market. The application in ventilated collectors requires better durability of the absorbers and a technology which can be applied to planar substrates. The coatings presented here are produced by dc-magnetron sputtering. The maximum sample size was 2 m multiplied by 3 m. A thermal emittance (at 373 K) below 5% was achieved together with a solar absorptance (AM 1.5) above 90%. The coating is deposited directly onto copper sheets without the commonly used anti-corrosion nickel coating in between. The durability of the absorbers was found to be sufficient for the application in ventilated flat-plate collectors containing moisture according to the tests and requirements proposed by Task X of the Solar Heating and Cooling Programme of the International Energy Agency.

  17. Derivation of a Levelized Cost of Coating (LCOC) metric for evaluation of solar selective absorber materials

    DOE PAGES

    Ho, C. K.; Pacheco, J. E.

    2015-06-05

    A new metric, the Levelized Cost of Coating (LCOC), is derived in this paper to evaluate and compare alternative solar selective absorber coatings against a baseline coating (Pyromark 2500). In contrast to previous metrics that focused only on the optical performance of the coating, the LCOC includes costs, durability, and optical performance for more comprehensive comparisons among candidate materials. The LCOC is defined as the annualized marginal cost of the coating to produce a baseline annual thermal energy production. Costs include the cost of materials and labor for initial application and reapplication of the coating, as well as the costmore » of additional or fewer heliostats to yield the same annual thermal energy production as the baseline coating. Results show that important factors impacting the LCOC include the initial solar absorptance, thermal emittance, reapplication interval, degradation rate, reapplication cost, and downtime during reapplication. The LCOC can also be used to determine the optimal reapplication interval to minimize the levelized cost of energy production. As a result, similar methods can be applied more generally to determine the levelized cost of component for other applications and systems.« less

  18. Derivation of a Levelized Cost of Coating (LCOC) metric for evaluation of solar selective absorber materials

    SciTech Connect

    Ho, C. K.; Pacheco, J. E.

    2015-06-05

    A new metric, the Levelized Cost of Coating (LCOC), is derived in this paper to evaluate and compare alternative solar selective absorber coatings against a baseline coating (Pyromark 2500). In contrast to previous metrics that focused only on the optical performance of the coating, the LCOC includes costs, durability, and optical performance for more comprehensive comparisons among candidate materials. The LCOC is defined as the annualized marginal cost of the coating to produce a baseline annual thermal energy production. Costs include the cost of materials and labor for initial application and reapplication of the coating, as well as the cost of additional or fewer heliostats to yield the same annual thermal energy production as the baseline coating. Results show that important factors impacting the LCOC include the initial solar absorptance, thermal emittance, reapplication interval, degradation rate, reapplication cost, and downtime during reapplication. The LCOC can also be used to determine the optimal reapplication interval to minimize the levelized cost of energy production. As a result, similar methods can be applied more generally to determine the levelized cost of component for other applications and systems.

  19. Improved perovskite film quality and solar cell performances using dual single solution coating

    NASA Astrophysics Data System (ADS)

    Baltakesmez, Ali; Biber, Mehmet; Tüzemen, Sebahattin

    2017-08-01

    In this study, we present high quality perovskite CH3NH3PbI3-xClx thin films prepared by a combination of static and dynamic coating approaches, named dual single solution coating. Static coating, dynamic coating and the combination of these are comparatively studied. Scanning electron microscopy, X-ray diffraction, atomic force microscopy, UV-visible spectroscopy, and photoluminescence techniques are used for the determination of morphological, structural, and optical properties of thin films prepared using different coating approaches and deposition temperatures. All the coating approaches are repeated at room temperature and with hot deposition. The high quality and density CH3NH3PbI3-xClx films with full surface coverage are obtained using the dual single solution coating, particularly with hot-deposition. The perovskite solar cells prepared by the dual coating approach with hot deposition have better values for all the performance parameters in comparison to the other coating approaches, resulting in high efficiencies. The best device has a short circuit current of 22.03 mA/cm2, an open circuit voltage of 0.91 V, a fill factor of 0.73, and a power conversion efficiency of 14.68% from short-circuit to forward bias, and 22.39 mA/cm2, 0.91 V, 75% and 15.32% for the vice-versa, respectively.

  20. Solar Probe thermal shield design and testing

    NASA Technical Reports Server (NTRS)

    Millard, Jerry M.; Miyake, Robert N.; Rainen, Richard A.

    1992-01-01

    This paper discusses the major thermal shield subsystem development activities in support of the Solar Probe study being conducted at JPL. The Solar Probe spacecraft will travel to within 4 solar radii of the sun's center to perform fundamental experiments in space physics. Exposure to 2900 earth suns at perihelion requires the spacecraft to be protected within the shadow envelope of a protective shield. In addition, the mass loss rate off of the shield at elevated temperature must comply with plasma instrument requirements and has become the driver of the shield design. This paper will focus on the analytical design work to size the shield and control the shield mass loss rate for the various spacecraft options under study, the application of carbon-carbon materials for shield components, development and preparation of carbon-carbon samples for materials testing, and a materials testing program for carbon-carbon and tungsten alloys to investigate thermal/optical properties, mass loss (carbon-carbon only), material integrity, and high velocity impact behavior.

  1. Solar coal gasification - Plant design and economics

    NASA Astrophysics Data System (ADS)

    Aiman, W. R.; Thorsness, C. B.; Gregg, D. W.

    A plant design and economic analysis is presented for solar coal gasification (SCG). Coal pyrolysis and char gasification to form the gasified product are reviewed, noting that the endothermic gasification reactions occur only at temperatures exceeding 1000 K, an energy input of 101-136 kJ/mol of char reformed. Use of solar heat offers the possibility of replacing fuels needed to perform the gasification and the oxygen necessary in order to produce a nitrogen-free product. Reactions, energetics, and byproducts from the gasification of subbituminous coal are modeled for a process analysis code used for the SCG plant. Gas generation is designed to occur in a unit exposed to the solar flux focus from a heliostat field. The SCG gas would have an H2 content of 88%, compared to the 55% offered by the Lurgi process. Initial capital costs for the SCG plant are projected to be 4 times those with the Lurgi process, with equality being achieved when coal costs $4/gJ.

  2. Solar Probe thermal shield design and testing

    NASA Technical Reports Server (NTRS)

    Millard, Jerry M.; Miyake, Robert N.; Rainen, Richard A.

    1992-01-01

    This paper discusses the major thermal shield subsystem development activities in support of the Solar Probe study being conducted at JPL. The Solar Probe spacecraft will travel to within 4 solar radii of the sun's center to perform fundamental experiments in space physics. Exposure to 2900 earth suns at perihelion requires the spacecraft to be protected within the shadow envelope of a protective shield. In addition, the mass loss rate off of the shield at elevated temperature must comply with plasma instrument requirements and has become the driver of the shield design. This paper will focus on the analytical design work to size the shield and control the shield mass loss rate for the various spacecraft options under study, the application of carbon-carbon materials for shield components, development and preparation of carbon-carbon samples for materials testing, and a materials testing program for carbon-carbon and tungsten alloys to investigate thermal/optical properties, mass loss (carbon-carbon only), material integrity, and high velocity impact behavior.

  3. Performance of Hydrogenated a-Si:H Solar Cells with Downshifting Coating: Preprint

    SciTech Connect

    Nemeth, B.; Xu, Y.; Wang, H.; Sun, T.; Lee, B. G.; Duda, A.; Wang, Q.

    2011-05-01

    We apply a thin luminescent downshifting (LDS) coating to a hydrogenated amorphous Si (a-Si:H) solar cell and study the mechanism of possible current enhancement. The conversion material used in this study converts wavelengths below 400 nm to a narrow line around 615 nm. This material is coated on the front of the glass of the a-Si:H solar cell with a glass/TCO/p/i/n/Ag superstrate configuration. The initial efficiency of the solar cell without the LDS coating is above 9.0 % with open circuit voltage of 0.84 V. Typically, the spectral response below 400 nm of an a-Si:H solar cell is weaker than that at 615 nm. By converting ultraviolet (UV) light to red light, the solar cell will receive more red photons; therefore, solar cell performance is expected to improve. We observe evidence of downshifting in reflectance spectra. The cell Jsc decreases by 0.13 mA/cm2, and loss mechanisms are identified.

  4. Research Update: Large-area deposition, coating, printing, and processing techniques for the upscaling of perovskite solar cell technology

    NASA Astrophysics Data System (ADS)

    Razza, Stefano; Castro-Hermosa, Sergio; Di Carlo, Aldo; Brown, Thomas M.

    2016-09-01

    To bring perovskite solar cells to the industrial world, performance must be maintained at the photovoltaic module scale. Here we present large-area manufacturing and processing options applicable to large-area cells and modules. Printing and coating techniques, such as blade coating, slot-die coating, spray coating, screen printing, inkjet printing, and gravure printing (as alternatives to spin coating), as well as vacuum or vapor based deposition and laser patterning techniques are being developed for an effective scale-up of the technology. The latter also enables the manufacture of solar modules on flexible substrates, an option beneficial for many applications and for roll-to-roll production.

  5. Material Science for High-Efficiency Photovoltaics: From Advanced Optical Coatings to Cell Design for High-Temperature Applications

    NASA Astrophysics Data System (ADS)

    Perl, Emmett Edward

    Solar cells based on III-V compound semiconductors are ideally suited to convert solar energy into electricity. The highest efficiency single-junction solar cells are made of gallium arsenide, and have attained an efficiency of 28.8%. Multiple III-V materials can be combined to construct multijunction solar cells, which have reached record efficiencies greater than 45% under concentration. III-V solar cells are also well suited to operate efficiently at elevated temperatures, due in large part to their high material quality. These properties make III-V solar cells an excellent choice for use in concentrator systems. Concentrator photovoltaic systems have attained module efficiencies that exceed 40%, and have the potential to reach the lowest levelized cost of electricity in sunny places like the desert southwest. Hybrid photovoltaic-thermal solar energy systems can utilize high-temperature III-V solar cells to simultaneously achieve dispatchability and a high sunlight-to-electricity efficiency. This dissertation explores material science to advance the state of III-V multijunction solar cells for use in concentrator photovoltaic and hybrid photovoltaic-thermal solar energy systems. The first half of this dissertation describes work on advanced optical designs to improve the efficiency of multijunction solar cells. As multijunction solar cells move to configurations with four or more subcells, they utilize a larger portion of the solar spectrum. Broadband antireflection coatings are essential to realizing efficiency gains for these state-of-the-art cells. A hybrid design consisting of antireflective nanostructures placed on top of multilayer interference-based optical coatings is developed. Antireflection coatings that utilize this hybrid approach yield unparalleled performance, minimizing reflection losses to just 0.2% on sapphire and 0.6% on gallium nitride for 300-1800nm light. Dichroic mirrors are developed for bonded 5-junction solar cells that utilize InGaN as

  6. Advanced photovoltaic solar array - Design and performance

    NASA Technical Reports Server (NTRS)

    Kurland, Richard; Stella, Paul

    1992-01-01

    This paper reports on the development of an ultralightweight flexible blanket, flatpack, foldout solar array design that can provide 3- to 4-fold improvement on specific power performance of current rigid panel arrays and a factor of two improvement over a first-generation flexible blanket array developed as a forerunner to the Space Station Freedom array. To date a prototype wing has been built with a projected specific power performance of about 138 W/kg at beginning-of-life (BOL) and 93 W/kg end-of-life (EOL) at 12 kW (BOL) for a 10-year geosynchronous (GEO) mission. The prototype wing hardware has been subjected to a series of system-level tests to demonstrate design feasibility. The design of the array is summarized. The major trade studies that led to the selection of the baseline design are discussed. Key system-level and component-level testing are described. Array-level performance projections are presented as a function of existing and advanced solar array component technology for various mission applications.

  7. Advanced photovoltaic solar array - Design and performance

    NASA Technical Reports Server (NTRS)

    Kurland, Richard; Stella, Paul

    1992-01-01

    This paper reports on the development of an ultralightweight flexible blanket, flatpack, foldout solar array design that can provide 3- to 4-fold improvement on specific power performance of current rigid panel arrays and a factor of two improvement over a first-generation flexible blanket array developed as a forerunner to the Space Station Freedom array. To date a prototype wing has been built with a projected specific power performance of about 138 W/kg at beginning-of-life (BOL) and 93 W/kg end-of-life (EOL) at 12 kW (BOL) for a 10-year geosynchronous (GEO) mission. The prototype wing hardware has been subjected to a series of system-level tests to demonstrate design feasibility. The design of the array is summarized. The major trade studies that led to the selection of the baseline design are discussed. Key system-level and component-level testing are described. Array-level performance projections are presented as a function of existing and advanced solar array component technology for various mission applications.

  8. Survey of coatings for solar collectors. [ceramic enamels and chromium

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. E.

    1974-01-01

    Ceramic enamel is found to be more solar selective, (i.e., has high solar absorptance in combination with low infrared emittance) than organic enamel, but neither is as solar selective as black chrome, black copper, black zinc, or black nickel. Ceramic enamel is matched only by black chrome in durability and wide availability. Ceramic enamel and organic enamel have approximately the same cost, and both are currently slightly lower in cost than black chrome, black copper, or black zinc. Black nickel is relatively unavailable and, because of that, realistic cost comparisons are not possible.

  9. In air durability study of solar selective coating for parabolic trough technology

    NASA Astrophysics Data System (ADS)

    Raccurt, Olivier; Matino, Francesca; Disdier, Angela; Braillon, Julien; Stollo, Alessio; Bourdon, Delphine; Maccari, Augusto

    2017-06-01

    The effectiveness of Parabolic Trough CSP (Concentrated Solar Power) is strongly dependent on the Heat Collector Element (HCE) and specifically on the thermal stability of solar absorber at high temperature. For Molten Salt applications, operative temperature up to 600°C can be reached with vacuum solar receiver tubes (HCE). Nevertheless operation in air is also possible: such operative mode requires yet a deep knowledge of the possible degradation mechanisms of the solar selective coating. Here we report on the results of the optical and thermal investigation performed by CEA LITEN on Archimede Solar Energy (ASE) absorber coating according to the established procedures and the experimental facilities settled in the framework of the STAGE-STE project. A complete study of the accelerating thermal ageing test in air at high temperatures (up to 500°C) of ASE solar absorber is presented. The relation between optical parameter, such as solar absorbance and emittance, and temperature as function of time is used to study the thermal stability of coating. To this aim, we use a performance criterion defined as the variation of solar emittance solar absorbance during the ageing test. The degradation mechanism at elevated temperatures has been identified as oxidation of the metallic part of the cermet layer, W to WO3 and WOx. By means of an Arrhenius analysis, an activation energy of approximately 150 kJ/mol is calculated for this degradation process. Such a value has been found consistent with the expects from literature. Additionally, the lifetime prediction in the case of CSP plant in Ouarzazate is presented. The results of this analysis show a good thermal stability of samples up to 375°C for 25 years of uses in CSP plants working in air.

  10. Nanostructured Semiconductor Device Design in Solar Cells

    NASA Astrophysics Data System (ADS)

    Dang, Hongmei

    We demonstrate the use of embedded CdS nanowires in improving spectral transmission loss and the low mechanical and electrical robustness of planar CdS window layer and thus enhancing the quantum efficiency and the reliability of the CdS-CdTe solar cells. CdS nanowire window layer enables light transmission gain at 300nm-550nm. A nearly ideal spectral response of quantum efficiency at a wide spectrum range provides an evidence for improving light transmission in the window layer and enhancing absorption and carrier generation in absorber. Nanowire CdS/CdTe solar cells with Cu/graphite/silver paste as back contacts, on SnO2/ITO-soda lime glass substrates, yield the highest efficiency of 12% in nanostructured CdS-CdTe solar cells. Reliability is improved by approximately 3 times over the cells with the traditional planar CdS counterpart. Junction transport mechanisms are delineated for advancing the basic understanding of device physics at the interface. Our results prove the efficacy of this nanowire approach for enhancing the quantum efficiency and the reliability in windowabsorber type solar cells (CdS-CdTe, CdS-CIGS and CdS-CZTSSe etc) and other optoelectronic devices. We further introduce MoO3-x as a transparent, low barrier back contact. We design nanowire CdS-CdTe solar cells on flexible foils of metals in a superstrate device structure, which makes low-cost roll-to-roll manufacturing process feasible and greatly reduces the complexity of fabrication. The MoO3 layer reduces the valence band offset relative to the CdTe, and creates improved cell performance. Annealing as-deposited MoO3 in N 2 reduces series resistance from 9.98 O/cm2 to 7.72 O/cm2, and hence efficiency of the nanowire solar cell is improved from 9.9% to 11%, which efficiency comparable to efficiency of planar counterparts. When the nanowire solar cell is illuminated from MoO 3-x /Au side, it yields an efficiency of 8.7%. This reduction in efficiency is attributed to decrease in Jsc from 25.5m

  11. Solar heating and cooling systems design and development

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Solar heating and heating/cooling systems were designed for single family, multifamily, and commercial applications. Subsystems considered included solar collectors, heat storage systems, auxiliary energy sources, working fluids, and supplementary controls, piping, and pumps.

  12. Design package for a solar-heating system

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Report contains sufficient information to assemble complete tested residential flat-plate solar heating system. Descriptive material provides design, performance, and hardware specifications for utilization by architectural engineers, and contractors in procurement, installation, operation, and maintenance of similar solar applications.

  13. Prototype designs for passive-solar apartments and townhouses

    NASA Astrophysics Data System (ADS)

    Kraft, D.

    1981-09-01

    Seven designs of passive solar apartments and townhouses are briefly described. Descriptions of the layouts, thermal insulation, thermal mass, source of passive solar gain, and thermal integrity factor for auxiliary heating are presented.

  14. Selective coating for solar panels. [using black chrome and black nickel

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. E. (Inventor)

    1977-01-01

    The energy absorbing properties of solar heating panels are improved by depositing a black chrome coating of controlled thickness on a specially prepared surface of a metal substrate. The surface is prepared by depositing a dull nickel on the substrate, and the black chrome is plated on this low emittance surface to a thickness between 0.5 micron and 2.5 microns.

  15. High performance anti-reflection coatings for broadband multi-junction solar cells

    SciTech Connect

    AIKEN,DANIEL J.

    2000-02-23

    The success of bandgap engineering has made high efficiency broadband multi-junction solar cells possible with photo-response out to the band edge of Ge. Modeling has been conducted which suggests that current double layer anti-reflection coating technology is not adequate for these devices in certain cases. Approaches for the development of higher performance anti-reflection coatings are examined. A new AR coating structure based on the use of Herpin equivalent layers is presented. Optical modeling suggests a decrease in the solar weighted reflectance of over 2.5{percent} absolute as a result. This structure requires no additional optical material development and characterization because no new optical materials are necessary. Experimental results and a sensitivity analysis are presented.

  16. Preparation of silver-coated glass frit and its application in silicon solar cells

    NASA Astrophysics Data System (ADS)

    Feng, Xiang; Biyuan, Li; Yingfen, Li; Jian, Zhou; Weiping, Gan

    2016-07-01

    A simple electroless plating process was employed to prepare silver-coated glass frits for solar cells. The surface of the glass frits was modified with polyvinyl-pyrrolidone (PVP) before the electroless plating process. Infrared (IR) spectroscopy, field emission scanning electron microscopy (FESEM), and x-ray diffraction (XRD) were used to characterize the PVP modified glass frits and investigate the mechanism of the modification process. It was found that the PVP molecules adsorbed on the glass frit surface and reduced the silver ions to the silver nanoparticles. Through epitaxial growth, these nanoparticles were uniformly deposited onto the surface of the glass frit. Silicon solar cells with this novel silver coating exhibited a photoelectric conversion efficiency increase of 0.33%. Compared with the electroless plating processes, this method provides a simple route to prepare silver-coated glass frits without introducing impurity ions.

  17. Systematic design assessment techniques for solar buildings

    NASA Astrophysics Data System (ADS)

    Page, J. K.; Rodgers, G. G.; Souster, C. G.

    1980-02-01

    The paper describes the various approaches developed for the detailed modelling of the relevant climatic input variables for systematic design assessments for solar housing techniques. A report is made of the techniques developed to generate systematic short wave radiation data for vertical and inclined surfaces for different types of weather. The analysis is based on different types of days, such as sunny, average and overcast. Work on the accurate estimation of the magnitude of the associated weather variables affecting heat transfer in the external environment is also reported, covering air temperature, wind speed and long wave radiation exchanges.

  18. Thermal implications of interactions between insulation, solar reflectance, and fur structure in the summer coats of diverse species of kangaroo.

    PubMed

    Dawson, Terence J; Maloney, Shane K

    2017-04-01

    Not all of the solar radiation that impinges on a mammalian coat is absorbed and converted into thermal energy at the coat surface. Some is reflected back to the environment, while another portion is reflected further into the coat where it is absorbed and manifested as heat at differing levels. Substantial insulation in a coat limits the thermal impact at the skin of solar radiation, irrespective where in the coat it is absorbed. In coats with low insulation, the zone where solar radiation is absorbed may govern the consequent heat load on the skin (HL-SR). Thin summer furs of four species of kangaroo from differing climatic zones were used to determine how variation in insulation and in coat spectral and structural characteristics influence the HL-SR. Coat depth, structure, and solar reflectance varied between body regions, as well as between species. The modulation of solar radiation and resultant heat flows in these coats were measured at low (1 m s(-1)) and high (6 m s(-1)) wind speeds by mounting them on a heat flux transducer/temperature-controlled plate apparatus in a wind tunnel. A lamp with a spectrum similar to solar radiation was used as a proxy for the sun. We established that coat insulation was largely determined by coat depth at natural fur lie, despite large variations in fibre density, fibre diameter, and fur mass. Higher wind speed decreased coat insulation, but depth still determined the overall level. A multiple regression analysis that included coat depth (insulation), fibre diameter, fibre density, and solar reflectance was used to determine the best predictors of HL-SR. Only depth and reflectance had significant impacts and both factors had negative weights, so, as either insulation or reflectance increased, HL-SR declined, the larger impact coming from coat reflectance. This reverses the pattern observed in deep coats where insulation dominates over effects of reflectance. Across all coats, as insulation declined, reflectance increased

  19. Application of amorphous carbon based materials as antireflective coatings on crystalline silicon solar cells

    NASA Astrophysics Data System (ADS)

    da Silva, D. S.; Côrtes, A. D. S.; Oliveira, M. H.; Motta, E. F.; Viana, G. A.; Mei, P. R.; Marques, F. C.

    2011-08-01

    We report on the investigation of the potential application of different forms of amorphous carbon (a-C and a-C:H) as an antireflective coating for crystalline silicon solar cells. Polymeric-like carbon (PLC) and hydrogenated diamond-like carbon films were deposited by plasma enhanced chemical vapor deposition. Tetrahedral amorphous carbon (ta-C) was deposited by the filtered cathodic vacuum arc technique. Those three different amorphous carbon structures were individually applied as single antireflective coatings on conventional (polished and texturized) p-n junction crystalline silicon solar cells. Due to their optical properties, good results were also obtained for double-layer antireflective coatings based on PLC or ta-C films combined with different materials. The results are compared with a conventional tin dioxide (SnO2) single-layer antireflective coating and zinc sulfide/magnesium fluoride (ZnS/MgF2) double-layer antireflective coatings. An increase of 23.7% in the short-circuit current density, Jsc, was obtained using PLC as an antireflective coating and 31.7% was achieved using a double-layer of PLC with a layer of magnesium fluoride (MgF2). An additional increase of 10.8% was obtained in texturized silicon, representing a total increase (texturization + double-layer) of about 40% in the short-circuit current density. The potential use of these materials are critically addressed considering their refractive index, optical bandgap, absorption coefficient, hardness, chemical inertness, and mechanical stability.

  20. Recovery Act: A Low Cost Spray Deposited Solar PV Anti-Reflection Coating Final Technical Report

    SciTech Connect

    Harvey, Michael D.

    2010-08-30

    PV module glass is typically low iron glass which exhibits extremely low absorption of light at solar wavelengths. However, reflection losses from typical high quality solar glass are about 4.5% of the input solar energy. By applying an antireflection coating to the cover glass of their modules, a PV module maker will gain at least a 3% increase in the light passing through the glass and being converted to electricity. Thus achieving an increase of >3% in electricity output from the modules. This Project focussed on developing a process that deposits a layer of porous silica (SiO2) on glass or plastic components, and testing the necessary subcomponents and subsystems required to demonstrate the commercial technology. This porous layer acts as a broadband single layer AR coating for glass and plastics, with the added benefit of being a hydrophilic surface for low surface soiling.

  1. Performance of "Moth Eye" Anti-Reflective Coatings for Solar Cell Applications

    SciTech Connect

    Clark, E.; Kane, M.; Jiang, P.

    2011-03-14

    An inexpensive, effective anti-reflective coating (ARC) has been developed at the University of Florida to significantly enhance the absorption of light by silicon in solar cells. This coating has nano-scale features, and its microstructure mimics that of various night active insects (e.g. a moth's eye). It is a square array of pillars, each about 700 nm high and having a diameter of about 300 nm. Samples of silicon having this coating were exposed either to various combinations of either elevated temperature and humidity or to gamma irradiation ({sup 60}Co) at the Savannah River National Laboratory, or to a broad spectrum ultraviolet light and to a 532 nm laser light at the University of Florida. The anti-reflective properties of the coatings were unaffected by any of these environmental stresses, and the microstructure of the coating was also unaffected. In fact, the reflectivity of the gamma irradiated ARC became lower (advantageous for solar cell applications) at wavelengths between 400 and 1000 nm. These results show that this coating is robust and should be tested in actual systems exposed to either weather or a space environment. Structural details of the ARCs were studied to optimize their performance. Square arrays performed better than hexagonal arrays - the natural moth-eye coating is indeed a square array. The optimal depth of the templated nanopillars in the ARC was investigated. A wet etching technology for ARC formation was developed that would be less expensive and much faster than dry etching. Theoretical modeling revealed that dimple arrays should perform better than nipple arrays. A method of fabricating both dimple and nipple arrays having the same length was developed, and the dimple arrays performed better than the nipple arrays, in agreement with the modeling. The commercial viability of the technology is quite feasible, since the technology is scalable and inexpensive. This technology is also compatible with current industrial fabrication of

  2. Design fabrication and testing of ceramic solar absorber plates

    SciTech Connect

    Sisson, J.C.

    1983-01-01

    The effects of fabrication procedures on the thermal performance of various ceramic systems for active solar applications were investigated. A shale-based structural clay body was used as a standard. This body was also coated with silicon carbide, a glossy black glaze and a matte black glaze. Metal samples used included copper, aluminum and aluminum coated with a flat black paint. Experiments were performed using a solar test box linked to an automated data acquisition system. Temperatures of samples were recorded at 3 min. intervals for 4 h solar periods. An F-statistical analysis was performed on the resulting data and was correlated with total solar emittance, total solar reflectance and monochromatic reflectance as a function of incident wavelength. The information above was also utilized in developing a computer model used to simulate the performance of various materials in active solar testing. Results suggest that a structural clay body fired to maturity and coated with a matte black glaze could be commercially useful for applications requiring large quantities of heated water.

  3. User participation in passive solar housing design

    SciTech Connect

    McLain-Kark, J.H.

    1985-01-01

    A field study was conducted in 1984 in order to compare the characteristics, lifestyle, attitudes, and behavioral adaptations of two groups of passive solar homeowners, those with high or low levels of participation in the design and/or building process. Forty-one Virginia passive solar homeowners were surveyed and interviewed in their home. Photographic slides and floor plans with furniture layout were also analyzed. The results indicate that the owner-built homeowners or those with high participation in design and/or building were older, more educated, and were more involved in community affairs than the low participation homeowners. They also were more involved in maintenance tasks, more likely to engage in a voluntary simplicity lifestyle, and more energy conserving. The owner-builders too had a higher level of satisfaction with their home. The majority of the homeowners expressed dissatisfaction with the flexibility of arranging furniture in the open plan. An analysis of the floor plans revealed that three factors were contributing to the problems: zones, circulation/furniture arrangement, and passive elements.

  4. POSS(Registered TradeMark) Coatings for Solar Cells: An Update

    NASA Technical Reports Server (NTRS)

    Brandhorst, Henry; Isaacs-Smith, Tamara; Wells, Brian; Lichtenhan, Joseph D.; Fu, Bruce X.

    2007-01-01

    Presently, solar cells are covered with Ce-doped microsheet cover glasses that are attached with Dow Corning DC 93-500 silicone adhesive. Various antireflection coatings are often applied to the cover glass to increase cell performance. This general approach has been used from the beginning of space exploration. However, it is expensive and time consuming. Furthermore, as the voltage of solar arrays increases, significant arcing has occurred in solar arrays, leading to loss of satellite power. The cause has been traced to differential voltages between strings and the close spacing between them with no insulation covering the edges of the solar cells. In addition, this problem could be ameliorated if the cover glass extended over the edges of the cell, but this would impact packing density. An alternative idea that might solve all these issues and be less expensive and more protective is to develop a coating that could be applied over the entire array. Such a coating must be resistant to atomic oxygen for low earth orbits below about 700 km, it must be resistant to ultraviolet radiation for all earth and near-sun orbits and, of course, it must withstand the damaging effects of space radiation. Coating flexibility would be an additional advantage. Based on past experience, one material that has many of the desired attributes of a universal protective coating is the Dow Corning DC 93-500. Of all the potential optical plastics, it appears to be the most suitable for use in space. As noted above, DC 93-500 has been extensively used to attach cover glasses to crystalline solar cells and has worked exceptionally well over the years. It is flexible and generally resistant to electrons, protons and ultraviolet (UV and VUV) radiation; although a VUV-rejection coating or VUV-absorbing ceria-doped cover glass may be required for long mission durations. It can also be applied in a thin coating (< 25 m) by conventional liquid coating processes. Unfortunately, when exposed to

  5. SEPS solar array design and technology evaluation. [Solar Electric Propulsion Stage

    NASA Technical Reports Server (NTRS)

    Elms, R. V., Jr.; Young, L. E.

    1975-01-01

    The solar array system considered is composed of two wings. Each wing consists of a solar array blanket, a blanket launch storage container, an extension/retraction mast assembly, a blanket tensioning system, and an array electrical harness. A technology evaluation is performed to assess the applicable solar array state-of-the-art and to define the supporting effort necessary to achieve technology readiness for meeting the Solar Electric Propulsion Stage (SEPS) solar array design requirements. Details of mechanical design are discussed along with questions of electrical design, operational reliability advantages, and array assembly advantages.

  6. Enhanced Erbium-Doped Ceria Nanostructure Coating to Improve Solar Cell Performance.

    PubMed

    Shehata, Nader; Clavel, Michael; Meehan, Kathleen; Samir, Effat; Gaballah, Soha; Salah, Mohammed

    2015-11-12

    This paper discusses the effect of adding reduced erbium-doped ceria nanoparticles (REDC NPs) as a coating on silicon solar cells. Reduced ceria nanoparticles doped with erbium have the advantages of both improving conductivity and optical conversion of solar cells. Oxygen vacancies in ceria nanoparticles reduce Ce(4+) to Ce(3+) which follow the rule of improving conductivity of solar cells through the hopping mechanism. The existence of Ce(3+) helps in the down-conversion from 430 nm excitation to 530 nm emission. The erbium dopant forms energy levels inside the low-phonon ceria host to up-convert the 780 nm excitations into green and red emissions. When coating reduced erbium-doped ceria nanoparticles on the back side of a solar cell, a promising improvement in the solar cell efficiency has been observed from 15% to 16.5% due to the mutual impact of improved electric conductivity and multi-optical conversions. Finally, the impact of the added coater on the electric field distribution inside the solar cell has been studied.

  7. Preliminary design package for Sunair SEC-601 solar collector

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The preliminary design of the Owens-Illinois model Sunair SEC-601 tubular air solar collector is presented. Information in this package includes the subsystem design and development approaches, hazard analysis, and detailed drawings available as the preliminary design review.

  8. Development of a Long-Life-Cycle, Highly Water-Resistant Solar Reflective Retrofit Roof Coating

    SciTech Connect

    Polyzos, Georgios; Hunter, Scott; Sharma, Jaswinder; Cheng, Mengdawn; Chen, Sharon S.; Demarest, Victoria; Fabiny, William; Destaillats, Hugo; Levinson, Ronnen

    2016-03-04

    Highly water-resistant and solar-reflective coatings for low-slope roofs are potentially among the most economical retrofit approaches to thermal management of the building envelope. Therefore, they represent a key building technology research program within the Department of Energy. Research efforts in industry and the Department of Energy are currently under way to increase long-term solar reflectance on a number of fronts. These include new polymer coatings technologies to provide longer-lasting solar reflectivity and improved test methodologies to predict long-term soiling and microbial performance. The focus on long-term improvements in soiling and microbial resistance for maximum reflectance does not address the single most important factor impacting the long-term sustainability of low-slope roof coatings: excellent water resistance. The hydrophobic character of asphaltic roof products makes them uniquely suitable for water resistance, but their low albedo and poor exterior durability are disadvantages. A reflective coating that maintains very high water resistance with increased long-term resistance to soiling and microbial activity would provide additional energy savings and extend roof service life.

  9. Variable Emittance Electrochromics Using Ionic Electrolytes and Low Solar Absorptance Coatings

    NASA Technical Reports Server (NTRS)

    Chandrasekhar, Prasanna

    2011-01-01

    One of the last remaining technical hurdles with variable emittance devices or skins based on conducting polymer electrochromics is the high solar absorptance of their top surfaces. This high solar absorptance causes overheating of the skin when facing the Sun in space. Existing technologies such as mechanical louvers or loop heat pipes are virtually inapplicable to micro (< 20 kg) and nano (< 5 kg) spacecraft. Novel coatings lower the solar absorption to Alpha(s) of between 0.30 and 0.46. Coupled with the emittance properties of the variable emittance skins, this lowers the surface temperature of the skins facing the Sun to between 30 and 60 C, which is much lower than previous results of 100 C, and is well within acceptable satellite operations ranges. The performance of this technology is better than that of current new technologies such as microelectromechanical systems (MEMS), electrostatics, and electrophoretics, especially in applications involving micro and nano spacecraft. The coatings are deposited inside a high vacuum, layering multiple coatings onto the top surfaces of variable emittance skins. They are completely transparent in the entire relevant infrared region (about 2 to 45 microns), but highly reflective in the visible-NIR (near infrared) region of relevance to solar absorptance.

  10. Electroless (autocatalytic) nickel-cobalt thin films as solar control coatings

    SciTech Connect

    John, S.; Srinivasan, K.N.; Selvam, M.; Anuradha, S.; Rajendran, S.

    1994-12-31

    This paper describes the deposition of nickel-cobalt-phosphorus coatings by the electroless deposition technique for use as solar control coatings in architectural glazing of buildings. Electroless deposition is characterized by the autocatalytic deposition of a metal/alloy from an aqueous solution of its ions by interaction with a chemical reducing agent. The reducing agent provides electrons for the metal ions to be neutralized. The reduction is initiated by the catalyzed surface of the substrate and continued by the self catalytic activity of the deposited metal/alloy as long as the substrate is immersed in the electroless bath and operating conditions are maintained. Electroless nickel-cobalt-phosphorus thin films were deposited from a solution containing 15 g/l nickel sulphate, 5 g/l cobalt sulphate, 60 g/l ammonium citrate and 25 g/l sodium hypophosphite operating at 30 C, at a pH of 9.5 for two minutes. Electroless nickel-cobalt-phosphorus coatings are found to satisfy the basic requirements of solar control coatings. Autocatalytic deposition technique offers the possibilities of producing large area coatings with low capital investment, stability and good adhesion to glass substrates.

  11. A gravity gradient stabilized solar power satellite design

    NASA Technical Reports Server (NTRS)

    Bowden, M. L.

    1981-01-01

    The concept of a solar power satellite (SPS) is reviewed, and a design proposed for such a satellite taking advantage of solar radiation pressure and gravity gradient forces to eliminate much of the structure from the baseline configuration. The SPS design consists of a solar cell array lying in the orbital plane and a free floating mirror above to reflect sunlight down onto it. The structural modes of the solar cell array are analyzed and found to be well within control limitations. Preliminary calculations concerning the free floating mirror and its position-keeping propellant requirements are also performed. A numerical example is presented, which shows that, even in terms of mass only, this configuration is a competitive design when compared to the conventional Department of Energy reference design. Other advantages, such as easier assembly in orbit, lower position-keeping propellant requirements, possibilities for decreasing necessary solar cell area, and longer solar cell life, may make this design superior.

  12. A software tool to design thermal barrier coatings

    NASA Technical Reports Server (NTRS)

    Petrus, G.; Ferguson, B. L.

    1995-01-01

    This paper summarizes work completed for a NASA Phase 1 SBIR program which demonstrated the feasibility of developing a software tool to aid in the design of thermal barrier coating (TBC) systems. Toward this goal, three tasks were undertaken and completed. Task 1 involved the development of a database containing the pertinent thermal and mechanical property data for the top coat, bond coat and substrate materials that comprise a TBC system. Task 2 involved the development of an automated set-up program for generating two dimensional (2D) finite element models of TBC systems. Most importantly, Task 3 involved the generation of a rule base to aid in the design of a TBC system. These rules were based on a factorial design of experiments involving FEM results, and were generated using a Yates analysis. A previous study has indicated the suitability and benefit of applying finite element analysis to perform computer based experiments to decrease but not eliminate physical experiments on TBC's. This program proved feasibility by expanding on these findings by developing a larger knowledge base and developing a procedure to extract rules to aid in TBC design.

  13. A software tool to design thermal barrier coatings

    NASA Technical Reports Server (NTRS)

    Petrus, Gregory; Ferguson, B. Lynn

    1995-01-01

    This paper summarizes work completed for a NASA Phase 1 SBIR program which demonstrated the feasibility of developing a software tool to aid in the design of thermal barrier coating (TBC) systems. Toward this goal, three tasks were undertaken and completed. Task 1 involved the development of a database containing the pertinent thermal and mechanical property data for the top coat, bond coat and substrate materials that comprise a TBC system. Task 2 involved the development of an automated set-up program for generating two dimensional (2D) finite element models of TBC systems. Most importantly, task 3 involved the generation of a rule base to aid in the design of a TBC system. These rules were based on a factorial design of experiments involving FEM results and were generated using a Yates analysis. A previous study had indicated the suitability and benefit of applying finite element analysis to perform computer based experiments to decrease but not eliminate physical experiments on TBC's. This program proved feasibility by expanding on these findings by developing a larger knowledgebase and developing a procedure to extract rules to aid in TBC design.

  14. Design Rules and Scaling for Solar Sails

    NASA Technical Reports Server (NTRS)

    Zeiders, Glenn W.

    2005-01-01

    Useful design rules and simple scaling models have been developed for solar sails. Chief among the conclusions are: 1. Sail distortions contribute to the thrust and moments primarily though the mean squared value of their derivatives (slopes), and the sail behaves like a flat sheet if the value is small. The RMS slope is therefore an important figure of merit, and sail distortion effects on the spacecraft can generally be disregarded if the RMS slope is less than about 10% or so. 2. The characteristic slope of the sail distortion varies inversely with the tension in the sail, and it is the tension that produces the principle loading on the support booms. The tension is not arbitrary, but rather is the value needed to maintain the allowable RMS slope. That corresponds to a halyard force about equal to three times the normal force on the supported sail area. 3. Both the AEC/SRS and L Garde concepts appear to be structurally capable of supporting sail sizes up to a kilometer or more with 1AU solar flux, but select transverse dimensions must be changed to do so. Operational issues such as fabrication, handling, storage and deployment will be the limiting factors.

  15. Solar absorptance and thermal emittance of some common spacecraft thermal-control coatings

    NASA Technical Reports Server (NTRS)

    Henninger, J. H.

    1984-01-01

    Solar absorptance and thermal emittance of spacecraft materials are critical parameters in determining spacecraft temperature control. Because thickness, surface preparation, coatings formulation, manufacturing techniques, etc. affect these parameters, it is usually necessary to measure the absorptance and emittance of materials before they are used. Absorptance and emittance data for many common types of thermal control coatings, are together with some sample spectral data curves of absorptance. In some cases for which ultraviolet and particle radiation data are available, the degraded absorptance and emittance values are also listed.

  16. Thermal and optical analysis of selective absorber coatings based on soot for applications in solar cookers

    NASA Astrophysics Data System (ADS)

    Servín, H.; Peña, M.; Sobral, H.; González, M.

    2017-01-01

    The thermal and optical properties of selective absorber coatings of a solar cooker have been investigated. Coatings have been prepared using soot from pine resin, wood stove and sugarcane, previously separated by size. Results show that the cooking power and the overall efficiency of these pots are higher than others painted with black primer. Besides, by using an integrating sphere, the diffuse reflectance of absorbers has been obtained. Lower values of the reflectance have been measured for the pots covered with soot, showing a high correlation with the results achieved from the thermal tests, considering the measurement errors.

  17. Design and measured performance of a solar chimney for natural circulation solar energy dryers

    SciTech Connect

    Ekechukwu, O.V.; Norton, B.

    1996-02-01

    An experimental solar chimney consisted of a cylindrical polyethylene-clad vertical chamber supported by steel framework and draped internally with a selectively absorbing surface. The performance of the chimney which was monitored extensively is reported. Issues related to the design and construction of solar chimneys for natural circulation solar energy dryers are discussed.

  18. Dip coating process: Silicon sheet growth development for the large-area silicon sheet task of the low-cost silicon solar array project

    NASA Technical Reports Server (NTRS)

    Heaps, J. D.; Maciolek, R. B.; Zook, J. D.; Harrison, W. B.; Scott, M. W.; Hendrickson, G.; Wolner, H. A.; Nelson, L. D.; Schuller, T. L.; Peterson, A. A.

    1976-01-01

    The technical and economic feasibility of producing solar cell quality sheet silicon by dip-coating one surface of carbonized ceramic substrates with a thin layer of large grain polycrystalline silicon was investigated. The dip-coating methods studied were directed toward a minimum cost process with the ultimate objective of producing solar cells with a conversion efficiency of 10% or greater. The technique shows excellent promise for low cost, labor-saving, scale-up potentialities and would provide an end product of sheet silicon with a rigid and strong supportive backing. An experimental dip-coating facility was designed and constructed, several substrates were successfully dip-coated with areas as large as 25 sq cm and thicknesses of 12 micron to 250 micron. There appears to be no serious limitation on the area of a substrate that could be coated. Of the various substrate materials dip-coated, mullite appears to best satisfy the requirement of the program. An inexpensive process was developed for producing mullite in the desired geometry.

  19. Solar Systems

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The solar collectors shown are elements of domestic solar hot water systems produced by Solar One Ltd., Virginia Beach, Virginia. Design of these systems benefited from technical expertise provided Solar One by NASA's Langley Research Center. The company obtained a NASA technical support package describing the d e sign and operation of solar heating equipment in NASA's Tech House, a demonstration project in which aerospace and commercial building technology are combined in an energy- efficient home. Solar One received further assistance through personal contact with Langley solar experts. The company reports that the technical information provided by NASA influenced Solar One's panel design, its selection of a long-life panel coating which increases solar collection efficiency, and the method adopted for protecting solar collectors from freezing conditions.

  20. Improvements In solar dry kiln design

    Treesearch

    E. M. Wengert

    1971-01-01

    Interest in solar drying of lumber has increased in recent years because previous results had indicated that: Drying times are shorter and final moisture contents are lower in solar drying than in air drying; much less lumber degrade occurs in solar drying when compared to air drying; and the cost of energy is less in solar drying than in kiln drying. Work in the field...

  1. Large integrated absorption enhancement in plasmonic solar cells by combining metallic gratings and antireflection coatings.

    PubMed

    Munday, Jeremy N; Atwater, Harry A

    2011-06-08

    We describe an ultrathin solar cell architecture that combines the benefits of both plasmonic photovoltaics and traditional antireflection coatings. Spatially resolved electron generation rates are used to determine the total integrated current improvement under AM1.5G solar illumination, which can reach a factor of 1.8. The frequency-dependent absorption is found to strongly correlate with the occupation of optical modes within the structure, and the improved absorption is mainly attributed to improved coupling to guided modes rather than localized resonant modes.

  2. Development of processing procedures for advanced silicon solar cells. [antireflection coatings and short circuit currents

    NASA Technical Reports Server (NTRS)

    Scott-Monck, J. A.; Stella, P. M.; Avery, J. E.

    1975-01-01

    Ten ohm-cm silicon solar cells, 0.2 mm thick, were produced with short circuit current efficiencies up to thirteen percent and using a combination of recent technical advances. The cells were fabricated in conventional and wraparound contact configurations. Improvement in cell collection efficiency from both the short and long wavelengths region of the solar spectrum was obtained by coupling a shallow junction and an optically transparent antireflection coating with back surface field technology. Both boron diffusion and aluminum alloying techniques were evaluated for forming back surface field cells. The latter method is less complicated and is compatible with wraparound cell processing.

  3. Antireflective coatings for multijunction solar cells under wide-angle ray bundles.

    PubMed

    Victoria, Marta; Domínguez, César; Antón, Ignacio; Sala, Gabriel

    2012-03-26

    Two important aspects must be considered when optimizing antireflection coatings (ARCs) for multijunction solar cells to be used in concentrators: the angular light distribution over the cell created by the particular concentration system and the wide spectral bandwidth the solar cell is sensitive to. In this article, a numerical optimization procedure and its results are presented. The potential efficiency enhancement by means of ARC optimization is calculated for several concentrating PV systems. In addition, two methods for ARCs direct characterization are presented. The results of these show that real ARCs slightly underperform theoretical predictions.

  4. Process and design considerations for high-efficiency solar cells

    NASA Technical Reports Server (NTRS)

    Rohati, A.; Rai-Choudhury, P.

    1985-01-01

    This paper shows that oxide surface passivation coupled with optimum multilayer anti-reflective coating can provide approx. 3% (absolute) improvement in solar cell efficiency. Use of single-layer AR coating, without passivation, gives cell efficiencies in the range of 15 to 15.5% on high-quality, 4 ohm-cm as well as 0.1 to 0.2 ohm-cm float-zone silicon. Oxide surface passivation alone raises the cell efficiency to or = 17%. An optimum double-layer AR coating on oxide-passivated cells provides an additional approx. 5 to 10% improvement over a single-layer AR-coated cell, resulting in cell efficiencies in excess of 18%. Experimentally observed improvements are supported by model calculations and an approach to or = 20% efficient cells is discussed.

  5. Optimization of textured-dielectric coatings for crystalline-silicon solar cells

    SciTech Connect

    Gee, J.M.; Gordon, R.; Liang, H.

    1996-07-01

    The authors report on the optimization of textured-dielectric coatings for reflectance control in crystalline-silicon (c-Si) photovoltaic modules. Textured-dielectric coatings reduce encapsulated-cell reflectance by promoting optical confinement in the module encapsulation; i.e., the textured-dielectric coating randomizes the direction of rays reflected from the dielectric and from the c-Si cell so that many of these reflected rays experience total internal reflection at the glass-air interface. Some important results of this work include the following: the authors demonstrated textured-dielectric coatings (ZnO) deposited by a high-throughput low-cost deposition process; they identified factors important for achieving necessary texture dimensions; they achieved solar-weighted extrinsic reflectances as low as 6% for encapsulated c-Si wafers with optimized textured-ZnO coatings; and they demonstrated improvements in encapsulated cell performance of up to 0.5% absolute compared to encapsulated planar cells with single-layer antireflection coatings.

  6. Photothermal Determination of Infrared Emissivity of Selective Solar Absorbing Coatings

    NASA Astrophysics Data System (ADS)

    Macias, J. D.; Ordonez-Miranda, J.; Lizama-Tzec, F. I.; Arés, O.; Bante-Guerra, J.; Oskam, G.; de Coss, R.; Alvarado-Gil, J. J.

    2015-06-01

    The infrared emissivity of glassy carbon, stainless steel, and stainless steel with a selective coating of NiNiO has been determined using a thermal-wave resonant cavity heated with a modulated laser beam. This is achieved performing a length scan of the cavity at a fixed frequency of 5 Hz. It is observed experimentally that (1) the mechanisms of heat conduction and radiation co-exist inside the cavity, through the coupling of the dc and ac components of the temperature, and (2) the radiation effect shows up in both the amplitude and phase signals for cavity thicknesses greater than the diffusion length of the intra-cavity air. Using a suitable theoretical model, the experimental data for the amplitude and phase have allowed the determination of the infrared emissivity of the studied materials.

  7. Design Rules for Efficient Organic Solar Cells

    NASA Astrophysics Data System (ADS)

    Zhu, Z.; Mühlbacher, D.; Morana, M.; Koppe, M.; Scharber, M. C.; Waller, D.; Dennler, G.; Brabec, C. J.

    There has been an intensive search for cost-effective photovoltaics since the development of the first solar cells in the 1950s [1-3]. Among all the alternative technologies to silicon-based pn-junction solar cells, organic solar cells are the approach that could lead to the most significant cost reduction [4]. The field of organic photovoltaics (OPV) is composed of organic/inorganic nanostructures, like the dyesensitized solar cell, multilayers of small organic molecules and mixtures of organic materials (bulk-heterojunction solar cell). A review of several so-called organic photovoltaic (OPV) technologies was recently presented [5].

  8. LDEF (Prelaunch), S1002 : Investigation of Critical Surface Degradation Effects on Coating and Solar

    NASA Technical Reports Server (NTRS)

    1984-01-01

    LDEF (Prelaunch), S1002 : Investigation of Critical Surface Degradation Effects on Coating and Solar Cells Developed in Germany, Tray E03 The prelaunch photograph provides a view of the two (2) experiments located in a six (6) inch LDEF experiment tray. The A0187-02 is located in the right two thirds (2/3rd) of the tray and the EECC containing the S1002 experiment occupies the remaining section. The tan colored strips on the tray flanges are protective coatings that are removed prior to tray testing. S1002 - The Effects on Coatings and Solar Cells experiment is contained within the Experiment Exposure Control Canister (EECC) that is located in the left one third (1/3rd) of the experiment tray. The EECC hardware consists of the housing, the drawer that contains the experiment samples, the drawer opening and closing mechanism (a screw drive system) and chromic anodized aluminum thermal covers that are seen in the photograph. The hardware is fabricated from aluminum or non-magnetic steels and is assembled with non-magnetic stainless steel fasteners. The canister will be opened in orbit after the LDEF has been deployed, the Orbiter has departed and initial outgassing of materials on the LDEF has occurred. The canister is programmed to close approximately nine (9) months after opening and prior to the scheduled LDEF retrieval. Experiment samples located in the EECC consist of Second Surface Mirrors (SSM), SSM with Interference Filters (SSM/IF), SSM/IF with a Conductive Layer (SSM/IF/LS, Optical Solar Reflectors (OSR), Quartz Crystal Microbalance (QCM), Coatings and Solar Cell Modules of the types flown on the GEOS and OTS satellites.

  9. Design and production of antireflection coating for the 8-10 µm spectral region.

    PubMed

    Tikhonravov, A V; Zhupanov, V G; Fedoseev, V N; Trubetskov, M K

    2014-12-29

    A special design procedure allowing to trap layer thicknesses inside specified limits is applied for designing of antireflection coating (AR) for the infrared spectral band of 8-10 µm. The obtained AR design has no too thick layers that may cause delaminating of the deposited AR coating. A special monitoring procedure taking into account wavelength positions of monitoring signal extrema is applied for coating deposition. The manufactured coating features excellent AR properties in the requested spectral region and possesses high mechanical stability.

  10. Applications of ``PV Optics`` for solar cell and module design

    SciTech Connect

    Sopori, B.L.; Madjdpour, J.; Chen, W.

    1998-09-01

    This paper describes some applications of a new optics software package, PV Optics, developed for the optical design of solar cells and modules. PV Optics is suitable for the analysis and design of both thick and thin solar cells. It also includes a feature for calculation of metallic losses related to contacts and back reflectors.

  11. The effect of leveling coatings on the atomic oxygen durability of solar concentrator surfaces

    NASA Technical Reports Server (NTRS)

    Degroh, Kim K.; Dever, Therese M.; Quinn, William F.

    1990-01-01

    Space power systems for Space Station Freedom will be exposed to the harsh environment of low earth orbit (LEO). Neutral atomic oxygen is the major constituent in LEO and has the potential of severely reducing the efficiency of solar dynamic power systems through degradation of the concentrator surfaces. Several transparent dielectric thin films have been found to provide atomic oxygen protection, but atomic oxygen undercutting at inherent defect sites is still a threat to solar dynamic power system survivability. Leveling coatings smooth microscopically rough surfaces, thus eliminating potential defect sites prone to oxidation attack on concentrator surfaces. The ability of leveling coatings to improve the atomic oxygen durability of concentrator surfaces was investigated. The application of a EPO-TEK 377 epoxy leveling coating on a graphite epoxy substrate resulted in an increase in solar specular reflectance, a decrease in the atomic oxygen defect density by an order of magnitude and a corresponding order of magnitude decrease in the percent loss of specular reflectance during atomic oxygen plasma ashing.

  12. The effect of leveling coatings on the atomic oxygen durability of solar concentrator surfaces

    SciTech Connect

    Degroh, K.K.; Dever, T.M.; Quinn, W.F.

    1990-04-01

    Space power systems for Space Station Freedom will be exposed to the harsh environment of low earth orbit (LEO). Neutral atomic oxygen is the major constituent in LEO and has the potential of severely reducing the efficiency of solar dynamic power systems through degradation of the concentrator surfaces. Several transparent dielectric thin films have been found to provide atomic oxygen protection, but atomic oxygen undercutting at inherent defect sites is still a threat to solar dynamic power system survivability. Leveling coatings smooth microscopically rough surfaces, thus eliminating potential defect sites prone to oxidation attack on concentrator surfaces. The ability of leveling coatings to improve the atomic oxygen durability of concentrator surfaces was investigated. The application of a EPO-TEK 377 epoxy leveling coating on a graphite epoxy substrate resulted in an increase in solar specular reflectance, a decrease in the atomic oxygen defect density by an order of magnitude and a corresponding order of magnitude decrease in the percent loss of specular reflectance during atomic oxygen plasma ashing.

  13. Combined Effects of Pyramid-Like Structures and Antireflection Coating on Si Solar Cell Efficiency.

    PubMed

    Cho, Chanseob; Oh, Junghwa; Lee, Byeungleul; Kim, Bonghwan

    2015-10-01

    We developed a novel process for synthesizing Si solar cells with improved efficiencies. The process involved the formation of pyramid-like structures on the Si substrate and the deposition and subsequent thermal annealing of an antireflection coating. The process consisted of three main stages. First, pyramid-like structures were textured on the Si substrate by reactive ion etching and subsequently etched using a mixture of HF, HNO3, and deionized water for 300 s. Next, an antireflection coating was deposited on the substrate and was subsequently thermally annealed in a furnace in a N2 atmosphere. After the annealing process, the minority carrier lifetime increased by approximately 40 μs. Further, because of the increase in the minority carrier lifetime and the uniform doping of the substrate, the leakage current decreased. As a result, the efficiency of resulting solar cell increased to 17.24%, in contrast to that of the reference cell, which was only 15.89%. Thus, uniform doping and the thermal annealing of the antireflective coating improved solar cell efficiency.

  14. Preliminary design activities for solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Information on the development of solar heating and cooling systems is presented. The major emphasis is placed on program organization, system size definition, site identification, system approaches, heat pump and equipment design, collector procurement, and other preliminary design activities.

  15. Design and installation package for a solar powered pump

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The design and installation procedures of a solar powered pump developed by Calmac Manufacturing Company are presented. Subsystem installation, operation and maintenance requirements, subsystem performance specifications, and detailed design drawings are included.

  16. Titanium dioxide antireflection coating for silicon solar cells by spray deposition

    NASA Technical Reports Server (NTRS)

    Kern, W.; Tracy, E.

    1980-01-01

    A high-speed production process is described for depositing a single-layer, quarter-wavelength thick antireflection coating of titanium dioxide on metal-patterned single-crystal silicon solar cells for terrestrial applications. Controlled atomization spraying of an organotitanium solution was selected as the most cost-effective method of film deposition using commercial automated equipment. The optimal composition consists of titanium isopropoxide as the titanium source, n-butyl acetate as the diluent solvent, sec-butanol as the leveling agent, and 2-ethyl-1-hexanol to render the material uniformly depositable. Application of the process to the coating of circular, large-diameter solar cells with either screen-printed silver metallization or with vacuum-evaporated Ti/Pd/Ag metallization showed increases of over 40% in the electrical conversion efficiency. Optical characteristics, corrosion resistance, and several other important properties of the spray-deposited film are reported. Experimental evidence indicates a wide tolerance in the coating thickness upon the overall efficiency of the cell. Considerations pertaining to the optimization of AR coatings in general are discussed, and a comprehensive critical survey of the literature is presented.

  17. Titanium dioxide antireflection coating for silicon solar cells by spray deposition

    NASA Technical Reports Server (NTRS)

    Kern, W.; Tracy, E.

    1980-01-01

    A high-speed production process is described for depositing a single-layer, quarter-wavelength thick antireflection coating of titanium dioxide on metal-patterned single-crystal silicon solar cells for terrestrial applications. Controlled atomization spraying of an organotitanium solution was selected as the most cost-effective method of film deposition using commercial automated equipment. The optimal composition consists of titanium isopropoxide as the titanium source, n-butyl acetate as the diluent solvent, sec-butanol as the leveling agent, and 2-ethyl-1-hexanol to render the material uniformly depositable. Application of the process to the coating of circular, large-diameter solar cells with either screen-printed silver metallization or with vacuum-evaporated Ti/Pd/Ag metallization showed increases of over 40% in the electrical conversion efficiency. Optical characteristics, corrosion resistance, and several other important properties of the spray-deposited film are reported. Experimental evidence indicates a wide tolerance in the coating thickness upon the overall efficiency of the cell. Considerations pertaining to the optimization of AR coatings in general are discussed, and a comprehensive critical survey of the literature is presented.

  18. Designing energy dissipation properties via thermal spray coatings

    SciTech Connect

    Brake, Matthew R. W.; Hall, Aaron Christopher; Madison, Jonathan D.

    2016-12-14

    The coefficient of restitution is a measure of energy dissipation in a system across impact events. Often, the dissipative qualities of a pair of impacting components are neglected during the design phase. This research looks at the effect of applying a thin layer of metallic coating, using thermal spray technologies, to significantly alter the dissipative properties of a system. We studied the dissipative properties across multiple impacts in order to assess the effects of work hardening, the change in microstructure, and the change in surface topography. The results of the experiments indicate that any work hardening-like effects are likely attributable to the crushing of asperities, and the permanent changes in the dissipative properties of the system, as measured by the coefficient of restitution, are attributable to the microstructure formed by the thermal spray coating. Furthermore, the microstructure appears to be robust across impact events of moderate energy levels, exhibiting negligible changes across multiple impact events.

  19. Shuttle Engine Designs Revolutionize Solar Power

    NASA Technical Reports Server (NTRS)

    2014-01-01

    The Space Shuttle Main Engine was built under contract to Marshall Space Flight Center by Rocketdyne, now part of Pratt & Whitney Rocketdyne (PWR). PWR applied its NASA experience to solar power technology and licensed the technology to Santa Monica, California-based SolarReserve. The company now develops concentrating solar power projects, including a plant in Nevada that has created 4,300 jobs during construction.

  20. Solar Orbiter- Solar Array- Thermal Design for an Extreme Temperature Mission

    NASA Astrophysics Data System (ADS)

    Muller, Jens; Paarmann, Carola; Lindner, Anton; Kreutz, Martin; Oberhuttinger, Carola; Costello, Ian; Icardi, Lidia

    2014-08-01

    The Solar Orbiter mission is an interdisciplinary mission to the sun, carried out by ESA in collaboration with NASA. The spacecraft will approach the sun close to 0.28 AU. At this distance, the solar array has to be operated under high solar array inclination angles to limit the temperatures to a maximum qualification temperature of 200°C for the photo voltaic assembly (PVA). Nevertheless, extreme temperatures appear at specific locations of the solar array which require purpose-built temperature protection measures. A very specific thermal protection is needed to keep the PVA and its supporting structures within the qualified temperature range and simultaneously minimize the thermal flux into the spacecraft.This paper describes the Solar Orbiter solar array design in general and its specific thermal design in particular. It describes the interdisciplinary steps between thermal- and mechanical analysis as well as design engineering necessary to result to the different shielding methods.

  1. TiO2-Coated Carbon Nanotube-Silicon Solar Cells with Efficiency of 15%

    PubMed Central

    Shi, Enzheng; Zhang, Luhui; Li, Zhen; Li, Peixu; Shang, Yuanyuan; Jia, Yi; Wei, Jinquan; Wang, Kunlin; Zhu, Hongwei; Wu, Dehai; Zhang, Sen; Cao, Anyuan

    2012-01-01

    Combining carbon nanotubes (CNTs), graphene or conducting polymers with conventional silicon wafers leads to promising solar cell architectures with rapidly improved power conversion efficiency until recently. Here, we report CNT-Si junction solar cells with efficiencies reaching 15% by coating a TiO2 antireflection layer and doping CNTs with oxidative chemicals, under air mass (AM 1.5) illumination at a calibrated intensity of 100 mW/cm2 and an active device area of 15 mm2. The TiO2 layer significantly inhibits light reflectance from the Si surface, resulting in much enhanced short-circuit current (by 30%) and external quantum efficiency. Our method is simple, well-controlled, and very effective in boosting the performance of CNT-Si solar cells. PMID:23181192

  2. Rapid double-dye-layer coating for dye-sensitized solar cells using a new method.

    PubMed

    Jung, Cho-long; Han, Chi-Hwan; Moon, Doo Kyung; Jun, Yongseok

    2014-10-01

    Intensive research with the specific aim of developing inexpensive renewable energy sources is currently being undertaken. In dye-sensitized solar cell (DSSC) production, the most time-consuming process is coating the dye on working electrodes: absorption of ruthenium-based dyes [e.g., N719=bis(trtrabutylammonium)-cis-di(thiocyanato)-N,N'-bis(4-carboxylato-4'-carboxylic acid-2,2'-bipyridine) ruthenium(II)] on a photoanode takes a long time. We report a simple dye-coating method using a mixed solvent of ethylene glycol (EG) and glycerol (Gly). According to our experiments, dye-coating time can be reduced to 5 min from several hours. Maximum performance was obtained with an EG/Gly ratio of 1:1. This mixture of solvents gave a performance of 9.1%. Furthermore, the viscous solvent system could control coating depth; positioning dye coatings to a specific depth was rapid and facile. A cell containing two different dyes (N719+black dye) had an efficiency of 9.4%.

  3. Seasonal adjustment of solar heat gain independent of coat coloration in a desert mammal.

    PubMed

    Walsberg, G E; Weaver, T; Wolf, B O

    1997-01-01

    Despite the apparent importance of solar radiation as a source of heat for free-living animals, there exists no substantial body of empirical data describing physiological responses to solar radiation under the range of convective conditions likely to occur in nature. We therefore quantified effects of simulated solar radiation and wind on metabolic heat production in the rock squirrel, Spermophilus variegatus. This diurnal mammal inhabits the Sonoran Desert and seasonally replaces its pelage in a fashion in which it retains constant external appearance but incorporates optical and structural changes that are thought to significantly alter heat-transfer properties of the coat. At a given wind speed, the presence of 950 W m-2 of simulated solar radiation reduces metabolic heat production by 15% (at a wind speed of 4 m s-1) to 37% (at a wind speed of 0.25 m s-1). Independent of effects of irradiance, metabolic heat production significantly increases with wind speed such that as wind speed is increased from 0.25 m s-1 to 4.0 m s-1, metabolic heat production is elevated by 66% (sunlight absent) or 88% (sunlight present). Previous analyses demonstrated that when exposed to identical radiative and convective environments rock squirrels with summer pelages accrue solar heat loads 33%-71% lower than those experienced by animals with winter coats. This reduction of solar heat gain during the extremely hot Sonoran Desert summer apparently constitutes a previously unappreciated mode of thermal adaptation by seasonal adjustment of radiative heat gain without changes in the animal's appearance.

  4. Efficient black silicon solar cell with a density-graded nanoporous surface: Optical properties, performance limitations, and design rules

    NASA Astrophysics Data System (ADS)

    Yuan, Hao-Chih; Yost, Vernon E.; Page, Matthew R.; Stradins, Paul; Meier, Daniel L.; Branz, Howard M.

    2009-09-01

    We study optical effects and factors limiting performance of our confirmed 16.8% efficiency "black silicon" solar cells. The cells incorporate density-graded nanoporous surface layers made by a one-step nanoparticle-catalyzed etch and reflect less than 3% of the solar spectrum, with no conventional antireflection coating. The cells are limited by recombination in the nanoporous layer which decreases short-wavelength spectral response. The optimum density-graded layer depth is then a compromise between reflectance reduction and recombination loss. Finally, we propose universal design rules for high-efficiency solar cells based on density-graded surfaces.

  5. Hybrid thermoelectric solar collector design and analysis

    NASA Technical Reports Server (NTRS)

    Roberts, A. S., Jr.; Shaheen, K. E.

    1982-01-01

    A flat-plate solar collector is conceived where energy cascades through thermoelectric power modules generating direct-current electricity. The intent of this work was to choose a collector configuration and to perform a steady-state thermal performance assessment. A set of energy balance equations were written and solved numerically for the purpose of optimizing collector thermal and electrical performance. The collector design involves finned columns of thermoelectric modules imbedded in the absorber plate (hot junction) over a parallel array of vertical tubes. The thermoelectric power output is limited by the small hot-junction/cold-junction temperature difference which can be maintained under steady-state conditions. The electric power per unit tube pass area is found to have a maximum as a function of a geometric parameter, while electric power is maximized with respect to an electric resistance ratio. Although the electric power efficiency is small, results indicate that there is sufficient electric power production to drive a coolant circulator, suggesting the potential for a stand-alone system.

  6. Global optimization framework for solar building design

    NASA Astrophysics Data System (ADS)

    Silva, N.; Alves, N.; Pascoal-Faria, P.

    2017-07-01

    The generative modeling paradigm is a shift from static models to flexible models. It describes a modeling process using functions, methods and operators. The result is an algorithmic description of the construction process. Each evaluation of such an algorithm creates a model instance, which depends on its input parameters (width, height, volume, roof angle, orientation, location). These values are normally chosen according to aesthetic aspects and style. In this study, the model's parameters are automatically generated according to an objective function. A generative model can be optimized according to its parameters, in this way, the best solution for a constrained problem is determined. Besides the establishment of an overall framework design, this work consists on the identification of different building shapes and their main parameters, the creation of an algorithmic description for these main shapes and the formulation of the objective function, respecting a building's energy consumption (solar energy, heating and insulation). Additionally, the conception of an optimization pipeline, combining an energy calculation tool with a geometric scripting engine is presented. The methods developed leads to an automated and optimized 3D shape generation for the projected building (based on the desired conditions and according to specific constrains). The approach proposed will help in the construction of real buildings that account for less energy consumption and for a more sustainable world.

  7. High Lifetime Solar Cell Processing and Design

    NASA Technical Reports Server (NTRS)

    Swanson, R. M.

    1985-01-01

    In order to maximize efficiency a solar cell must: (1) absorb as much light as possible in electron-hole production, (2) transport as large a fraction as possible of the electrons to the n-type terminal and holes to the p-type terminal without their first recombining, and (3) produce as high as possible terminal voltage. Step (1) is largely fixed by the spectrum of sunlight and the fundamental absorption characteristics of silicon, although some improvements are possible through texturizing induced light trapping and back surface reflectors. Steps (2) and (3) are, however, dependent on the recombination mechanisms of the cell. The recombination, on the contrary, is strongly influenced by cell processing and design. Some of the lessons during the development of point-contact-cell are discussed. Cell dependence on recombination, surface recombination, and contact recombination are discussed. Results show the overwhelming influence of contact recombination on the operation of the cell when the other sources of recombination are reduced by careful processing.

  8. Hybrid thermoelectric solar collector design and analysis

    NASA Technical Reports Server (NTRS)

    Roberts, A. S., Jr.; Shaheen, K. E.

    1982-01-01

    A flat-plate solar collector is conceived where energy cascades through thermoelectric power modules generating direct-current electricity. The intent of this work was to choose a collector configuration and to perform a steady-state thermal performance assessment. A set of energy balance equations were written and solved numerically for the purpose of optimizing collector thermal and electrical performance. The collector design involves finned columns of thermoelectric modules imbedded in the absorber plate (hot junction) over a parallel array of vertical tubes. The thermoelectric power output is limited by the small hot-junction/cold-junction temperature difference which can be maintained under steady-state conditions. The electric power per unit tube pass area is found to have a maximum as a function of a geometric parameter, while electric power is maximized with respect to an electric resistance ratio. Although the electric power efficiency is small, results indicate that there is sufficient electric power production to drive a coolant circulator, suggesting the potential for a stand-alone system.

  9. Solar Water-Heater Design and Installation

    NASA Technical Reports Server (NTRS)

    Harlamert, P.; Kennard, J.; Ciriunas, J.

    1982-01-01

    Solar/Water heater system works as follows: Solar--heated air is pumped from collectors through rock bin from top to bottom. Air handler circulates heated air through an air-to-water heat exchanger, which transfers heat to incoming well water. In one application, it may reduce oil use by 40 percent.

  10. Solar Water-Heater Design and Installation

    NASA Technical Reports Server (NTRS)

    Harlamert, P.; Kennard, J.; Ciriunas, J.

    1982-01-01

    Solar/Water heater system works as follows: Solar--heated air is pumped from collectors through rock bin from top to bottom. Air handler circulates heated air through an air-to-water heat exchanger, which transfers heat to incoming well water. In one application, it may reduce oil use by 40 percent.

  11. Aluminide slurry coatings for protection of ferritic steel in molten nitrate corrosion for concentrated solar power technology

    NASA Astrophysics Data System (ADS)

    Audigié, Pauline; Bizien, Nicolas; Baráibar, Ignacio; Rodríguez, Sergio; Pastor, Ana; Hernández, Marta; Agüero, Alina

    2017-06-01

    Molten nitrates can be employed as heat storage fluids in solar concentration power plants. However molten nitrates are corrosive and if operating temperatures are raised to increase efficiencies, the corrosion rates will also increase. High temperature corrosion resistant coatings based on Al have demonstrated excellent results in other sectors such as gas turbines. Aluminide slurry coated and uncoated P92 steel specimens were exposed to the so called Solar Salt (industrial grade), a binary eutectic mixture of 60 % NaNO3 - 40 % KNO3, in air for 2000 hours at 550°C and 580°C in order to analyze their behavior as candidates to be used in future solar concentration power plants employing molten nitrates as heat transfer fluids. Coated ferritic steels constitute a lower cost technology than Ni based alloy. Two different coating morphologies resulting from two heat treatment performed at 700 and 1050°C after slurry application were tested. The coated systems exhibited excellent corrosion resistance at both temperatures, whereas uncoated P92 showed significant mass loss from the beginning of the test. The coatings showed very slow reaction with the molten Solar Salt. In contrast, uncoated P92 developed a stratified, unprotected Fe, Cr oxide with low adherence which shows oscillating Cr content as a function of coating depth. NaFeO2 was also found at the oxide surface as well as within the Fe, Cr oxide.

  12. Preliminary space station solar array structural design study

    NASA Technical Reports Server (NTRS)

    Dorsey, J. T.; Bush, H. G.; Mikulas, M. M., Jr.

    1984-01-01

    Structurally efficient ways to support the large solar arrays (3,716 square meters which are currently considered for space station use) are examined. An erectable truss concept is presented for the on orbit construction of winged solar arrays. The means for future growth, maintenance, and repair are integrally designed into this concept. Results from parametric studies, which highlight the physical and structural differences between various configuration options are presented. Consideration is given to both solar blanket and hard panel arrays.

  13. Approach to interior design for passive direct gain solar homes

    SciTech Connect

    Kachadorian, C.C.

    1980-01-01

    In response to requests from buyers and builders of direct gain passive solar homes interior design criteria either specific to, or emphasized by, passive solar buildings are investigated. Problems of high sunlight penetration, secondary illumination, material selection, sound control and psychology are approached. Material deterioration, fading, glare, noise, and a sense of spacial confinement can be minimized, contributing to the appeal and saleability of passive solar homes.

  14. Preliminary design package for prototype solar heating system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A summary is given of the preliminary analysis and design activity on solar heating systems. The analysis was made without site specific data other than weather; therefore, the results indicate performance expected under these special conditions. Major items include system candidates, design approaches, trade studies and other special data required to evaluate the preliminary analysis and design. The program calls for the development and delivery of eight prototype solar heating and cooling systems for installation and operational test.

  15. Morphology-insensitive Performance Facilitates Transition from Spin-Coating to Roll-to-Roll Coating For High-Performance, Solution-Processed Solar Cells

    NASA Astrophysics Data System (ADS)

    Delongchamp, Dean

    Solution processing via roll-to-roll (R2R) coating promises a low cost, low thermal-budget, sustainable revolution for the production of solar cells. Yet virtually all high efficiency solution processed research cells have been demonstrated by spin-coating, a low-volume deposition process. We present detailed device and morphology studies of an organic photovoltaic (OPV) system deposited by a high volume manufacturing technique, blade-coating, that achieves greater than 9.5 % power conversion efficiency (PCE). The average crystal domain orientation and characteristic phase separation length distribution are markedly different when deposited by blade-coating rather than spin-coating,. This result allows us to determine which aspects of morphology are not relevant to the PCE of this system. Whether the crystallites are ``face on'' or ``edge on'' does not appear to impact the PCE of system, nor does the length scale or ``hierarchical'' nature of the phase length scale. Persistent morphological qualities that may be associated with high PCE in this system are relatively pure phases and relatively strong diffraction. We posit that OPV systems in which the PCE is less sensitive to morphology may also be less sensitive to film thickness, enabling some to maintain high PCE in active layers thicker than greater than ~200 nm. We confirm that blade-coating is a suitable prototyping technique for R2R coating by demonstrating nominally identical morphologies for both piece blade-coating and continuous-web, slot-die coating.

  16. Design of a solar sail mission to Mars

    NASA Technical Reports Server (NTRS)

    Fleri, E. J., Jr.; Galliano, P. A.; Harrison, M. E.; Johnson, W. B.; Meyer, G. J.

    1989-01-01

    A new area of interest in space vehicles is the solar sail. Various applications for which it has been considered are attitude control of satellites, focusing light on the jungles of Vietnam, and a Halley's comet rendezvous. Although for various reasons these projects were never completed, new interest in solar sails has arisen. The solar sail is an alternative to the rocket-propelled space vehicle as an interplanetary cargo vehicle, and manufacture of solar sails on the space station is a possibility. Solar sails have several advantages over rockets, including an unlimited power supply and low maintenance. The purpose of this project is to design a solar sail mission to Mars. The spacecraft will efficiently journey to Mars powered only by a solar sail. The vehicle weighs 487.16 kg and will be launchable on an expendable launch vehicle. The project includes an investigation of options to minimize cost, weight, and flight duration. The design of the sail and its deployment system are a major part of the project, as is the actual mission planning. Various topics researched include solar power, material, space environment, thermal control, trajectories, and orbit transfer. Various configurations are considered in order to determine the optimal structure. Another design consideration is the control system of the vehicle. This system includes the attitude control and the communication system of the sail. This project will aid in determining the feasibility of a solar sail and will raise public interest in space research.

  17. Organic grain coatings in primitive interplanetary dust particles: Implications for grain sticking in the Solar Nebula

    NASA Astrophysics Data System (ADS)

    Flynn, George J.; Wirick, Sue; Keller, Lindsay P.

    2013-10-01

    The chondritic porous interplanetary dust particles (CP IDPs), fragments of asteroids and comets collected by NASA high-altitude research aircraft from the Earth's stratosphere, are recognized as the least altered samples of the original dust of the Solar Nebula available for laboratory examination. We performed high-resolution, ~25 nm/pixel, x-ray imaging and spectroscopy on ultramicrotome sections of CP IDPs, which are aggregates of >104 grains, and identified and characterized ~100 nm thick coatings of organic matter on the surfaces of the individual grains. We estimated the minimum tensile strength of this organic glue to be ~150 to 325 N/m2, comparable to the strength of the weakest cometary meteors, based on the observation that the individual grains of ~5 μm diameter aggregate CP IDPs are not ejected from the particle by electrostatic repulsion due to charging of these IDPs to 10 to 15 volts at 1 A.U. in space. Since organic coatings can increase the sticking coefficient over that of bare mineral grains, these organic grain coatings are likely to have been a significant aid in grain sticking in the Solar Nebula, allowing the first dust particles to aggregate over a much wider range of collision speeds than for bare mineral grains.

  18. Feasibility Study & Design of Brightfield Solar Farm

    SciTech Connect

    Law, Susan

    2014-09-28

    This Congressionally Directed Project originally provided funds to the Township of Lower Providence, Pennsylvania for the purpose of investigating the potential for a renewable energy generation facility to make beneficial reuse of a closed landfill located within the Township, known as Moyer Landfill. Early in the course of the project, it was determined through collaboration and discussion with DOE to alter the scope of the project to include a feasibility assessment of a landfill solar project, as well as to construct a demonstration solar project at the municipal facilities to provide an educational and community outreach opportunity for the Township to offer regarding solar photovoltaic (“PV”) electricity generation.

  19. Solar heating and cooling system design and development

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The design and development of marketable solar heating and cooling systems for single family and commercial applications is described. The delivery, installation, and monitoring of the prototype systems are discussed. Seven operational test sites are discussed in terms of system performance. Problems encountered with equipment and installation were usually due to lack of skills required for solar system installation.

  20. Design data brochure for a pyramidal optics solar system

    SciTech Connect

    Not Available

    1980-09-01

    This Design Data Brochure provides information on a Pyramidal Optics Solar System for solar heating and domestic hot water. The system is made up of the collecting, storage, and distribution subsystems. Contained in the brochure are such items as system description, available accessories, installation arrangements, physical data, piping and wiring diagrams, and guide specifications.

  1. Efficient Colorful Perovskite Solar Cells Using a Top Polymer Electrode Simultaneously as Spectrally Selective Antireflection Coating.

    PubMed

    Jiang, Youyu; Luo, Bangwu; Jiang, Fangyuan; Jiang, Fuben; Fuentes-Hernandez, Canek; Liu, Tiefeng; Mao, Lin; Xiong, Sixing; Li, Zaifang; Wang, Tao; Kippelen, Bernard; Zhou, Yinhua

    2016-12-14

    Organometal halide perovskites have shown excellent optoelectronic properties and have been used to demonstrate a variety of semiconductor devices. Colorful solar cells are desirable for photovoltaic integration in buildings and other aesthetically appealing applications. However, the realization of colorful perovskite solar cells is challenging because of their broad and large absorption coefficient that commonly leads to cells with dark-brown colors. Herein, for the first time, we report a simple and efficient strategy to achieve colorful perovskite solar cells by using the transparent conducting polymer (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), PEDOT:PSS) as a top electrode and simultaneously as an spectrally selective antireflection coating. Vivid colors across the visible spectrum are attained by engineering optical interference effects among the transparent PEDOT:PSS polymer electrode, the hole-transporting layer and the perovskite layer. The colored perovskite solar cells display power conversion efficiency values from 12.8 to 15.1% (from red to blue) when illuminated from the FTO glass side and from 11.6 to 13.8% (from red to blue) when illuminated from the PEDOT:PSS side. The new approach provides an advanced solution for fabricating colorful perovskite solar cells with easy processing and high efficiency.

  2. Design and performance of differential pumping system of coating unit

    NASA Astrophysics Data System (ADS)

    Karmakar, P.; Maiti, N.; Bapat, A. V.

    2008-05-01

    A box type coating unit has been developed in view of dual purpose of optical and reactive coating. The system is divided in two parts namely, substrate chamber (800mm × 800 mm × 100 mm) and gun chamber (800mm × 800 mm × 100 mm). Coating material is evaporated in the substrate chamber by traverse (270°) electron beams. Reactive gas is injected in the substrate chamber by up-stream pressure controller to reach set pressures in the range of 1×10-3 mbar to 1×10-4 mbar for gas flow rate in the range of 0-30 sccm. Traverse EB guns (10 kV, 15 kW, 2 No) are mounted inside gun chamber. The gun chamber vacuum should be better than 1×10-5 mbar for the operation of EB guns. Both these chambers are connected by the apertures provided on the intermediate bifurcation plate for the passage of electron beams. Through the apertures the reactive gas leaks from the substrate chamber to the gun chamber due to differential pressure. The differential pumping system consists of individual pumping modules for the substrate chamber and the gun chamber. The paper focuses upon the design of differential pumping system in view of determination of steady state differential pressures for different flow rates of reactive gas. It has been noticed that on introduction of reactive gas in the substrate chamber, the pressures in the substrate chamber and the gun chamber oscillates before converging to steady state values. Theoretically calculated values have been compared with the experimental values as design validation.

  3. Blade-coated sol-gel indium-gallium-zinc-oxide for inverted polymer solar cell

    NASA Astrophysics Data System (ADS)

    Lee, Yan-Huei; Tsai, Pei-Ting; Chang, Chia-Ju; Meng, Hsin-Fei; Horng, Sheng-Fu; Zan, Hsiao-Wen; Lin, Hung-Cheng; Liu, Hung-Chuan; Tseng, Mei-Rurng; Yeh, Han-Cheng

    2016-11-01

    The inverted organic solar cell was fabricated by using sol-gel indium-gallium-zinc-oxide (IGZO) as the electron-transport layer. The IGZO precursor solution was deposited by blade coating with simultaneous substrate heating at 120 °C from the bottom and hot wind from above. Uniform IGZO film of around 30 nm was formed after annealing at 400 °C. Using the blend of low band-gap polymer poly[(4,8-bis-(2-ethylhexyloxy)-benzo(1,2-b:4,5-b')dithiophene)-2,6-diyl-alt- (4-(2-ethylhexanoyl)-thieno [3,4-b]thiophene-)-2-6-diyl)] (PBDTTT-C-T) and [6,6]-Phenyl C71 butyric acid methyl ester ([70]PCBM) as the active layer for the inverted organic solar cell, an efficiency of 6.2% was achieved with a blade speed of 180 mm/s for the IGZO. The efficiency of the inverted organic solar cells was found to depend on the coating speed of the IGZO films, which was attributed to the change in the concentration of surface OH groups. Compared to organic solar cells of conventional structure using PBDTTT-C-T: [70]PCBM as active layer, the inverted organic solar cells showed significant improvement in thermal stability. In addition, the chemical composition, as well as the work function of the IGZO film at the surface and inside can be tuned by the blade speed, which may find applications in other areas like thin-film transistors.

  4. Plasmonic enhancement of thin-film solar cells using gold-black coatings

    SciTech Connect

    Fredricksen, Christopher J.; Panjwani, D. R.; Arnold, J. P.; Figueiredo, P. N.; Rezaie, F. K.; Colwell, J. E.; Baillie, K.; Peppernick, Samuel J.; Joly, Alan G.; Beck, Kenneth M.; Hess, Wayne P.; Peale, Robert E.

    2011-08-11

    Coatings of conducting gold-black nano-structures on commercial thin-film amorphous-silicon solar cells enhance the short-circuit current by 20% over a broad spectrum from 400 to 800 nm wavelength. The efficiency, i.e. the ratio of the maximum electrical output power to the incident solar power, is found to increase 7% for initial un-optimized coatings. Metal blacks are produced cheaply and quickly in a low-vacuum process requiring no lithographic patterning. The inherently broad particle-size distribution is responsible for the broad spectrum enhancement in comparison to what has been reported for mono-disperse lithographically deposited or self-assembled metal nano-particles. Photoemission electron microscopy reveals the spatial-spectral distribution of hot-spots for plasmon resonances, where scattering of normally-incident solar flux into the plane increases the effective optical path in the thin film to enhance light harvesting. Efficiency enhancement is correlated with percent coverage and particle size distribution, which are determined from histogram and wavelet analysis of scanning electron microscopy images. Electrodynamic simulations reveal how the gold-black particles scatter the radiation and locally enhance the field strength.

  5. Preliminary design of an air solar collector

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Report containing performance specifications and engineering drawings of concentric-tube air solar collector show details of collector and subcomponents that indicate efficiency surpassing predetermined performance baseline for air collectors.

  6. Controller for solar heating-design package

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Report contains performance specifications and detailed drawings for two instruments: (1) differential controller, and (2) temperature monitor, for solar-powered water-heating systems. Included in package are schematics, wiring diagrams, test procedures, and parts list.

  7. Nanostructured Indium Oxide Coated Silicon Nanowire Arrays: A Hybrid Photothermal/Photochemical Approach to Solar Fuels.

    PubMed

    Hoch, Laura B; O'Brien, Paul G; Jelle, Abdinoor; Sandhel, Amit; Perovic, Douglas D; Mims, Charles A; Ozin, Geoffrey A

    2016-09-27

    The field of solar fuels seeks to harness abundant solar energy by driving useful molecular transformations. Of particular interest is the photodriven conversion of greenhouse gas CO2 into carbon-based fuels and chemical feedstocks, with the ultimate goal of providing a sustainable alternative to traditional fossil fuels. Nonstoichiometric, hydroxylated indium oxide nanoparticles, denoted In2O3-x(OH)y, have been shown to function as active photocatalysts for CO2 reduction to CO via the reverse water gas shift reaction under simulated solar irradiation. However, the relatively wide band gap (2.9 eV) of indium oxide restricts the portion of the solar irradiance that can be utilized to ∼9%, and the elevated reaction temperatures required (150-190 °C) reduce the overall energy efficiency of the process. Herein we report a hybrid catalyst consisting of a vertically aligned silicon nanowire (SiNW) support evenly coated by In2O3-x(OH)y nanoparticles that utilizes the vast majority of the solar irradiance to simultaneously produce both the photogenerated charge carriers and heat required to reduce CO2 to CO at a rate of 22.0 μmol·gcat(-1)·h(-1). Further, improved light harvesting efficiency of the In2O3-x(OH)y/SiNW films due to minimized reflection losses and enhanced light trapping within the SiNW support results in a ∼6-fold increase in photocatalytic conversion rates over identical In2O3-x(OH)y films prepared on roughened glass substrates. The ability of this In2O3-x(OH)y/SiNW hybrid catalyst to perform the dual function of utilizing both light and heat energy provided by the broad-band solar irradiance to drive CO2 reduction reactions represents a general advance that is applicable to a wide range of catalysts in the field of solar fuels.

  8. Design and production of bicolour reflecting coatings with Au metal island films.

    PubMed

    Janicki, Vesna; Amotchkina, Tatiana V; Sancho-Parramon, Jordi; Zorc, H; Trubetskov, Michael K; Tikhonravov, Alexander V

    2011-12-05

    Optical properties of metal island films (MIFs) can be combined with interference of dielectric coatings. A set of multilayer designs containing metal clusters reflecting different colours from front and back side of the coating was obtained by numerical optimization. The chosen designs presenting the range of feasible colours were deposited by electron beam evaporation. Spectrophotometric and ellipsometric measurements verified that the produced coatings present an excellent agreement with the optical performance calculated from the designs. Numerical optimization was verified as a useful method in designing of coatings containing MIFs. This approach can ease the implementation of metal clusters into multilayer designs and broaden the applications of MIFs.

  9. Conceptual design of an aircraft automated coating removal system

    SciTech Connect

    Baker, J.E.; Draper, J.V.; Pin, F.G.; Primm, A.H.; Shekhar, S.

    1996-05-01

    Paint stripping of the U.S. Air Force`s large transport aircrafts is currently a labor-intensive, manual process. Significant reductions in costs, personnel and turnaround time can be accomplished by the judicious use of automation in some process tasks. This paper presents the conceptual design of a coating removal systems for the tail surfaces of the C-5 plane. Emphasis is placed on the technology selection to optimize human-automation synergy with respect to overall costs, throughput, quality, safety, and reliability. Trade- offs between field-proven vs. research-requiring technologies, and between expected gain vs. cost and complexity, have led to a conceptual design which is semi-autonomous (relying on the human for task specification and disturbance handling) yet incorporates sensor- based automation (for sweep path generation and tracking, surface following, stripping quality control and tape/breach handling).

  10. Development of a new low cost antireflective coating technique for solar cells

    NASA Technical Reports Server (NTRS)

    Wohlgemuth, J. H.; Warfield, D. B.; Johnson, G. A.

    1982-01-01

    The goal of this study was the development of an antireflective (AR) coating technique that has the potential for high throughput and low cost yet is capable of producing films of good optical quality. Previous efforts to develop sprayed AR coatings had utilized titanium isopropoxide mixed with volatile solvents. These films worked well on smooth surfaces but when applied to etched semi-crystalline silicon surfaces yielded inconsistent results with more than 20 percent of the AM1 incident light being reflected. In this program titanium isopropoxide was sprayed directly onto heater wafers (410 C) to produce a uniform AR coating even on highly textured surfaces. Tests on various types of solar cells yielded performance improvements for the hot sprayed AR cells that are equivalent to that observed for evaporated TiOx AR coated cells. As an extension of this effort a new double layer AR consisting of a bottom layer of hot sprayed titanium isopropoxide and a top layer of hot sprayed aluminum isopropoxide in methylene chloride has resulted in more than 10 percent improvement in cell output as compared to a single layer AR cell.

  11. Performance and stability improvements for dye-sensitized solar cells in the presence of luminescent coatings

    NASA Astrophysics Data System (ADS)

    Bella, Federico; Griffini, Gianmarco; Gerosa, Matteo; Turri, Stefano; Bongiovanni, Roberta

    2015-06-01

    Here we present how the sunlight radiation incident on a dye-sensitized solar cell (DSSC) can be shifted of a few tens of nanometers by means of an economical, easy to prepare and multifunctional photocurable fluoropolymeric light-shifting (LS) coating, to achieve both improved efficiency and device stability. By the introduction of a very small amount of a luminescent agent in the LS coating, the down-shifting of near-UV photons to higher wavelengths easily harvestable by the organic dye of a DSSC is successfully demonstrated. This optical effect not only results in an over 60% improvement of the power conversion efficiency of DSSC devices, but the UV light filtering action promoted by the luminescent agent also provides protection to the photosensitive DSSC components. This aspect, combined with a potential thermal shielding effect and the easy-cleaning behavior imparted to the coating by its fluorinated nature, leads to excellent device stability as evidenced from an aging test performed outdoors under real operating conditions for more than 2000 h. Our study demonstrates that the use of light-cured multifunctional coatings with light management characteristics at the nanometer scale represents a new promising strategy to simultaneously increase the performance and durability of DSSC devices.

  12. Increasing Community Access to Solar: Designing and Developing a Shared Solar Photovoltaic System (Fact Sheet)

    SciTech Connect

    Not Available

    2012-06-01

    This document introduces the Energy Department's new Guide to Community Shared Solar: Utility, Private, and Nonprofit Project Development. The guide is designed to help those who want to develop community shared solar projects - from community organizers and advocates to utility managers and government officials - navigate the process of developing shared systems, from early planning to implementation.

  13. UV testing of solar cells: Effects of antireflective coating, prior irradiation, and UV source

    NASA Technical Reports Server (NTRS)

    Meulenberg, A.

    1993-01-01

    Short-circuit current degradation of electron irradiated double-layer antireflective-coated cells after 3000 hours ultraviolet (UV) exposure exceeds 3 percent; extrapolation of the data to 10(exp 5) hours (11.4 yrs.) gives a degradation that exceeds 10 percent. Significant qualitative and quantitative differences in degradation were observed in cells with double- and single-layer antireflective coatings. The effects of UV-source age were observed and corrections were made to the data. An additional degradation mechanism was identified that occurs only in previously electron-irradiated solar cells since identical unirradiated cells degrade to only 6 +/- 3 percent when extrapolated 10(exp 5) hours of UV illumination.

  14. A flexible polypyrrole-coated fabric counter electrode for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Xu, Jie; Li, Meixia; Wu, Lei; Sun, Yongyuan; Zhu, Ligen; Gu, Shaojin; Liu, Li; Bai, Zikui; Fang, Dong; Xu, Weilin

    2014-07-01

    The current dye-sensitized solar cell (DSSC) technology is mostly based on fluorine doped tin oxide (FTO) coated glass substrate. The main problem with the FTO glass substrate is its rigidity, heavyweight and high cost. DSSCs with a fabric as substrate not only offer the advantages of flexibility, stretchability and light mass, but also provide the opportunities for easy implantation to wearable electronics. Herein, a novel fabric counter electrode (CE) for DSSCs has been reported employing a daily-used cotton fabric as substrate and polypyrrole (PPy) as catalytic material. Nickel (Ni) is deposited on the cotton fabric as metal contact by a simple electroless plating method to replace the expensive FTO. PPy is synthesized by in situ polymerization of pyrrole monomer on the Ni-coated fabric. The fabric CE shows sufficient catalytic activity towards the reduction of I3-. The DSSC fabricated using the fabric CE exhibits power conversion efficiency of ∼3.30% under AM 1.5.

  15. Fabrication of carbon-coated silicon nanowires and their application in dye-sensitized solar cells.

    PubMed

    Kim, Junhee; Lim, Jeongmin; Kim, Minsoo; Lee, Hae-Seok; Jun, Yongseok; Kim, Donghwan

    2014-11-12

    We report the fabrication of silicon/carbon core/shell nanowire arrays using a two-step process, involving electroless metal deposition and chemical vapor deposition. In general, foreign shell materials that sheath core materials change the inherent characteristics of the core materials. The carbon coating functionalized the silicon nanowire arrays, which subsequently showed electrocatalytic activities for the reduction of iodide/triiodide. This was verified by cyclic voltammetry and electrochemical impedance spectroscopy. We employed the carbon-coated silicon nanowire arrays in dye-sensitized solar cells as counter electrodes. We optimized the carbon shells to maximize the photovoltaic performance of the resulting devices, and subsequently, a peak power conversion efficiency of 9.22% was achieved.

  16. Commercialization of High-Temperature Solar Selective Coating: Cooperative Research and Development Final Report, CRADA Number CRD-08-300

    SciTech Connect

    Gray, M. H.

    2014-01-01

    The goal for Concentrating Solar Power (CSP) technologies is to produce electricity at 15 cents/kilowatt-hour (kWh) with six hours of thermal storage in 2015 (intermediate power) and close to 10 cents/kWh with 12-17 hours of thermal storage in 2020 (baseload power). Cost reductions of up to 50% to the solar concentrator are targeted through technology advances. The overall solar-to-electric efficiency of parabolic-trough solar power plants can be improved and the cost of solar electricity can be reduced by improving the properties of the selective coating on the receiver and increasing the solar-field operating temperature to >450 degrees C. New, more-efficient selective coatings will be needed that have both high solar absorptance and low thermal emittance at elevated temperatures. Conduction and convection losses from the hot absorber surface are usually negligible for parabolic trough receivers. The objective is to develop new, more-efficient selective coatings with both high solar absorptance (..alpha.. > 0.95) and low thermal emittance (..epsilon.. < 0.08 @ 450 degrees C) that are thermally stable above 450 degrees C, ideally in air, with improved durability and manufacturability, and reduced cost.

  17. Prototype residential solar-energy system-design package

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Compilation includes documents and drawings for complete solar-heating system. It discussed system installed in residential building at Veterns' Administration Hospital in Togus, Maine. System can be adapted to other buildings without changing design.

  18. Preliminary design package for prototype solar heating system

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A preliminary design review on the development of a prototype solar heating system for single family dwellings is presented. The collector, storage, transport, control, and site data acquisition subsystems are described.

  19. Prototype residential solar-energy system-design package

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Compilation includes documents and drawings for complete solar-heating system. It discussed system installed in residential building at Veterns' Administration Hospital in Togus, Maine. System can be adapted to other buildings without changing design.

  20. Preliminary design package for solar heating and hot water system

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Two prototype solar heating and hot water systems for use in single-family dwellings or commercial buildings were designed. Subsystems included are: collector, storage, transport, hot water, auxiliary energy, and government-furnished site data acquisition. The systems are designed for Yosemite, California, and Pueblo, Colorado. The necessary information to evaluate the preliminary design for these solar heating and hot water systems is presented. Included are a proposed instrumentation plan, a training program, hazard analysis, preliminary design drawings, and other information about the design of the system.

  1. Design package for solar domestic hot water system

    SciTech Connect

    1980-09-01

    Information used to evaluate the initial design of the Elcam, Inc., Solar Domestic Hot Water System is presented. Included are such items as the system performance specification, detailed design drawings and other information. Elcam, Inc., has developed two solar heated prototype hot water systems and two heat exchangers. The hot water systems consist of the following subsystems: collector, storage, control, transport, auxiliary energy, and government-furnished Site Data Acquisition. The two systems are installed at Tempe, Arizona, and San Diego, California.

  2. Development of technique for air coating and nickel and copper metalization of solar cells

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Solar cells were made with a variety of base metal screen printing inks applied over silicon nitride AR coating and copper electroplated. Fritted and fritless nickel and fritless tin base printing inks were evaluated. Conversion efficiencies as high as 9% were observed with fritted nickel ink contacts, however, curve shapes were generally poor, reflecting high series resistance. Problems encountered in addition to high series reistance included loss of adhesion of the nickel contacts during plating and poor adhesion, oxidation and inferior curve shapes with the tin base contacts.

  3. Development of technique for air coating and nickel and copper metalization of solar cells

    NASA Astrophysics Data System (ADS)

    Solar cells were made with a variety of base metal screen printing inks applied over silicon nitride AR coating and copper electroplated. Fritted and fritless nickel and fritless tin base printing inks were evaluated. Conversion efficiencies as high as 9% were observed with fritted nickel ink contacts, however, curve shapes were generally poor, reflecting high series resistance. Problems encountered in addition to high series reistance included loss of adhesion of the nickel contacts during plating and poor adhesion, oxidation and inferior curve shapes with the tin base contacts.

  4. Ultrafast Fabrication of Flexible Dye-Sensitized Solar Cells by Ultrasonic Spray-Coating Technology.

    PubMed

    Han, Hyun-Gyu; Weerasinghe, Hashitha C; Min Kim, Kwang; Soo Kim, Jeong; Cheng, Yi-Bing; Jones, David J; Holmes, Andrew B; Kwon, Tae-Hyuk

    2015-09-30

    This study investigates novel deposition techniques for the preparation of TiO2 electrodes for use in flexible dye-sensitized solar cells. These proposed new methods, namely pre-dye-coating and codeposition ultrasonic spraying, eliminate the conventional need for time-consuming processes such as dye soaking and high-temperature sintering. Power conversion efficiencies of over 4.0% were achieved with electrodes prepared on flexible polymer substrates using this new deposition technology and N719 dye as a sensitizer.

  5. Anodic Bonding of Transparent Conductive Oxide Coated Silicon Wafer to Glass Substrate for Solar Cell Applications

    NASA Astrophysics Data System (ADS)

    Yuda, Yohei; Koida, Takashi; Kaneko, Tetsuya; Kondo, Michio

    2013-01-01

    We report on the anodic bonding of Si wafer coated by thin transparent conductive oxide (TCO) with a glass substrate, for the first time. We obtained sufficient bonding strength of as high as 9.5 MPa using a 30-nm-thick indium tin oxide (ITO) layer. We have also found that the ITO sample shows much stronger bonding strength does a sample that with a zinc oxide layer. The bonding mechanism is discussed in terms of the permeation of indium elements into the glass side driven by electric field. Finally we demonstrated a solar cell using this substrate.

  6. Ultrafast Fabrication of Flexible Dye-Sensitized Solar Cells by Ultrasonic Spray-Coating Technology

    PubMed Central

    Han, Hyun-Gyu; Weerasinghe, Hashitha C.; Min Kim, Kwang; Soo Kim, Jeong; Cheng, Yi-Bing; Jones, David J.; Holmes, Andrew B.; Kwon, Tae-Hyuk

    2015-01-01

    This study investigates novel deposition techniques for the preparation of TiO2 electrodes for use in flexible dye-sensitized solar cells. These proposed new methods, namely pre-dye-coating and codeposition ultrasonic spraying, eliminate the conventional need for time-consuming processes such as dye soaking and high-temperature sintering. Power conversion efficiencies of over 4.0% were achieved with electrodes prepared on flexible polymer substrates using this new deposition technology and N719 dye as a sensitizer. PMID:26420466

  7. Solar Trees: First Large-Scale Demonstration of Fully Solution Coated, Semitransparent, Flexible Organic Photovoltaic Modules.

    PubMed

    Berny, Stephane; Blouin, Nicolas; Distler, Andreas; Egelhaaf, Hans-Joachim; Krompiec, Michal; Lohr, Andreas; Lozman, Owen R; Morse, Graham E; Nanson, Lana; Pron, Agnieszka; Sauermann, Tobias; Seidler, Nico; Tierney, Steve; Tiwana, Priti; Wagner, Michael; Wilson, Henry

    2016-05-01

    The technology behind a large area array of flexible solar cells with a unique design and semitransparent blue appearance is presented. These modules are implemented in a solar tree installation at the German pavilion in the EXPO2015 in Milan/IT. The modules show power conversion efficiencies of 4.5% and are produced exclusively using standard printing techniques for large-scale production.

  8. Passivation of Si solar cells by hetero-epitaxial compound semiconductor coatings

    NASA Technical Reports Server (NTRS)

    Vernon, S. M.; Spitzer, M. B.; Keavney, C. J.; Haven, V. E.; Sekula, P. A.

    1986-01-01

    A development status evaluation is made for high efficiency Si solar cells, with emphasis on the suppression of the deleterious effects of surface recombination. ZnS(0.9)Se(0.1) and GaP are identified as candidates for the reduction of surface recombination. Attention is given to methods developed for the deposition of heteroepitaxial compounds designed to block minority carrier transport to the Si solar cell surface without interfering with the majority carrier flow.

  9. Coupling flexible solar cell with parabolic trough solar-concentrator-prototype design and performance

    NASA Astrophysics Data System (ADS)

    Panin, Alexander; Bergquist, Jonathon

    2007-10-01

    Solar cells are still too expensive (5-20/watt) to compete with traditional fossil fuel power generating methods (˜1/watt). Parabolic trough solar concentrator has the advantage of modest concentration ratio (10-100) which is well suited for coupling with solar cell. Thus using small area solar cell placed in the focal line of parabolic trough may be economically viable alternative to flat solar panels. We experiment with flexible solar cell (backed by water cooling pipe) placed in the focus of parabolic trough reflector. Another advantage of parabolic trough concentrator is very relaxed tracking requirement. For example, east-west oriented concentrator (aligned with the ecliptic plane) does not even need any tracking during core 4-6 hours around noon (when maximum illumination is available). The design and the performance of the prototype, as well as possible economical benefits of full scale projects are discussed in the presentation.

  10. An economic model for passive solar designs in commercial environments

    NASA Astrophysics Data System (ADS)

    Powell, J. W.

    1980-06-01

    The model incorporates a life cycle costing approach that focuses on the costs of purchase, installation, maintenance, repairs, replacement, and energy. It includes a detailed analysis of tax laws affecting the use of solar energy in commercial buildings. Possible methods of treating difficult to measure benefits and costs, such as effects of the passive solar design on resale value of the building and on lighting costs, rental income from the building, and the use of commercial space, are presented. The model is illustrated in two case examples of prototypical solar design for low rise commercial buildings in an urban setting.

  11. Spectral reflectance properties of electroplated and converted zinc for use as a solar selective coating

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. E.; Curtis, H. B.; Gianelos, L.

    1975-01-01

    The spectral reflectance properties of electroplated and chemically converted zinc were measured for both chromate and chloride conversion coatings. The reflectance properties were measured for various times of conversion and for conversion at various chromate concentrations. The values of absorptance, alpha, integrated over the solar spectrum, and of infrared emittance, epsilon, integrated over black body radiation at 250 F were then calculated from the measured reflectance values. The interdependent variations of alpha and epsilon were plotted. The results indicate that the optimum combination of the highest absorptance in the solar spectrum and the lowest emittance in the infrared of the converted electroplated zinc is produced by chromate conversion at 1/2 concentration of the standard NEOSTAR chromate black solution for 0.50 minute or by chloride conversion for 0.50 minute.

  12. Spectral reflectance properties of electroplated and converted zinc for use as a solar selective coating

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. E.; Curtis, H. B.; Gianelos, L.

    1975-01-01

    The spectral reflectance properties of electroplated and chemically converted zinc were measured for both chromate and chloride conversion coatings. The reflectance properties were measured for various times of conversion and for conversion at various chromate concentrations. The values of absorptance, integrated over the solar spectrum, and of infrared emittance, integrated over black body radiation at 250 F were then calculated from the measured reflectance values. The interdependent variations of absorptance and infrared emittance were plotted. The results indicate that the optimum combination of the highest absorptance in the solar spectrum and the lowest emittance in the infrared of the converted electroplated zinc is produced by chromate conversion at 1/2 concentration of the standard NEOSTAR chromate black solution for 0.50 minute or by chloride conversion for 0.50 minute.

  13. Spectral reflectance properties of electroplated and converted zinc for use as a solar selective coating

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. E.; Curtis, H. B.; Gianelos, L.

    1975-01-01

    The spectral reflectance properties of electroplated and chemically converted zinc were measured for both chromate and chloride conversion coatings. The reflectance properties were measured for various times of conversion and for conversion at various chromate concentrations. The values of absorptance, alpha, integrated over the solar spectrum, and of infrared emittance, epsilon, integrated over black body radiation at 250 F were then calculated from the measured reflectance values. The interdependent variations of alpha and epsilon were plotted. The results indicate that the optimum combination of the highest absorptance in the solar spectrum and the lowest emittance in the infrared of the converted electroplated zinc is produced by chromate conversion at 1/2 concentration of the standard NEOSTAR chromate black solution for 0.50 minute or by chloride conversion for 0.50 minute.

  14. Analysis and design of holographic solar concentrators

    NASA Astrophysics Data System (ADS)

    Kostuk, Raymond K.; Rosenberg, Glenn

    2008-08-01

    The diffraction and the dispersion properties of holographic optical elements are examined for use as solar concentrators for photovoltaic and hybrid photovoltaic/thermal energy conversion systems. The diffraction angle and efficiency are computed for folded optical geometries that are potentially useful for low concentration ratio systems that can reduce the cost of residential solar energy systems. An investigation of the collection efficiency of a holographic planar concentrator and a spectrum splitting concentrator are analyzed with different construction parameters. It is found that collection angles of 40o and spectral bandwidth of 70 nm result with folded optical geometries for single volume holograms.

  15. Designing energy dissipation properties via thermal spray coatings

    DOE PAGES

    Brake, Matthew R. W.; Hall, Aaron Christopher; Madison, Jonathan D.

    2016-12-14

    The coefficient of restitution is a measure of energy dissipation in a system across impact events. Often, the dissipative qualities of a pair of impacting components are neglected during the design phase. This research looks at the effect of applying a thin layer of metallic coating, using thermal spray technologies, to significantly alter the dissipative properties of a system. We studied the dissipative properties across multiple impacts in order to assess the effects of work hardening, the change in microstructure, and the change in surface topography. The results of the experiments indicate that any work hardening-like effects are likely attributablemore » to the crushing of asperities, and the permanent changes in the dissipative properties of the system, as measured by the coefficient of restitution, are attributable to the microstructure formed by the thermal spray coating. Furthermore, the microstructure appears to be robust across impact events of moderate energy levels, exhibiting negligible changes across multiple impact events.« less

  16. The extreme ultraviolet imager of solar orbiter: optical design and alignment scheme

    NASA Astrophysics Data System (ADS)

    Halain, J.-P.; Mazzoli, A.; Meining, S.; Rochus, P.; Renotte, E.; Auchère, F.; Schühle, U.; Delmotte, F.; Dumesnil, C.; Philippon, A.; Mercier, R.; Hermans, A.

    2015-09-01

    The Extreme Ultraviolet Imager (EUI) is one of the remote sensing instruments on-board the Solar Orbiter mission. It will provide dual-band full-Sun images of the solar corona in the extreme ultraviolet (17.1 nm and 30.4 nm), and high resolution images of the solar disk in both extreme ultraviolet (17.1 nm) and vacuum ultraviolet (Lyman-alpha 121.6 nm). The EUI optical design takes heritage of previous similar instruments. The Full Sun Imager (FSI) channel is a single mirror Herschel design telescope. The two High Resolution Imager (HRI) channels are based on a two-mirror optical refractive scheme, one Ritchey-Chretien and one Gregory optical design for the EUV and the Lyman-alpha channels, respectively. The spectral performances of the EUI channels are obtained thanks to dedicated mirror multilayer coatings and specific band-pass filters. The FSI channel uses a dual-band mirror coating combined with aluminum and zirconium band-pass filters. The HRI channels use optimized band-pass selection mirror coatings combined with aluminum band-pass filters and narrow band interference filters for Lyman-alpha. The optical performances result from accurate mirror manufacturing tolerances and from a two-step alignment procedure. The primary mirrors are first co-aligned. The HRI secondary mirrors and focal planes positions are then adjusted to have an optimum interferometric cavity in each of these two channels. For that purpose a dedicated alignment test setup has been prepared, composed of a dummy focal plane assembly representing the detector position. Before the alignment on the flight optical bench, the overall alignment method has been validated on the Structural and Thermal Model, on a dummy bench using flight spare optics, then on the Qualification Model to be used for the system verification test and qualifications.

  17. Coatings.

    ERIC Educational Resources Information Center

    Anderson, Dennis G.

    1989-01-01

    This review covers analytical techniques applicable to the examination of coatings, raw materials, and substrates upon which coatings are placed. Techniques include chemical and electrochemical methods, chromatography, spectroscopy, thermal analysis, microscopy, and miscellaneous techniques. (MVL)

  18. Coatings.

    ERIC Educational Resources Information Center

    Anderson, Dennis G.

    1989-01-01

    This review covers analytical techniques applicable to the examination of coatings, raw materials, and substrates upon which coatings are placed. Techniques include chemical and electrochemical methods, chromatography, spectroscopy, thermal analysis, microscopy, and miscellaneous techniques. (MVL)

  19. Spectral reflectance properties of black chrome for use as a solar selective coating

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. E.

    1974-01-01

    The NASA-Lewis Research Center has determined that a widely available commercially electroplated decorative finish known as black chrome has desirable solar selective properties. Black chrome electroplated coating has high absorbtance in the solar spectrum and low emissivity in the 250 F blackbody thermal spectrum. The spectral reflectance properties of a commercially prepared black chrome on steel have been measured. Values are presented for reflectance of the black chrome, and compared with the reflectance of black paint and with two available samples of black nickel which had been prepared for solar selective properties. The reflectance of black chrome, of the two black nickels, and of black paint integrated over the solar spectrum for air mass 2 were 0.132, 0.123, 0.133, and 0.033, respectively. The reflectance of the black chrome, two black nickels, and of the black paint integrated over the blackbody spectrum for 250 F from 3 to 15 microns are 0.912, 0.934, 0.891, and 0.033, respectively. These reflectance measurements indicate absorptivity-to-emissivity values of 9.8, 13.8, 8.0, and 1.00, respectively.

  20. 17.1%-Efficient Multi-Scale-Textured Black Silicon Solar Cells without Dielectric Antireflection Coating

    SciTech Connect

    Toor, F.; Page, M. R.; Branz, H. M.; Yuan, H. C.

    2011-01-01

    In this work we present 17.1%-efficient p-type single crystal Si solar cells with a multi-scale-textured surface and no dielectric antireflection coating. Multi-scale texturing is achieved by a gold-nanoparticle-assisted nanoporous etch after conventional micron scale KOH-based pyramid texturing (pyramid black etching). By incorporating geometric enhancement of antireflection, this multi-scale texturing reduces the nanoporosity depth required to make silicon `black' compared to nanoporous planar surfaces. As a result, it improves short-wavelength spectral response (blue response), previously one of the major limiting factors in `black-Si' solar cells. With multi-scale texturing, the spectrum-weighted average reflectance from 350- to 1000-nm wavelength is below 2% with a 100-nm deep nanoporous layer. In comparison, roughly 250-nm deep nanopores are needed to achieve similar reflectance on planar surface. Here, we characterize surface morphology, reflectivity and solar cell performance of the multi-scale textured solar cells.

  1. Coating requirements for an ICF dry-wall design

    SciTech Connect

    Taylor, L.H.; Sucov, E.W.

    1981-06-30

    A new concept for protecting the first wall of an ICF reactor has been developed which relies heavily on a coating to protect the steel tubes which comprise the first wall. This coating must survive the pellet explosion, be ductile, and be compatible with the materials in the ICF pellet. Calculations indicate that tantalum is the best choice for the coating material and that tantalum coated steel tubes can handle fusion thermal powers of 3500 MW in a 10 m radius spherical chamber.

  2. Enhanced broadband and omni-directional performance of polycrystalline Si solar cells by using discrete multilayer antireflection coatings.

    PubMed

    Oh, Seung Jae; Chhajed, Sameer; Poxson, David J; Cho, Jaehee; Schubert, E Fred; Tark, Sung Ju; Kim, Donghwan; Kim, Jong Kyu

    2013-01-14

    The performance enhancement of polycrystalline Si solar cells by using an optimized discrete multilayer anti-reflection (AR) coating with broadband and omni-directional characteristics is presented. Discrete multilayer AR coatings are optimized by a genetic algorithm, and experimentally demonstrated by refractive-index tunable SiO₂ nano-helix arrays and co-sputtered (SiO₂)x(TiO₂)₁₋x thin film layers. The optimized multilayer AR coating shows a reduced total reflection, leading to the high incident-photon-to-electron conversion efficiency over a correspondingly wide range of wavelengths and incident angles, offering a very promising way to harvest more solar energy by virtually any type of solar cells for a longer time of a day.

  3. Design review of a liquid solar collector

    NASA Technical Reports Server (NTRS)

    Wiesewmaier, B. L.

    1979-01-01

    Report documents procedures, results, and recommendations for in-depth analysis of problems with liquid-filled version of concentric-tube solar collector. Problems are related to loss of vacuum and/or violent fracture of collector elements, fluid leakage, freezing, flow anomalies, manifold damage, and other component failures.

  4. Gas Turbine/Solar Parabolic Trough Hybrid Designs: Preprint

    SciTech Connect

    Turchi, C. S.; Ma, Z.; Erbes, M.

    2011-03-01

    A strength of parabolic trough concentrating solar power (CSP) plants is the ability to provide reliable power by incorporating either thermal energy storage or backup heat from fossil fuels. Yet these benefits have not been fully realized because thermal energy storage remains expensive at trough operating temperatures and gas usage in CSP plants is less efficient than in dedicated combined cycle plants. For example, while a modern combined cycle plant can achieve an overall efficiency in excess of 55%; auxiliary heaters in a parabolic trough plant convert gas to electricity at below 40%. Thus, one can argue the more effective use of natural gas is in a combined cycle plant, not as backup to a CSP plant. Integrated solar combined cycle (ISCC) systems avoid this pitfall by injecting solar steam into the fossil power cycle; however, these designs are limited to about 10% total solar enhancement. Without reliable, cost-effective energy storage or backup power, renewable sources will struggle to achieve a high penetration in the electric grid. This paper describes a novel gas turbine / parabolic trough hybrid design that combines solar contribution of 57% and higher with gas heat rates that rival that for combined cycle natural gas plants. The design integrates proven solar and fossil technologies, thereby offering high reliability and low financial risk while promoting deployment of solar thermal power.

  5. NASA advanced aeronautics design solar powered remotely piloted vehicle

    NASA Technical Reports Server (NTRS)

    Elario, David S.; Guillmette, Neal H.; Lind, Gregory S.; Webster, Jonathan D.; Ferreira, Michael J.; Konstantakis, George C.; Marshall, David L.; Windt, Cari L.

    1991-01-01

    Environmental problems such as the depletion of the ozone layer and air pollution demand a change in traditional means of propulsion that is sensitive to the ecology. Solar powered propulsion is a favorable alternative that is both ecologically harmless as well as cost effective. Integration of solar energy into designs ranging from futuristic vehicles to heating is beneficial to society. The design and construction of a Multi-Purpose Remotely Piloted Vehicle (MPRPV) seeks to verify the feasibility of utilizing solar propulsion as a primary fuel source. This task has been a year long effort by a group of ten students, divided into five teams, each dealing with different aspects of the design. The aircraft was designed to take-off, climb to the design altitude, fly in a sustained figure-eight flight path, and cruise for approximately one hour. This mission requires flight at Reynolds numbers between 150,000 and 200,000 and demands special considerations in the aerodynamic design in order to achieve flight in this regime. Optimal performance requires a light weight configuration with both structural integrity and maximum power availability. The structure design and choice of solar cells for the propulsion was governed by the weight, efficiency, and cost considerations. The final design is a MPRPV weighting 35 N which cruises 7 m/s at the design altitude of 50 m. The configuration includes a wing composed of balsa and foam NACA 6409 airfoil sections and carbon fiber spars, a tail of similar construction, and a truss structure fuselage. The propulsion system consists of 98 10 percent efficient solar cells donated by Mobil Solar, a NiCad battery for energy storage, and a folding propeller regulated by a lightweight and efficient control system. The airfoils and propeller chosen for the design were research and tested during the design process.

  6. Design of anti-reflection coating for spherical silicon photovoltaic devices

    NASA Astrophysics Data System (ADS)

    Gharghi, M.; Sivoththaman, S.

    2008-08-01

    Spherical silicon photovoltaic devices are bonded to flexible substrates to produce light-weight flexible solar modules. In order to maximize the conversion efficiency, the optical loss must be minimized. The concept of conventional anti reflection coating (ARC) does not directly apply to the spherical device due to different geometry. The optimum design of the ARC must maximize the optical power transmission from air to the Si crystal bulk. In addition to the refractive index and the thickness of the ARC, the power distribution on the exposed spherical surface, incidence angle dependent reflection, and multiple reflections at the spherical air-ARC and ARC-silicon interfaces also influence the ARC design. The effects of the spherical shape on the variations of the reflection are analyzed. It is shown that the optimum design is essentially different from the conventional ARC with uniform quarter-wavelength thickness. It is required that the design compensates the effect of variation of the incidence angle across the spherical surface. To achieve this, the thickness should have a zenith-angle dependence. Chemical vapor deposition techniques can potentially be employed for the deposition of the designed films.

  7. Implications of solar energy alternatives for community design

    SciTech Connect

    Santos, A.; Steinitz, C.

    1980-06-01

    A graduate-level studio at the Harvard School of Design explored how a policy of solar-based energy independence will influence the design of a new community of approximately 4500 housing units and other uses. Three large sites outside Tucson (a cooling problem), Atlanta (a humidity problem), and Boston (a heating problem) were selected. Each is typical of its region. A single program was assumed and designed for. Each site had two teams, one following a compact approach and one following a more dispersed approach. Each was free to choose the most appropriate mix of (solar) technology and scale, and was free to integrate energy and community in the design as it saw fit. These choice and integration issues are key areas where our experience may be of interest to those involved in community design and solar energy.

  8. High-Performance Fully Printable Perovskite Solar Cells via Blade-Coating Technique under the Ambient Condition

    SciTech Connect

    Yang, Zhibin; Chueh, Chu-Chen; Zuo, Fan; Kim, Jong H.; Liang, Po-Wei; Jen, Alex K. -Y.

    2015-04-30

    A fully printable perovskite solar cell (PVSC) is demonstrated using a blade-coating technique under ambient conditions with controlled humidity. The influence of humidity on perovskite's crystallization is systematically investigated to realize the ambient processing condition. A high power conversion efficiency of 10.44% is achieved after optimizing the blade-coating process and, more importantly, a high-performance flexible PVSC is demonstrated for the first time. A high efficiency of 7.14% is achieved.

  9. Design progress of the solar UV-Vis-IR telescope (SUVIT) aboard SOLAR-C

    NASA Astrophysics Data System (ADS)

    Katsukawa, Y.; Ichimoto, K.; Suematsu, Y.; Hara, H.; Kano, R.; Shimizu, T.; Matsuzaki, K.

    2013-09-01

    We present a design progress of the Solar UV-Vis-IR Telescope (SUVIT) aboard the next Japanese solar mission SOLAR-C. SUVIT has an aperture diameter of ~1.4 m for achieving spectro-polarimetric observations with spatial and temporal resolution exceeding the Hinode Solar Optical Telescope (SOT). We have studied structural and thermal designs of the optical telescope as well as the optical interface between the telescope and the focal plane instruments. The focal plane instruments are installed into two packages, filtergraph and spectrograph packages. The spectropolarimeter is the instrument dedicated to accurate polarimetry in the three spectrum windows at 525 nm, 854 nm, and 1083 nm for observing magnetic fields at both the photospheric and chromospheric layers. We made optical design of the spectrograph accommodating the conventional slit spectrograph and the integral field unit (IFU) for two-dimensional coverage. We are running feasibility study of the IFU using fiber arrays consisting of rectangular cores.

  10. Solar-Powered Europa Orbiter Design Study (2007)

    NASA Technical Reports Server (NTRS)

    Elliott, John; Langmaier, Jerry; Pappalardo, Robert; Strange, Nathan; Spilker, Tom; Lock, Rob; Reh, Kim

    2008-01-01

    The feasibility of implementing a solar-powered mission around Europa has been evaluated periodically over the last decade. Most recently, an assessment was performed as part of the 2006 Europa Explorer (EE) Study, which evaluated the practicality of implementing that mission design with large solar arrays instead of radioisotope power systems (RPS). This previous study went into some depth in considering the issues related to the use of solar arrays in the Europa orbit illumination and radiation environment. The study concluded that an all-solar option was impractical to meet the science objectives as defined in that study by the science team. This conclusion resulted from the prohibitive mass, packaging and articulation issues associated with the very large (approx.300 sq m) solar arrays required to accommodate frequent eclipse periods associated with the particular Europa orbit used.

  11. Solar-Powered Europa Orbiter Design Study (2007)

    NASA Technical Reports Server (NTRS)

    Elliott, John; Langmaier, Jerry; Pappalardo, Robert; Strange, Nathan; Spilker, Tom; Lock, Rob; Reh, Kim

    2008-01-01

    The feasibility of implementing a solar-powered mission around Europa has been evaluated periodically over the last decade. Most recently, an assessment was performed as part of the 2006 Europa Explorer (EE) Study, which evaluated the practicality of implementing that mission design with large solar arrays instead of radioisotope power systems (RPS). This previous study went into some depth in considering the issues related to the use of solar arrays in the Europa orbit illumination and radiation environment. The study concluded that an all-solar option was impractical to meet the science objectives as defined in that study by the science team. This conclusion resulted from the prohibitive mass, packaging and articulation issues associated with the very large (approx.300 sq m) solar arrays required to accommodate frequent eclipse periods associated with the particular Europa orbit used.

  12. Emerging Semitransparent Solar Cells: Materials and Device Design.

    PubMed

    Tai, Qidong; Yan, Feng

    2017-09-01

    Semitransparent solar cells can provide not only efficient power-generation but also appealing images and show promising applications in building integrated photovoltaics, wearable electronics, photovoltaic vehicles and so forth in the future. Such devices have been successfully realized by incorporating transparent electrodes in new generation low-cost solar cells, including organic solar cells (OSCs), dye-sensitized solar cells (DSCs) and organometal halide perovskite solar cells (PSCs). In this review, the advances in the preparation of semitransparent OSCs, DSCs, and PSCs are summarized, focusing on the top transparent electrode materials and device designs, which are all crucial to the performance of these devices. Techniques for optimizing the efficiency, color and transparency of the devices are addressed in detail. Finally, a summary of the research field and an outlook into the future development in this area are provided. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Truscott Brine Lake solar-pond system conceptual design

    NASA Astrophysics Data System (ADS)

    Leboeuf, C. M.; May, E. K.

    1982-08-01

    Discussed is a conceptual design study for a system of electricity-producing salt-gradient solar ponds that will provide power to a chloride control project under construction near Truscott, Tex. The chloride control project comprises a 1200-ha (3000-acre) brine impoundment lake to which brine will be pumped from several salty sources in the Wichita River basin. The solar ponds are formed by natural evaporation of the briny water pumped to Truscott. Heat is extraced from the solar ponds and used to drive organic Rankine-cycle generators. Ponds were sized to provide the pumping needs of the chloride control project and the maintenance requirements of the solar ponds. The system includes six solar pond modules for a total area of 63.1 ha, and produces 1290 kW of base load electricity. Although sized for continuous power production, alternative operating scenarios involving production of peak power for shorter durations were also examined.

  14. Metal-AlN cermet solar selective coatings deposited by direct current magnetron sputtering technology

    NASA Astrophysics Data System (ADS)

    Zhang, Qi-Chu

    1998-02-01

    A series of metal-aluminium nitride (M-AlN) cermet materials for solar selective coatings was deposited by a novel direct current (d.c.) magnetron sputtering technology. Aluminium nitride was used as the ceramic component in the cermets, and stainless steel (SS), nickel-based alloy 0022-3727/31/4/003/img1 (NiCr), molybdenum-based alloy 0022-3727/31/4/003/img2 (TZM) and tungsten were used as the metallic components. The aluminium nitride ceramic and metallic components of the cermets were deposited by simultaneously running both an aluminium target and another metallic target in a gas mixture of argon and nitrogen. The ceramic component was deposited by d.c. reactive sputtering and the metallic component by d.c. non-reactive sputtering. The total sputtering gas pressure was 0.8-1.0 Pa and the partial pressure of reactive nitrogen gas was set at 0.020-0.025 Pa which is sufficiently high to ensure that a nearly pure AlN ceramic sublayer was deposited by d.c. reactive sputtering. Because of the excellent nitriding resistance of stainless steel and the other alloys and metal, a nearly pure metallic sublayer was deposited by d.c. sputtering at this low nitrogen partial pressure. A multilayered system, consisting of alternating metallic and AlN ceramic sublayers, was deposited by substrate rotation. This multisublayer system can be considered as a macrohomogeneous cermet layer with metal volume fraction determined by controlling the thicknesses of metallic and ceramic sublayers. Following this procedure, M-AlN cermet solar selective coatings with a double cermet layer structure were deposited. The films of these selective surfaces have the following structure: a low metal volume fraction cermet layer is placed on a high metal volume fraction cermet layer which in turn is placed on an aluminium metal infrared reflection layer. The top surface layer consists of an aluminium nitride antireflection layer. A solar absorptance of 0.92-0.96 and a normal emittance of 0.03-0.05 at

  15. Design considerations for solar power satellites

    NASA Technical Reports Server (NTRS)

    Arndt, G. D.; Leopold, L.

    1978-01-01

    This report summarizes the performance characteristics of a conceptual solar power satellite (SPS) system with emphasis on the microwave power transmission system. The latest tradeoff studies on photovoltaic and thermal systems for converting solar energy into electricity at the satellite are reviewed. The microwave system, consisting of dc-RF amplifiers, a 1-km phased array, and a ground antenna/rectifier scheme is capable of delivering 5 GW of power to the commercial grid. The transmission efficiencies of smaller system sizes (down to 1 GW) are compared with that of the nominal 5 GW system. At present the frequency region of interest is the IMS (industrial, medical, and scientific) band at 2450 plus or minus 50 MHz. Economic and technical tradeoffs as a function of the microwave operating frequency are considered. Candidate dc-RF power converter tubes, including medium-power amplitrons, high-power klystrons, and low-power solid state amplifiers, are examined.

  16. Synchronous Deployed Solar Sail Subsystem Design Concept

    DTIC Science & Technology

    2007-04-01

    is actuated by rotating the central drum around which the masts, spars, and film are wrapped. Tensioned radial cords deterministically unfold the...Typical solar sail systems must rely heavily on tension -only members in order to maximize mass efficiency. For example, many baseline concepts consist...of a highly flexible membrane film suspended between cables.5,6,7,8 The structural compliance of these tension -only components renders them

  17. Design of wide-angle solar-selective absorbers using aperiodic metal-dielectric stacks.

    PubMed

    Sergeant, Nicholas P; Pincon, Olivier; Agrawal, Mukul; Peumans, Peter

    2009-12-07

    Spectral control of the emissivity of surfaces is essential in applications such as solar thermal and thermophotovoltaic energy conversion in order to achieve the highest conversion efficiencies possible. We investigated the spectral performance of planar aperiodic metal-dielectric multilayer coatings for these applications. The response of the coatings was optimized for a target operational temperature using needle-optimization based on a transfer matrix approach. Excellent spectral selectivity was achieved over a wide angular range. These aperiodic metal-dielectric stacks have the potential to significantly increase the efficiency of thermophotovoltaic and solar thermal conversion systems. Optimal coatings for concentrated solar thermal conversion were modeled to have a thermal emissivity <7% at 720K while absorbing >94% of the incident light. In addition, optimized coatings for solar thermophotovoltaic applications were modeled to have thermal emissivity <16% at 1750K while absorbing >85% of the concentrated solar radiation.

  18. Modified-DBR-based semi-omnidirectional multilayer anti-reflection coating for tandem solar cells

    NASA Astrophysics Data System (ADS)

    Ali, Bahrami; Shahram, Mohammadnejad; Nima Jouyandeh, Abkenar

    2014-02-01

    In this paper, multilayer antireflection coatings are designed by modifying the thickness of two and three paired layer distributed Bragg reflector (DBR) structure. Our proposed DBR-based structures show antireflection behaviors, in spite of the reflection treatment in traditional DBR structures. Firstly, the proposed structures are designed to be equivalent to the theoretical ideal triple-layer (TL) antireflection coating (ARC). Therefore, the problem of finding a suitable material for the middle layer of triple structure is solved. Simulation results show the significant equivalency for the reflectance of proposed structures to the ideal TL ARC at the same wavelengths and incident angles. Also, the design of the structure is changed in order to present the constant reflectance coefficient over a wide range of wavelengths. This structure enhances the omni-directionality of the multilayer ARC.

  19. Preliminary design of the INPE's Solar Vector Magnetograph

    NASA Astrophysics Data System (ADS)

    Vieira, L. E. A.; de Gonzalez, A. L. Clúa; Lago, A. Dal; Wrasse, C.; Echer, E.; Guarnieri, F. L.; Cardoso, F. Reis; Guerrero, G.; Costa, J. Rezende; Palacios, J.; Balmaceda, L.; Alves, L. Ribeiro; da Silva, L.; Costa, L. L.; Sampaio, M.; Soares, M. C. Rabello; Barbosa, M.; Domingues, M.; Rigozo, N.; Mendes, O.; Jauer, P.; Dallaqua, R.; Branco, R. H.; Stekel, T.; Gonzalez, W.; Kabata, W.

    2015-10-01

    We describe the preliminary design of a magnetograph and visible-light imager instrument to study the solar dynamo processes through observations of the solar surface magnetic field distribution. The instrument will provide measurements of the vector magnetic field and of the line-of-sight velocity in the solar photosphere. As the magnetic field anchored at the solar surface produces most of the structures and energetic events in the upper solar atmosphere and significantly influences the heliosphere, the development of this instrument plays an important role in reaching the scientific goals of The Atmospheric and Space Science Coordination (CEA) at the Brazilian National Institute for Space Research (INPE). In particular, the CEA's space weather program will benefit most from the development of this technology. We expect that this project will be the starting point to establish a strong research program on Solar Physics in Brazil. Our main aim is acquiring progressively the know-how to build state-of-the-art solar vector magnetograph and visible-light imagers for space-based platforms to contribute to the efforts of the solar-terrestrial physics community to address the main unanswered questions on how our nearby Star works.

  20. Analysis on design and performance of a solar rotary house

    NASA Astrophysics Data System (ADS)

    Fan, Xuhong; Zhang, Zhaochang; Yang, Fan; Cao, Lilin; Xu, Jing; Yuan, Mingyang

    2017-04-01

    A solar rotary house is designed, composed of rotating main structure, fixed cylinder, rotating drive system, solar photovoltaic system and so on, to achieve 360° rotation. Thus it can change the dark and humid situation of the traditional fixed house shade. Its bearing capacity, driving force and safety are analyzed. Rotary driving force and living energy are provided by solar photovoltaic system on roofs and walls. The Phonenics, Ecotect simulation analysis conclude that the rotating house indoor has better natural ventilation effect, more uniform lighting, better the sunshine time compared with traditional houses, becoming a green, energy-saving, comfortable building model.

  1. Innovative multilayer coatings for space solar physics: performances and stability over time

    NASA Astrophysics Data System (ADS)

    Zuppella, Paola; Corso, Alain J.; Nicolosi, Piergiorgio; Windt, David L.; Pelizzo, Maria G.

    2011-05-01

    Different solar mission are in progress and others are foreseen in the next future to study the structure and the dynamics of the Sun and its interaction with the Earth. Different instruments devoted to solar physics are required to have high reflecting MultiLayers (MLs) coatings. For example, the Multi Element Telescope for Imaging and Spectroscopy (METIS) coronograph will fly on board of SOLar Orbiter (SOLO) mission to perform simultaneous observation at 30.4 nm (He - II Lyman - α line), 121.6 nm (H - I Lyman - α line) and in the visible range, therefore its optics will require high performances in a wide spectral region. It should be desirable to reach higher reflectivity as well as long term stability and lifetime, then different candidate coatings will be considered. The Sounding - Rocket Coronographic Experiment (SCORE) is a prototype of METIS equipped with Mg/SiC optics and it has flown on board of a NASA sounding rocket. The Mg/SiC multilayers offer good performances in terms of reflectivity, but the long term stability and the lifetime have been preliminary investigated and there are open problems to be further studied. Besides standard Mo/Si multilayer, a possible alternative is represented by new multilayer structures based on well known Mo/Si stack in which the performances have been improved by superimposing innovative capping layers. Another alternative is represented by a recently developed multilayer based on an Ir/Si material couple. In this paper we review and compare the performances of such multilayer in all the spectral ranges of interest for SOLO.

  2. Abrams Primary School passive solar design. Phase 1. Final report

    SciTech Connect

    1980-01-01

    The general project documentation and the design process documentation for the project are presented. The following are appended: analysis of thermal transfer and internal heat contributions to the heating and cooling loads for a typical four-classroom teaching module using bin-chart temperature data, trace simulation for the original building design, Teanet simulation of original building design for the month of January 1959, Teanet simulation of Solar 2 for the month of January 1959, incremental solar cost assessment, and diffuse radiation incident on the monitor glass. (MHR)

  3. Preliminary design package for prototype solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A summary is given of the preliminary analysis and design activity on solar heating and cooling systems. The analysis was made without site specific data other than weather; therefore, the results indicate performance expected under these special conditions. Major items include a market analysis, design approaches, trade studies and other special data required to evaluate the preliminary analysis and design. The program calls for the development and delivery of eight prototype solar heating and cooling systems for installation and operational test. Two heating and six heating and cooling units will be delivered for Single Family Residences, Multiple-family Residences and commercial applications.

  4. Design, Fabrication and Test of a High Efficiency Refractive Secondary Concentrator for Solar Applications

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.; Geng, Steven M.; Castle, Charles H.; Macosko, Robert P.

    2000-01-01

    Common to many of the space applications that utilize solar thermal energy such as electric power conversion, thermal propulsion, and furnaces, is a need for highly efficient, solar concentration systems. An effort is underway to develop the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced primary concentrators, the refractive secondary concentrator enables very high system concentration ratios (10,000 to 1) and very high temperatures (greater than 2000 K). Presented is an overview of the effort at the NASA Glenn Research Center to evaluate the performance of a prototype single crystal sapphire refractive secondary concentrator and to compare the performance with analytical models. The effort involves the design and fabrication of a secondary concentrator, design and fabrication of a calorimeter and its support hardware, calibration of the calorimeter, testing of the secondary concentrator in NASA Glenn's Tank 6 solar thermal vacuum facility, and comparing the test results with predictions. Test results indicate an average throughput efficiency of 87%. It is anticipated that reduction of a known reflection loss with an anti-reflective coating would result in a secondary concentrator throughput efficiency of approximately 93%.

  5. Solar pond performance estimation, engineering design, and construction experience

    SciTech Connect

    Hull, J.R.

    1983-12-11

    A solar pond is a low-cost solar collector and storage device for low-temperature (less than 110/sup 0/C) heat. However, there are many design and construction details that must be considered to obtain the optimum efficiencies necessary to achieve economical performance. Several of these considerations, as well as a brief description of mathematical models for estimating performance, are discussed in this paper.

  6. Solar-heating and cooling system design package

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Package of information includes design data, performance specifications, drawings, hazard analysis, and spare parts list for commercially produced system installed in single-family dwelling in Akron, Ohio. System uses air flat-plate collectors, 12000 kg rock storage and backup heat pump. Solar portion requires 0.7 kW, and provides 35% of average total heating load including hot water. Information aids persons considering installing solar home-heating systems.

  7. Solar-heating and cooling system design package

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Package of information includes design data, performance specifications, drawings, hazard analysis, and spare parts list for commercially produced system installed in single-family dwelling in Akron, Ohio. System uses air flat-plate collectors, 12000 kg rock storage and backup heat pump. Solar portion requires 0.7 kW, and provides 35% of average total heating load including hot water. Information aids persons considering installing solar home-heating systems.

  8. Silica-sol-based spin-coating barrier layer against phosphorous diffusion for crystalline silicon solar cells.

    PubMed

    Uzum, Abdullah; Fukatsu, Ken; Kanda, Hiroyuki; Kimura, Yutaka; Tanimoto, Kenji; Yoshinaga, Seiya; Jiang, Yunjian; Ishikawa, Yasuaki; Uraoka, Yukiharu; Ito, Seigo

    2014-01-01

    The phosphorus barrier layers at the doping procedure of silicon wafers were fabricated using a spin-coating method with a mixture of silica-sol and tetramethylammonium hydroxide, which can be formed at the rear surface prior to the front phosphorus spin-on-demand (SOD) diffusion and directly annealed simultaneously with the front phosphorus layer. The optimization of coating thickness was obtained by changing the applied spin-coating speed; from 2,000 to 8,000 rpm. The CZ-Si p-type silicon solar cells were fabricated with/without using the rear silica-sol layer after taking the sheet resistance measurements, SIMS analysis, and SEM measurements of the silica-sol material evaluations into consideration. For the fabrication of solar cells, a spin-coating phosphorus source was used to form the n(+) emitter and was then diffused at 930°C for 35 min. The out-gas diffusion of phosphorus could be completely prevented by spin-coated silica-sol film placed on the rear side of the wafers coated prior to the diffusion process. A roughly 2% improvement in the conversion efficiency was observed when silica-sol was utilized during the phosphorus diffusion step. These results can suggest that the silica-sol material can be an attractive candidate for low-cost and easily applicable spin-coating barrier for any masking purpose involving phosphorus diffusion.

  9. Silica-sol-based spin-coating barrier layer against phosphorous diffusion for crystalline silicon solar cells

    NASA Astrophysics Data System (ADS)

    Uzum, Abdullah; Fukatsu, Ken; Kanda, Hiroyuki; Kimura, Yutaka; Tanimoto, Kenji; Yoshinaga, Seiya; Jiang, Yunjian; Ishikawa, Yasuaki; Uraoka, Yukiharu; Ito, Seigo

    2014-12-01

    The phosphorus barrier layers at the doping procedure of silicon wafers were fabricated using a spin-coating method with a mixture of silica-sol and tetramethylammonium hydroxide, which can be formed at the rear surface prior to the front phosphorus spin-on-demand (SOD) diffusion and directly annealed simultaneously with the front phosphorus layer. The optimization of coating thickness was obtained by changing the applied spin-coating speed; from 2,000 to 8,000 rpm. The CZ-Si p-type silicon solar cells were fabricated with/without using the rear silica-sol layer after taking the sheet resistance measurements, SIMS analysis, and SEM measurements of the silica-sol material evaluations into consideration. For the fabrication of solar cells, a spin-coating phosphorus source was used to form the n+ emitter and was then diffused at 930°C for 35 min. The out-gas diffusion of phosphorus could be completely prevented by spin-coated silica-sol film placed on the rear side of the wafers coated prior to the diffusion process. A roughly 2% improvement in the conversion efficiency was observed when silica-sol was utilized during the phosphorus diffusion step. These results can suggest that the silica-sol material can be an attractive candidate for low-cost and easily applicable spin-coating barrier for any masking purpose involving phosphorus diffusion.

  10. Silica-sol-based spin-coating barrier layer against phosphorous diffusion for crystalline silicon solar cells

    PubMed Central

    2014-01-01

    The phosphorus barrier layers at the doping procedure of silicon wafers were fabricated using a spin-coating method with a mixture of silica-sol and tetramethylammonium hydroxide, which can be formed at the rear surface prior to the front phosphorus spin-on-demand (SOD) diffusion and directly annealed simultaneously with the front phosphorus layer. The optimization of coating thickness was obtained by changing the applied spin-coating speed; from 2,000 to 8,000 rpm. The CZ-Si p-type silicon solar cells were fabricated with/without using the rear silica-sol layer after taking the sheet resistance measurements, SIMS analysis, and SEM measurements of the silica-sol material evaluations into consideration. For the fabrication of solar cells, a spin-coating phosphorus source was used to form the n+ emitter and was then diffused at 930°C for 35 min. The out-gas diffusion of phosphorus could be completely prevented by spin-coated silica-sol film placed on the rear side of the wafers coated prior to the diffusion process. A roughly 2% improvement in the conversion efficiency was observed when silica-sol was utilized during the phosphorus diffusion step. These results can suggest that the silica-sol material can be an attractive candidate for low-cost and easily applicable spin-coating barrier for any masking purpose involving phosphorus diffusion. PMID:25520602

  11. Design package for solar domestic hot water system

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The initial design of a solar domestic hot water system is considered. The system performance specification and detailed design drawings are included. The hot water systems consist of the following subsystems: collector, storage, control, transport, auxiliary energy, and government-furnished site data acquisition. The two systems are installed at Tempe, Arizona, and San Diego, California.

  12. Update on the Solar Power Satellite transmitter design

    SciTech Connect

    Brown, W.C.

    1986-01-01

    A number of remaining problems in the conceptual design of the transmitting antenna for the Solar Power Satellite have been solved as a result of additional technology development. Much of the technology was derived from the conceptual design of a ground-based transmitting antenna for beaming power to a high altitude airship or airplane.

  13. Cookin' with Sun: Design and Build Solar Cookers

    ERIC Educational Resources Information Center

    Brand, Lance; Warren, Ande; Fitzgerald, Mike

    2006-01-01

    Having students design and construct solar cookers is a great way to teach them about designing to meet human needs and about many basic global issues related to health and the environment. Because the activity includes solid content from the fields of math, science and technology, it is an excellent vehicle for technology educators who want to…

  14. Cookin' with Sun: Design and Build Solar Cookers

    ERIC Educational Resources Information Center

    Brand, Lance; Warren, Ande; Fitzgerald, Mike

    2006-01-01

    Having students design and construct solar cookers is a great way to teach them about designing to meet human needs and about many basic global issues related to health and the environment. Because the activity includes solid content from the fields of math, science and technology, it is an excellent vehicle for technology educators who want to…

  15. Solar Heating and Cooling of Residential Buildings: Design of Systems.

    ERIC Educational Resources Information Center

    Colorado State Univ., Ft. Collins. Solar Energy Applications Lab.

    This is the second of two training courses designed to develop the capability of practitioners in the home building industry to design solar heating and cooling systems. The course is organized in 23 modules to separate selected topics and to facilitate learning. Although a compact schedule of one week is shown, a variety of formats can be…

  16. Residential solar-heating system-design package

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Design package for modular solar heating system includes performance specifications, design data, installation guidelines, and other information that should be valuable to those interested in system (or similar systems) for projected installation. When installed in insulated "energy saver" home, system can supply large percentage of total energy needs of building.

  17. Residential solar-heating system-design package

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Design package for modular solar heating system includes performance specifications, design data, installation guidelines, and other information that should be valuable to those interested in system (or similar systems) for projected installation. When installed in insulated "energy saver" home, system can supply large percentage of total energy needs of building.

  18. Design, fabrication, and bench testing of a solar chemical receiver

    NASA Technical Reports Server (NTRS)

    Summers, W. A.; Pierre, J. F.

    1981-01-01

    Solar thermal energy can be effectively collected, transported, stored, and utilized by means of a chemical storage and transport system employing the reversible SO2 oxidation reaction. A solar chemical receiver for SO3 thermal decomposition to SO2 and oxygen was analyzed. Bench tests of a ten foot section of a receiver module were conducted with dissociated sulfuric acid (SO3 and H2O) in an electrical furnace. Measured percent conversion of SO3 was 85% of the equilibrium value. Methods were developed to fabricate and assemble a complete receiver module. These methods included applying an aluminide coating to certain exposed surfaces, assembling concentric tubes with a wire spacer, applying a platinum catalyst to the tubing wall, and coiling the entire assembly into the desired configuration.

  19. Advanced Silicon Solar Cell Device Physics and Design

    NASA Astrophysics Data System (ADS)

    Deceglie, Michael Gardner

    A fundamental challenge in the development and deployment of solar photovoltaic technology is a reduction in cost enabling direct competition with fossil-fuel-based energy sources. A key driver in this cost reduction is optimized device efficiency, because increased energy output leverages all photovoltaic system costs, from raw materials and module manufacturing to installation and maintenance. To continue progress toward higher conversion efficiencies, solar cells are being fabricated with increasingly complex designs, including engineered nanostructures, heterojunctions, and novel contacting and passivation schemes. Such advanced designs require a comprehensive and unified understanding of the optical and electrical device physics at the microscopic scale. This thesis focuses on a microscopic understanding of solar cell optoelectronic performance and its impact on cell optimization. We consider this in three solar cell platforms: thin-film crystalline silicon, amorphous/crystalline silicon heterojunctions, and thin-film cells with nanophotonic light trapping. The work described in this thesis represents a powerful design paradigm, based on a detailed physical understanding of the mechanisms governing solar cell performance. Furthermore, we demonstrate the importance of understanding not just the individual mechanisms, but also their interactions. Such an approach to device optimization is critical for the efficiency and competitiveness of future generations of solar cells.

  20. FGM (Functionally Graded Material) Thermal Barrier Coatings for Hypersonic Structures - Design and Thermal Structural Analysis

    DTIC Science & Technology

    2007-06-29

    1 AOARD REPORT Contract No. 064043 FGM (Functionally Graded Material) Thermal Barrier Coatings for Hypersonic Structures – Design and...Material) Thermal Barrier Coatings for Hypersonic Structures ? Design and Thermal Structural Analysis 5a. CONTRACT NUMBER FA48690610074 5b. GRANT...modeling. Additionally, the TBCs will be applied to realistic hypersonic structures such as a cylindrical combustor and tested under realistic combustion

  1. Optimization of the antireflection coating of thin epitaxial crystalline silicon solar cells

    SciTech Connect

    Selj, Josefine K.; Young, David; Grover, Sachit

    2015-08-28

    In this study we use an effective weighting function to include the internal quantum efficiency (IQE) and the effective thickness, Te, of the active cell layer in the optical modeling of the antireflection coating (ARC) of very thin crystalline silicon solar cells. The spectrum transmitted through the ARC is hence optimized for efficient use in the given cell structure and the solar cell performance can be improved. For a 2-μm thick crystalline silicon heterojunction solar cell the optimal thickness of the Indium Tin Oxide (ITO) ARC is reduced by ~8 nm when IQE data and effective thickness are taken into account compared to the standard ARC optimization, using the AM1.5 spectrum only. The reduced ARC thickness will shift the reflectance minima towards shorter wavelengths and hence better match the absorption of very thin cells, where the short wavelength range of the spectrum is relatively more important than the long, weakly absorbed wavelengths. For this cell, we find that the optimal thickness of the ITO starts at 63 nm for very thin (1 μm) active Si layer and then increase with increasing Te until it saturates at 71 nm for Te > 30 μm.

  2. Optimization of the antireflection coating of thin epitaxial crystalline silicon solar cells

    DOE PAGES

    Selj, Josefine K.; Young, David; Grover, Sachit

    2015-08-28

    In this study we use an effective weighting function to include the internal quantum efficiency (IQE) and the effective thickness, Te, of the active cell layer in the optical modeling of the antireflection coating (ARC) of very thin crystalline silicon solar cells. The spectrum transmitted through the ARC is hence optimized for efficient use in the given cell structure and the solar cell performance can be improved. For a 2-μm thick crystalline silicon heterojunction solar cell the optimal thickness of the Indium Tin Oxide (ITO) ARC is reduced by ~8 nm when IQE data and effective thickness are taken intomore » account compared to the standard ARC optimization, using the AM1.5 spectrum only. The reduced ARC thickness will shift the reflectance minima towards shorter wavelengths and hence better match the absorption of very thin cells, where the short wavelength range of the spectrum is relatively more important than the long, weakly absorbed wavelengths. For this cell, we find that the optimal thickness of the ITO starts at 63 nm for very thin (1 μm) active Si layer and then increase with increasing Te until it saturates at 71 nm for Te > 30 μm.« less

  3. MOS solar cells with oxides deposited by sol-gel spin-coating techniques

    SciTech Connect

    Huang, Chia-Hong; Chang, Chung-Cheng; Tsai, Jung-Hui

    2013-06-15

    The metal-oxide-semiconductor (MOS) solar cells with sol-gel derived silicon dioxides (SiO{sub 2}) deposited by spin coating are proposed in this study. The sol-gel derived SiO{sub 2} layer is prepared at low temperature of 450 Degree-Sign C. Such processes are simple and low-cost. These techniques are, therefore, useful for largescale and large-amount manufacturing in MOS solar cells. It is observed that the short-circuit current (I{sub sc}) of 2.48 mA, the open-circuit voltage (V{sub os}) of 0.44 V, the fill factor (FF) of 0.46 and the conversion efficiency ({eta}%) of 2.01% were obtained by means of the current-voltage (I-V) measurements under AM 1.5 (100 mW/cm{sup 2}) irradiance at 25 Degree-Sign C in the MOS solar cell with sol-gel derived SiO{sub 2}.

  4. Orbiting solar observatory battery and power design

    NASA Technical Reports Server (NTRS)

    Ford, F. E.; Bober, S.

    1977-01-01

    The OSO-1 represents a recent vintage satellite, or more recent design satellite. A summary of the battery design used on OSO-1 is presented. The temperature effects on voltage and charging-discharging of the battery system are discussed.

  5. Solar Power Tower Design Basis Document, Revision 0

    SciTech Connect

    ZAVOICO,ALEXIS B.

    2001-07-01

    This report contains the design basis for a generic molten-salt solar power tower. A solar power tower uses a field of tracking mirrors (heliostats) that redirect sunlight on to a centrally located receiver mounted on top a tower, which absorbs the concentrated sunlight. Molten nitrate salt, pumped from a tank at ground level, absorbs the sunlight, heating it up to 565 C. The heated salt flows back to ground level into another tank where it is stored, then pumped through a steam generator to produce steam and make electricity. This report establishes a set of criteria upon which the next generation of solar power towers will be designed. The report contains detailed criteria for each of the major systems: Collector System, Receiver System, Thermal Storage System, Steam Generator System, Master Control System, and Electric Heat Tracing System. The Electric Power Generation System and Balance of Plant discussions are limited to interface requirements. This design basis builds on the extensive experience gained from the Solar Two project and includes potential design innovations that will improve reliability and lower technical risk. This design basis document is a living document and contains several areas that require trade-studies and design analysis to fully complete the design basis. Project- and site-specific conditions and requirements will also resolve open To Be Determined issues.

  6. Solar Energy: Progress and Design Concerns of Nanostructured Solar Energy Harvesting Devices (Small 19/2016).

    PubMed

    Leung, Siu-Fung; Zhang, Qianpeng; Tavakoli, Mohammad Mahdi; He, Jin; Mo, Xiaoliang; Fan, Zhiyong

    2016-05-01

    Nanoengineered materials and structures can harvest light efficiently for photovoltaic applications. Device structure design optimization and material property improvement are equally important for high performance. On page 2536, X. Mo, Z. Fan, and co-workers summarize the design guidelines of solar energy harvesting devices to assist with a better understanding of device physics.

  7. Design approach for solar cell and battery of a persistent solar powered GPS tracker

    NASA Astrophysics Data System (ADS)

    Sahraei, Nasim; Watson, Sterling M.; Pennes, Anthony; Marius Peters, Ian; Buonassisi, Tonio

    2017-08-01

    Sensors with wireless communication can be powered by photovoltaic (PV) devices. However, using solar power requires thoughtful design of the power system, as well as a careful management of the power consumption, especially for devices with cellular communication (because of their higher power consumption). A design approach can minimize system size, weight, and/or cost, while maximizing device performance (data transmission rate and persistence). In this contribution, we describe our design approach for a small form-factor, solar-powered GPS tracker with cellular communication. We evaluate the power consumption of the device in different stages of operation. Combining measured power consumption and the calculated energy-yield of a solar cell, we estimate the battery capacity and solar cell area required for 5 years of continuous operation. We evaluate trade-offs between PV and battery size by simulating the battery state of charge. The data show a trade-off between battery capacity and solar-cell area for given target data transmission rate and persistence. We use this analysis to determine the combination of solar panel area and battery capacity for a given application and the data transmission rate that results in minimum cost or total weight of the system.

  8. Microstructural design of functionally graded coatings composed of suspension plasma sprayed hydroxyapatite and bioactive glass.

    PubMed

    Cattini, Andrea; Bellucci, Devis; Sola, Antonella; Pawłowski, Lech; Cannillo, Valeria

    2014-04-01

    Various bioactive glass/hydroxyapatite (HA) functional coatings were designed by the suspension plasma spraying (SPS) technique. Their microstructure, scratch resistance, and apatite-forming ability in a simulated body fluid (SBF) were compared. The functional coatings design included: (i) composite coating, that is, randomly distributed constituent phases; (ii) duplex coating with glass top layer onto HA layer; and (iii) graded coating with a gradual changing composition starting from pure HA at the interface with the metal substrate up to pure glass on the surface. The SPS was a suitable coating technique to produce all the coating designs. The SBF tests revealed that the presence of a pure glass layer on the working surface significantly improved the reactivity of the duplex and graded coatings, but the duplex coating suffered a relatively low scratch resistance because of residual stresses. The graded coating therefore provided the best compromise between mechanical reliability and apatite-forming ability in SBF. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 551-560, 2014.

  9. Facile and Low-Temperature Fabrication of Thermochromic Cr2O3/VO2 Smart Coatings: Enhanced Solar Modulation Ability, High Luminous Transmittance and UV-Shielding Function.

    PubMed

    Chang, Tianci; Cao, Xun; Li, Ning; Long, Shiwei; Gao, Xiang; Dedon, Liv R; Sun, Guangyao; Luo, Hongjie; Jin, Ping

    2017-08-09

    In the pursuit of energy efficient materials, vanadium dioxide (VO2) based smart coatings have gained much attention in recent years. For smart window applications, VO2 thin films should be fabricated at low temperature to reduce the cost in commercial fabrication and solve compatibility problems. Meanwhile, thermochromic performance with high luminous transmittance and solar modulation ability, as well as effective UV shielding function has become the most important developing strategy for ideal smart windows. In this work, facile Cr2O3/VO2 bilayer coatings on quartz glasses were designed and fabricated by magnetron sputtering at low temperatures ranging from 250 to 350 °C as compared with typical high growth temperatures (>450 °C). The bottom Cr2O3 layer not only provides a structural template for the growth of VO2 (R), but also serves as an antireflection layer for improving the luminous transmittance. It was found that the deposition of Cr2O3 layer resulted in a dramatic enhancement of the solar modulation ability (56.4%) and improvement of luminous transmittance (26.4%) when compared to single-layer VO2 coating. According to optical measurements, the Cr2O3/VO2 bilayer structure exhibits excellent optical performances with an enhanced solar modulation ability (ΔTsol = 12.2%) and a high luminous transmittance (Tlum,lt = 46.0%), which makes a good balance between ΔTsol and Tlum for smart windows applications. As for UV-shielding properties, more than 95.8% UV radiation (250-400 nm) can be blocked out by the Cr2O3/VO2 structure. In addition, the visualized energy-efficient effect was modeled by heating a beaker of water using infrared imaging method with/without a Cr2O3/VO2 coating glass.

  10. Materials characterization and design for solar-thermal propulsion

    NASA Astrophysics Data System (ADS)

    Delarosa, M. J.; Tuffias, R. H.

    1993-11-01

    Solar-thermal propulsion relies on the convection of concentrated solar energy into kinetic energy (in the exhaust gases) in order to provide thrust. Solar radiation is focused into a blackbody cavity in which the heat is absorbed and transferred to the hydrogen fuel through a thermal absorber/heat exchanger. Performance increases are obtained by increasing the efficiency of the absorber, thereby increasing the heat transfer to the hydrogen fuel. The absorber/exchanger itself provides structural properties, which involves the severe structural constraint of needing to withstand the high internal hydrogen pressure. Thus, the absorber/exchanger becomes the critical component in the thruster, and the enabling technology for the development of a successful solar-heated hydrogen propulsion system is a combination of materials and processing. The maximum operating temperature of a solar-thermal propulsion devices is governed primarily by the strength and resistance of hydrogen degradation of the constituent materials at the operating temperature of 3000 K and above. Six candidate refractory materials were selected for investigation with regard to their potential for use in solar-thermal propulsion, with the aim of developing a properties and processing database in advance of designing, fabricating, and testing a solar-powered rocket engine (SPRE).

  11. Dorsal skin necrosis secondary to a solar-induced thermal burn in a brown-coated dachshund.

    PubMed

    Sumner, Julia P; Pucheu-Haston, Cherie M; Fowlkes, Natalie; Merchant, Sandra

    2016-03-01

    A 5-year-old neutered male brown dachshund dog was presented for a large dorsal cutaneous burn that occurred following direct sunlight exposure outdoors in high ambient temperatures. Although burns are quite common in dogs, full-thickness solar-induced radiation burns are less common and have not been previously reported in animals without a black hair coat.

  12. Single-material zinc sulfide bi-layer antireflection coatings for GaAs solar cells.

    PubMed

    Leem, Jung Woo; Jun, Dong-Hwan; Heo, Jonggon; Park, Won-Kyu; Park, Jin-Hong; Cho, Woo Jin; Kim, Do Eok; Yu, Jae Su

    2013-09-09

    We demonstrated the efficiency improvement of GaAs single-junction (SJ) solar cells with the single-material zinc sulfide (ZnS) bi-layer based on the porous/dense film structure, which was fabricated by the glancing angle deposition (GLAD) method, as an antireflection (AR) coating layer. The porous ZnS film with a low refractive index was formed at a high incident vapor flux angle of 80° in the GLAD. Each optimum thickness of ZnS bi-layer was determined by achieving the lowest solar weighted reflectance (SWR) using a rigorous coupled-wave analysis method in the wavelength region of 350-900 nm, extracting the thicknesses of 20 and 50 nm for dense and porous films, respectively. The ZnS bi-layer with a low SWR of ~5.8% considerably increased the short circuit current density (J(sc)) of the GaAs SJ solar cell to 25.57 mA/cm(2), which leads to a larger conversion efficiency (η) of 20.61% compared to the conventional one without AR layer (i.e., SWR~31%, J(sc) = 18.81 mA/cm(2), and η = 14.82%). Furthermore, after the encapsulation, its J(sc) and η values were slightly increased to 25.67 mA/cm(2) and 20.71%, respectively. For the fabricated solar cells, angle-dependent reflectance properties and external quantum efficiency were also studied.

  13. Mariner 9 Solar Array Design, Manufacture, and Performance

    NASA Technical Reports Server (NTRS)

    Sequeira, E. A.

    1973-01-01

    The mission of Mariner 9, the first spacecraft to orbit another planet, was to make scientific observations of the surface of Mars. Throughout this unique mission, the Mariner 9 solar array successfully supported the power requirements of the spacecraft without experiencing anomalies. Basically, the design of the solar array was similar to those of Mariners 6 and 7; however, Mariner 9 had the additional flight operational requirement to perform in a Mars orbit environment mode. The array special tests provided information on the current-voltage characteristics and array space degradation. Tests indicated that total solar array current degradation was 3.5 percent, which could probably be attributed to the gradual degradation of the cover glass and/or the RTV 602 adhesive employed to cement the cover glass to the solar cell.

  14. Design and realization of an autonomous solar system

    NASA Astrophysics Data System (ADS)

    Gaga, A.; Diouri, O.; Es-sbai, N.; Errahimi, F.

    2017-03-01

    The aim of this work is the design and realization of an autonomous solar system, with MPPT control, a regulator charge/discharge of batteries, an H-bridge multi-level inverter with acquisition system and supervising based on a microcontroller. The proposed approach is based on developing a software platform in the LabVIEW environment which gives the system a flexible structure for controlling, monitoring and supervising the whole system in real time while providing power maximization and best quality of energy conversion from DC to AC power. The reliability of the proposed solar system is validated by the simulation results on PowerSim and experimental results achieved with a solar panel, a Lead acid battery, solar regulator and an H-bridge cascaded topology of single-phase inverter.

  15. Bates solar industrial process-steam application: preliminary design review

    SciTech Connect

    Not Available

    1980-01-07

    The design is analyzed for a parabolic trough solar process heat system for a cardboard corrugation fabrication facility in Texas. The program is briefly reviewed, including an analysis of the plant and process. The performance modeling for the system is discussed, and the solar system structural design, collector subsystem, heat transport and distribution subsystem are analyzed. The selection of the heat transfer fluid, and ullage and fluid maintenance are discussed, and the master control system and data acquisition system are described. Testing of environmental degradation of materials is briefly discussed. A brief preliminary cost analysis is included. (LEW)

  16. Phosphor coated NiO-based planar inverted organometallic halide perovskite solar cells with enhanced efficiency and stability

    NASA Astrophysics Data System (ADS)

    Cui, Jin; Li, Pengfei; Chen, Zhifan; Cao, Kun; Li, Dan; Han, Junbo; Shen, Yan; Peng, Mingying; Fu, Yong Qing; Wang, Mingkui

    2016-10-01

    This work investigates non-rare-earth phosphor (Sr4Al14O25:Mn4+, 0.5%Mg) with intensively red luminescence as a luminescent down-shifting layer for perovskite solar cells. The power conversion efficiency of the fabricated device with a structure of NiO/CH3NH3PbI3/[6,6]-phenyl C61-butyric acid methyl ester/Au coated with phosphor layer shows a 10% increase as compared with that of the control devices. Importantly, the phosphor layer coating can realize UV-protection as well as waterproof capability, achieving a reduced moisture-degradation of CH3NH3PbI3 perovskite upon applying an UV irradiation. Therefore, perovskite devices using this luminescent coating show a combined enhancement in both UV down-shifting conversion and long term stability. This can be expanded as a promising encapsulation technique in the perovskite solar cell community.

  17. Modeling the absorption behavior of solar thermal collector coatings utilizing graded alpha-C:H/TiC layers.

    PubMed

    Gruber, D P; Engel, G; Sormann, H; Schüler, A; Papousek, W

    2009-03-10

    Wavelength selective coatings are of common use in order to enhance the efficiency of devices heated by radiation such as solar thermal collectors. The use of suitable materials and the optimization of coating layer thicknesses are advisable ways to maximize the absorption. Further improvement is achievable by embedding particles in certain layers in order to modify material properties. We focus on optimizing the absorption behavior of a solar collector setup using copper as substrate, a layer of amorphous hydrogenated carbon with embedded titanium carbide particles (a-C:H/TiC), and an antireflection coating of amorphous silicon dioxide (aSiO(2)). For the setup utilizing homogeneous particle distribution, a relative absorption of 90.98% was found, while inhomogeneous particle embedding yielded 98.29%. These results are particularly interesting since until now, absorption of more than 95% was found only by using embedded Cr but not by using the more biocompatible Ti.

  18. Detailed Characterization of AR Coatings on Si Solar Cells: A New Application of GT-FabScan 6000; Preprint

    SciTech Connect

    Sopori, B.; Butterfield, B.; Amieva, J.

    2004-08-01

    We have developed a new application of GT-FabScan for rapid mapping of AR coatings on Si solar cells. The system generates an image of the AR thickness and presents it in a color format using false colors. This measurement is made in less than 100 ms. The development of this application enables the system to generate thickness maps of the AR coating to determine the repeatability of the deposition system, as well as to ensure that downstream processing can be controlled. These data can also be used to determine the average thickness of the coating. Downstream processing is an important issue in current solar cell technology. This paper describes its importance to the PV industry and discusses the principles and method of this measurement.

  19. Passive Solar Construction--Design and Performance.

    ERIC Educational Resources Information Center

    Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

    Presented is a list of books and reports intended to serve as technical sources of information for the building professional interested in energy conservation. These publications are grouped under these headings: (1) energy-conserving building design; (2) passive systems/design; (3) passive systems/performance; and (4) proceedings (of the American…

  20. Design review of the Brazilian Experimental Solar Telescope

    NASA Astrophysics Data System (ADS)

    Dal Lago, A.; Vieira, L. E. A.; Albuquerque, B.; Castilho, B.; Guarnieri, F. L.; Cardoso, F. R.; Guerrero, G.; Rodríguez, J. M.; Santos, J.; Costa, J. E. R.; Palacios, J.; da Silva, L.; Alves, L. R.; Costa, L. L.; Sampaio, M.; Dias Silveira, M. V.; Domingues, M. O.; Rockenbach, M.; Aquino, M. C. O.; Soares, M. C. R.; Barbosa, M. J.; Mendes, O., Jr.; Jauer, P. R.; Branco, R.; Dallaqua, R.; Stekel, T. R. C.; Pinto, T. S. N.; Menconi, V. E.; Souza, V. M. C. E. S.; Gonzalez, W.; Rigozo, N.

    2015-12-01

    The Brazilian's National Institute for Space Research (INPE), in collaboration with the Engineering School of Lorena/University of São Paulo (EEL/USP), the Federal University of Minas Gerais (UFMG), and the Brazilian's National Laboratory for Astrophysics (LNA), is developing a solar vector magnetograph and visible-light imager to study solar processes through observations of the solar surface magnetic field. The Brazilian Experimental Solar Telescope is designed to obtain full disk magnetic field and line-of-sight velocity observations in the photosphere. Here we discuss the system requirements and the first design review of the instrument. The instrument is composed by a Ritchey-Chrétien telescope with a 500 mm aperture and 4000 mm focal length. LCD polarization modulators will be employed for the polarization analysis and a tuning Fabry-Perot filter for the wavelength scanning near the Fe II 630.25 nm line. Two large field-of-view, high-resolution 5.5 megapixel sCMOS cameras will be employed as sensors. Additionally, we describe the project management and system engineering approaches employed in this project. As the magnetic field anchored at the solar surface produces most of the structures and energetic events in the upper solar atmosphere and significantly influences the heliosphere, the development of this instrument plays an important role in advancing scientific knowledge in this field. In particular, the Brazilian's Space Weather program will benefit most from the development of this technology. We expect that this project will be the starting point to establish a strong research program on Solar Physics in Brazil. Our main aim is to progressively acquire the know-how to build state-of-art solar vector magnetograph and visible-light imagers for space-based platforms.

  1. Photovoltaic characteristics of polymer solar cells fabricated by pre-metered coating process.

    PubMed

    Park, Byoungchoo; Han, Mi-Young

    2009-08-03

    We present the results of a study of flat and uniform poly(3-hexylthiophene):methanofullerene bulk-heterojunction photovoltaic (PV) layers that were produced by a simple pre-metered horizontal-dipping process for the fabrication of polymer solar cells (PSCs). It is shown that this process can produce high quality and thin films by utilizing the downstream meniscus of the solution, which can be controlled by adjusting experimental parameters of the gap height and the carrying speed. It is also shown that the produced PV film exhibits high power conversion efficiency of ca. 4.2% with a large active area. It was demonstrated that this pre-metered process for solution coating may be promising for achieving highly efficient, reliable, and large-area PSCs.

  2. Ag-Coated Heterostructures of ZnO-TiO2/Delaminated Montmorillonite as Solar Photocatalysts

    PubMed Central

    Hinojosa, Mariana; Tobajas, Montserrat; Alvarez, Maria Ariadna; Rodríguez-González, Vicente; Rodriguez, Juan Jose

    2017-01-01

    Heterostructures based on ZnO-TiO2/delaminated montmorillonite coated with Ag have been prepared by sol–gel and photoreduction procedures, varying the Ag and ZnO contents. They have been thoroughly characterized by XRD, WDXRF, UV–Vis, and XPS spectroscopies, and N2 adsorption, SEM, and TEM. In all cases, the montmorillonite was effectively delaminated with the formation of TiO2 anatase particles anchored on the clay layer’s surface, yielding porous materials with high surface areas. The structural and textural properties of the heterostructures synthesized were unaffected by the ZnO incorporated. The photoreduction led to solids with Ag nanoparticles decorating the surface. These materials were tested as photocatalysts for the degradation of several emerging contaminants with different nitrogen-bearing chemical structures under solar light. The catalysts yielded high rates of disappearance of the starting pollutants and showed quite stable performance upon successive applications. PMID:28817106

  3. Single-material multilayer ZnS as anti-reflective coating for solar cell applications

    NASA Astrophysics Data System (ADS)

    Salih, Ammar T.; Najim, Aus A.; Muhi, Malek A. H.; Gbashi, Kadhim R.

    2017-04-01

    Multilayer Zinc Sulfide (ZnS) is a promising low cost antireflective coating for solar cell applications, in this work; thin films with novel structure containing cubic and hexagonal phases were successfully deposited by thermal evaporation technique with three different layers. XRD analysis confirms the existence of both phases and high specific surface area. AFM analysis reveals that films with three layers have lower roughness and average grain size than other films. The optical measurements obtained by UV-vis, the calculated values of refractive index and reflectivity using some well known refractive index-band gap relations indicate that thin films with triple layer TL-ZnS have lower refractive index and reflectivity than other films, empirical equations were suggested and show the quantum confinement effects on band gap and reflectivity.

  4. Ag-Coated Heterostructures of ZnO-TiO₂/Delaminated Montmorillonite as Solar Photocatalysts.

    PubMed

    Belver, Carolina; Hinojosa, Mariana; Bedia, Jorge; Tobajas, Montserrat; Alvarez, Maria Ariadna; Rodríguez-González, Vicente; Rodriguez, Juan Jose

    2017-08-17

    Heterostructures based on ZnO-TiO₂/delaminated montmorillonite coated with Ag have been prepared by sol-gel and photoreduction procedures, varying the Ag and ZnO contents. They have been thoroughly characterized by XRD, WDXRF, UV-Vis, and XPS spectroscopies, and N₂ adsorption, SEM, and TEM. In all cases, the montmorillonite was effectively delaminated with the formation of TiO₂ anatase particles anchored on the clay layer's surface, yielding porous materials with high surface areas. The structural and textural properties of the heterostructures synthesized were unaffected by the ZnO incorporated. The photoreduction led to solids with Ag nanoparticles decorating the surface. These materials were tested as photocatalysts for the degradation of several emerging contaminants with different nitrogen-bearing chemical structures under solar light. The catalysts yielded high rates of disappearance of the starting pollutants and showed quite stable performance upon successive applications.

  5. Dip coated nanocrystalline CdZnS thin films for solar cell application

    NASA Astrophysics Data System (ADS)

    Dongre, J. K.; Chaturvedi, Mahim; Patil, Yuvraj; Sharma, Sandhya; Jain, U. K.

    2015-07-01

    Nanocrystalline cadmium sulfide (CdS) and zinc cadmium sulfide (ZnCdS) thin films have been grown via simple and low cost dip coating technique. The prepared films are characterized by X-ray diffraction (XRD), atomic force microscopic (AFM) and UV-VIS spectrophotometer techniques to reveal their structural, morphological and optical properties. XRD shows that both samples grown have zinc blende structure. The grain size is calculated as 6.2 and 8 nm using Scherrer's formula. The band gap value of CdS and CdZnS film is estimated to be 2.58 and 2.69 eV respectively by UV-vis spectroscopy. Photoelectrochemical (PEC) investigations are carried out using cell configuration as n-CdZnS/(1M NaOH + 1M Na2S + 1M S)/C. The photovoltaic output characteristic is used to calculate fill-factor (FF) and solar conversion efficiency (η).

  6. Cocktails of paste coatings for performance enhancement of CuInGaS(2) thin-film solar cells.

    PubMed

    An, Hee Sang; Cho, Yunae; Park, Se Jin; Jeon, Hyo Sang; Hwang, Yun Jeong; Kim, Dong-Wook; Min, Byoung Koun

    2014-01-22

    To fabricate low-cost and printable wide-bandgap CuInxGa1-xS2 (CIGS) thin-film solar cells, a method based on a precursor solution was developed. In particular, under this method, multiple coatings with two pastes with different properties (e.g., viscosity) because of the different binder materials added were applied. Paste A could form a thin, dense layer enabling a high-efficiency solar cell but required several coating and drying cycles for the desired film thickness. On the other hand, paste B could easily form one-micrometer-thick films by means of a one-time spin-coating process but the porous microstructure limited the solar cell performance. Three different configurations of the CIGS films (A + B, B + A, and A + B + A) were realized by multiple coatings with the two pastes to find the optimal stacking configuration for a combination of the advantages of each paste. Solar cell devices using these films showed a notable difference in their photovoltaic characteristics. The bottom dense layer increased the minority carrier diffusion length and enhanced the short-circuit current. The top dense layer could suppress interface recombination but exhibited a low optical absorption, thereby decreasing the photocurrent. As a result, the A + B configuration could be suggested as a desirable simple stacking structure. The solar cell with A + B coating showed a highly improved efficiency (4.66%) compared to the cell with a film prepared by paste B only (2.90%), achieved by simple insertion of a single thin (200 nm), dense layer between the Mo back contact and a thick porous CIGS layer.

  7. Thermal and cost goal analysis for passive solar heating designs

    SciTech Connect

    Noll, S.A.; Kirschner, C.

    1980-01-01

    Economic methodologies developed over the past several years for the design of residential solar systems have been based on life cycle cost (LCC) minimization. Because of uncertainties involving future economic conditions and the varied decision making processes of home designers, builders, and owners, LCC design approaches are not always appropriate. To deal with some of the constraints that enter the design process, and to narrow the number of variables to those that do not depend on future economic conditions, a simplified thermal and cost goal approach for passive designs is presented. Arithmetic and graphical approaches are presented with examples given for each. Goals discussed include simple payback, solar savings fraction, collection area, maximum allowable construction budget, variable cost goals, and Btu savings.

  8. Precise Morphology Control and Continuous Fabrication of Perovskite Solar Cells Using Droplet-Controllable Electrospray Coating System.

    PubMed

    Hong, Seung Chan; Lee, Gunhee; Ha, Kyungyeon; Yoon, Jungjin; Ahn, Namyoung; Cho, Woohyung; Park, Mincheol; Choi, Mansoo

    2017-03-08

    Herein, we developed a novel electrospray coating system for continuous fabrication of perovskite solar cells with high performance. Our system can systemically control the size of CH3NH3PbI3 precursor droplets by modulating the applied electrical potential, shown to be a crucial factor for the formation of perovskite films. As a result, we have obtained pinhole-free and large grain-sized perovskite solar cells, yielding the best PCE of 13.27% with little photocurrent hysteresis. Furthermore, the average PCE through the continuous coating process was 11.56 ± 0.52%. Our system demonstrates not only the high reproducibility but also a new way to commercialize high-quality perovskite solar cells.

  9. Design of Albumin-Coated Microbubbles Loaded With Polylactide Nanoparticles.

    PubMed

    Gauthier, Marianne; Yin, Qian; Cheng, Jianjun; O'Brien, William D

    2015-08-01

    A protocol was designed to produce albumin-coated microbubbles (MBs) loaded with functionalized polylactide (PLA) nanoparticles (NPs) for future drug delivery studies. Microbubbles resulted from the sonication of 5% bovine serum albumin and 15% dextrose solution. Functionalized NPs were produced by mixing fluorescent PLA and PLA-polyethylene glycol-carboxylate conjugates. Nanoparticle-loaded MBs resulted from the covalent conjugation of functionalized NPs and MBs. Three NP/MB volume ratios (1/1, 1/10, and 1/100) and unloaded MBs were produced and compared. Statistical evaluations were based on quantitative analysis of 3 parameters at 4 time points (1, 4, 5, and 6 days post MB fabrication): MB diameter using a circle detection routine based on the Hough transform, MB number density using a hemocytometer, and NP-loading yield based on MB counts from fluorescence and light microscopic images. Loading capacity of the albumin-coated MBs was evaluated by fluorescence. Loaded MB sizes were stable over 6 days after production and were not significantly different from that of time-matched unloaded MBs. Number density evaluation showed that only 1/1 NP/MB volume ratio and unloaded MB number densities were stable over time, and that the 1/1 MB number density evaluated at each time point was not significantly different from that of unloaded MBs. The 1/10 and 1/100 NP/MB volume ratios had unstable number densities that were significantly different from that of unloaded MBs (P < .05). Fluorescence evaluation suggested that 1/1 MBs had a higher NP-loading yield than 1/10 and 1/100 MBs. Quantitative loading evaluation suggested that the 1/1 MBs had a loading capacity of 3700 NPs/MB. A protocol was developed to load albumin MBs with functionalized PLA NPs for further drug delivery studies. The 1/1 NP/MB volume ratio appeared to be the most efficient to produce stable loaded MBs with a loading capacity of 3700 NPs/MB. © 2015 by the American Institute of Ultrasound in Medicine.

  10. Design of Albumin-Coated Microbubbles Loaded With Polylactide Nanoparticles

    PubMed Central

    Gauthier, Marianne; Yin, Qian; Cheng, Jianjun; O'Brien, William D.

    2015-01-01

    Objectives A protocol was designed to produce albumin-coated microbubbles (MBs) loaded with functionalized polylactide (PLA) nanoparticles (NPs) for future drug delivery studies. Methods Microbubbles resulted from the sonication of 5% bovine serum albumin and 15% dextrose solution. Functionalized NPs were produced by mixing fluorescent PLA and PLA-polyethylene glycol-carboxylate conjugates. Nanoparticle-loaded MBs resulted from the covalent conjugation of functionalized NPs and MBs. Three NP/MB volume ratios (1/1, 1/10, and 1/100) and unloaded MBs were produced and compared. Statistical evaluations were based on quantitative analysis of 3 parameters at 4 time points (1, 4, 5, and 6 days post MB fabrication): MB diameter using a circle detection routine based on the Hough transform, MB number density using a hemocytometer, and NP-loading yield based on MB counts from fluorescence and light microscopic images. Loading capacity of the albumin-coated MBs was evaluated by fluorescence. Results Loaded MB sizes were stable over 6 days after production and were not significantly different from that of time-matched unloaded MBs. Number density evaluation showed that only 1/1 NP/MB volume ratio and unloaded MB number densities were stable over time, and that the 1/1 MB number density evaluated at each time point was not significantly different from that of unloaded MBs. The 1/10 and 1/100 NP/MB volume ratios had unstable number densities that were significantly different from that of unloaded MBs (P < .05). Fluorescence evaluation suggested that 1/1 MBs had a higher NP-loading yield than 1/10 and 1/100 MBs. Quantitative loading evaluation suggested that the 1/1 MBs had a loading capacity of 3700 NPs/MB. Conclusions A protocol was developed to load albumin MBs with functionalized PLA NPs for further drug delivery studies. The 1/1 NP/MB volume ratio appeared to be the most efficient to produce stable loaded MBs with a loading capacity of 3700 NPs/MB. PMID:26206822

  11. Advanced solar concentrator: Preliminary and detailed design

    NASA Technical Reports Server (NTRS)

    Bell, D. M.; Maraschin, R. A.; Matsushita, M. T.; Erskine, D.; Carlton, R.; Jakovcevic, A.; Yasuda, A. K.

    1981-01-01

    A single reflection point focusing two-axis tracking paraboloidal dish with a reflector aperture diameter of approximately 11 m has a reflective surface made up of 64 independent, optical quality gores. Each gore is a composite of a thin backsilvered mirror glass face sheet continuously bonded to a contoured substrate of lightweight, rigid cellular glass. The use of largely self-supporting gores allows a significant reduction in the weight of the steel support structure as compared to alternate design concepts. Primary emphasis in the preliminary design package for the low-cost, low-weight, mass producible concentrator was placed on the design of the higher cost subsystems. The outer gore element was sufficiently designed to allow fabrication of prototype gores.

  12. Design and monitoring of a passive solar mobile home

    SciTech Connect

    Schiller, S.; Gumerlock, A.

    1982-01-01

    The project reported was to design and build a prototype mobile home which would use substantially less energy than conventional designs. The final design employs a shaded south-facing clerestory window. During the heating season, the clerestory window allows solar energy to heat Glauber's salts contained in laminated plastic bags. During the cooling season the attic space is ventilated at night with outside air to cool the Glauber's salts. The bags lie on top of highly conductive ceiling panels through which heat is tranferred to or from the living space. The design was compared with a conventional mobile home design using computer simulation and life cycle cost analysis for three locations. (LEW)

  13. Design package for concentrating solar collector panels

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Information used to evaluate the design of the Northrup concentrating collector is presented. Included are the system performance specifications, the applications manual, and the detailed design drawings of the collector. The collector is a water/glycol/working fluid type, with a dipped galvanized steel housing, transparent acrylic Fresnel lens cover, copper absorber tube, and fiber glass insulation. It weights 98 pounds. A collector assembly includes four collector units within a tracking mount array.

  14. Ultraviolet antireflection coatings for use in silicon detector design

    SciTech Connect

    Hamden, Erika T.; Greer, Frank; Hoenk, Michael E.; Blacksberg, Jordana; Dickie, Matthew R.; Nikzad, Shouleh; Martin, D. Christopher; Schiminovich, David

    2011-07-20

    We report on the development of coatings for a charged-coupled device (CCD) detector optimized for use in a fixed dispersion UV spectrograph. Because of the rapidly changing index of refraction of Si, single layer broadband antireflection (AR) coatings are not suitable to increase quantum efficiency at all wavelengths of interest. Instead, we describe a creative solution that provides excellent performance over UV wavelengths. We describe progress in the development of a coated CCD detector with theoretical quantum efficiencies (QEs) of greater than 60% at wavelengths from 120 to 300 nm. This high efficiency may be reached by coating a backside-illuminated, thinned, delta-doped CCD with a series of thin film AR coatings. The materials tested include MgF{sub 2} (optimized for highest performance from 120-150 nm), SiO{sub 2} (150-180 nm), Al{sub 2}O{sub 3} (180-240 nm), MgO (200-250 nm), and HfO{sub 2} (240-300 nm). A variety of deposition techniques were tested and a selection of coatings that minimized reflectance on a Si test wafer were applied to functional devices. We also discuss future uses and improvements, including graded and multilayer coatings.

  15. Ultraviolet antireflection coatings for use in silicon detector design.

    PubMed

    Hamden, Erika T; Greer, Frank; Hoenk, Michael E; Blacksberg, Jordana; Dickie, Matthew R; Nikzad, Shouleh; Martin, D Christopher; Schiminovich, David

    2011-07-20

    We report on the development of coatings for a charged-coupled device (CCD) detector optimized for use in a fixed dispersion UV spectrograph. Because of the rapidly changing index of refraction of Si, single layer broadband antireflection (AR) coatings are not suitable to increase quantum efficiency at all wavelengths of interest. Instead, we describe a creative solution that provides excellent performance over UV wavelengths. We describe progress in the development of a coated CCD detector with theoretical quantum efficiencies (QEs) of greater than 60% at wavelengths from 120 to 300 nm. This high efficiency may be reached by coating a backside-illuminated, thinned, delta-doped CCD with a series of thin film AR coatings. The materials tested include MgF(2) (optimized for highest performance from 120-150 nm), SiO(2) (150-180 nm), Al(2)O(3) (180-240 nm), MgO (200-250 nm), and HfO(2) (240-300 nm). A variety of deposition techniques were tested and a selection of coatings that minimized reflectance on a Si test wafer were applied to functional devices. We also discuss future uses and improvements, including graded and multilayer coatings.

  16. Ultraviolet antireflection coatings for use in silicon detector design

    NASA Astrophysics Data System (ADS)

    Hamden, Erika T.; Greer, Frank; Hoenk, Michael E.; Blacksberg, Jordana; Dickie, Matthew R.; Nikzad, Shouleh; Martin, D. Christopher; Schiminovich, David

    2011-07-01

    We report on the development of coatings for a charged-coupled device (CCD) detector optimized for use in a fixed dispersion UV spectrograph. Because of the rapidly changing index of refraction of Si, single layer broadband antireflection (AR) coatings are not suitable to increase quantum efficiency at all wavelengths of interest. Instead, we describe a creative solution that provides excellent performance over UV wavelengths. We describe progress in the development of a coated CCD detector with theoretical quantum efficiencies (QEs) of greater than 60% at wavelengths from 120 to 300nm. This high efficiency may be reached by coating a backside-illuminated, thinned, delta-doped CCD with a series of thin film AR coatings. The materials tested include MgF2 (optimized for highest performance from 120--150nm), SiO2 (150--180nm), Al2O3 (180--240nm), MgO (200--250nm), and HfO2 (240--300nm). A variety of deposition techniques were tested and a selection of coatings that minimized reflectance on a Si test wafer were applied to functional devices. We also discuss future uses and improvements, including graded and multilayer coatings.

  17. Atomic oxygen interaction with solar array blankets at protective coating defect sites

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Auer, Bruce M.; Rutledge, Sharon K.; Hill, Carol M.

    1991-01-01

    Atomic oxygen in the low-Earth-orbital environment oxidizes SiOx protected polyimide Kapton solar array blankets at sites which are not protected such as pin windows or scratches in the protective coatings. The magnitude and shape of the atomic oxygen undercutting which occurs at these sites is dependent upon the exposure environment details such as arrival direction and reaction probability. The geometry of atomic oxygen undercutting at defect sites exposed to atomic oxygen in plasma asher was used to develop a Monte Carlo model to simulate atomic oxygen erosion processes at defect sites in protected Kapton. Comparisons of Monte Carlo predictions and experimental results are presented for plasma asher atomic oxygen exposures for large and small defects as well as for protective coatings on one or both sides of Kapton. The model is used to predict in-space exposure results at defect sites for both directed and sweeping atomic oxygen exposure. A comparison of surface textures predicted by the Monte Carlo model and those experimentally observed from both directed space ram and laboratory plasma asher atomic oxygen exposure indicate substantial agreement.

  18. The use of trivalent chromium bath to obtain a solar selective black chromium coating

    NASA Astrophysics Data System (ADS)

    Survilienė, S.; Češūnienė, A.; Juškėnas, R.; Selskienė, A.; Bučinskienė, D.; Kalinauskas, P.; Juškevičius, K.; Jurevičiūtė, I.

    2014-06-01

    Black chromium coatings were electrodeposited from a trivalent chromium bath using a ZnO additive as a second main component. Black chromium was electrodeposited on steel and copper plates and substrates plated with bright nickel prior to black chromium electrodeposition. The black chromium coatings were characterized by XRD and SEM. The XRD data suggest that the phase structure of black chromium may be defined as a zinc solid solution in chromium or a chromium solid solution in zinc depending on the chromium/zinc ratio in the deposit. The role of substrate finish was evaluated through the corrosion resistance and reflectance of black chromium. According to corrosion tests the samples plated with bright nickel prior to black chromium deposition have shown the highest corrosion resistance. The electrodeposited black chromium possesses good optical properties for the absorption of solar energy. The absorption coefficient of black chromium was found to be over 0.99 for the samples obtained without the Ni undercoat and below 0.99 for those obtained with the use of Ni undercoat. However, the use of nickel undercoat before black chromium plating is recommended because it remarkably improves the corrosion resistance of samples.

  19. Mechanical design of the solar telescope GREGOR

    NASA Astrophysics Data System (ADS)

    Volkmer, R.; Eisenträger, P.; Emde, P.; Fischer, A.; von der Lühe, O.; Nicklas, H.; Soltau, D.; Schmidt, W.; Weis, U.

    2012-11-01

    The mechanical structure of the GREGOR telescope was installed at the Observatorio del Teide, Tenerife, in 2004. New concepts for mounting and cooling of the 1.5-meter primary mirror were introduced. GREGOR is an open telescope, therefore the dome is completely open during observations to allow for air flushing through the open, but stiff telescope structure. Backside cooling system of the primary mirror keeps the mirror surface close to ambient temperature to prevent mirror seeing. The large collecting area of the primary mirror results in high energy density at the field stop at the prime focus of the primary which needs to be removed. The optical elements are supported by precision alignment systems and should provide a stable solar image at the optical lab. The coudé train can be evacuated and serves as a natural barrier between the outer environmental conditions and the air-conditioned optical laboratory with its sensitive scientific instrumentation. The telescope was successfully commissioned and will start its nominal operation during 2013.

  20. Development and testing of high temperature coatings for the Integrated Solar Upper Stage thermal energy storage system

    NASA Astrophysics Data System (ADS)

    Miles, Barry J.

    1997-01-01

    Key components within the Integrated Solar Upper Stage (ISUS) bimodal system must be able to operate at temperatures as high as 2500 K within both hard vacuum and hot hydrogen environments. Graphite has been selected as the primary thermal energy storage device for ISUS system level and engine ground demonstration testing. The selection of graphite dictated the need for development and testing of high temperature coatings to identify a candidate that can maintain structural integrity at elevated temperatures, be compatible with graphite, and mitigate carbon loss from the graphite. This paper presents the methodology and test results that led to selection of rhenium as the coating material. Vacuum and hydrogen flow tests conducted between 2000 K and 2600 K on rhenium coated graphite coupons indicate mass loss reductions as much as one order of magnitude lower than unprotected graphite under similar temperatures, pressures, hydrogen flowrates, and exposure durations. The durability of rhenium coatings up to 0.381 mm thick was also demonstrated.

  1. Metal-dielectric frequency-selective surface for high performance solar window coatings

    NASA Astrophysics Data System (ADS)

    Toor, Fatima; Guneratne, Ananda C.; Temchenko, Marina

    2016-03-01

    We demonstrate a solar control window film consisting of metallic nanoantennas designed to reflect infrared (IR) light while allowing visible light to pass through. The film consists of a capacitive frequency-selective surface (CFSS) which acts as a band-stop filter, reflecting only light at target wavelengths. The designed CFSS when installed on windows will lower air conditioning costs by reflecting undesired wavelengths of light and thus reduce the amount of heat that enters a building. State-of-the-art commercial solar control films consist of a multilayer stack which is costly ( 13/m2 to 40/m2) to manufacture and absorbs IR radiation, causing delamination or glass breakage when attached to windows. Our solar control film consists of a nanostructured metallic layer on a polyethylene terephthalate (PET) substrate that reflects IR radiation instead of absorbing it, solving the delamination problem. The CFSS is also easy to manufacture with roll-to-roll nanoimprint lithography at a cost of <$12/m2. We design the CFSS using the COMSOL Wave Optics module to solve for electromagnetic wave propagation in optical media via the finite element method. The simulation domain is reduced to a single unit cell with periodic boundary conditions to account for the symmetries of the planar, periodic CFSS. The design is optimized using parametric sweeps around the various geometric components of the metallic nanoantenna. Our design achieves peak reflection of 80% at 1000 nm and has a broadband IR response that will allow for optimum solar control without significantly affecting the transmission of visible light.

  2. Design of Solar Heat Sheet for Air Heaters

    NASA Astrophysics Data System (ADS)

    Priya, S. Shanmuga; Premalatha, M.; Thirunavukkarasu, I.

    2011-12-01

    The technique of harnessing solar energy for drying offers significant potential to dry agricultural products such as food grains, fruits, vegetables and medicinal plants, thereby eliminating many of the problems experienced with open-sun drying and industrial drying, besides saving huge quantities of fossil fuels. A great deal of experimental work over the last few decades has already demonstrated that agricultural products can be satisfactorily dehydrated using solar energy. Various designs of small scale solar dryers have been developed in the recent past, mainly for drying agricultural products. Major problems experienced with solar dryers are their non-reliability as their operation largely depends on local weather conditions. While back-up heaters and hybrid dryers partly solved this issue, difficulties in controlling the drying air temperature and flow rate remains a problem, and affects the quality of the dried product. This study is aimed at eliminating the fluctuations in the quality of hot air supplied by simple solar air heaters used for drying fruits, vegetables and other applications. It is an attempt to analyse the applicability of the combination of an glazed transpired solar collector (tank), thermal storage and a intake fan(suction fan) to achieve a steady supply of air at a different atmospheric temperature and flow rate for drying fruits and vegetables. Development of an efficient, low-cost and reliable air heating system for drying applications is done.

  3. Design of plasmonic enhanced silicon-based solar cells

    NASA Astrophysics Data System (ADS)

    Hejazi, F.; Ding, S. Y.; Sun, Y.; Bottomley, A.; Ianoul, A.; Ye, W. N.

    2012-10-01

    We report a novel plasmonic solar cell design implemented on an amorphous silicon platform. The enhancement of the scattering and trapping of the light is achieved by embedding nano-metallic cubic particles within the cell's junction. Amorphous silicon cell with a thickness of 1200nm is used. The spectral absorption of the silicon cell is limited to wavelengths larger than 1.1 u. Our proposed solar cell has a p-i-n configuration, with the amorphous silicon as the photo-active layer. Silver cubic nanoparticles are embedded at different locations within the photoactive layers of the solar cell. With the use of an FDTD simulator, we are able to characterize the optical performance of the solar cell. Our results show that the plasmonic properties of the cubic nanoparticles are more attractive for sensing applications compared to the traditional spherical configuration. The geometry of the cubic nanoparticles enables control over plasmon resonances both in the resonant wavelength and the degree of field enhancement. This is done by improving the refractive-index sensitivity on a thin silicon film, as well as increasing the scattering and trapping of light. Our simulations predict that the silver metallic nanoparticles will enhance the solar cell efficiency, by optimizing the plasmonic properties of the silver nanocube monolayer. We have achieved a 67% increase (from 7.5% to 12.5%) in the cell's efficiency by adding plasmonics to traditional amorphous p-i-n solar cell.

  4. Solar cells design for low and medium concentrating photovoltaic systems

    NASA Astrophysics Data System (ADS)

    Baig, Hasan; Heasman, Keith C.; Sarmah, Nabin; Mallick, Tapas

    2012-10-01

    The solar cell is the key element of any CPV system, and its design plays an important role in enhancing the performance of the entire system. Special types of cells are required in the CPV systems capable of operating at high concentrations and elevated temperatures. These Concentrator solar cells differ significantly from the usual solar cells in the method of manufacture, the overall cell design and their performance. Systematic design and manufacture of the cell ensures better performance in a given CPV system. A number of factors come into play while designing the solar cell for a specific system these include concentration, cell material properties, expected operating temperature, shape, bus bar configuration and finger spacing. Most of these variables are decided on based on some rules of thumb and PC1D calculations. However, there is scope for design improvement and cell optimization by performing a detailed analysis based on the illumination profile incident on the cell. Recent studies demonstrated the use of Finite element method to analyze the electrical behavior of PV cell under the influence of arbitrarily chosen illumination flux profiles. This study outlines a methodology and analysis procedure while performing a case study of a CPV system under development having a non-uniform illumination profile towards the exit of the concentrator. The LCPV system chosen is the Photovoltaic Facades of Reduced Costs Incorporating Devices with Optically Concentrating Elements (PRIDE) concentrator made of dielectric material. A coupled optical, thermal and electrical analysis is performed on the system to demonstrate the method useful in designing solar cells for low and medium concentrations.

  5. Numerical methods for the design of gradient-index optical coatings.

    PubMed

    Anzengruber, Stephan W; Klann, Esther; Ramlau, Ronny; Tonova, Diana

    2012-12-01

    We formulate the problem of designing gradient-index optical coatings as the task of solving a system of operator equations. We use iterative numerical procedures known from the theory of inverse problems to solve it with respect to the coating refractive index profile and thickness. The mathematical derivations necessary for the application of the procedures are presented, and different numerical methods (Landweber, Newton, and Gauss-Newton methods, Tikhonov minimization with surrogate functionals) are implemented. Procedures for the transformation of the gradient coating designs into quasi-gradient ones (i.e., multilayer stacks of homogeneous layers with different refractive indices) are also developed. The design algorithms work with physically available coating materials that could be produced with the modern coating technologies.

  6. Preparation of H2SO4 doped Polyaniline thin film solar cells by spin coating technique

    NASA Astrophysics Data System (ADS)

    Patel, Abhishek; Pataniya, Pratik; Patel, K. D.; Solanki, G. K.; Pathak, V. M.

    2017-05-01

    A water diluted H2SO4 solution was used to dissolve Polyaniline in order to obtain a solution for preparation of thin films by spin coating technique. The chemical bonding characteristics of the prepared films were investigated using Furrier transform infrared spectroscopy (FTIR) and the structural characterizations were accomplished by X-ray diffraction (XRD). UV-VIS absorption spectroscopy was used to determine the optical band gap of the deposited PANi films and the indirect optical band gap of PANi was estimated to be in the range of 1.3 to 1.8 eV from the Tauc's plot. Further, these films were deposited on the n-MoSe2 crystal in order to complete a solar cell structure. The polychromatic photo response of the prepared solar cells for different intensities was studied at room temperature and the efficiency and fill factor were found to be 1% and 0.26 respectively. The obtained Photo-conversion characteristics (I-V) were also used to determined series and shunt resistances of the prepared device. The series resistance was found to be around 33.3 kΩ which is quite high. This may be a reason for such a low efficiency of this cell.

  7. Investigation of Some Transparent Metal Oxides as Damp Heat Protective Coating for CIGS Solar Cells: Preprint

    SciTech Connect

    Pern, F. J.; Yan, F.; Zaaunbrecher, B.; To, B.; Perkins, J.; Noufi, R.

    2012-10-01

    We investigated the protective effectiveness of some transparent metal oxides (TMO) on CIGS solar cell coupons against damp heat (DH) exposure at 85oC and 85% relative humidity (RH). Sputter-deposited bilayer ZnO (BZO) with up to 0.5-um Al-doped ZnO (AZO) layer and 0.2-um bilayer InZnO were used as 'inherent' part of device structure on CdS/CIGS/Mo/SLG. Sputter-deposited 0.2-um ZnSnO and atomic layer deposited (ALD) 0.1-um Al2O3 were used as overcoat on typical BZO/CdS/CIGS/Mo/SLG solar cells. The results were all negative -- all TMO-coated CIGS cells exhibited substantial degradation in DH. Combining the optical photographs, PL and EL imaging, SEM surface micro-morphology, coupled with XRD, I-V and QE measurements, the causes of the device degradations are attributed to hydrolytic corrosion, flaking, micro-cracking, and delamination induced by the DH moisture. Mechanical stress and decrease in crystallinity (grain size effect) could be additional degrading factors for thicker AZO grown on CdS/CIGS.

  8. Antireflection TiO x Coating with Plasmonic Metal Nanoparticles for Silicon Solar Cells.

    PubMed

    Starowicz, Z; Lipiński, M; Berent, K; Socha, R; Szczepanowicz, K; Kruk, T

    2013-03-01

    It is known that the light scattering from the metal particles deposited on the surfaces of cells can be used for increasing light trapping in the solar cells. In this work, plasmonic structures are composite materials that consisted of silver nanoparticles embedded in dielectric films of TiO x -used as cell antireflection coating. The films are deposited by sol-gel method using spin-on technique. Microstructure of prepared samples is analyzed by SEM observation. Good homogenity and particles density was obtained by this simple, cheap, and short time-demanding method. We demonstrate that due to light scattering by metal particles, the plasmonic-ARC layer is more effective than TiO x layer without Ag nanoparticles. Implementation of nanoparticles on bare cell surface was carried out too. The influence of the plasmonic structures on the silicon solar cells parameters is presented as well. We announce about 5 % additional growth in short circuit current for cells with nanoparticles.

  9. Diamond-Like Carbon Coatings as Encapsulants for Photovoltaic Solar Cells

    SciTech Connect

    Pern, F. J.; Panosyan, Zh.; Gippius, A. A.; Kontsevoy, J. A.; Touryan, K.; Voskanyan, S.; Yengibaryan, Y.

    2005-02-01

    High-quality single-layer and bilayer diamond-like carbon (DLC) thin films are fabricated by two technologies, namely, ion-assisted plasma-enhanced deposition (IAPED) and electron cyclotron resonance (ECR) deposition. Deposition on various substrates, such as sapphires and solar cells, has been performed at low substrate temperatures (50 {approx} 80 C). The two deposition technologies allow good control over the growth conditions to produce DLC films with desired optical properties, thickness, and energy bandgap. The bilayer-structured DLC can be fabricated by using IAPED for the bottom layer followed by ECR for the top layer, or just by IAPED for both layers with different compositions. The DLC films have shown good spatial uniformity, density, microhardness, and adhesion strength. They exhibit excellent stability against attack by strong acids, prolonged damp-heat exposure at 85 C and 85% relative humidity, mechanical scratch, ultrasonication, and irradiation by ultraviolet (UV), protons, and electrons. When deposited on crystalline Si and GaAs solar cells in single-layer and/or bilayer structure, the DLC films not only serve as antireflection coating and protective encapsulant, but also improve the cell efficiencies.

  10. Hybrid Composite Coatings for Durable and Efficient Solar Hydrogen Generation under Diverse Operating Conditions

    DOE PAGES

    Walczak, Karl A.; Segev, Gideon; Larson, David M.; ...

    2017-02-17

    Safe and practical solar-driven hydrogen generators must be capable of efficient and stable operation under diurnal cycling with full separation of gaseous H2 and O2 products. In this paper, a novel architecture that fulfills all of these requirements is presented. The approach is inherently scalable and provides versatility for operation under diverse electrolyte and lighting conditions. The concept is validated using a 1 cm2 triple-junction photovoltaic cell with its illuminated photocathode protected by a composite coating comprising an organic encapsulant with an embedded catalytic support. The device is compatible with operation under conditions ranging from 1 M H2SO4 to 1more » M KOH, enabling flexibility in selection of semiconductor, electrolyte, membrane, and catalyst. Stable operation at a solar-to-hydrogen conversion efficiency of >10% is demonstrated under continuous operation, as well as under diurnal light cycling for at least 4 d, with simulated sunlight. Operational characteristics are validated by extended time outdoor testing. A membrane ensures products are separated, with nonexplosive gas streams generated for both alkaline and acidic systems. Finally, analysis of operational characteristics under different lighting conditions is enabled by comparison of a device model to experimental data.« less

  11. Preliminary design package for solar heating and hot water system

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The preliminary design review on the development of a multi-family solar heating and domestic hot water prototype system is presented. The report contains the necessary information to evaluate the system. The system consists of the following subsystems: collector, storage, transport, control and Government-furnished site data acquisition.

  12. Solar cell submodule design facilitates assembly of lightweight arrays

    NASA Technical Reports Server (NTRS)

    Yasui, R. K.

    1966-01-01

    Solar cell submodules with bus bars that leave tabs along one end of the submodule and wires with raised portions along the other end are assembled by interlocking the tabs and wires of adjacent submodules. This structural design is lightweight and reliable and requires no metallic substructure.

  13. Progress and Design Concerns of Nanostructured Solar Energy Harvesting Devices.

    PubMed

    Leung, Siu-Fung; Zhang, Qianpeng; Tavakoli, Mohammad Mahdi; He, Jin; Mo, Xiaoliang; Fan, Zhiyong

    2016-05-01

    Integrating devices with nanostructures is considered a promising strategy to improve the performance of solar energy harvesting devices such as photovoltaic (PV) devices and photo-electrochemical (PEC) solar water splitting devices. Extensive efforts have been exerted to improve the power conversion efficiencies (PCE) of such devices by utilizing novel nanostructures to revolutionize device structural designs. The thicknesses of light absorber and material consumption can be substantially reduced because of light trapping with nanostructures. Meanwhile, the utilization of nanostructures can also result in more effective carrier collection by shortening the photogenerated carrier collection path length. Nevertheless, performance optimization of nanostructured solar energy harvesting devices requires a rational design of various aspects of the nanostructures, such as their shape, aspect ratio, periodicity, etc. Without this, the utilization of nanostructures can lead to compromised device performance as the incorporation of these structures can result in defects and additional carrier recombination. The design guidelines of solar energy harvesting devices are summarized, including thin film non-uniformity on nanostructures, surface recombination, parasitic absorption, and the importance of uniform distribution of photo-generated carriers. A systematic view of the design concerns will assist better understanding of device physics and benefit the fabrication of high performance devices in the future. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. SIMS prototype system 1: Design data brochure. [solar heating system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A prototype solar heating and hot water system using air as the collector fluid and a pebble bed for heat storage was designed for installation into a single family dwelling. The system, subsystem, and installation requirements are described. System operation and performance are discussed, and procedures for sizing the system to a specific site are presented.

  15. Some design considerations for solar-powered aircraft

    NASA Technical Reports Server (NTRS)

    Phillips, W. H.

    1980-01-01

    Performance and operating characteristics are presented for a solar powered aircraft intended to remain aloft for long periods. The critical technologies which limit the performance are identified. By using the techniques presented, the effects of variation in the system parameters are studied. Practical design consideration are discussed.

  16. Design and development of a solar array drive

    NASA Technical Reports Server (NTRS)

    Rees, T.; Standing, J. M.

    1977-01-01

    The design and development of a dry lubricated direct solar array pointing mechanism is discussed from its inception in 1970 to its present development into a flight mechanism for use on the Orbital Test Satellite (OTS), MAROTS, European Communication satellite and others. Results of life testing the original prototype and the OTS mechanism are presented together with an appraisal of expected future development.

  17. Mussel-designed Protective Coatings for Compliant Substrates

    PubMed Central

    Holten-Andersen, N.; Waite, J. H.

    2008-01-01

    The byssus of marine mussels has attracted attention as a paradigm of strong and versatile underwater adhesion. As the first of the 3,4-dihydroxyphenylalanine (Dopa)-containing byssal precursors to be purified, Mytilus edulis foot protein-1 (mefp-1) has been much investigated with respect to its molecular structure, physical properties, and adsorption to surfaces. Although mefp-1 undoubtedly contributes to the durability of byssus, it is not directly involved in adhesion. Rather, it provides a robust coating that is 4-5 times stiffer and harder than the byssal collagens that it covers. Protective coatings for compliant tissues and materials are highly appealing to technology, notwithstanding the conventional wisdom that coating extensibility can be increased only at the expense of hardness and stiffness. The byssal cuticle is the only known coating in which high compliance and hardness co-exist without mutual detriment; thus, the role of mefp-1 in accommodating both parameters deserves further study. PMID:18650539

  18. Optimization and design of pigments for heat-insulating coatings

    NASA Astrophysics Data System (ADS)

    Wang, Guang-Hai; Zhang, Yue

    2010-12-01

    This paper reports that heat insulating property of infrared reflective coatings is obtained through the use of pigments which diffuse near-infrared thermal radiation. Suitable structure and size distribution of pigments would attain maximum diffuse infrared radiation and reduce the pigment volume concentration required. The optimum structure and size range of pigments for reflective infrared coatings are studied by using Kubelka—Munk theory, Mie model and independent scattering approximation. Taking titania particle as the pigment embedded in an inorganic coating, the computational results show that core-shell particles present excellent scattering ability, more so than solid and hollow spherical particles. The optimum radius range of core-shell particles is around 0.3 ~ 1.6 μm. Furthermore, the influence of shell thickness on optical parameters of the coating is also obvious and the optimal thickness of shell is 100-300 nm.

  19. High altitude solar power platform. [aircraft design analysis

    NASA Technical Reports Server (NTRS)

    Bailey, M. D.; Bower, M. V.

    1992-01-01

    Solar power is a preeminent alternative to conventional aircraft propulsion. With the continued advances in solar cells, fuel cells, and composite materials technology, the solar powered airplane is no longer a simple curiosity constrained to flights of several feet in altitude or minutes of duration. A high altitude solar powered platform (HASPP) has several potential missions, including communications and agriculture. In remote areas, a HASPP could be used as a communication link. In large farming areas, a HASPP could perform remote sensing of crops. The impact of HASPP in continuous flight for one year on agricultural monitoring mission is presented. This mission provides farmers with near real-time data twice daily from an altitude which allows excellant resolution on water conditions, crop diseases, and insect infestation. Accurate, timely data will enable farmers to increase their yield and efficiency. A design for HASPP for the foregoing mission is presented. In the design power derived from solar cells covering the wings is used for propulsion, avionics, and sensors. Excess power produced midday will be stored in fuel cells for use at night to maintain altitude and course.

  20. Scaling nominal solar cell impedances for array design

    SciTech Connect

    Mueller, R.L.; Wallace, M.T.; Iles, P.

    1994-12-31

    A methodology for estimating the AC impedance of solar arrays and in particular the Mars Pathfinder (MPF) spacecraft cruise stage and lander solar arrays is presented. During an early stage in the spacecraft design, the MPF mission, cost and mass constraints resulted in a proposal to use a gallium arsenide on germanium (GaAs/Ge) cell solar array for the cruise stage and a silicon, back surface field/reflector (Si BSFR) cell solar array for the Mars lander. Previous work had shown that the AC impedance of Si BSFR cells was very different from that of GaAs/Ge cells. There was concern over how the difference in AC impedance would influence the design of the power bus voltage control circuitry and the stability of the power bus in general. The results presented in this paper are based on AC impedance measurements made on single cells and small solar cell arrays. Those measurements were then scaled to the larger spacecraft arrays. In each case, a generic AC model was used to construct impedance equations which were then correlated to test results to find the resistive and capacitive components of the cell impedance between 100 Hz and 100 Khz. The data was obtained using dark forward biasing to simulate different load points and intensities. Cell impedance tests show a large difference between Si BSFR and either Si non-BSF or GaAs/Ge cells, mainly because of the inherently high effective capacitance of the BSFR cells.

  1. A heat receiver design for solar dynamic space power systems

    NASA Technical Reports Server (NTRS)

    Baker, Karl W.; Dustin, Miles O.; Crane, Roger

    1990-01-01

    An advanced heat pipe receiver designed for a solar dynamic space power system is described. The power system consists of a solar concentrator, solar heat receiver, Stirling heat engine, linear alternator and waste heat radiator. The solar concentrator focuses the sun's energy into a heat receiver. The engine and alternator convert a portion of this energy to electric power and the remaining heat is rejected by a waste heat radiator. Primary liquid metal heat pipes transport heat energy to the Stirling engine. Thermal energy storage allows this power system to operate during the shade portion of an orbit. Lithium fluoride/calcium fluoride eutectic is the thermal energy storage material. Thermal energy storage canisters are attached to the midsection of each heat pipe. The primary heat pipes pass through a secondary vapor cavity heat pipe near the engine and receiver interface. The secondary vapor cavity heat pipe serves three important functions. First, it smooths out hot spots in the solar cavity and provides even distribution of heat to the engine. Second, the event of a heat pipe failure, the secondary heat pipe cavity can efficiently transfer heat from other operating primary heat pipes to the engine heat exchanger of the defunct heat pipe. Third, the secondary heat pipe vapor cavity reduces temperature drops caused by heat flow into the engine. This unique design provides a high level of reliability and performance.

  2. Design, fabrication, test, qualification, and price analysis of third generation design solar cell modules

    SciTech Connect

    Not Available

    1981-10-01

    The fabrication of solar cell modules is detailed with emphasis upon laminating and interconnecting the panels that hold the simicrystalline silicon cells. Design problems and enviromental tests are described as well as performance characteristics.

  3. Design, fabrication, test, qualification, and price analysis of third generation design solar cell modules

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The fabrication of solar cell modules is detailed with emphasis upon laminating and interconnecting the panels that hold the simicrystalline silicon cells. Design problems and enviromental tests are described as well as performance characteristics.

  4. Design of Aerosol Particle Coating: Thickness, Texture and Efficiency

    PubMed Central

    Buesser, B.; Pratsinis, S.E.

    2013-01-01

    Core-shell particles preserve the performance (e.g. magnetic, plasmonic or opacifying) of a core material while modifying its surface with a shell that facilitates (e.g. by blocking its reactivity) their incorporation into a host liquid or polymer matrix. Here coating of titania (core) aerosol particles with thin silica shells (films or layers) is investigated at non-isothermal conditions by a trimodal aerosol dynamics model, accounting for SiO2 generation by gas phase and surface oxidation of hexamethyldisiloxane (HMDSO) vapor, coagulation and sintering. After TiO2 particles have reached their final primary particle size (e.g. upon completion of sintering during their flame synthesis), coating starts by uniformly mixing them with HMDSO vapor that is oxidized either in the gas phase or on the particles’ surface resulting in SiO2 aerosols or deposits, respectively. Sintering of SiO2 deposited onto the core TiO2 particles takes place transforming rough into smooth coating shells depending on process conditions. The core-shell characteristics (thickness, texture and efficiency) are calculated for two limiting cases of coating shells: perfectly smooth (e.g. hermetic) and fractal-like. At constant TiO2 core particle production rate, the influence of coating weight fraction, surface oxidation and core particle size on coating shell characteristics is investigated and compared to pertinent experimental data through coating diagrams. With an optimal temperature profile for complete precursor conversion, the TiO2 aerosol and SiO2-precursor (HMDSO) vapor concentrations have the strongest influence on product coating shell characteristics. PMID:23729833

  5. Non-Isocyanate Polymer Design and Coating Development

    DTIC Science & Technology

    2012-09-11

    Allen - Manager of Coating Operations 3 Problem Statement ● 1.2 million gallons of Chemical Agent Resistant Coating (CARC) purchased in 2011  Up...Approach ● Project Management Principles  Frequent sample exchanges to ensure reproducibility and maintain program focus  Monthly team meetings...Maintenance Center (MDMC) Albany and a representative from that organization is included in the projet team. • Final field use will require introducing a

  6. Investigation of ZnSe-coated silicon substrates for GaAs solar cells

    NASA Technical Reports Server (NTRS)

    Huber, Daniel A.; Olsen, Larry C.; Dunham, Glen; Addis, F. William

    1993-01-01

    Studies are being carried out to determine the feasibility of using ZnSe as a buffer layer for GaAs solar cells grown on silicon. This study was motivated by reports in the literature indicating ZnSe films had been grown by metallorganic chemical vapor deposition (MOCVD) onto silicon with EPD values of 2 x 10(exp 5) cm(sup -2), even though the lattice mismatch between silicon and ZnSe is 4.16 percent. These results combined with the fact that ZnSe and GaAs are lattice matched to within 0.24 percent suggest that the prospects for growing high efficiency GaAs solar cells onto ZnSe-coated silicon are very good. Work to date has emphasized development of procedures for MOCVD growth of (100) ZnSe onto (100) silicon wafers, and subsequent growth of GaAs films on ZnSe/Si substrates. In order to grow high quality single crystal GaAs with a (100) orientation, which is desirable for solar cells, one must grow single crystal (100) ZnSe onto silicon substrates. A process for growth of (100) ZnSe was developed involving a two-step growth procedure at 450 C. Single crystal, (100) GaAs films were grown onto the (100) ZnSe/Si substrates at 610 C that are adherent and specular. Minority carrier diffusion lengths for the GaAs films grown on ZnSe/Si substrates were determined from photoresponse properties of Al/GaAs Schottky barriers. Diffusion lengths for n-type GaAs films are currently on the order of 0.3 microns compared to 2.0 microns for films grown simultaneously by homoepitaxy.

  7. Designing optimal formulations for hot-melt coating.

    PubMed

    Lopes, Diogo Gomes; Salar-Behzadi, Sharareh; Zimmer, Andreas

    2017-08-24

    Hot-melt coating (HMC) as a solvent-free technology grants faster and more economic coating processes with reduced risk of dissolving the drug during the process. Moreover, traditional coating equipment can be modified to enable the HMC process. Despite the indubitable advantages and feasibility of the process, HMC is not well-known to pharmaceutical industry and its employment is still limited. The main aspect hindering the widespread application of this technique is the need of materials alternative to the conventional polymeric coatings. The current work reviews the published HMC formulations and describes the properties that have led to their selection. As these materials are mainly solid lipid excipients, attention should be paid to their crystallization and solid state behavior, and their impact on the performance of coated drug products, particularly on the stable drug release profile. Although different drug release profiles can be easily tailored, much development work is needed to respond to the unmet requirements of a stable formulation. Ensuring stable solid-state behavior and providing a mechanistic understanding of the macroscopic properties are essential steps towards fulfilling these requirements and establishing of HMC as advanced coating technology for manufacturing of pharmaceutical products. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  8. Design and fabrication of brayton cycle solar heat receiver

    NASA Technical Reports Server (NTRS)

    Mendelson, I.

    1971-01-01

    A detail design and fabrication of a solar heat receiver using lithium fluoride as the heat storage material was completed. A gas flow analysis was performed to achieve uniform flow distribution within overall pressure drop limitations. Structural analyses and allowable design criteria were developed for anticipated environments such as launch, pressure containment, and thermal cycling. A complete heat receiver assembly was fabricated almost entirely from the refractory alloy, niobium-1% zirconium.

  9. Fluid manifold design for a solar energy storage tank

    NASA Technical Reports Server (NTRS)

    Humphries, W. R.; Hewitt, H. C.; Griggs, E. I.

    1975-01-01

    A design technique for a fluid manifold for use in a solar energy storage tank is given. This analytical treatment generalizes the fluid equations pertinent to manifold design, giving manifold pressures, velocities, and orifice pressure differentials in terms of appropriate fluid and manifold geometry parameters. Experimental results used to corroborate analytical predictions are presented. These data indicate that variations in discharge coefficients due to variations in orifices can cause deviations between analytical predictions and actual performance values.

  10. Preliminary design package for solar heating and hot water system

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The preliminary design review on the development of two prototype solar heating and hot water systems is presented. The information contained in this report includes system certification, system functional description, system configuration, system specification, system performance and other documents pertaining to the progress and the design of the system. This system, which is intended for use in the normal single-family residence, consists of the following subsystems: collector, storage, control, transport, and Government-furnished Site Data Acquisition.

  11. Final system instrumentation design package for Decade 80 solar house

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The final configuration of the Decade 80 solar house to monitor and collect system performance data is presented. A review demonstrated by actual operation that the system and the data acquisition subsystem operated satisfactorily and installation of instrumentation was in accordance with the design. This design package is made up of (1) site and system description, (2) operating and control modes, and (3) instrumentation program (including sensor schematic).

  12. Tower-shaped solar power plants: general design solutions

    NASA Astrophysics Data System (ADS)

    Tepliakov, D. I.; Aparisi, R. R.; Goncharenko, V. M.

    General design characteristics of tower-shaped solar power stations are summarized, and the principal types of design solutions are identified. In particular, attention is given to the requirements for the topography of the construction site, configurations of the heliostat field, the position of the tower relative to the heliostat field and linear dimensions of the heliostat field. The discussion also covers the geometry of the collector and consideration of the geographic latitude of the plant location.

  13. A Robust Design Approach to Cost Estimation: Solar Energy for Marine Corps Expeditionary Operations

    DTIC Science & Technology

    2014-07-14

    Resources Energy Technology Basics Electricity Grid Basics Costs Renewable Technologies Biomass Geothermal Solar Concentrators Solar Photovoltaics Wind...SPONSORED REPORT SERIES A Robust Design Approach to Cost Estimation: Solar Energy for Marine Corps Expeditionary Operations 14 July 2014...SUBTITLE A Robust Design Approach to Cost Estimation: Solar Energy for Marine Corps Expeditionary Operations 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  14. Pin-Hole Free Perovskite Film for Solar Cells Application Prepared by Controlled Two-Step Spin-Coating Method

    NASA Astrophysics Data System (ADS)

    Bahtiar, A.; Rahmanita, S.; Inayatie, Y. D.

    2017-05-01

    Morphology of perovskite film is a key important for achieving high performance perovskite solar cells. Perovskite films are commonly prepared by two-step spin-coating method. However, pin-holes are frequently formed in perovskite films due to incomplete conversion of lead-iodide (PbI2) into perovskite CH3NH3PbI3. Pin-holes in perovskite film cause large hysteresis in current-voltage curve of solar cells due to large series resistance between perovskite layer-hole transport material. Moreover, crystal structure and grain size of perovskite crystal are also other important parameters for achieving high performance solar cells, which are significantly affected by preparation of perovskite film. We studied the effect of preparation of perovskite film using controlled spin-coating parameters on crystal structure and morphological properties of perovskite film. We used two-step spin-coating method for preparation of perovskite film with varied spinning speed, spinning time and temperature of spin-coating process to control growth of perovskite crystal aimed to produce high quality perovskite crystal with pin-hole free and large grain size. All experiment was performed in air with high humidity (larger than 80%). The best crystal structure, pin-hole free with large grain crystal size of perovskite film was obtained from film prepared at room temperature with spinning speed 1000 rpm for 20 seconds and annealed at 100°C for 300 seconds.

  15. Design colloidal particle morphology and self-assembly for coating applications

    DOE PAGES

    Jiang, Shan; Van Dyk, Antony; Maurice, Alvin; ...

    2017-05-04

    The progressive replacement of organic solvent-based coatings by waterborne latex polymer coatings has substantially renovated the coating industry, and generated huge environmental and health benefits. Today, on top of the continuing demand for higher performance and lower costs, the coating industry faces tighter regulation and higher sustainability standards. In addition, the new waterborne coatings have created unique opportunities and challenges in terms of fundamental understanding and research development. To address these challenges, polymer latex binders with diverse particle morphologies have been developed to improve coating performance. Furthermore, colloidal self-assembly has been utilized to help manufacturers make better paint with lessmore » cost. In this report, we review the recent progress in both fundamental study and industrial application in the context of developing new generation architectural coating materials. We introduce the basic concepts in coating materials and showcase several key technologies that have been implemented to improve coating performance. As a result, these technologies also represent the most important considerations in architectural coating design.« less

  16. A thick multilayer thermal barrier coating: Design, deposition, and internal stresses

    NASA Astrophysics Data System (ADS)

    Samadi, Hamed

    Yttria Partially Stabilized Zirconia (Y-PSZ) plasma-sprayed coatings are widely used in turbine engines as thermal barrier coatings. However, in diesel engines Y-PSZ TBCs have not met with wide success. To reach the desirable temperature of 850-900°C in the combustion chamber from the current temperature of 400-600°C, a coating with a thickness of approximately 1mm is required. This introduces different considerations than in the case of turbine blade coatings, which are on the order of 100mum thick. Of the many factors affecting the durability and failure mechanism of TBCs, in service and residual stresses play an especially important role as the thickness of the coating increases. For decreasing the residual stress in the system, a multi-layer coating is helpful. The design of a multilayer coating employing relatively low cost materials with complementary thermal properties is described. Numerical models were used to describe the residual stress after deposition and under operating conditions for a multilayer coating that exhibited the desired temperature gradient. Results showed that the multilayer coating had a lower maximum stress under service conditions than a conventional Y-PSZ coating. Model validation with experiments showed a good match between the two.

  17. Design and development of a solar array drive. [a direct drive solar array pointing mechanism

    NASA Technical Reports Server (NTRS)

    Rees, T.; Standing, J. M.

    1977-01-01

    The design and development of a dry lubricated direct drive solar array pointing mechanism is discussed for use on the Orbital Test Satellite (OTS), MAROTS, European Communication Satellite (ECS), and others. Results of life testing the original prototype and the OTS mechanism are presented together with an appraisal of expected future development.

  18. Key aspects of cost effective collector and solar field design

    NASA Astrophysics Data System (ADS)

    von Reeken, Finn; Nicodemo, Dario; Keck, Thomas; Weinrebe, Gerhard; Balz, Markus

    2016-05-01

    A study has been performed where different key parameters influencing solar field cost are varied. By using levelised cost of energy as figure of merit it is shown that parameters like GoToStow wind speed, heliostat stiffness or tower height should be adapted to respective site conditions from an economical point of view. The benchmark site Redstone (Northern Cape Province, South Africa) has been compared to an alternate site close to Phoenix (AZ, USA) regarding site conditions and their effect on cost-effective collector and solar field design.

  19. SolarOil Project, Phase I preliminary design report. [Solar Thermal Enhanced Oil Recovery project

    SciTech Connect

    Baccaglini, G.; Bass, J.; Neill, J.; Nicolayeff, V.; Openshaw, F.

    1980-03-01

    The preliminary design of the Solar Thermal Enhanced Oil Recovery (SolarOil) Plant is described in this document. This plant is designed to demonstrate that using solar thermal energy is technically feasible and economically viable in enhanced oil recovery (EOR). The SolarOil Plant uses the fixed mirror solar concentrator (FMSC) to heat high thermal capacity oil (MCS-2046) to 322/sup 0/C (611/sup 0/F). The hot fluid is pumped from a hot oil storage tank (20 min capacity) through a once-through steam generator which produces 4.8 MPa (700 psi) steam at 80% quality. The plant net output, averaged over 24 hr/day for 365 days/yr, is equivalent to that of a 2.4 MW (8.33 x 10/sup 6/ Btu/hr) oil-fired steam generator having an 86% availability. The net plant efficiency is 57.3% at equinox noon, a 30%/yr average. The plant will be demonstrated at an oilfield site near Oildale, California.

  20. Approaches to solar cell design for pulsed laser power receivers

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Landis, Geoffrey A.

    1993-01-01

    Using a laser to beam power from Earth to a photovoltaic receiver in space could be a technology with applications to many space missions. Extremely high average-power lasers would be required in a wavelength range of 700-1000 nm. However, high-power lasers inherently operate in a pulsed format. Existing solar cells are not well designed to respond to pulsed incident power. To better understand cell response to pulsed illumination at high intensity, the PC-1D finite-element computer model was used to analyze the response of solar cells to continuous and pulsed laser illumination. Over 50 percent efficiency was calculated for both InP and GaAs cells under steady-state illumination near the optimum wavelength. The time-dependent response of a high-efficiency GaAs concentrator cell to a laser pulse was modeled, and the effect of laser intensity, wavelength, and bias point was studied. Three main effects decrease the efficiency of a solar cell under pulsed laser illumination: series resistance, L-C 'ringing' with the output circuit, and current limiting due to the output inductance. The problems can be solved either by changing the pulse shape or designing a solar cell to accept the pulsed input. Cell design possibilities discussed are a high-efficiency, light-trapping silicon cell, and a monolithic, low-inductance GaAs cell.

  1. Design and Development of NEA Scout Solar Sail Deployer Mechanism

    NASA Technical Reports Server (NTRS)

    Sobey, Alexander R.; Lockett, Tiffany Russell

    2016-01-01

    The 6U (approximately 10cm x 20cm x 30cm) cubesat Near Earth Asteroid (NEA) Scout1, projected for launch in September 2018 aboard the maiden voyage of the Space Launch System (SLS), will utilize a solar sail as its main method of propulsion throughout its approximately 3 year mission to a Near Earth Asteroid (NEA). Due to the extreme volume constraints levied onto the mission, an acutely compact solar sail deployment mechanism has been designed to meet the volume and mass constraints, as well as provide enough propulsive solar sail area and quality in order to achieve mission success. The design of such a compact system required the development of approximately half a dozen prototypes in order to identify unforeseen problems, advance solutions, and build confidence in the final design product. This paper focuses on the obstacles of developing a solar sail deployment mechanism for such an application and the lessons learned from a thorough development process. The lessons presented will have significant applications beyond the NEA Scout mission, such as the development of other deployable boom mechanisms and uses for gossamer-thin films in space.

  2. Design and Development of NEA Scout Solar Sail Deployer Mechanism

    NASA Technical Reports Server (NTRS)

    Sobey, Alexander R.; Lockett, Tiffany Russell

    2016-01-01

    The 6U (approx.10 cm x 20 cm x 30 cm) cubesat Near Earth Asteroid (NEA) Scout1, projected for launch in September 2018 aboard the maiden voyage of the Space Launch System, will utilize a solar sail as its main method of propulsion throughout its approx.3-year mission to a Near Earth Asteroid. Due to the extreme volume constraints levied onto the mission, an acutely compact solar sail deployment mechanism has been designed to meet the volume and mass constraints, as well as provide enough propulsive solar sail area and quality in order to achieve mission success. The design of such a compact system required the development of approximately half a dozen prototypes in order to identify unforeseen problems, advance solutions, and build confidence in the final design product. This paper focuses on the obstacles of developing a solar sail deployment mechanism for such an application and the lessons learned from a thorough development process. The lessons presented will have significant applications beyond the NEA Scout mission, such as the development of other deployable boom mechanisms and uses for gossamer-thin films in space.

  3. Design and development of a solar powered mobile laboratory

    NASA Astrophysics Data System (ADS)

    Jiao, L.; Simon, A.; Barrera, H.; Acharya, V.; Repke, W.

    2016-08-01

    This paper describes the design and development of a solar powered mobile laboratory (SPML) system. The SPML provides a mobile platform that schools, universities, and communities can use to give students and staff access to laboratory environments where dedicated laboratories are not available. The lab includes equipment like 3D printers, computers, and soldering stations. The primary power source of the system is solar PV which allows the laboratory to be operated in places where the grid power is not readily available or not sufficient to power all the equipment. The main system components include PV panels, junction box, battery, charge controller, and inverter. Not only is it used to teach students and staff how to use the lab equipment, but it is also a great tool to educate the public about solar PV technologies.

  4. Design of nitride semiconductors for solar energy conversion

    SciTech Connect

    Zakutayev, Andriy

    2016-01-01

    Nitride semiconductors are a promising class of materials for solar energy conversion applications, such as photovoltaic and photoelectrochemical cells. Nitrides can have better solar absorption and electrical transport properties than the more widely studied oxides, as well as the potential for better scalability than other pnictides or chalcogenides. In addition, nitrides are also relatively unexplored compared to other chemistries, so they provide a great opportunity for new materials discovery. This paper reviews the recent advances in the design of novel semiconducting nitrides for solar energy conversion technologies. Both binary and multinary nitrides are discussed, with a range of metal chemistries (Cu3N, ZnSnN2, Sn3N4, etc.) and crystal structures (delafossite, perovskite, spinel, etc.), including a brief overview of wurtzite III-N materials and devices. The current scientific challenges and promising future directions in the field are also highlighted.

  5. A technique for determining solar irradiance deficits. [photovoltaic arrays design

    NASA Technical Reports Server (NTRS)

    Gonzalez, C. C.; Ross, R. G., Jr.

    1982-01-01

    An analytic technique which determines the variation of solar irradiance from long term averages is presented. The technique involves computer-assisted data reduction techniques, and was designed to improve system reliability by determining the amount of storage capability required to supplement a baseline system. Variations in time intervals of up to 60 days can be determined, and 10 years of data collection are reviewed. The technique involves first calculating average monthly irradiance values, then examining the average irradiance deviation over time intervals. The calculation procedure is clarified by determining solar energy level probabilities and the long term solar energy deviation (achieved by repeatedly integrating actual irradiance figures). It is found that a 15% increase in collector area and the addition of energy storage or backup are essential contributions to achieving cost-effectiveness. In addition, one to seven no-sun day storage capacities are required to accommodate weather caused deficits.

  6. An optimized top contact design for solar cell concentrators

    NASA Technical Reports Server (NTRS)

    Desalvo, Gregory C.; Barnett, Allen M.

    1985-01-01

    A new grid optimization scheme is developed for point focus solar cell concentrators which employs a separated grid and busbar concept. Ideally, grid lines act as the primary current collectors and receive all of the current from the semiconductor region. Busbars are the secondary collectors which pick up current from the grids and carry it out of the active region of the solar cell. This separation of functions leads to a multithickness metallization design, where the busbars are made larger in cross section than the grids. This enables the busbars to carry more current per unit area of shading, which is advantageous under high solar concentration where large current densities are generated. Optimized grid patterns using this multilayer concept can provide a 1.6 to 20 percent increase in output power efficiency over optimized single thickness grids.

  7. An optimized top contact design for solar cell concentrators

    NASA Technical Reports Server (NTRS)

    Desalvo, Gregory C.; Barnett, Allen M.

    1985-01-01

    A new grid optimization scheme is developed for point focus solar cell concentrators which employs a separated grid and busbar concept. Ideally, grid lines act as the primary current collectors and receive all of the current from the semiconductor region. Busbars are the secondary collectors which pick up current from the grids and carry it out of the active region of the solar cell. This separation of functions leads to a multithickness metallization design, where the busbars are made larger in cross section than the grids. This enables the busbars to carry more current per unit area of shading, which is advantageous under high solar concentration where large current densities are generated. Optimized grid patterns using this multilayer concept can provide a 1.6 to 20 percent increase in output power efficiency over optimized single thickness grids.

  8. Heat-rejection design for large concentrating solar arrays

    NASA Technical Reports Server (NTRS)

    French, E. P.

    1980-01-01

    This paper considers the effect of heat rejection devices (radiators) on the performance and cost of large concentrating solar arrays for space application. Overall array characteristics are derived from the weight, cost, and performance of four major components; namely primary structure, optics/secondary structure, radiator, and solar panel. An ideal concentrator analysis is used to establish general cost and performance trends independent of specific array design. Both passive and heat-pipe radiation are evaluated, with an incremental cost-of-power approach used in the evaluation. Passive radiators are found to be more cost effective with silicon than with gallium arsenide (GaAs) arrays. Representative concentrating arrays have been evaluated for both near-term and advanced solar cell technology. Minimum cost of power is achieved at geometric concentration ratios in the range 2 to 6.

  9. A design of experiment study of plasma sprayed alumina-titania coatings

    SciTech Connect

    Steeper, T.J.; Varacalle, D.J. Jr.; Wilson, G.C.; Riggs, W.L. II; Rotolico, A.J.; Nerz, J.E.

    1992-08-01

    An experimental study of the plasma spraying of alumina-titania powder is presented in this paper. This powder system is being used to fabricate heater tubes that emulate nuclear fuel tubes for use in thermal-hydraulic testing. Coating experiments were conducted using a Taguchi fractional-factorial design parametric study. Operating parameters were varied around the typical spray parameters in a systematic design of experiments in order to display the range of plasma processing conditions and their effect on the resultant coating. The coatings were characterized by hardness and electrical tests, image analysis, and optical metallography. Coating qualities are discussed with respect to dielectric strength, hardness, porosity, surface roughness, deposition efficiency, and microstructure. The attributes of the coatings are correlated with the changes in operating parameters.

  10. Solar Probe Plus: Mission design challenges and trades

    NASA Astrophysics Data System (ADS)

    Guo, Yanping

    2010-11-01

    NASA plans to launch the first mission to the Sun, named Solar Probe Plus, as early as 2015, after a comprehensive feasibility study that significantly changed the original Solar Probe mission concept. The original Solar Probe mission concept, based on a Jupiter gravity assist trajectory, was no longer feasible under the new guidelines given to the mission. A complete redesign of the mission was required, which called for developing alternative trajectories that excluded a flyby of Jupiter. Without the very powerful gravity assist from Jupiter it was extremely difficult to get to the Sun, so designing a trajectory to reach the Sun that is technically feasible under the new mission guidelines became a key enabler to this highly challenging mission. Mission design requirements and challenges unique to this mission are reviewed and discussed, including various mission scenarios and six different trajectory designs utilizing various planetary gravity assists that were considered. The V 5GA trajectory design using five Venus gravity assists achieves a perihelion of 11.8 solar radii ( RS) in 3.3 years without any deep space maneuver (DSM). The V 7GA trajectory design reaches a perihelion of 9.5 RS using seven Venus gravity assists in 6.39 years without any DSM. With nine Venus gravity assists, the V 9GA trajectory design shows a solar orbit at inclination as high as 37.9° from the ecliptic plane can be achieved with the time of flight of 5.8 years. Using combined Earth and Venus gravity assists, as close as 9 RS from the Sun can be achieved in less than 10 years of flight time at moderate launch C3. Ultimately the V 7GA trajectory was chosen as the new baseline mission trajectory. Its design allowing for science investigation right after launch and continuing for nearly 7 years is unprecedented for interplanetary missions. The redesigned Solar Probe Plus mission is not only feasible under the new guidelines but also significantly outperforms the original mission concept

  11. Optofluidic solar concentrators using electrowetting tracking: Concept, design, and characterization

    SciTech Connect

    Cheng, JT; Park, S; Chen, CL

    2013-03-01

    We introduce a novel optofluidic solar concentration system based on electrowetting tracking. With two immiscible fluids in a transparent cell, we can actively control the orientation of fluid fluid interface via electrowetting. The naturally-formed meniscus between the two liquids can function as a dynamic optical prism for solar tracking and sunlight steering. An integrated optofluidic solar concentrator can be constructed from the liquid prism tracker in combination with a fixed and static optical condenser (Fresnel lens). Therefore, the liquid prisms can adaptively focus sunlight on a concentrating photovoltaic (CPV) cell sitting on the focus of the Fresnel lens as the sun moves. Because of the unique design, electrowetting tracking allows the concentrator to adaptively track both the daily and seasonal changes of the sun's orbit (dual-axis tracking) without bulky, expensive and inefficient mechanical moving parts. This approach can potentially reduce capital costs for CPV and increases operational efficiency by eliminating the power consumption of mechanical tracking. Importantly, the elimination of bulky tracking hardware and quiet operation will allow extensive residential deployment of concentrated solar power. In comparison with traditional silicon-based photovoltaic (PV) solar cells, the electrowetting-based self-tracking technology will generate,similar to 70% more green energy with a 50% cost reduction. (C) 2013 Elsevier Ltd. All rights reserved.

  12. Plasmonic Solar Cells: From Rational Design to Mechanism Overview.

    PubMed

    Jang, Yoon Hee; Jang, Yu Jin; Kim, Seokhyoung; Quan, Li Na; Chung, Kyungwha; Kim, Dong Ha

    2016-12-28

    Plasmonic effects have been proposed as a solution to overcome the limited light absorption in thin-film photovoltaic devices, and various types of plasmonic solar cells have been developed. This review provides a comprehensive overview of the state-of-the-art progress on the design and fabrication of plasmonic solar cells and their enhancement mechanism. The working principle is first addressed in terms of the combined effects of plasmon decay, scattering, near-field enhancement, and plasmonic energy transfer, including direct hot electron transfer and resonant energy transfer. Then, we summarize recent developments for various types of plasmonic solar cells based on silicon, dye-sensitized, organic photovoltaic, and other types of solar cells, including quantum dot and perovskite variants. We also address several issues regarding the limitations of plasmonic nanostructures, including their electrical, chemical, and physical stability, charge recombination, narrowband absorption, and high cost. Next, we propose a few potentially useful approaches that can improve the performance of plasmonic cells, such as the inclusion of graphene plasmonics, plasmon-upconversion coupling, and coupling between fluorescence resonance energy transfer and plasmon resonance energy transfer. This review is concluded with remarks on future prospects for plasmonic solar cell use.

  13. Design and Performance of 20 Watts Portable Solar Generator

    NASA Astrophysics Data System (ADS)

    Majid, Z. A. Abdul; Hazali, N.; Hanafiah, M. A. K. M.; Abdullah, A. A.; Ismail, A. F.; Ruslan, M. H.; Sopian, K.; Mohd Azmi, M. S.

    2012-09-01

    A new portable solar generator has been developed to generate electricity. It has the potential to replace petrol generator, widely used by peddlers at night markets (pasar malam). Conventional generators are heavy, oily, have high maintenance and use fossil fuel to generate electricity. The solar generator can generate 20 Watts of electricity. This amount of power can supply up to 96 hours of electricity for the purpose of lighting and running small electrical appliances. The power output is (alternating current) AC current using 150 Watts inverter with 200 Watts surge, suitable for all commercial single phase electric appliances. Solar charge controller is used to maximize the charging rate and to protect the battery. The system has low maintenance whereby the batteries need to be changed every three to four years, depending on the usage. The main concepts of portable solar generator are to reduce installation cost and to introduce a compact design of an optimal energy sizing system. The materials used to develop the solar generator can be easily obtained from local markets, thus reducing the cost of developing the system and making it suitable for commercialization.

  14. Development of Anti-Reflection Coating Layer for Efficiency Enhancement of ZnO Dye-Sensitized Solar Cells.

    PubMed

    Chanta, E; Bhoomanee, C; Gardchareon, A; Wongratanaphisan, D; Phadungdhitidhada, S; Choopun, S

    2015-09-01

    In this research, we investigated the effects of ZnO anti-reflection coating layers on power conversion efficiency enhancement of ZnO dye-sensitized solar cells. ZnO thin films were prepared by rf-magnetron sputtering by varying sputtering time of 10, 30, 60, 80, 100 min. Surface morphology, thickness and optical reflective index were investigated by field emission scanning electron microscopy and ellipsometry. Then, transmittance and reflectance were investigated by UV-vis spectroscopy. Furthermore, we found that ZnO anti-reflection coating layers with sputtering time of 30 and 60 min showed lower reflection and higher transmission than that of reference film. In addition, ZnO anti-reflection coating layers have rough surface with sputtering rate has 2.14 nm/min. Thus, the ZnO anti-reflection coating layers with sputtering time in the range of 10-60 min have a potential as anti-reflection coating applications. The ZnO anti-reflection coating layers were used in ZnO dye-sensitized solar cells and exhibited a short circuit current density of 5.16 mA/cm2 and the maximum power conversion efficiency of 1.54% from a sample with sputtering time at 60 min while the reference cell exhibited 3.88 mA/cm2 and 1.19%, respectively. Thus, we suggested an alternative improvement of ZnO DSSCs by adding the ZnO anti-reflection coating layers.

  15. Final design review report for K Basin Dose Reduction Project Clean and Coat Task

    SciTech Connect

    Blackburn, L.D.

    1996-02-01

    The strategy for reducing radiation dose originating from radionuclides absorbed in the concrete is to raise the pool water level to provide additional shielding. The concrete walls need to be coated to prevent future radionuclide absorption into the walls. This report documents a final design review of equipment to clean and coat basin walls. The review concluded that the design presented was acceptable for release for fabrication.

  16. Conceptual design review report for K Basin Dose Reduction Project clean and coat task

    SciTech Connect

    Blackburn, L.D.

    1996-01-01

    The strategy for reducing radiation dose originating from radionuclides absorbed in the concrete is to raise the pool water level to provide additional shielding. The concrete walls need to be coated to prevent future radionuclide absorption into the walls. This report documents a conceptual design review of equipment to clean and coat basin walls. The review concluded that the proposed concepts were and acceptable basis for proceeding with detailed final design.

  17. Constructing 3D branched nanowire coated macroporous metal oxide electrodes with homogeneous or heterogeneous compositions for efficient solar cells.

    PubMed

    Wu, Wu-Qiang; Xu, Yang-Fan; Rao, Hua-Shang; Feng, Hao-Lin; Su, Cheng-Yong; Kuang, Dai-Bin

    2014-05-05

    Light-harvesting and charge collection have attracted increasing attention in the domain of photovoltaic cells, and can be facilitated dramatically by appropriate design of a photonic nanostructure. However, the applicability of current light-harvesting photoanode materials with single component and/or morphology (such as, particles, spheres, wires, sheets) is still limited by drawbacks such as insufficient electron-hole separation and/or light-trapping. Herein, we introduce a universal method to prepare hierarchical assembly of macroporous material-nanowire coated homogenous or heterogeneous metal oxide composite electrodes (TiO2 -TiO2 , SnO2 -TiO2 , and Zn2 SnO4 -TiO2 ; homogenous refers to a material in which the nanowire and the macroporous material have the same composition, i.e. both are TiO2 . Heterogeneous refers to a material in which the nanowires and the macroporous material have different compositions). The dye-sensitized solar cell based on a TiO2 -macroporous material-TiO2 -nanowire homogenous composition electrode shows an impressive conversion efficiency of 9.51 %, which is much higher than that of pure macroporous material-based photoelectrodes to date.

  18. Planetary spacecraft - SEPS interface design. [Solar Electric Propulsion System

    NASA Technical Reports Server (NTRS)

    Pless, L. C.

    1980-01-01

    The interactions between a spacecraft which would rendezvous with the comet Tempel II, the stage, and the mission design are summarized along with solar electric propulsion system design issues. Attention is given to data communication, the spacecraft pointing control system, spacecraft power, plasma interactions, the release of a probe to study the comet Halley, and thruster usage. It was concluded that for a planetary mission design using a low-thrust stage, the control of the mission should reside in the payload spacecraft and that the power should be provided by the stage; the NASA standard 28 VDC bus is recommended.

  19. Improved performance design of gallium arsenide solar cells for space

    NASA Technical Reports Server (NTRS)

    Parekh, R. H.; Barnett, A. M.

    1984-01-01

    An improved design, shallow junction heteroface, n-p, gallium arsenide solar cell for space applications is reported, with a predicted AM0 efficiency in the 21.9 to 23.0 percent range. The optimized n-p structure, while slightly more efficient, has the added advantage of being less susceptible to radiation-induced degradation by virtue of this thin top junction layer. Detailed spectral response curves and an analysis of the loss mechanisms are reported. The details of the design are readily measurable. The optimized designs were reached by quantifying the dominant loss mechanisms and then minimizing them by using computer simulations.

  20. Design and Development of NEA Scout Solar Sail Deployer Mechanism

    NASA Technical Reports Server (NTRS)

    Sobey, Alexander R.; Lockett, Tiffany Russell

    2016-01-01

    The 6U (approximately10cm x 20cm x 30cm) cubesat Near Earth Asteroid (NEA) Scout, projected for launch in September 2018 aboard the maiden voyage of the Space Launch System (SLS), will utilize a solar sail as its main method of propulsion throughout its approximately 3 year mission to a near earth asteroid. Due to the extreme volume constraints levied onto the mission, an acutely compact solar sail deployment mechanism has been designed to meet the volume and mass constraints, as well as provide enough propulsive solar sail area and quality in order to achieve mission success. The design of such a compact system required the development of approximately half a dozen prototypes in order to identify unforeseen problems and advance solutions. Though finite element analysis was performed during this process in an attempt to quantify forces present within the mechanism during deployment, both the boom and the sail materials do not lend themselves to achieving high-confidence results. This paper focuses on the obstacles of developing a solar sail deployment mechanism for such an application and the lessons learned from a thorough development process. The lessons presented here will have significant applications beyond the NEA Scout mission, such as the development of other deployable boom mechanisms and uses for gossamer-thin films in space.

  1. Micro-optical designs for angular confinement in solar cells

    NASA Astrophysics Data System (ADS)

    Gordon, Jeffrey M.; Feuermann, Daniel; Mashaal, Heylal

    2015-01-01

    We identify and evaluate a variety of efficient and feasible micro-optics for confining the radiative emission of solar cells. The key criteria used for assessing viable designs are (1) high optical efficiency for both the transmission of impinging solar beam radiation and the external recycling of isotropic cell luminescent emission; (2) liberal optical tolerance; (3) compactness and (4) being amenable to fabrication from existing materials and manufacturing processes. Both imaging and nonimaging candidate designs are presented, and their superiority to previous proposals is quantified. The strategy of angular confinement for boosting cell open-circuit voltage-thereby enhancing conversion efficiency-is limited to cells where radiative recombination is the dominant carrier recombination pathway. Optical systems that restrict the angular range for emission of cell luminescence must, by reciprocity, commensurately restrict the angular range for the collection of solar radiation. This, in turn, mandates the introduction of concentrators, but not for the objective of delivering concentrated flux onto the cell. Rather, the optical system must project an acceptably uniform spatial distribution of solar flux onto the cell surface at a nominal averaged irradiance of 1 sun.

  2. Optimization of Cardiovascular Stent against Restenosis: Factorial Design-Based Statistical Analysis of Polymer Coating Conditions

    PubMed Central

    Acharya, Gayathri

    2012-01-01

    The objective of this study was to optimize the physicodynamic conditions of polymeric system as a coating substrate for drug eluting stents against restenosis. As Nitric Oxide (NO) has multifunctional activities, such as regulating blood flow and pressure, and influencing thrombus formation, a continuous and spatiotemporal delivery of NO loaded in the polymer based nanoparticles could be a viable option to reduce and prevent restenosis. To identify the most suitable carrier for S-Nitrosoglutathione (GSNO), a NO prodrug, stents were coated with various polymers, such as poly (lactic-co-glycolic acid) (PLGA), polyethylene glycol (PEG) and polycaprolactone (PCL), using solvent evaporation technique. Full factorial design was used to evaluate the effects of the formulation variables in polymer-based stent coatings on the GSNO release rate and weight loss rate. The least square regression model was used for data analysis in the optimization process. The polymer-coated stents were further assessed with Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy analysis (FTIR), Scanning electron microscopy (SEM) images and platelet adhesion studies. Stents coated with PCL matrix displayed more sustained and controlled drug release profiles than those coated with PLGA and PEG. Stents coated with PCL matrix showed the least platelet adhesion rate. Subsequently, stents coated with PCL matrix were subjected to the further optimization processes for improvement of surface morphology and enhancement of the drug release duration. The results of this study demonstrated that PCL matrix containing GSNO is a promising system for stent surface coating against restenosis. PMID:22937015

  3. TiO{sub 2}-coated foams as a medium for solar catalysis

    SciTech Connect

    Plantard, G.; Goetz, V.; Sacco, D.

    2011-02-15

    Graphical abstract: Photographs taken at the Scanning Electron Microscope of (a) a surface coating of TiO{sub 2}, (b) a mesh of a foam (mesh diameter of 2 mm) and (c) a foam. Research highlights: {yields} Assess the efficiency of the foams as a photocatalytic media. {yields} Foam to improve the apparent quantum yield. {yields} Foam makes good use of the UV rays to break down molecules. -- Abstract: Sunlight irradiating the surface of the Earth represents a maximum input available for a solar catalytic process of 50 W{sub UV} m{sup -2}. We propose using high-porosity, metallic, reticulated foams as the support medium for the photocatalyst in order to improve the apparent quantum yield. The layer of TiO{sub 2} was applied by dip-coating. The measurement of the degradation kinetics was carried out on a model target molecule, 2,4 dichlorophenol, at an initial concentration of 10 mg l{sup -1}. The aim was to assess the efficiency of the foams as a photocatalytic media compared to that of a suspension of catalytic powder (Degussa P25) and the flat 2D support (Ahlstrom cellulose media). The apparent quantum yield of the foam scaffold carrying the TiO{sub 2} was high, showing that, as with the powder suspension, foam makes good use of the UV rays to break down molecules. It is noteworthy that the apparent quantum yield of the foam tended towards that observed for suspensions which form the ideal support thanks to their optimal ability to harness the light.

  4. In situ monitoring of structure formation in the active layer of polymer solar cells during roll-to-roll coating

    SciTech Connect

    Rossander, Lea H.; Zawacka, Natalia K.; Dam, Henrik F.; Krebs, Frederik C.; Andreasen, Jens W.

    2014-08-15

    The active layer crystallization during roll-to-roll coating of organic solar cells is studied in situ. We developed an X-ray setup where the coater unit is an integrated part of the small angle X-ray scattering instrument, making it possible to control the coating process while recording scattering measurements in situ, enabling us to follow the crystal formation during drying. By varying the distance between the coating head and the point where the X-ray beam hits the film, we obtained measurements of 4 different stages of drying. For each of those stages, the scattering from as long a foil as possible is summed together, with the distance from coating head to scattering point kept constant. The results are average crystallographic properties for the active layer coated on a 30 m long foil. With this insight into the dynamics of crystallization in a roll-coated polymer film, we find that the formation of textured and untextured crystallites seems uncorrelated, and happens at widely different rates. Untextured P3HT crystallites form later in the drying process than expected which may explain previous studies speculating that untextured crystallization depends on concentration. Textured crystallites, however, begin forming much earlier and steadily increases as the film dries, showing a development similar to other in situ studies of these materials.

  5. Guidelines for selecting a solar heating, cooling or hot water design

    SciTech Connect

    Kelly, C.J. Jr.

    1981-12-01

    Guidelines are presented for the professional who may have to choose between competing solar heating and cooling designs for buildings. The experience of the National Solar Data Network in monitoring over 100 solar installations are drawn upon. Three basic principles and a design selection checklist are developed which will aid in choosing the most cost effective design.

  6. SOLCOST-PHOTOVOLTAIC solar energy design program: Users guide

    NASA Astrophysics Data System (ADS)

    1980-10-01

    The SOLCOST-PHOTOVOLTAIC (PV) solar energy design program is a public domain interactive computer design tool intended for use by non-solar specialists to predict the long term performance for photovoltaic systems. A life cycle cost analysis is included along with an economic analysis which predicts energy costs for the photovoltaic system assuming ownership by an electric utility. SOLCOST-PV currently can evaluate flat plate arrays and concentrating arrays which use Fresnel lenses and passive cooling. An overview of the SOLCOST-PV capabilities and methodology is given. A detailed guide to the SOLCOST-PV input parameters is included, and examples showing typical interactive execution sessions and the resulting SOLCOST-PV output are presented. Appendices A and B provide additional information on the SOLCOST-PV analysis.

  7. An effective methodology to design scale model for magnetic absorbing coatings based on ORL

    NASA Astrophysics Data System (ADS)

    Yuan, Liming; Wang, Bin; Gao, Wei; Xu, Yonggang; Wang, Xiaobing; Wu, Qilin

    The scale measurement has a great significance in studying electromagnetic scattering properties. But there still exist great difficulties in constructing an accurate scale model including nonmetallic materials such as magnetic absorbing coatings. Based on the reflective loss of a coating irradiated obliquely by plane microwave, a method is proposed to solve the problem of designing the scale coating. The commercial simulation software FEKO is used to investigate the use of the method. According to simulating monostatic RCS of coating plate models, coating sphere models and coating spherecone models, results reveal that the monostatic RCS of the designed scale model have a great agreement with that of the theoretical scale model in the whole incidence angle range. Furthermore, the coating SLICY models, which include many electromagnetic scattering mechanisms, are constructed to verify the proposed method. The simulated result of the designed scale SLICY model is very close to that of the theoretical scale SLICY model. All the simulated results indicate that the method proposed in this paper is valid.

  8. Evaluating newly designed lint cleaner grid bars to remove seed coat fragments

    USDA-ARS?s Scientific Manuscript database

    Seed coat fragments (SCF) cause spinning problems and undesirable defects in finished goods. An experiment was conducted to remove SCF at a saw-type lint cleaner using newly-designed grid bars. The test consisted of five experimental grid bar designs, one control grid bar design, and a treatment t...

  9. Design data brochure for CSI series V solar heating system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Generalized information on system configuration, system sizing, and mechanical layout is presented to assist the architect or designer in preparing construction drawings and specifications for the installation of the CSI integrated solar heating systems. Efficiency in space utilization of a full length collector and the importance of proper sizing of the collector array are among the topics discussed. Details of storage and transport subsystems are provided along with drawings and specifications of all components of the CSI system.

  10. Constellations Solar Array Design, Industrialization And In-Flight Results

    NASA Astrophysics Data System (ADS)

    Combet, Yannick; Clapper, Paul

    2011-10-01

    Constellations has become a recurring opportunities in Thales Alenia Space since 3 majors programs had been awarded: Globalstar was the pathfinder with 48 flight sets followed by O3b with 8 an the latest is Iridium Next with 81 models. For these 3 programs, the Solar Array is fully developed, validated and produced by Thales Alenia Space with major subcontractors. This new segment of the activity leads to new development, design and industrialization approaches. This paper describes the Solar Array design and the alternative to current approach build and applied with the following drivers: - the low recurring cost and mass of the flight hardware, with particular attention on the Solar Array, - high robustness for system integration and in-orbit operations, - a long mission duration (typically 15 years in LEO) leading to take into account high number of thermal cycles (60 to 72.000 cycles), - new production concept with strict schedule management, - design segmented in subassemblies to reduce the integration time as well as a improved trouble shooting management, - delivery rate up to 1 wing per week and after learning curve effect, a integration duration divided by 3 compared to current production, - a delivery of a qualified PFM solar array in 22 months including the design to producibility constrains, This demanding requirement for delivery scheme and cost target did not jeopardize the requirements and standards for space application. After a brief description of the way the main drivers have been considered, the paper presents the main features and performances of the subsystem and shows the main validation test results. The first launch was successful in October 2010 and the first in-orbit results are presented.

  11. Improved heliostat field design for solar tower plants

    NASA Astrophysics Data System (ADS)

    Collado, Francisco J.; Guallar, Jesús

    2017-06-01

    In solar power tower (SPT) systems, selecting the optimum location of thousands of heliostats and the most profitable tower height and receiver size remains a challenge. Campo code is prepared for the detailed design of such plants in particular, the optimum layout, provided that the plant size is known. Therefore, less exhaustive codes, as DELSOL3, are also needed to perform preliminary parametric analysis that narrows the most economic size of the plant.

  12. The Advanced Technology Solar Telescope: design and early construction

    NASA Astrophysics Data System (ADS)

    McMullin, Joseph P.; Rimmele, Thomas R.; Keil, Stephen L.; Warner, Mark; Barden, Samuel; Bulau, Scott; Craig, Simon; Goodrich, Bret; Hansen, Eric; Hegwer, Steve; Hubbard, Robert; McBride, William; Shimko, Steve; Wöger, Friedrich; Ditsler, Jennifer

    2012-09-01

    The National Solar Observatory’s (NSO) Advanced Technology Solar Telescope (ATST) is the first large U.S. solar telescope accessible to the worldwide solar physics community to be constructed in more than 30 years. The 4-meter diameter facility will operate over a broad wavelength range (0.35 to 28 μm ), employing adaptive optics systems to achieve diffraction limited imaging and resolve features approximately 20 km on the Sun; the key observational parameters (collecting area, spatial resolution, spectral coverage, polarization accuracy, low scattered light) enable resolution of the theoretically-predicted, fine-scale magnetic features and their dynamics which modulate the radiative output of the sun and drive the release of magnetic energy from the Sun’s atmosphere in the form of flares and coronal mass ejections. In 2010, the ATST received a significant fraction of its funding for construction. In the subsequent two years, the project has hired staff and opened an office on Maui. A number of large industrial contracts have been placed throughout the world to complete the detailed designs and begin constructing the major telescope subsystems. These contracts have included the site development, AandE designs, mirrors, polishing, optic support assemblies, telescope mount and coudé rotator structures, enclosure, thermal and mechanical systems, and high-level software and controls. In addition, design development work on the instrument suite has undergone significant progress; this has included the completion of preliminary design reviews (PDR) for all five facility instruments. Permitting required for physically starting construction on the mountaintop of Haleakalā, Maui has also progressed. This paper will review the ATST goals and specifications, describe each of the major subsystems under construction, and review the contracts and lessons learned during the contracting and early construction phases. Schedules for site construction, key factory testing of

  13. Diffractive flat panel solar concentrators of a novel design.

    PubMed

    de Jong, Ties M; de Boer, Dick K G; Bastiaansen, Cees W M

    2016-07-11

    A novel design for a flat panel solar concentrator is presented which is based on a light guide with a grating applied on top that diffracts light into total internal reflection. By combining geometrical and diffractive optics the geometrical concentration ratio is optimized according to the principles of nonimaging optics, while the thickness of the device is minimized due to the use of total internal reflection.

  14. Using mixed solvent and changing spin-coating parameters to increase the efficiency and lifetime of organic solar cells.

    PubMed

    Tsai, Yu Sheng; Chu, Wei-Ping; Tang, Rong-Ming; Juang, Fuh-Shyang; Chang, Ming-Hua; Liu, Mark O; Hsieh, Tsung-Eong

    2008-10-01

    The derivative of C60, i.e., PCBM, and P3HT (3-hexylthiophene) were dissolved in chloroform:dichlorobenzene mixed solvent, then spin-coated as the active layer for organic solar cells (OSC). The experimental parameters were studied carefully to obtain the optimum power conversion efficiency (PCE), including the solvent mixing ratio, spin-coating speed, annealing conditions for the active layer, etc. The OSC devices were packaged with glass and a newly developed UV-glue to improve the lifetime and PCE. Dichlorobenzene solvent has great effect upon the PCE. Changing the spin-coating speed and increasing the number of steps increased the PCE apparently to 1.4%.

  15. Design of multichannel image processing on the Space Solar Telescope

    NASA Astrophysics Data System (ADS)

    Zhang, Bin

    2000-07-01

    The multi-channel image processing system on the Space Solar Telescope (SST) is described in this paper. This system is main part of science data unit (SDU), which is designed for dealing with the science data from every payload on the SST. First every payload on the SST and its scientific objective are introduced. They are main optic telescope, four soft X- ray telescopes, an H-alpha and white light (full disc) telescope, a coronagraph, a wide band X-ray and Gamma-ray spectrometer, and a solar and interplanetary radio spectrometer. Then the structure of SDU is presented. In this part, we discuss the hardware and software structure of SDU, which is designed for multi-payload. The science data scream of every payload is summarized, too. Solar magnetic and velocity field processing that occupies more than 90% of the data processing of SDU is discussed, which includes polarizing unit, image receiver and image adding unit. Last the plan of image data compression and mass memory that is designed for science data storage are presented.

  16. Comprehensive design of omnidirectional high-performance perovskite solar cells

    PubMed Central

    Zhang, Yutao; Xuan, Yimin

    2016-01-01

    The comprehensive design approach is established with coupled optical-electrical simulation for perovskite-based solar cell, which emerged as one of the most promising competitors to silicon solar cell for its low-cost fabrication and high PCE. The selection of structured surface, effect of geometry parameters, incident angle-dependence and polarization-sensitivity are considered in the simulation. The optical modeling is performed via the finite-difference time-domain method whilst the electrical properties are obtained by solving the coupled nonlinear equations of Poisson, continuity, and drift-diffusion equations. The optical and electrical performances of five different structured surfaces are compared to select a best structured surface for perovskite solar cell. The effects of the geometry parameters on the optical and electrical properties of the perovskite cell are analyzed. The results indicate that the light harvesting is obviously enhanced by the structured surface. The electrical performance can be remarkably improved due to the enhanced light harvesting of the designed best structured surface. The angle-dependence for s- and p-polarizations is investigated. The structured surface exhibits omnidirectional behavior and favorable polarization-insensitive feature within a wide incident angle range. Such a comprehensive design approach can highlight the potential of perovskite cell for power conversion in the full daylight. PMID:27405419

  17. Comprehensive design of omnidirectional high-performance perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Zhang, Yutao; Xuan, Yimin

    2016-07-01

    The comprehensive design approach is established with coupled optical-electrical simulation for perovskite-based solar cell, which emerged as one of the most promising competitors to silicon solar cell for its low-cost fabrication and high PCE. The selection of structured surface, effect of geometry parameters, incident angle-dependence and polarization-sensitivity are considered in the simulation. The optical modeling is performed via the finite-difference time-domain method whilst the electrical properties are obtained by solving the coupled nonlinear equations of Poisson, continuity, and drift-diffusion equations. The optical and electrical performances of five different structured surfaces are compared to select a best structured surface for perovskite solar cell. The effects of the geometry parameters on the optical and electrical properties of the perovskite cell are analyzed. The results indicate that the light harvesting is obviously enhanced by the structured surface. The electrical performance can be remarkably improved due to the enhanced light harvesting of the designed best structured surface. The angle-dependence for s- and p-polarizations is investigated. The structured surface exhibits omnidirectional behavior and favorable polarization-insensitive feature within a wide incident angle range. Such a comprehensive design approach can highlight the potential of perovskite cell for power conversion in the full daylight.

  18. Comprehensive design of omnidirectional high-performance perovskite solar cells.

    PubMed

    Zhang, Yutao; Xuan, Yimin

    2016-07-13

    The comprehensive design approach is established with coupled optical-electrical simulation for perovskite-based solar cell, which emerged as one of the most promising competitors to silicon solar cell for its low-cost fabrication and high PCE. The selection of structured surface, effect of geometry parameters, incident angle-dependence and polarization-sensitivity are considered in the simulation. The optical modeling is performed via the finite-difference time-domain method whilst the electrical properties are obtained by solving the coupled nonlinear equations of Poisson, continuity, and drift-diffusion equations. The optical and electrical performances of five different structured surfaces are compared to select a best structured surface for perovskite solar cell. The effects of the geometry parameters on the optical and electrical properties of the perovskite cell are analyzed. The results indicate that the light harvesting is obviously enhanced by the structured surface. The electrical performance can be remarkably improved due to the enhanced light harvesting of the designed best structured surface. The angle-dependence for s- and p-polarizations is investigated. The structured surface exhibits omnidirectional behavior and favorable polarization-insensitive feature within a wide incident angle range. Such a comprehensive design approach can highlight the potential of perovskite cell for power conversion in the full daylight.

  19. Design and calculation of low infrared transmittance and low emissivity coatings for heat radiative applications

    NASA Astrophysics Data System (ADS)

    Wang, Guang-Hai; Zhang, Yue; Zhang, Da-Hai; Fan, Jin-Peng

    2012-02-01

    The infrared transmittance and emissivity of heat-insulating coatings pigmented with various structural particles were studied using Kubelka-Munk theory and Mie theory. The primary design purpose was to obtain the low transmittance and low emissivity coatings to reduce the heat transfer by thermal radiation for high-temperature applications. In the case of silica coating layers constituted with various structural titania particles (solid, hollow, and core-shell spherical), the dependence of transmittance and emissivity of the coating layer on the particle structure and the layer thickness was investigated and optimized. The results indicate that the coating pigmented with core-shell titania particles exhibits a lower infrared transmittance and a lower emissivity value than that with other structural particles and is suitable to radiative heat-insulating applications.

  20. Environmental Barrier Coatings for Turbine Engines: A Design and Performance Perspective

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming; Fox, Dennis S.; Ghosn, Louis; Smialek, James L.; Miller, Robert A.

    2009-01-01

    Ceramic thermal and environmental barrier coatings (TEBC) for SiC-based ceramics will play an increasingly important role in future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. However, the coating long-term durability remains a major concern with the ever-increasing temperature, strength and stability requirements in engine high heat-flux combustion environments, especially for highly-loaded rotating turbine components. Advanced TEBC systems, including nano-composite based HfO2-aluminosilicate and rare earth silicate coatings are being developed and tested for higher temperature capable SiC/SiC ceramic matrix composite (CMC) turbine blade applications. This paper will emphasize coating composite and multilayer design approach and the resulting performance and durability in simulated engine high heat-flux, high stress and high pressure combustion environments. The advances in the environmental barrier coating development showed promise for future rotating CMC blade applications.

  1. Durability of Solar Reflective Materials with an Alumina Hard Coat Produced by Ion-Beam-Assisted Deposition: Preprint

    SciTech Connect

    Kennedy, C. E.; Smilgys, R. V.

    2002-10-01

    A promising low-cost reflector material for solar concentrating power (CSP) generation is a silvered substrate protected by an alumina coating several microns thick. The alumina hard coat is deposited under high vacuum by ion-beam-assisted-deposition (IBAD). Samples of this material have been produced both by batch and continuous roll-coating processes. The substrate materials investigated were polyethylene terephthalate (PET), PET laminated to stainless-steel foil, and chrome-plated carbon steel strip. The advantage of steel strip compared to PET is that it withstands a higher process temperature and lowers the final product installation costs. In this paper, we compare the durability of batch and roll-coated reflective materials with an alumina deposition rate as high as 10 nm/s. In general, the durability of the samples is found to be excellent. Comparisons between accelerated and outdoor exposure testing results indicate that these front-surface mirrors are more susceptible to weather conditions not simulated by accelerated tests (i.e., rain, sleet, snow, etc.) than other types of solar reflectors. For long-term durability, edge protection will be necessary, and durability could be improved by the addition of an adhesion-promoting layer between the silver and alumina.

  2. Controlled Deposition and Performance Optimization of Perovskite Solar Cells Using Ultrasonic Spray-Coating of Photoactive Layers.

    PubMed

    Chang, Wei-Chieh; Lan, Ding-Hung; Lee, Kun-Mu; Wang, Xiao-Feng; Liu, Cheng-Liang

    2016-12-27

    This study investigated a new film-deposition technique, ultrasonic spray-coating, for use in the production of a photoactive layer of perovskite solar cells. Stable atomization and facile fabrication of perovskite thin films by ultrasonic spray-coating were achieved in a one-step method through manipulating the ink formulation (e.g., solution concentration, precursor composition, and mixing solvent ratio) and the drying kinetics (e.g., post-annealing temperature). The performance of the perovskite solar cells was mainly influenced by the intrinsic film morphology and crystalline orientation of the deposited perovskite layer. By suitable optimization of the spreading and drying conditions of the ink, ultrasonic spray-coated perovskite photovoltaic devices were obtained with a maximum power conversion efficiency of 11.30 %, a fill factor of 73.6 %, a short-circuit current of 19.7 mA cm(-1) , and an open-circuit voltage of 0.78 V, respectively. Notably, the average power efficiency reached above 10 %, attributed to the large flower-like perovskite crystal with orientation along the (1 1 2)/(2 0 0) and (2 2 4)/(4 0 0) directions. Thus, the ultrasonic spray-coating method for perovskite photoactive layers, combining advantages of good photovoltaic performance results and benefits from cost and processing, has the potential for large-scale commercial production.

  3. Dip coated nanocrystalline CdZnS thin films for solar cell application

    SciTech Connect

    Dongre, J. K. Chaturvedi, Mahim; Patil, Yuvraj; Sharma, Sandhya; Jain, U. K.

    2015-07-31

    Nanocrystalline cadmium sulfide (CdS) and zinc cadmium sulfide (ZnCdS) thin films have been grown via simple and low cost dip coating technique. The prepared films are characterized by X-ray diffraction (XRD), atomic force microscopic (AFM) and UV-VIS spectrophotometer techniques to reveal their structural, morphological and optical properties. XRD shows that both samples grown have zinc blende structure. The grain size is calculated as 6.2 and 8 nm using Scherrer’s formula. The band gap value of CdS and CdZnS film is estimated to be 2.58 and 2.69 eV respectively by UV-vis spectroscopy. Photoelectrochemical (PEC) investigations are carried out using cell configuration as n-CdZnS/(1M NaOH + 1M Na2S + 1M S)/C. The photovoltaic output characteristic is used to calculate fill-factor (FF) and solar conversion efficiency (η)

  4. Performance measurements of new silicon carbide coated reflectors for concentrated solar power applications

    NASA Astrophysics Data System (ADS)

    Belasri, Djawed; Nakamura, Kazuki; Armstrong, Peter; Calvet, Nicolas

    2016-05-01

    The new silicon carbide coated mirrors (SiC-mirrors) developed by Ibiden Co., Ltd. and tested at the Masdar Institute of Science and Technology offer several advantages in concentrated solar power (CSP) structure and operation. The purpose of this paper is to present the results of the reflectance and durability of the SiC-mirrors compared to high quality CSP glass mirrors in conjunction with two different applied cleaning methods. SiC-mirrors are 40 % lighter than high quality CSP glass mirrors, which leads to reduce costs of heliostat, parabolic trough or linear Fresnel structures, including assembly and installation time, lower drive power requirements, and stress during tracking operation. Lab and field tests show the SiC mirrors' reflectance is as high as the high quality CSP glass mirrors. Indeed, after 32 weeks of exposure, the high quality CSP glass mirrors' reflectance has decreased by 19 %, while the SiC mirrors' reflectance has decreased by 20 % when the brushing with water cleaning was applied. Using the brushing without water cleaning, the reflectance has decreased by 13 % and 2 % for the high quality CSP glass mirrors and the SiC-mirrors, respectively.

  5. Efficient spin-coating-free planar heterojunction perovskite solar cells fabricated with successive brush-painting

    NASA Astrophysics Data System (ADS)

    Lee, Jin-Won; Na, Seok-In; Kim, Seok-Soon

    2017-01-01

    To demonstrate fully brush-painted planar heterojunction perovskite solar cells (PeSCs), poly (3,4-ethylendioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) hole transport layer (HTL), CH3NH3PbI3 perovskite photoactive layer, and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) electron acceptor layer are successively brush-painted. In particular, correlation between morphology of perovskites and overall performance of PeSCs are investigated depending on the perovskites precursor. Devices with brush-painted perovskite using generally used N,N-dimethylformamide (DMF) solvent show poor performance and large deviation in cell-performance. However, PeSCs with brush-painted perovskite employing protic 2-Methoxyethanol (2-M) as DMF-alternative solvent exhibit comparable power conversion efficiency (PCE) of 9.08% to conventional spin-coated device and excellent reproducibility in device performance is observed as well. Furthermore, a fully brush-painted PeSC based on flexible substrates, showing PCE of 7.75%, is successfully demonstrated.

  6. Automated solar collector installation design including ability to define heterogeneous design preferences

    DOEpatents

    Wayne, Gary; Frumkin, Alexander; Zaydman, Michael; Lehman, Scott; Brenner, Jules

    2013-01-08

    Embodiments may include systems and methods to create and edit a representation of a worksite, to create various data objects, to classify such objects as various types of pre-defined "features" with attendant properties and layout constraints. As part of or in addition to classification, an embodiment may include systems and methods to create, associate, and edit intrinsic and extrinsic properties to these objects. A design engine may apply of design rules to the features described above to generate one or more solar collectors installation design alternatives, including generation of on-screen and/or paper representations of the physical layout or arrangement of the one or more design alternatives. Embodiments may also include definition of one or more design apertures, each of which may correspond to boundaries in which solar collector layouts should comply with distinct sets of user-defined design preferences. Distinct apertures may provide heterogeneous regions of collector layout according to the user-defined design preferences.

  7. Automated solar collector installation design including ability to define heterogeneous design preferences

    DOEpatents

    Wayne, Gary; Frumkin, Alexander; Zaydman, Michael; Lehman, Scott; Brenner, Jules

    2014-04-29

    Embodiments may include systems and methods to create and edit a representation of a worksite, to create various data objects, to classify such objects as various types of pre -defined "features" with attendant properties and layout constraints. As part of or in addition to classification, an embodiment may include systems and methods to create, associate, and edit intrinsic and extrinsic properties to these objects. A design engine may apply of design rules to the features described above to generate one or more solar collectors installation design alternatives, including generation of on-screen and/or paper representations of the physical layout or arrangement of the one or more design alternatives. Embodiments may also include definition of one or more design apertures, each of which may correspond to boundaries in which solar collector layouts should comply with distinct sets of user-defined design preferences. Distinct apertures may provide heterogeneous regions of collector layout according to the user-defined design preferences.

  8. Mortality monitoring design for utility-scale solar power facilities

    USGS Publications Warehouse

    Huso, Manuela; Dietsch, Thomas; Nicolai, Chris

    2016-05-27

    IntroductionSolar power represents an important and rapidly expanding component of the renewable energy portfolio of the United States (Lovich and Ennen, 2011; Hernandez and others, 2014). Understanding the impacts of renewable energy development on wildlife is a priority for the U.S. Fish and Wildlife Service (FWS) in compliance with Department of Interior Order No. 3285 (U.S. Department of the Interior, 2009) to “develop best management practices for renewable energy and transmission projects on the public lands to ensure the most environmentally responsible development and delivery of renewable energy.” Recent studies examining effects of renewable energy development on mortality of migratory birds have primarily focused on wind energy (California Energy Commission and California Department of Fish and Game, 2007), and in 2012 the FWS published guidance for addressing wildlife conservation concerns at all stages of land-based wind energy development (U.S. Fish and Wildlife Service, 2012). As yet, no similar guidelines exist for solar development, and no published studies have directly addressed the methodology needed to accurately estimate mortality of birds and bats at solar facilities. In the absence of such guidelines, ad hoc methodologies applied to solar energy projects may lead to estimates of wildlife mortality rates that are insufficiently accurate and precise to meaningfully inform conversations regarding unintended consequences of this energy source and management decisions to mitigate impacts. Although significant advances in monitoring protocols for wind facilities have been made in recent years, there remains a need to provide consistent guidance and study design to quantify mortality of bats, and resident and migrating birds at solar power facilities (Walston and others, 2015).In this document, we suggest methods for mortality monitoring at solar facilities that are based on current methods used at wind power facilities but adapted for the

  9. PSO based PI controller design for a solar charger system.

    PubMed

    Yau, Her-Terng; Lin, Chih-Jer; Liang, Qin-Cheng

    2013-01-01

    Due to global energy crisis and severe environmental pollution, the photovoltaic (PV) system has become one of the most important renewable energy sources. Many previous studies on solar charger integrated system only focus on load charge control or switching Maximum Power Point Tracking (MPPT) and charge control modes. This study used two-stage system, which allows the overall portable solar energy charging system to implement MPPT and optimal charge control of Li-ion battery simultaneously. First, this study designs a DC/DC boost converter of solar power generation, which uses variable step size incremental conductance method (VSINC) to enable the solar cell to track the maximum power point at any time. The voltage was exported from the DC/DC boost converter to the DC/DC buck converter, so that the voltage dropped to proper voltage for charging the battery. The charging system uses constant current/constant voltage (CC/CV) method to charge the lithium battery. In order to obtain the optimum PI charge controller parameters, this study used intelligent algorithm to determine the optimum parameters. According to the simulation and experimental results, the control parameters resulted from PSO have better performance than genetic algorithms (GAs).

  10. Concept designs for NASA's Solar Electric Propulsion Technology Demonstration Mission

    NASA Technical Reports Server (NTRS)

    Mcguire, Melissa L.; Hack, Kurt J.; Manzella, David H.; Herman, Daniel A.

    2014-01-01

    Multiple Solar Electric Propulsion Technology Demonstration Mission were developed to assess vehicle performance and estimated mission cost. Concepts ranged from a 10,000 kilogram spacecraft capable of delivering 4000 kilogram of payload to one of the Earth Moon Lagrange points in support of future human-crewed outposts to a 180 kilogram spacecraft capable of performing an asteroid rendezvous mission after launched to a geostationary transfer orbit as a secondary payload. Low-cost and maximum Delta-V capability variants of a spacecraft concept based on utilizing a secondary payload adapter as the primary bus structure were developed as were concepts designed to be co-manifested with another spacecraft on a single launch vehicle. Each of the Solar Electric Propulsion Technology Demonstration Mission concepts developed included an estimated spacecraft cost. These data suggest estimated spacecraft costs of $200 million - $300 million if 30 kilowatt-class solar arrays and the corresponding electric propulsion system currently under development are used as the basis for sizing the mission concept regardless of launch vehicle costs. The most affordable mission concept developed based on subscale variants of the advanced solar arrays and electric propulsion technology currently under development by the NASA Space Technology Mission Directorate has an estimated cost of $50M and could provide a Delta-V capability comparable to much larger spacecraft concepts.

  11. PSO Based PI Controller Design for a Solar Charger System

    PubMed Central

    Yau, Her-Terng; Lin, Chih-Jer; Liang, Qin-Cheng

    2013-01-01

    Due to global energy crisis and severe environmental pollution, the photovoltaic (PV) system has become one of the most important renewable energy sources. Many previous studies on solar charger integrated system only focus on load charge control or switching Maximum Power Point Tracking (MPPT) and charge control modes. This study used two-stage system, which allows the overall portable solar energy charging system to implement MPPT and optimal charge control of Li-ion battery simultaneously. First, this study designs a DC/DC boost converter of solar power generation, which uses variable step size incremental conductance method (VSINC) to enable the solar cell to track the maximum power point at any time. The voltage was exported from the DC/DC boost converter to the DC/DC buck converter, so that the voltage dropped to proper voltage for charging the battery. The charging system uses constant current/constant voltage (CC/CV) method to charge the lithium battery. In order to obtain the optimum PI charge controller parameters, this study used intelligent algorithm to determine the optimum parameters. According to the simulation and experimental results, the control parameters resulted from PSO have better performance than genetic algorithms (GAs). PMID:23766713

  12. NREL Designs Promising New Oxides for Solar Cells (Fact Sheet)

    SciTech Connect

    Not Available

    2012-04-01

    High-efficiency, thin-film solar cells require electrical contacts with high electrical conductivity, and the top contact must also have high optical transparency. This need is currently met by transparent conducting oxides (TCOs), which conduct electricity but are 90% transparent to visible light. Scientists at the National Renewable Energy Laboratory (NREL) have derived three key design principles for selecting promising materials for TCO contacts. NREL's application of these design principles has resulted in a 10,000-fold improvement in conductivity for one TCO material.

  13. Solar heating and cooling system design and development

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The progress of the program during the sixth program quarter is reported. The program calls for the development and delivery of eight prototype solar heating and cooling systems for installation and operational test. The William O'Brien single-family heating system was installed and is operational. The New Castle single-family heating residence is under construction. The Kansas University (KU) system is in the final design stages. The 25 ton cooling subsystem for KU is the debugging stage. Pressure drops that were greater than anticipated were encountered. The 3 ton simulation work is being finalized and the design parameters for the Rankine system were determined from simulation output.

  14. Solar central electric power generation - A baseline design

    NASA Technical Reports Server (NTRS)

    Powell, J. C.

    1976-01-01

    The paper presents the conceptual technical baseline design of a solar electric power plant using the central receiver concept, and derives credible cost estimates from the baseline design. The major components of the plant - heliostats, tower, receiver, tower piping, and thermal storage - are discussed in terms of technical and cost information. The assumed peak plant output is 215 MW(e), over 4000 daylight hours. The contribution of total capital investment to energy cost is estimated to be about 55 mills per kwh in mid-1974 dollars.

  15. Nacre biomimetic design--a possible approach to prepare low infrared emissivity composite coatings.

    PubMed

    Zhang, Weigang; Xu, Guoyue; Ding, Ruya; Duan, Kaige; Qiao, Jialiang

    2013-01-01

    Mimicking the highly organized brick-and-mortar structure of nacre, a kind of nacre-like organic-inorganic composite material of polyurethane (PU)/flaky bronze composite coatings with low infrared emissivity was successfully designed and prepared by using PU and flaky bronze powders as adhesives and pigments, respectively. The infrared emissivity and microstructure of the coatings were systematically investigated by infrared emissometer and scanning electron microscopy, respectively, and the cause of low infrared emissivity of the coatings was discussed by using the theories of one-dimensional photonic structure. The results show that the infrared emissivity of the nacre-like PU/flaky bronze composite coatings can be as low as 0.206 at the bronze content of 60 wt. %, and it is significantly lower than the value of PU/sphere bronze composite coatings. Microstructure observation illustrated that the nacre-like PU/flaky bronze composite coatings have similar one-dimensional photonic structural characteristics. The low infrared emissivity of PU/flaky bronze composite coatings is derived from the similar one-dimensional photonic structure in the coatings. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Design and calibration of the solar irradiance monitor

    NASA Astrophysics Data System (ADS)

    Yang, Dong-jun; Fang, Wei; Ye, Xin; Wang, Yu-peng; Gong, Cheng-hu; Zhang, Guang-wei

    2011-08-01

    The solar irradiance monitor (SIM), with the design accuracy of 5%, used to monitor the secular changes of the total solar irradiance on FY-3 satellite, takes the sun-scanning measurement method on-orbit. Compared to the sun-tracking measurement method, this method simplifies the structure and cuts the cost, but the measuring accuracy is affected by the sun-synchronous orbit, sunlight incidence angle and the installing angle of the SIM in the satellite. Through the ground calibration experiment, studies on the affection of different sunlight incidence angles to the measurement accuracy. First, by the satellite tool kit (STK) simulation software, simulates the orbital parameters of the sun-synchronous satellite, and calculates the Sun ascension and declination at any time. By the orbit coordinate transformation matrix gets the components of the Sun vectors to the axes of the satellite, and base on the components designs the field of view and the installing angles of the SIM. Then, designs and completes the calibration experiment to calibrate the affection of the incidence angles. Selecting 11 different angles between the sunlight and the satellite X-axis, measures the total solar irradiance by the SIM at each angle, and compares to the irradiances of the SIAR reference radiometers, and gets the coefficient curves of the three channels of the SIM. Finally, by the quadratic fitting, gets the correction equations on the incidence angles: 5 2 3 R1 5.71x10-5α2 - 2.453 10-5 α2 1.0302, R2 = 2.84×10-5α2-1.965x10-3α+1.0314 and R3 =1.72x10-5α2-4.184x10-4α+0.9946. The equations will improve the on-orbit measurement accuracy of the solar irradiance, and are very important to the on-orbit data processing after the satellite launched.

  17. Architectural design of diamond-like carbon coatings for long-lasting joint replacements.

    PubMed

    Liu, Yujing; Zhao, Xiaoli; Zhang, Lai-Chang; Habibi, Daryoush; Xie, Zonghan

    2013-07-01

    Surface engineering through the application of super-hard, low-friction coatings as a potential approach for increasing the durability of metal-on-metal replacements is attracting significant attention. In this study innovative design strategies are proposed for the development of diamond-like-carbon (DLC) coatings against the damage caused by wear particles on the joint replacements. Finite element modeling is used to analyze stress distributions induced by wear particles of different sizes in the newly-designed coating in comparison to its conventional monolithic counterpart. The critical roles of architectural design in regulating stress concentrations and suppressing crack initiation within the coatings is elucidated. Notably, the introduction of multilayer structure with graded modulus is effective in modifying the stress field and reducing the magnitude and size of stress concentrations in the DLC diamond-like-carbon coatings. The new design is expected to greatly improve the load-carrying ability of surface coatings on prosthetic implants, in addition to the provision of damage tolerance through crack arrest. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Steam generator design for solar towers using solar salt as heat transfer fluid

    NASA Astrophysics Data System (ADS)

    González-Gómez, Pedro Ángel; Petrakopoulou, Fontina; Briongos, Javier Villa; Santana, Domingo

    2017-06-01

    Since the operation of a concentrating solar power plant depends on the intermittent character of solar energy, the steam generator is subject to daily start-ups, stops and load variations. Faster start-up and load changes increase the plant flexibility and the daily energy production. However, it involves high thermal stresses on thick-walled components. Continuous operational conditions may eventually lead to a material failure. For these reasons, it is important to evaluate the transient behavior of the proposed designs in order to assure the reliability. The aim of this work is to analyze different steam generator designs for solar power tower plants using molten salt as heat transfer fluid. A conceptual steam generator design is proposed and associated heat transfer areas and steam drum size are calculated. Then, dynamic models for the main parts of the steam generator are developed to represent its transient performance. A temperature change rate that ensures safe hot start-up conditions is studied for the molten salt. The thermal stress evolution on the steam drum is calculated as key component of the steam generator.

  19. Habitat Design Considerations for Implementing Solar Particle Event Radiation Protection

    NASA Technical Reports Server (NTRS)

    Simon, Mathew A.; Clowdsley, Martha S.; Walker, Steven A.

    2013-01-01

    Radiation protection is an important habitat design consideration for human exploration missions beyond Low Earth Orbit. Fortunately, radiation shelter concepts can effectively reduce astronaut exposure for the relatively low proton energies of solar particle events, enabling moderate duration missions of several months before astronaut exposure (galactic cosmic ray and solar particle event) approaches radiation exposure limits. In order to minimize habitat mass for increasingly challenging missions, design of radiation shelters must minimize dedicated, single-purpose shielding mass by leveraging the design and placement of habitat subsystems, accommodations, and consumables. NASA's Advanced Exploration Systems RadWorks Storm Shelter Team has recently designed and performed radiation analysis on several low dedicated mass shelter concepts for a year-long mission. This paper describes habitat design considerations identified during the study's radiation analysis. These considerations include placement of the shelter within a habitat for improved protection, integration of human factors guidance for sizing shelters, identification of potential opportunities for habitat subsystems to compromise on individual subsystem performances for overall vehicle mass reductions, and pre-configuration of shelter components for reduced deployment times.

  20. Photoresponsive polymer design for solar concentrator self-steering heliostats

    NASA Astrophysics Data System (ADS)

    Barker, Jessica; Basnet, Amod; Bhaduri, Moinak; Burch, Caroline; Chow, Amenda; Li, Xue; Oates, William S.; Massad, Jordan E.; Smith, Ralph

    2014-03-01

    Concentrating solar energy and transforming it into electricity is clean, economical and renewable. One design of solar power plants consists of an array of heliostats which redirects sunlight to a fixed receiver tower and the generated heat is converted into electricity. Currently, the angles of elevation of heliostats are controlled by motors and drives that are costly and require diverting power that can otherwise be used for producing electricity. We consider replacing the motor and drive system of the heliostat with a photosensitive polymer design that can tilt the mirror using the ability of the polymer to deform when subjected to light. The light causes the underlying molecular structure to change and subsequently, the polymer deforms. The deformation of the polymer is quantified in terms of photostrictive constitutive relations. A mathematical model is derived governing the behaviour of the angle of elevation as the photostrain varies. Photostrain depends on the composition of the polymer, intensity and temperature of light and angle of light polarization. Preliminary findings show a photomechanical rod structural design can provide 60° elevation for temperatures of about 40°C. A photomechanical beam structural design can generate more tilt at lower temperatures. The mathematical analysis illustrates that photostrains on the order of 1% to 10% are desired for both rod and beam designs to produce sufficient tilt under most heliostat field conditions.