Sample records for absorbs solar energy

  1. Semiconductor-based Multilayer Selective Solar Absorber for Unconcentrated Solar Thermal Energy Conversion.

    PubMed

    Thomas, Nathan H; Chen, Zhen; Fan, Shanhui; Minnich, Austin J

    2017-07-13

    Solar thermal energy conversion has attracted substantial renewed interest due to its applications in industrial heating, air conditioning, and electricity generation. Achieving stagnation temperatures exceeding 200 °C, pertinent to these technologies, with unconcentrated sunlight requires spectrally selective absorbers with exceptionally low emissivity in the thermal wavelength range and high visible absorptivity for the solar spectrum. In this Communication, we report a semiconductor-based multilayer selective absorber that exploits the sharp drop in optical absorption at the bandgap energy to achieve a measured absorptance of 76% at solar wavelengths and a low emittance of approximately 5% at thermal wavelengths. In field tests, we obtain a peak temperature of 225 °C, comparable to that achieved with state-of-the-art selective surfaces. With straightforward optimization to improve solar absorption, our work shows the potential for unconcentrated solar thermal systems to reach stagnation temperatures exceeding 300 °C, thereby eliminating the need for solar concentrators for mid-temperature solar applications such as supplying process heat.

  2. Semiconductor-based Multilayer Selective Solar Absorber for Unconcentrated Solar Thermal Energy Conversion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Thomas, Nathan H.; Chen, Zhen; Fan, Shanhui

    Solar thermal energy conversion has attracted substantial renewed interest due to its applications in industrial heating, air conditioning, and electricity generation. Achieving stagnation temperatures exceeding 200 °C, pertinent to these technologies, with unconcentrated sunlight requires spectrally selective absorbers with exceptionally low emissivity in the thermal wavelength range and high visible absorptivity for the solar spectrum. In this Communication, we then report a semiconductor-based multilayer selective absorber that exploits the sharp drop in optical absorption at the bandgap energy to achieve a measured absorptance of 76% at solar wavelengths and a low emittance of approximately 5% at thermal wavelengths. In fieldmore » tests, we obtain a peak temperature of 225 °C, comparable to that achieved with state-of-the-art selective surfaces. Furthemore, with straightforward optimization to improve solar absorption, our work shows the potential for unconcentrated solar thermal systems to reach stagnation temperatures exceeding 300 °C, thereby eliminating the need for solar concentrators for mid-temperature solar applications such as supplying process heat« less

  3. Semiconductor-based Multilayer Selective Solar Absorber for Unconcentrated Solar Thermal Energy Conversion

    DOE PAGES

    Thomas, Nathan H.; Chen, Zhen; Fan, Shanhui; ...

    2017-07-13

    Solar thermal energy conversion has attracted substantial renewed interest due to its applications in industrial heating, air conditioning, and electricity generation. Achieving stagnation temperatures exceeding 200 °C, pertinent to these technologies, with unconcentrated sunlight requires spectrally selective absorbers with exceptionally low emissivity in the thermal wavelength range and high visible absorptivity for the solar spectrum. In this Communication, we then report a semiconductor-based multilayer selective absorber that exploits the sharp drop in optical absorption at the bandgap energy to achieve a measured absorptance of 76% at solar wavelengths and a low emittance of approximately 5% at thermal wavelengths. In fieldmore » tests, we obtain a peak temperature of 225 °C, comparable to that achieved with state-of-the-art selective surfaces. Furthemore, with straightforward optimization to improve solar absorption, our work shows the potential for unconcentrated solar thermal systems to reach stagnation temperatures exceeding 300 °C, thereby eliminating the need for solar concentrators for mid-temperature solar applications such as supplying process heat« less

  4. Optical analysis of solar energy tubular absorbers.

    PubMed

    Saltiel, C; Sokolov, M

    1982-11-15

    The energy absorbed by a solar energy tubular receiver element for a single incident ray is derived. Two types of receiver elements were analyzed: (1) an inner tube with an absorbing coating surrounded by a semitransparent cover tube, and (2) a semitransparent inner tube filled with an absorbing fluid surrounded by a semitransparent cover tube. The formation of ray cascades in the semitransparent tubes is considered. A numerical simulation to investigate the influence of the angle of incidence, sizing, thickness, and coefficient of extinction of the tubes was performed. A comparison was made between receiver elements with and without cover tubes. Ray tracing analyses in which rays were followed within the tubular receiver element as well as throughout the rest of the collector were performed for parabolic and circular trough concentrating collectors.

  5. Solar sustained plasma/absorber conceptual design

    NASA Technical Reports Server (NTRS)

    Rodgers, R. J.; Krascella, N. L.; Kendall, J. S.

    1979-01-01

    A space power system concept was evaluated which uses concentrated solar energy to heat a working fluid to temperatures as high as 4000 K. The high temperature working fluid could be used for efficient electric power production in advanced thermal or magnetohydrodynamic conversion cycles. Energy absorber configurations utilizing particles or cesium vapor absorber material were investigaed. Results of detailed radiant heat transfer calculations indicated approximately 86 percent of the incident solar energy could be absorbed within a 12-cm-dia flowing stream of gas borne carbon particles. Calculated total energy absorption in the cesium vapor seeded absorber configuration ranged from 34 percent to 64 percent of the incident solar energy. Solar flux concentration ratios of between approximately 3000 and 10,000 will be required to sustain absorber temperatures in the range from 3000 K to 4000 K.

  6. Solar energy collector

    DOEpatents

    Brin, Raymond L.; Pace, Thomas L.

    1978-01-01

    The invention relates to a solar energy collector comprising solar energy absorbing material within chamber having a transparent wall, solar energy being transmitted through the transparent wall, and efficiently absorbed by the absorbing material, for transfer to a heat transfer fluid. The solar energy absorbing material, of generally foraminous nature, absorbs and transmits the solar energy with improved efficiency.

  7. Dynamic tuning of optical absorbers for accelerated solar-thermal energy storage.

    PubMed

    Wang, Zhongyong; Tong, Zhen; Ye, Qinxian; Hu, Hang; Nie, Xiao; Yan, Chen; Shang, Wen; Song, Chengyi; Wu, Jianbo; Wang, Jun; Bao, Hua; Tao, Peng; Deng, Tao

    2017-11-14

    Currently, solar-thermal energy storage within phase-change materials relies on adding high thermal-conductivity fillers to improve the thermal-diffusion-based charging rate, which often leads to limited enhancement of charging speed and sacrificed energy storage capacity. Here we report the exploration of a magnetically enhanced photon-transport-based charging approach, which enables the dynamic tuning of the distribution of optical absorbers dispersed within phase-change materials, to simultaneously achieve fast charging rates, large phase-change enthalpy, and high solar-thermal energy conversion efficiency. Compared with conventional thermal charging, the optical charging strategy improves the charging rate by more than 270% and triples the amount of overall stored thermal energy. This superior performance results from the distinct step-by-step photon-transport charging mechanism and the increased latent heat storage through magnetic manipulation of the dynamic distribution of optical absorbers.

  8. Colorful solar selective absorber integrated with different colored units.

    PubMed

    Chen, Feiliang; Wang, Shao-Wei; Liu, Xingxing; Ji, Ruonan; Li, Zhifeng; Chen, Xiaoshuang; Chen, Yuwei; Lu, Wei

    2016-01-25

    Solar selective absorbers are the core part for solar thermal technologies such as solar water heaters, concentrated solar power, solar thermoelectric generators and solar thermophotovoltaics. Colorful solar selective absorber can provide new freedom and flexibility beyond energy performance, which will lead to wider utilization of solar technologies. In this work, we present a monolithic integration of colored solar absorber array with different colors on a single substrate based on a multilayered structure of Cu/TiN(x)O(y)/TiO(2)/Si(3)N(4)/SiO(2). A colored solar absorber array with 16 color units is demonstrated experimentally by using combinatorial deposition technique via changing the thickness of SiO(2) layer. The solar absorptivity and thermal emissivity of all the color units is higher than 92% and lower than 5.5%, respectively. The colored solar selective absorber array can have colorful appearance and designable patterns while keeping high energy performance at the same time. It is a new candidate for a number of solar applications, especially for architecture integration and military camouflage.

  9. Solar radiation absorbing material

    DOEpatents

    Googin, John M.; Schmitt, Charles R.; Schreyer, James M.; Whitehead, Harlan D.

    1977-01-01

    Solar energy absorbing means in solar collectors are provided by a solar selective carbon surface. A solar selective carbon surface is a microporous carbon surface having pores within the range of 0.2 to 2 micrometers. Such a surface is provided in a microporous carbon article by controlling the pore size. A thermally conductive substrate is provided with a solar selective surface by adhering an array of carbon particles in a suitable binder to the substrate, a majority of said particles having diameters within the range of about 0.2-10 microns.

  10. Selective solar absorber emittance measurement at elevated temperature

    NASA Astrophysics Data System (ADS)

    Giraud, Philémon; Braillon, Julien; Raccurt, Olivier

    2017-06-01

    Durability of solar components for CSP (Concentrated Solar Power Plant) technologies is a key point to lower cost and ensure their large deployment. These technologies concentrated the solar radiation by means of mirrors on a receiver tube where it is collected as thermal energy. The absorbers are submitted to strong environmental constraints and the degradation of their optical properties (emittance and solar absorbance) have a direct impact on performance. The characterization of a material in such condition is complicated and requires advanced apparatuses, and different measurement methods exist for the determination of the two quantities of relevance regarding an absorber, which are its emittance and its solar absorbance. The objective is to develop new optical equipment for measure the emittance of this solar absorber at elevated temperature. In this paper, we present an optical bench developed for emittance measurement on absorbers is conditions of use. Results will be shown, with a discussion of some factors of influence over this measurement and how to control them.

  11. Temperature Response of Emissivity in Intrinsic Silicon: A Selective Absorber for Solar Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Heredia, Cristian Alonso

    The National Academy of Engineers named affordable solar energy as one of the grand challenges for the twenty-first century. Even in sunniest U.S. locations, without subsidies, home generation is still cost prohibitive. To address the cost of solar energy, we investigated intrinsic silicon as a low emissivity selective absorber. We wanted to determine the emissivity of intrinsic silicon at elevated temperatures. At elevated temperatures, a selective absorber coupled to a heat engine could efficiently generate electrical power. Photothermal efficiency depends on the absorber's emissivity. I analyzed total hemispherical emissivity for graphite and intrinsic silicon using a thermal decay method inside a thermal isolation chamber. The results show low emissivity values for intrinsic silicon. Consequently, for temperatures less than 300 °C, intrinsic silicon has a small emissivity (0.16). This small value is in agreement with doped silicon experiments. However, unlike doped silicon, at elevated temperatures of 600 °C, intrinsic silicon emissivity values remain low (0.33). Our analysis suggests intrinsic silicon could convert more solar power into heat than an ideal blackbody. Specifically, the harvested heat could drive a heat engine for efficient power generation. Thus, a cost-effective electrical generating system can operate with a small land footprint using earth abundant silicon.

  12. Thin film absorber for a solar collector

    DOEpatents

    Wilhelm, William G.

    1985-01-01

    This invention pertains to energy absorbers for solar collectors, and more particularly to high performance thin film absorbers. The solar collectors comprising the absorber of this invention overcome several problems seen in current systems, such as excessive hardware, high cost and unreliability. In the preferred form, the apparatus features a substantially rigid planar frame with a thin film window bonded to one planar side of the frame. An absorber in accordance with the present invention is comprised of two thin film layers that are sealed perimetrically. In a preferred embodiment, thin film layers are formed from a metal/plastic laminate. The layers define a fluid-tight planar envelope of large surface area to volume through which a heat transfer fluid flows. The absorber is bonded to the other planar side of the frame. The thin film construction of the absorber assures substantially full envelope wetting and thus good efficiency. The window and absorber films stress the frame adding to the overall strength of the collector.

  13. Development of a carbonaceous selective absorber for solar thermal energy collection and process for its formation

    NASA Astrophysics Data System (ADS)

    Garrison, John D.

    1989-02-01

    The main goal of the US Department of Energy supported part of this project is to develop information about controlling the complicated chemical processes involved in the formation of a carbonaceous selective absorber and learn what equipment will allow production of this absorber commercially. The work necessary to accomplish this goal is not yet complete. Formation of the carbonaceous selective absorber in the conveyor oven tried so far has been unsatisfactory, because the proper conditions for applying the carbonaceous coating in each conveyor oven fabricated, either have been difficult to obtain, or have been difficult to maintain over an extended period of time. A new conveyor oven is nearing completion which is expected to allow formation of the carbonaceous selective absorber on absorber tubes in a continuous operation over many days without the necessity of cleaning the conveyor oven or changing the thickness of the electroplated nickel catalyst to compensate for changes in the coating environment in the oven. Work under this project concerned with forming and sealing glass panels to test ideas on evacuated glass solar collector designs and production have been generally quite satisfactory. Delays in completion of the selective absorber work, has caused postponement of the fabrication of a small prototype evacuated glass solar collector panel. Preliminary cost estimates of the selective absorber and solar collector panel indicate that this collector system should be lower in cost than evacuated solar collectors now on the market.

  14. Solar Energy Technician/Installer

    ERIC Educational Resources Information Center

    Moore, Pam

    2007-01-01

    Solar power (also known as solar energy) is solar radiation emitted from the sun. Large panels that absorb the sun's energy as the sun beats down on them gather solar power. The energy in the rays can be used for heat (solar thermal energy) or converted to electricity (photovoltaic energy). Each solar energy project, from conception to…

  15. New Insight into the Angle Insensitivity of Ultrathin Planar Optical Absorbers for Broadband Solar Energy Harvesting.

    PubMed

    Liu, Dong; Yu, Haitong; Duan, Yuanyuan; Li, Qiang; Xuan, Yimin

    2016-09-01

    Two challenging problems still remain for optical absorbers consisting of an ultrathin planar semiconductor film on top of an opaque metallic substrate. One is the angle-insensitive mechanism and the other is the system design needed for broadband solar energy harvesting. Here, first we theoretically demonstrates that the high refractive index, instead of the ultrathin feature as reported in previous studies, is the physical origin of the angle insensitivity for ultrathin planar optical absorbers. They exhibit omnidirectional resonance for TE polarization due to the high complex refractive index difference between the semiconductor and the air, while for TM polarization the angle insensitivity persists up to an incident angle related to the semiconductor refractive index. These findings were validated by fabricating and characterizing an 18 nm Ge/Ag absorber sample (representative of small band gap semiconductors for photovoltaic applications) and a 22 nm hematite/Ag sample (representative of large band gap semiconductors for photoelectrochemical applications). Then, we took advantage of angle insensitivity and designed a spectrum splitting configuration for broadband solar energy harvesting. The cascaded solar cell and unassisted solar water splitting systems have photovoltaic and photoelectrochemical cells that are also spectrum splitters, so an external spectrum splitting element is not needed.

  16. Seasonal Evolution and Interannual Variability of the Local Solar Energy Absorbed by the Arctic Sea Ice-Ocean System

    NASA Technical Reports Server (NTRS)

    Perovich, Donald K.; Nghiem, Son V.; Markus, Thorsten; Schwieger, Axel

    2007-01-01

    The melt season of the Arctic sea ice cover is greatly affected by the partitioning of the incident solar radiation between reflection to the atmosphere and absorption in the ice and ocean. This partitioning exhibits a strong seasonal cycle and significant interannual variability. Data in the period 1998, 2000-2004 were analyzed in this study. Observations made during the 1997-1998 SHEBA (Surface HEat Budget of the Arctic Ocean) field experiment showed a strong seasonal dependence of the partitioning, dominated by a five-phase albedo evolution. QuikSCAT scatterometer data from the SHEBA region in 1999-2004 were used to further investigate solar partitioning in summer. The time series of scatterometer data were used to determine the onset of melt and the beginning of freezeup. This information was combined with SSM/I-derived ice concentration, TOVS-based estimates of incident solar irradiance, and SHEBA results to estimate the amount of solar energy absorbed in the ice-ocean system for these years. The average total solar energy absorbed in the ice-ocean system from April through September was 900 MJ m(sup -2). There was considerable interannual variability, with a range of 826 to 1044 MJ m(sup -2). The total amount of solar energy absorbed by the ice and ocean was strongly related to the date of melt onset, but only weakly related to the total duration of the melt season or the onset of freezeup. The timing of melt onset is significant because the incident solar energy is large and a change at this time propagates through the entire melt season, affecting the albedo every day throughout melt and freezeup.

  17. Solar energy collection system

    NASA Technical Reports Server (NTRS)

    Miller, C. G.; Stephens, J. B. (Inventor)

    1979-01-01

    A fixed, linear, ground-based primary reflector having an extended curved sawtooth-contoured surface covered with a metalized polymeric reflecting material, reflects solar energy to a movably supported collector that is kept at the concentrated line focus reflector primary. The primary reflector may be constructed by a process utilizing well known freeway paving machinery. The solar energy absorber is preferably a fluid transporting pipe. Efficient utilization leading to high temperatures from the reflected solar energy is obtained by cylindrical shaped secondary reflectors that direct off-angle energy to the absorber pipe. A seriatim arrangement of cylindrical secondary reflector stages and spot-forming reflector stages produces a high temperature solar energy collection system of greater efficiency.

  18. Organometal Halide Perovskite Solar Absorbers and Ferroelectric Nanocomposites for Harvesting Solar Energy

    NASA Astrophysics Data System (ADS)

    Hettiarachchi, Chaminda Lakmal

    Organometal halide perovskite absorbers such as methylammonium lead iodide chloride (CH3NH3PbI3-xClx), have emerged as an exciting new material family for photovoltaics due to its appealing features that include suitable direct bandgap with intense light absorbance, band gap tunability, ultra-fast charge carrier generation, slow electron-hole recombination rates, long electron and hole diffusion lengths, microsecond-long balanced carrier mobilities, and ambipolarity. The standard method of preparing CH3NH3PbI3-xClx perovskite precursors is a tedious process involving multiple synthesis steps and, the chemicals being used (hydroiodic acid and methylamine) are quite expensive. This work describes a novel, single-step, simple, and cost-effective solution approach to prepare CH3NH3PbI3-xClx thin films by the direct reaction of the commercially available CH3NH 3Cl (or MACl) and PbI2. A detailed analysis of the structural and optical properties of CH3NH3PbI3-xCl x thin films deposited by aerosol assisted chemical vapor deposition is presented. Optimum growth conditions have been identified. It is shown that the deposited thin films are highly crystalline with intense optical absorbance. Charge carrier separation of these thin films can be enhanced by establishing a local internal electric field that can reduce electron-hole recombination resulting in increased photo current. The intrinsic ferroelectricity in nanoparticles of Barium Titanate (BaTiO3 -BTO) embedded in the solar absorber can generate such an internal field. A hybrid structure of CH3NH 3PbI3-xClx perovskite and ferroelectric BTO nanocomposite FTO/TiO2/CH3NH3PbI3-xClx : BTO/P3HT/Cu as a new type of photovoltaic device is investigated. Aerosol assisted chemical vapor deposition process that is scalable to large-scale manufacturing was used for the growth of the multilayer structure. TiO 2 and P3HT with additives were used as ETL and HTL respectively. The growth process of the solar absorber layer includes the

  19. Internal absorber solar collector

    DOEpatents

    Sletten, Carlyle J.; Herskovitz, Sheldon B.; Holt, F. S.; Sletten, E. J.

    1981-01-01

    Thin solar collecting panels are described made from arrays of small rod collectors consisting of a refracting dielectric rod lens with an absorber imbedded within it and a reflecting mirror coated on the back side of the dielectric rod. Non-tracking collector panels on vertical walls or roof tops receive approximately 90% of solar radiation within an acceptance zone 60.degree. in elevation angle by 120.degree. or more in the azimuth sectors with a collector concentration ratio of approximately 3.0. Miniaturized construction of the circular dielectric rods with internal absorbers reduces the weight per area of glass, plastic and metal used in the collector panels. No external parts or insulation are needed as heat losses are low due to partial vacuum or low conductivity gas surrounding heated portions of the collector. The miniature internal absorbers are generally made of solid copper with black selective surface and the collected solar heat is extracted at the collector ends by thermal conductivity along the absorber rods. Heat is removed from end fittings by use of liquid circulants. Several alternate constructions are provided for simplifying collector panel fabrication and for preventing the thermal expansion and contraction of the heated absorber or circulant tubes from damaging vacuum seals. In a modified version of the internal absorber collector, oil with temperature dependent viscosity is pumped through a segmented absorber which is now composed of closely spaced insulated metal tubes. In this way the circulant is automatically diverted through heated portions of the absorber giving higher collector concentration ratios than theoretically possible for an unsegmented absorber.

  20. Superlattice photonic crystal as broadband solar absorber for high temperature operation.

    PubMed

    Rinnerbauer, Veronika; Shen, Yichen; Joannopoulos, John D; Soljačić, Marin; Schäffler, Friedrich; Celanovic, Ivan

    2014-12-15

    A high performance solar absorber using a 2D tantalum superlattice photonic crystal (PhC) is proposed and its design is optimized for high-temperature energy conversion. In contrast to the simple lattice PhC, which is limited by diffraction in the short wavelength range, the superlattice PhC achieves solar absorption over broadband spectral range due to the contribution from two superposed lattices with different cavity radii. The superlattice PhC geometry is tailored to achieve maximum thermal transfer efficiency for a low concentration system of 250 suns at 1500 K reaching 85.0% solar absorptivity. In the high concentration case of 1000 suns, the superlattice PhC absorber achieves a solar absorptivity of 96.2% and a thermal transfer efficiency of 82.9% at 1500 K, amounting to an improvement of 10% and 5%, respectively, versus the simple square lattice PhC absorber. In addition, the performance of the superlattice PhC absorber is studied in a solar thermophotovoltaic system which is optimized to minimize absorber re-emission by reducing the absorber-to-emitter area ratio and using a highly reflective silver aperture.

  1. Tuning Transpiration by Interfacial Solar Absorber-Leaf Engineering.

    PubMed

    Zhuang, Shendong; Zhou, Lin; Xu, Weichao; Xu, Ning; Hu, Xiaozhen; Li, Xiuqiang; Lv, Guangxin; Zheng, Qinghui; Zhu, Shining; Wang, Zhenlin; Zhu, Jia

    2018-02-01

    Plant transpiration, a process of water movement through a plant and its evaporation from aerial parts especially leaves, consumes a large component of the total continental precipitation (≈48%) and significantly influences global water distribution and climate. To date, various chemical and/or biological explorations have been made to tune the transpiration but with uncertain environmental risks. In recent years, interfacial solar steam/vapor generation is attracting a lot of attention for achieving high energy transfer efficiency. Various optical and thermal designs at the solar absorber-water interface for potential applications in water purification, seawater desalination, and power generation appear. In this work, the concept of interfacial solar vapor generation is extended to tunable plant transpiration by showing for the first time that the transpiration efficiency can also be enhanced or suppressed through engineering the solar absorber-leaf interface. By tuning the solar absorption of membrane in direct touch with green leaf, surface temperature of green leaf will change accordingly because of photothermal effect, thus the transpiration efficiency as well as temperature and relative humidity in the surrounding environment will be tuned. This tunable transpiration by interfacial absorber-leaf engineering can open an alternative avenue to regulate local atmospheric temperature, humidity, and eventually hydrologic cycle.

  2. Solar Energy - An Option for Future Energy Production

    ERIC Educational Resources Information Center

    Glaser, Peter E.

    1972-01-01

    Discusses the exponential growth of energy consumption and future consequences. Possible methods of converting solar energy to power such as direct energy conversion, focusing collectors, selective rediation absorbers, ocean thermal gradient, and space solar power are considered. (DF)

  3. Intensity and absorbed-power distribution in a cylindrical solar-pumped dye laser

    NASA Technical Reports Server (NTRS)

    Williams, M. D.

    1984-01-01

    The internal intensity and absorbed-power distribution of a simplified hypothetical dye laser of cylindrical geometry is calculated. Total absorbed power is also calculated and compared with laboratory measurements of lasing-threshold energy deposition in a dye cell to determine the suitability of solar radiation as a pump source or, alternatively, what modifications, if any, are necessary to the hypothetical system for solar pumping.

  4. Reducing heat loss from the energy absorber of a solar collector

    DOEpatents

    Chao, Bei Tse; Rabl, Ari

    1976-01-01

    A device is provided for reducing convective heat loss in a cylindrical radiant energy collector. It includes a curved reflective wall in the shape of the arc of a circle positioned on the opposite side of the exit aperture from the reflective side walls of the collector. Radiant energy exiting the exit aperture is directed by the curved wall onto an energy absorber such that the portion of the absorber upon which the energy is directed faces downward to reduce convective heat loss from the absorber.

  5. Aluminium or copper substrate panel for selective absorption of solar energy

    NASA Technical Reports Server (NTRS)

    Roberts, M. L.; Sharpe, M. H.; Krupnick, A. C. (Inventor)

    1979-01-01

    A method for making panels which selectively absorb solar energy is disclosed. The panels are comprised of an aluminum substrate, a layer of zinc thereon, a layer of nickel over the zinc layer and an outer layer of solar energy absorbing nickel oxide or a copper substrate with a layer of nickel thereon and a layer of solar energy absorbing nickel oxide distal from the copper substrate.

  6. Development of optical tools for the characterization of selective solar absorber at elevated temperature

    NASA Astrophysics Data System (ADS)

    Giraud, Philemon; Braillon, Julien; Delord, Christine; Raccurt, Olivier

    2016-05-01

    Durability of solar components for CSP (Concentrated Solar Power Plant) technologies is a key point to lower cost and ensure their large deployment. These technologies concentrated the solar radiation by means of mirrors on a receiver tube where it is collected as thermal energy. The absorbers are submitted to strong environmental constraints and the degradation of their optical properties (emittance and solar absorbance) have a direct impact on performance. The objective is to develop new optical equipment for characterization of this solar absorber in condition of use that is to say in air and at elevated temperature. In this paper we present two new optical test benches developed for optical characterization of solar absorbers in condition of use up to 800°C. The first equipment is an integrated sphere with heated sample holder which measures the hemispherical reflectance between 280 and 2500 nm to calculate the solar absorbance at high temperature. The second optical test bench measures the emittance of samples up to 1000°C in the range of 1.25 to 28.57 µm. Results of high temperature measurements on a series of metallic absorbers with selective coating and refractory material for high thermal receiver are presented.

  7. Metasurface Broadband Solar Absorber

    PubMed Central

    Azad, Abul K.; Kort-Kamp, Wilton J. M.; Sykora, Milan; Weisse-Bernstein, Nina R.; Luk, Ting S.; Taylor, Antoinette J.; Dalvit, Diego A. R.; Chen, Hou-Tong

    2016-01-01

    We demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributions to elucidate how the absorption occurs within the metasurface structure. PMID:26828999

  8. Metasurface Broadband Solar Absorber.

    PubMed

    Azad, Abul K; Kort-Kamp, Wilton J M; Sykora, Milan; Weisse-Bernstein, Nina R; Luk, Ting S; Taylor, Antoinette J; Dalvit, Diego A R; Chen, Hou-Tong

    2016-02-01

    We demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributions to elucidate how the absorption occurs within the metasurface structure.

  9. Central solar-energy receiver

    DOEpatents

    Not Available

    1981-10-27

    An improved tower-mounted central solar energy receiver for heating air drawn through the receiver by an induced draft fan is described. A number of vertically oriented, energy absorbing, fin-shaped slats are radially arranged in a number of concentric cylindrical arrays on top of the tower coaxially surrounding a pipe having air holes through which the fan draws air which is heated by the slats which receive the solar radiation from a heliostat field. A number of vertically oriented and wedge-shaped columns are radially arranged in a number of concentric cylindrical clusters surrounding the slat arrays. The columns have two mirror-reflecting sides to reflect radiation into the slat arrays and one energy absorbing side to reduce reradiation and reflection from the slat arrays.

  10. Central solar energy receiver

    DOEpatents

    Drost, M. Kevin

    1983-01-01

    An improved tower-mounted central solar energy receiver for heating air drawn through the receiver by an induced draft fan. A number of vertically oriented, energy absorbing, fin-shaped slats are radially arranged in a number of concentric cylindrical arrays on top of the tower coaxially surrounding a pipe having air holes through which the fan draws air which is heated by the slats which receive the solar radiation from a heliostat field. A number of vertically oriented and wedge-shaped columns are radially arranged in a number of concentric cylindrical clusters surrounding the slat arrays. The columns have two mirror-reflecting sides to reflect radiation into the slat arrays and one energy absorbing side to reduce reradiation and reflection from the slat arrays.

  11. Metasurface Broadband Solar Absorber

    DOE PAGES

    Azad, Abul K.; Kort-Kamp, Wilton J. M.; Sykora, Milan; ...

    2016-02-01

    Here, we demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Moreover, our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributionsmore » to elucidate how the absorption occurs within the metasurface structure.« less

  12. Unglazed transpired solar collector having a low thermal-conductance absorber

    DOEpatents

    Christensen, Craig B.; Kutscher, Charles F.; Gawlik, Keith M.

    1997-01-01

    An unglazed transpired solar collector using solar radiation to heat incoming air for distribution, comprising an unglazed absorber formed of low thermal-conductance material having a front surface for receiving the solar radiation and openings in the unglazed absorber for passage of the incoming air such that the incoming air is heated as it passes towards the front surface of the absorber and the heated air passes through the openings in the absorber for distribution.

  13. Unglazed transpired solar collector having a low thermal-conductance absorber

    DOEpatents

    Christensen, C.B.; Kutscher, C.F.; Gawlik, K.M.

    1997-12-02

    An unglazed transpired solar collector using solar radiation to heat incoming air for distribution, comprises an unglazed absorber formed of low thermal-conductance material having a front surface for receiving the solar radiation and openings in the unglazed absorber for passage of the incoming air such that the incoming air is heated as it passes towards the front surface of the absorber and the heated air passes through the openings in the absorber for distribution. 3 figs.

  14. 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.

  15. Mechanically Robust, Stretchable Solar Absorbers with Submicron-Thick Multilayer Sheets for Wearable and Energy Applications.

    PubMed

    Lee, Hye Jin; Jung, Dae-Han; Kil, Tae-Hyeon; Kim, Sang Hyeon; Lee, Ki-Suk; Baek, Seung-Hyub; Choi, Won Jun; Baik, Jeong Min

    2017-05-31

    A facile method to fabricate a mechanically robust, stretchable solar absorber for stretchable heat generation and an enhanced thermoelectric generator (TEG) is demonstrated. This strategy is very simple: it uses a multilayer film made of titanium and magnesium fluoride optimized by a two-dimensional finite element frequency-domain simulation, followed by the application of mechanical stresses such as bending and stretching to the film. This process produces many microsized sheets with submicron thickness (∼500 nm), showing great adhesion to any substrates such as fabrics and polydimethylsiloxane. It exhibits a quite high light absorption of approximately 85% over a wavelength range of 0.2-4.0 μm. Under 1 sun illumination, the solar absorber on various stretchable substrates increased the substrate temperature to approximately 60 °C, irrespective of various mechanical stresses such as bending, stretching, rubbing, and even washing. The TEG with the absorber on the top surface also showed an enhanced output power of 60%, compared with that without the absorber. With an incident solar radiation flux of 38.3 kW/m 2 , the output power significantly increased to 24 mW/cm 2 because of the increase in the surface temperature to 141 °C.

  16. 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

  17. Robust optimization of a tandem grating solar thermal absorber

    NASA Astrophysics Data System (ADS)

    Choi, Jongin; Kim, Mingeon; Kang, Kyeonghwan; Lee, Ikjin; Lee, Bong Jae

    2018-04-01

    Ideal solar thermal absorbers need to have a high value of the spectral absorptance in the broad solar spectrum to utilize the solar radiation effectively. Majority of recent studies about solar thermal absorbers focus on achieving nearly perfect absorption using nanostructures, whose characteristic dimension is smaller than the wavelength of sunlight. However, precise fabrication of such nanostructures is not easy in reality; that is, unavoidable errors always occur to some extent in the dimension of fabricated nanostructures, causing an undesirable deviation of the absorption performance between the designed structure and the actually fabricated one. In order to minimize the variation in the solar absorptance due to the fabrication error, the robust optimization can be performed during the design process. However, the optimization of solar thermal absorber considering all design variables often requires tremendous computational costs to find an optimum combination of design variables with the robustness as well as the high performance. To achieve this goal, we apply the robust optimization using the Kriging method and the genetic algorithm for designing a tandem grating solar absorber. By constructing a surrogate model through the Kriging method, computational cost can be substantially reduced because exact calculation of the performance for every combination of variables is not necessary. Using the surrogate model and the genetic algorithm, we successfully design an effective solar thermal absorber exhibiting a low-level of performance degradation due to the fabrication uncertainty of design variables.

  18. Study of thermal effects and optical properties of an innovative absorber in integrated collector storage solar water heater

    NASA Astrophysics Data System (ADS)

    Taheri, Yaser; Alimardani, Kazem; Ziapour, Behrooz M.

    2015-10-01

    Solar passive water heaters are potential candidates for enhanced heat transfer. Solar water heaters with an integrated water tank and with the low temperature energy resource are used as the simplest and cheapest recipient devices of the solar energy for heating and supplying hot water in the buildings. The solar thermal performances of one primitive absorber were determined by using both the experimental and the simulation model of it. All materials applied for absorber such as the cover glass, the black colored sands and the V shaped galvanized plate were submerged into the water. The water storage tank was manufactured from galvanized sheet of 0.0015 m in thickness and the effective area of the collector was 0.67 m2. The absorber was installed on a compact solar water heater. The constructed flat-plate collectors were tested outdoors. However the simulation results showed that the absorbers operated near to the gray materials and all experimental results showed that the thermal efficiencies of the collector are over than 70 %.

  19. Fluid absorption solar energy receiver

    NASA Technical Reports Server (NTRS)

    Bair, Edward J.

    1993-01-01

    A conventional solar dynamic system transmits solar energy to the flowing fluid of a thermodynamic cycle through structures which contain the gas and thermal energy storage material. Such a heat transfer mechanism dictates that the structure operate at a higher temperature than the fluid. This investigation reports on a fluid absorption receiver where only a part of the solar energy is transmitted to the structure. The other part is absorbed directly by the fluid. By proportioning these two heat transfer paths the energy to the structure can preheat the fluid, while the energy absorbed directly by the fluid raises the fluid to its final working temperature. The surface temperatures need not exceed the output temperature of the fluid. This makes the output temperature of the gas the maximum temperature in the system. The gas can have local maximum temperatures higher than the output working temperature. However local high temperatures are quickly equilibrated, and since the gas does not emit radiation, local high temperatures do not result in a radiative heat loss. Thermal radiation, thermal conductivity, and heat exchange with the gas all help equilibrate the surface temperature.

  20. Low cost solar energy collection system

    NASA Technical Reports Server (NTRS)

    Miller, C. G.; Stephans, J. B. (Inventor)

    1977-01-01

    A fixed, linear, ground-based primary reflector having an extended, curved sawtooth contoured surface covered with a metallized polymeric reflecting material, reflected solar energy to a movably supported collector that was kept at the concentrated line focus of the reflector primary. Efficient utilization leading to high temperatures from the reflected solar energy was obtained by cylindrical shaped secondary reflectors that directed off-angle energy to the absorber pipe.

  1. Characterization of selective solar absorber under high vacuum.

    PubMed

    Russo, Roberto; Monti, Matteo; di Giamberardino, Francesco; Palmieri, Vittorio G

    2018-05-14

    Total absorption and emission coefficients of selective solar absorbers are measured under high vacuum conditions from room temperature up to stagnation temperature. The sample under investigation is illuminated under vacuum @1000W/m 2 and the sample temperature is recorded during heat up, equilibrium and cool down. During stagnation, the absorber temperature exceeds 300°C without concentration. Data analysis allows evaluating the solar absorptance and thermal emittance at different temperatures. These in turn are useful to predict evacuated solar panel performances at operating conditions.

  2. Method for making an aluminum or copper substrate panel for selective absorption of solar energy

    NASA Technical Reports Server (NTRS)

    Roberts, M. L.; Sharpe, M. H.; Krupnick, A. C. (Inventor)

    1978-01-01

    A panel is described for selectively absorbing solar energy comprising an aluminum substrate. A zinc layer was covered by a layer of nickel and an outer layer of solar energy absorbing nickel oxide or a copper substrate with a nickel layer. A layer of solar energy absorbing nickel oxide distal from the copper substrate was included. A method for making these panels is disclosed.

  3. Two new methods used to simulate the circumferential solar flux density concentrated on the absorber of a parabolic trough solar collector

    NASA Astrophysics Data System (ADS)

    Guo, Minghuan; Wang, Zhifeng; Sun, Feihu

    2016-05-01

    The optical efficiencies of a solar trough concentrator are important to the whole thermal performance of the solar collector, and the outer surface of the tube absorber is a key interface of energy flux. So it is necessary to simulate and analyze the concentrated solar flux density distributions on the tube absorber of a parabolic trough solar collector for various sun beam incident angles, with main optical errors considered. Since the solar trough concentrators are linear focusing, it is much of interest to investigate the solar flux density distribution on the cross-section profile of the tube absorber, rather than the flux density distribution along the focal line direction. Although a few integral approaches based on the "solar cone" concept were developed to compute the concentrated flux density for some simple trough concentrator geometries, all those integral approaches needed special integration routines, meanwhile, the optical parameters and geometrical properties of collectors also couldn't be changed conveniently. Flexible Monte Carlo ray trace (MCRT) methods are widely used to simulate the more accurate concentrated flux density distribution for compound parabolic solar trough concentrators, while generally they are quite time consuming. In this paper, we first mainly introduce a new backward ray tracing (BRT) method combined with the lumped effective solar cone, to simulate the cross-section flux density on the region of interest of the tube absorber. For BRT, bundles of rays are launched at absorber-surface points of interest, directly go through the glass cover of the absorber, strike on the uniformly sampled mirror segment centers in the close-related surface region of the parabolic reflector, and then direct to the effective solar cone around the incident sun beam direction after the virtual backward reflection. All the optical errors are convoluted into the effective solar cone. The brightness distribution of the effective solar cone is supposed

  4. Emitter/absorber interface of CdTe solar cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Song, Tao; Kanevce, Ana; Sites, James R.

    The performance of CdTe solar cells can be very sensitive to their emitter/absorber interfaces, especially for high-efficiency cells with improved bulk properties. When interface defect states are located at efficient recombination energies, performance losses from acceptor-type interface defects can be significant. Numerical simulations show that the emitter/absorber band alignment, the emitter doping and thickness, and the defect properties of the interface (i.e. defect density, defect type, and defect energy) can all play significant roles in the interface recombination. In particular, a type I heterojunction with small conduction-band offset (0.1 eV /= 0.4 eV), however, can impede electron transport and leadmore » to a reduction of photocurrent and fill-factor. In contrast to the spike, a 'cliff' (.delta..EC < 0 eV) is likely to allow many holes in the vicinity of the interface, which will assist interface recombination and result in a reduced open-circuit voltage. In addition, a thin and highly-doped emitter can invert the absorber, form a large hole barrier, and decrease device performance losses due to high interface defect density. CdS is the most common emitter material used in CdTe solar cells, but the CdS/CdTe interface is in the cliff category and is not favorable from the band-offset perspective. Other n-type emitter choices, such as (Mg,Zn)O, Cd(S,O), or (Cd,Mg)Te, can be tuned by varying the elemental ratio for an optimal positive value of ..delta..EC. These materials are predicted to yield higher voltages and would therefore be better candidates for the CdTe-cell emitter.« less

  5. Evaluation of Solar Air Heater Performance with Artificial Rib Roughness over the Absorber Plate using Finite Element Modelling Analysis

    NASA Astrophysics Data System (ADS)

    Kumar, K. Ravi; Nikhil Varma, P.; Jagadeesh, N.; Sandeep, J. V.; Cheepu, Muralimohan; Venkateswarlu, D.; Srinivas, B.

    2018-03-01

    Among the different renewable energy resources, solar energy is widely used due to its quantitative intensity factor. Solar air heater is cheap, simple in design and has got wide range of applications. A modest solar air heater has a lower in heat transfer and thermal performance as it has heat transfer coefficient lower in between coated absorber plate and the carrier fluid. This low thermal performance can be reduced to a greater extent by introducing the artificially created roughness over the absorber plate of the solar heater. In the present study, the combination of various geometries and roughness’s on the absorber plate are reported. Methods have been developed and implemented in order to improve the rate of the heat transfer. A comparison is drawn among different geometries to select the most effective absorber plate roughness. For flow analysis k-ω SST model was used and the constant heat flux was taken as 1100 W/m2. The Reynolds number is varied in a range from 3000 to 20000. The variation of different parameters temperature, Nusselt number, turbulence kinetic energy and heat transfer coefficient with Reynolds number were examined and discussed.

  6. Tower-supported solar-energy collector

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K.

    1977-01-01

    Multiple-collector tower system supports three receiver/concentrators that absorb solar energy reflected from surrounding field of heliostats. System overcomes disadvantages of tower-supported collectors. Booms can be lowered during heavy winds to protect arms and collectors.

  7. Spray CVD for Making Solar-Cell Absorber Layers

    NASA Technical Reports Server (NTRS)

    Banger, Kulbinder K.; Harris, Jerry; Jin, Michael H.; Hepp, Aloysius

    2007-01-01

    Spray chemical vapor deposition (spray CVD) processes of a special type have been investigated for use in making CuInS2 absorber layers of thin-film solar photovoltaic cells from either of two subclasses of precursor compounds: [(PBu3) 2Cu(SEt)2In(SEt)2] or [(PPh3)2Cu(SEt)2 In(SEt)2]. The CuInS2 films produced in the experiments have been characterized by x-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and four-point-probe electrical tests.

  8. Thermodynamic Inefficiency of Conversion of Solar Energy to Work.

    ERIC Educational Resources Information Center

    Adamson, Arthur W.; And Others

    1984-01-01

    Considers the thermodynamic limitation to the efficiency with which light energy can be converted into work, indicating that no single chemical system converting solar energy into useful work can be very efficient. Also indicates that if solar energy is absorbed as heat for heating purposes, it is almost completely used. (JN)

  9. Trade-Offs in Thin Film Solar Cells with Layered Chalcostibite Photovoltaic Absorbers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Welch, Adam W.; Baranowski, Lauryn L.; Peng, Haowei

    Discovery of novel semiconducting materials is needed for solar energy conversion and other optoelectronic applications. However, emerging low-dimensional solar absorbers often have unconventional crystal structures and unusual combinations of optical absorption and electrical transport properties, which considerably slows down the research and development progress. Here, the effect of stronger absorption and weaker carrier collection of 2D-like absorber materials are studied using a high-throughput combinatorial experimental approach, complemented by advanced characterization and computations. It is found that the photoexcited charge carrier collection in CuSbSe 2 solar cells is enhanced by drift in an electric field, addressing a different absorption/collection balance. Themore » resulting drift solar cells efficiency is <5% due to inherent J SC/ V OC trade-off, suggesting that improved carrier diffusion and better contacts are needed to further increase the CuSbSe 2 performance. Furthermore, this study also illustrates the advantages of high-throughput experimental methods for fast optimization of the optoelectronic devices based on emerging low-dimensional semiconductor materials.« less

  10. Trade-Offs in Thin Film Solar Cells with Layered Chalcostibite Photovoltaic Absorbers

    DOE PAGES

    Welch, Adam W.; Baranowski, Lauryn L.; Peng, Haowei; ...

    2017-01-25

    Discovery of novel semiconducting materials is needed for solar energy conversion and other optoelectronic applications. However, emerging low-dimensional solar absorbers often have unconventional crystal structures and unusual combinations of optical absorption and electrical transport properties, which considerably slows down the research and development progress. Here, the effect of stronger absorption and weaker carrier collection of 2D-like absorber materials are studied using a high-throughput combinatorial experimental approach, complemented by advanced characterization and computations. It is found that the photoexcited charge carrier collection in CuSbSe 2 solar cells is enhanced by drift in an electric field, addressing a different absorption/collection balance. Themore » resulting drift solar cells efficiency is <5% due to inherent J SC/ V OC trade-off, suggesting that improved carrier diffusion and better contacts are needed to further increase the CuSbSe 2 performance. Furthermore, this study also illustrates the advantages of high-throughput experimental methods for fast optimization of the optoelectronic devices based on emerging low-dimensional semiconductor materials.« less

  11. Energy from solar balloons

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Grena, Roberto

    2010-04-15

    Solar balloons are hot air balloons in which the air is heated directly by the sun, by means of a black absorber. The lift force of a tethered solar balloon can be used to produce energy by activating a generator during the ascending motion of the balloon. The hot air is then discharged when the balloon reaches a predefined maximum height. A preliminary study is presented, along with an efficiency estimation and some considerations on possible realistic configurations. (author)

  12. Scalable, "Dip-and-Dry" Fabrication of a Wide-Angle Plasmonic Selective Absorber for High-Efficiency Solar-Thermal Energy Conversion.

    PubMed

    Mandal, Jyotirmoy; Wang, Derek; Overvig, Adam C; Shi, Norman N; Paley, Daniel; Zangiabadi, Amirali; Cheng, Qian; Barmak, Katayun; Yu, Nanfang; Yang, Yuan

    2017-11-01

    A galvanic-displacement-reaction-based, room-temperature "dip-and-dry" technique is demonstrated for fabricating selectively solar-absorbing plasmonic-nanoparticle-coated foils (PNFs). The technique, which allows for facile tuning of the PNFs' spectral reflectance to suit different radiative and thermal environments, yields PNFs which exhibit excellent, wide-angle solar absorptance (0.96 at 15°, to 0.97 at 35°, to 0.79 at 80°), and low hemispherical thermal emittance (0.10) without the aid of antireflection coatings. The thermal emittance is on par with those of notable selective solar absorbers (SSAs) in the literature, while the wide-angle solar absorptance surpasses those of previously reported SSAs with comparable optical selectivities. In addition, the PNFs show promising mechanical and thermal stabilities at temperatures of up to 200 °C. Along with the performance of the PNFs, the simplicity, inexpensiveness, and environmental friendliness of the "dip-and-dry" technique makes it an appealing alternative to current methods for fabricating selective solar absorbers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Nanostructured Solar Irradiation Control Materials for Solar Energy Conversion

    NASA Technical Reports Server (NTRS)

    Kang, Jinho; Marshall, I. A.; Torrico, M. N.; Taylor, C. R.; Ely, Jeffry; Henderson, Angel Z.; Kim, J.-W.; Sauti, G.; Gibbons, L. J.; Park, C.; hide

    2012-01-01

    Tailoring the solar absorptivity (alpha(sub s)) and thermal emissivity (epsilon(sub T)) of materials constitutes an innovative approach to solar energy control and energy conversion. Numerous ceramic and metallic materials are currently available for solar absorbance/thermal emittance control. However, conventional metal oxides and dielectric/metal/dielectric multi-coatings have limited utility due to residual shear stresses resulting from the different coefficient of thermal expansion of the layered materials. This research presents an alternate approach based on nanoparticle-filled polymers to afford mechanically durable solar-absorptive and thermally-emissive polymer nanocomposites. The alpha(sub s) and epsilon(sub T) were measured with various nano inclusions, such as carbon nanophase particles (CNPs), at different concentrations. Research has shown that adding only 5 wt% CNPs increased the alpha(sub s) and epsilon(sub T) by a factor of about 47 and 2, respectively, compared to the pristine polymer. The effect of solar irradiation control of the nanocomposite on solar energy conversion was studied. The solar irradiation control coatings increased the power generation of solar thermoelectric cells by more than 380% compared to that of a control power cell without solar irradiation control coatings.

  14. Development of an innovative solar absorber

    NASA Astrophysics Data System (ADS)

    Goodchild, Gavin

    Solar thermal systems have great potential to replace or reduce the dependence of conventional fossil fuel based heating technologies required for space and water heating. Specifically solar domestic hot water systems can contribute 50-75% of the annual thermal load. To date residential users have been slow to purchase and install systems, primarily due to the large monetary investment required to purchase and install a system. Recent innovations in materials design and manufacturing techniques, offer opportunities for the development of absorber plate designs that have the potential to reduce cost, increase efficiency and reduce payback periods. Consequently, this design study was conducted in conjunction with industrial partners to develop an improved absorber based on roll bond manufacturing that can be produced at reduced cost with comparable or greater thermal efficiency.

  15. Analysis of solar water heater with parabolic dish concentrator and conical absorber

    NASA Astrophysics Data System (ADS)

    Rajamohan, G.; Kumar, P.; Anwar, M.; Mohanraj, T.

    2017-06-01

    This research focuses on developing novel technique for a solar water heating system. The novel solar system comprises a parabolic dish concentrator, conical absorber and water heater. In this system, the conical absorber tube directly absorbs solar radiation from the sun and the parabolic dish concentrator reflects the solar radiations towards the conical absorber tube from all directions, therefore both radiations would significantly improve the thermal collector efficiency. The working fluid water is stored at the bottom of the absorber tubes. The absorber tubes get heated and increases the temperature of the working fluid inside of the absorber tube and causes the working fluid to partially evaporate. The partially vaporized working fluid moves in the upward direction due to buoyancy effect and enters the heat exchanger. When fresh water passes through the heat exchanger, temperature of the vapour decreases through heat exchange. This leads to condensation of the vapour and forms liquid phase. The working fluid returns to the bottom of the collector absorber tube by gravity. Hence, this will continue as a cyclic process inside the system. The proposed investigation shows an improvement of collector efficiency, enhanced heat transfer and a quality water heating system.

  16. Self-assembly of highly efficient, broadband plasmonic absorbers for solar steam generation.

    PubMed

    Zhou, Lin; Tan, Yingling; Ji, Dengxin; Zhu, Bin; Zhang, Pei; Xu, Jun; Gan, Qiaoqiang; Yu, Zongfu; Zhu, Jia

    2016-04-01

    The study of ideal absorbers, which can efficiently absorb light over a broad range of wavelengths, is of fundamental importance, as well as critical for many applications from solar steam generation and thermophotovoltaics to light/thermal detectors. As a result of recent advances in plasmonics, plasmonic absorbers have attracted a lot of attention. However, the performance and scalability of these absorbers, predominantly fabricated by the top-down approach, need to be further improved to enable widespread applications. We report a plasmonic absorber which can enable an average measured absorbance of ~99% across the wavelengths from 400 nm to 10 μm, the most efficient and broadband plasmonic absorber reported to date. The absorber is fabricated through self-assembly of metallic nanoparticles onto a nanoporous template by a one-step deposition process. Because of its efficient light absorption, strong field enhancement, and porous structures, which together enable not only efficient solar absorption but also significant local heating and continuous stream flow, plasmonic absorber-based solar steam generation has over 90% efficiency under solar irradiation of only 4-sun intensity (4 kW m(-2)). The pronounced light absorption effect coupled with the high-throughput self-assembly process could lead toward large-scale manufacturing of other nanophotonic structures and devices.

  17. Imperfectly geometric shapes of nanograting structures as solar absorbers with superior performance for solar cells.

    PubMed

    Nguyen-Huu, Nghia; Cada, Michael; Pištora, Jaromír

    2014-03-10

    The expectation of perfectly geometric shapes of subwavelength grating (SWG) structures such as smoothness of sidewalls and sharp corners and nonexistence of grating defects is not realistic due to micro/nanofabrication processes. This work numerically investigates optical properties of an optimal solar absorber comprising a single-layered silicon (Si) SWG deposited on a finite Si substrate, with a careful consideration given to effects of various types of its imperfect geometry. The absorptance spectra of the solar absorber with different geometric shapes, namely, the grating with attached nanometer-sized features at the top and bottom of sidewalls and periodic defects within four and ten grating periods are investigated comprehensively. It is found that the grating with attached features at the bottom absorbs more energy than both the one at the top and the perfect grating. In addition, it is shown that the grating with defects in each fourth period exhibits the highest average absorptance (91%) compared with that of the grating having defects in each tenth period (89%), the grating with attached features (89%), and the perfect one (86%). Moreover, the results indicate that the absorptance spectrum of the imperfect structures is insensitive to angles of incidence. Furthermore, the absorptance enhancement is clearly demonstrated by computing magnetic field, energy density, and Poynting vector distributions. The results presented in this study prove that imperfect geometries of the nanograting structure display a higher absorptance than the perfect one, and provide such a practical guideline for nanofabrication capabilities necessary to be considered by structure designers.

  18. Self-assembly of highly efficient, broadband plasmonic absorbers for solar steam generation

    PubMed Central

    Zhou, Lin; Tan, Yingling; Ji, Dengxin; Zhu, Bin; Zhang, Pei; Xu, Jun; Gan, Qiaoqiang; Yu, Zongfu; Zhu, Jia

    2016-01-01

    The study of ideal absorbers, which can efficiently absorb light over a broad range of wavelengths, is of fundamental importance, as well as critical for many applications from solar steam generation and thermophotovoltaics to light/thermal detectors. As a result of recent advances in plasmonics, plasmonic absorbers have attracted a lot of attention. However, the performance and scalability of these absorbers, predominantly fabricated by the top-down approach, need to be further improved to enable widespread applications. We report a plasmonic absorber which can enable an average measured absorbance of ~99% across the wavelengths from 400 nm to 10 μm, the most efficient and broadband plasmonic absorber reported to date. The absorber is fabricated through self-assembly of metallic nanoparticles onto a nanoporous template by a one-step deposition process. Because of its efficient light absorption, strong field enhancement, and porous structures, which together enable not only efficient solar absorption but also significant local heating and continuous stream flow, plasmonic absorber–based solar steam generation has over 90% efficiency under solar irradiation of only 4-sun intensity (4 kW m−2). The pronounced light absorption effect coupled with the high-throughput self-assembly process could lead toward large-scale manufacturing of other nanophotonic structures and devices. PMID:27152335

  19. 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.

  20. Mechanical energy absorber

    NASA Technical Reports Server (NTRS)

    Wesselski, Clarence J. (Inventor)

    1993-01-01

    An energy absorbing system for controlling the force where a moving object engages a stationary stop and where the system utilized telescopic tubular members, energy absorbing diaphragm elements, force regulating disc springs, and a return spring to return the telescoping member to its start position after stroking is presented. The energy absorbing system has frusto-conical diaphragm elements frictionally engaging the shaft and are opposed by a force regulating set of disc springs. In principle, this force feedback mechanism serves to keep the stroking load at a reasonable level even if the friction coefficient increases greatly. This force feedback device also serves to desensitize the singular and combined effects of manufacturing tolerances, sliding surface wear, temperature changes, dynamic effects, and lubricity.

  1. Spectrally selective solar absorber with sharp and temperature dependent cut-off based on semiconductor nanowire arrays

    NASA Astrophysics Data System (ADS)

    Wang, Yang; Zhou, Lin; Zheng, Qinghui; Lu, Hong; Gan, Qiaoqiang; Yu, Zongfu; Zhu, Jia

    2017-05-01

    Spectrally selective absorbers (SSA) with high selectivity of absorption and sharp cut-off between high absorptivity and low emissivity are critical for efficient solar energy conversion. Here, we report the semiconductor nanowire enabled SSA with not only high absorption selectivity but also temperature dependent sharp absorption cut-off. By taking advantage of the temperature dependent bandgap of semiconductors, we systematically demonstrate that the absorption cut-off profile of the semiconductor-nanowire-based SSA can be flexibly tuned, which is quite different from most of the other SSA reported so far. As an example, silicon nanowire based selective absorbers are fabricated, with the measured absorption efficiency above (below) bandgap ˜97% (15%) combined with an extremely sharp absorption cut-off (transition region ˜200 nm), the sharpest SSA demonstrated so far. The demonstrated semiconductor-nanowire-based SSA can enable a high solar thermal efficiency of ≳86% under a wide range of operating conditions, which would be competitive candidates for the concentrated solar energy utilizations.

  2. Light Absorbers and Catalysts for Solar to Fuel Conversion

    NASA Astrophysics Data System (ADS)

    Kornienko, Nikolay I.

    Increasing fossil fuel consumption and the resulting consequences to the environment has propelled research into means of utilizing alternative, clean energy sources. Solar power is among the most promising of renewable energy sources but must be converted into an energy dense medium such as chemical bonds to render it useful for transport and energy storage. Photoelectrochemistry (PEC), the splitting of water into oxygen and hydrogen fuel or reducing CO 2 to hydrocarbon fuels via sunlight is a promising approach towards this goal. Photoelectrochemical systems are comprised of several components, including light absorbers and catalysts. These parts must all synergistically function in a working device. Therefore, the continual development of each component is crucial for the overall goal. For PEC systems to be practical for large scale use, the must be efficient, stable, and composed of cost effective components. To this end, my work focused on the development of light absorbing and catalyst components of PEC solar to fuel converting systems. In the direction of light absorbers, I focused of utilizing Indium Phosphide (InP) nanowires (NWs) as photocathodes. I first developed synthetic techniques for InP NW solution phase and vapor phase growth. Next, I developed light absorbing photocathodes from my InP NWs towards PEC water splitting cells. I studied cobalt sulfide (CoSx) as an earth abundant catalyst for the reductive hydrogen evolution half reaction. Using in situ spectroscopic techniques, I elucidated the active structure of this catalyst and offered clues to its high activity. In addition to hydrogen evolution catalysts, I established a new generation of earth abundant catalysts for CO2 reduction to CO fuel/chemical feedstock. I first worked with molecularly tunable homogeneous catalysts that exhibited high selectivity for CO2 reduction in non-aqueous media. Next, in order to retain molecular tunability while achieving stability and efficiency in aqueous

  3. Experimental investigation of a nanofluid absorber employed in a low-profile, concentrated solar thermal collector

    NASA Astrophysics Data System (ADS)

    Li, Qiyuan; Zheng, Cheng; Mesgari, Sara; Hewakuruppu, Yasitha L.; Hjerrild, Natasha; Crisostomo, Felipe; Morrison, Karl; Woffenden, Albert; Rosengarten, Gary; Scott, Jason A.; Taylor, Robert A.

    2015-12-01

    Recent studies [1-3] have demonstrated that nanotechnology, in the form of nanoparticles suspended in water and organic liquids, can be employed to enhance solar collection via direct volumetric absorbers. However, current nanofluid solar collector experimental studies are either relevant to low-temperature flat plate solar collectors (<100 °C) [4] or higher temperature (>100 °C) indoor laboratory-scale concentrating solar collectors [1, 5]. Moreover, many of these studies involve in thermal properties of nanofluid (such as thermal conductivity) enhancement in solar collectors by using conventional selective coated steel/copper tube receivers [6], and no full-scale concentrating collector has been tested at outdoor condition by employing nanofluid absorber [2, 6]. Thus, there is a need of experimental researches to evaluate the exact performance of full-scale concentrating solar collector by employing nanofluids absorber at outdoor condition. As reported previously [7-9], a low profile (<10 cm height) solar thermal concentrating collector was designed and analysed which can potentially supply thermal energy in the 100-250 °C range (an application currently met by gas and electricity). The present study focuses on the design and experimental investigation of a nanofluid absorber employed in this newly designed collector. The nanofluid absorber consists of glass tubes used to contain chemically functionalized multi-walled carbon nanotubes (MWCNTs) dispersed in DI water. MWCNTs (average diameter of 6-13 nm and average length of 2.5-20 μm) were functionalized by potassium persulfate as an oxidant. The nanofluids were prepared with a MCWNT concentration of 50 +/- 0.1 mg/L to form a balance between solar absorption depth and viscosity (e.g. pumping power). Moreover, experimentally comparison of the thermal efficiency between two receivers (a black chrome-coated copper tube versus a MWCNT nanofluid contained within a glass tubetube) is investigated. Thermal

  4. 10.4% Efficient triple organic solar cells containing near infrared absorbers

    NASA Astrophysics Data System (ADS)

    Meerheim, Rico; Körner, Christian; Oesen, Benjamin; Leo, Karl

    2016-03-01

    The efficiency of organic solar cells can be increased by serially stacked subcells with spectrally different absorber materials. For the triple junction devices presented here, we use the small molecule donor materials DCV5T-Me for the green region and Tol2-benz-bodipy or Ph2-benz-bodipy as near infrared absorbers. The broader spectral response allows an efficiency increase from a pure DCV5T-Me triple cell to a triple junction containing a Ph2-benz-bodipy subcell, reaching 10.4%. As often observed for organic photovoltaics, the efficiency is further increased at low light intensities to 11%, which allows improved energy harvesting under real outdoor conditions and better performance indoor.

  5. Emitter/absorber interface of CdTe solar cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Song, Tao, E-mail: tsong241@gmail.com; Sites, James R.; Kanevce, Ana

    The performance of CdTe solar cells can be very sensitive to the emitter/absorber interface, especially for high-efficiency cells with high bulk lifetime. Performance losses from acceptor-type interface defects can be significant when interface defect states are located near mid-gap energies. Numerical simulations show that the emitter/absorber band alignment, the emitter doping and thickness, and the defect properties of the interface (i.e., defect density, defect type, and defect energy) can all play significant roles in the interface recombination. In particular, a type I heterojunction with small conduction-band offset (0.1 eV ≤ ΔE{sub C} ≤ 0.3 eV) can help maintain good cell efficiency in spite of high interfacemore » defect density, much like with Cu(In,Ga)Se{sub 2} (CIGS) cells. The basic principle is that positive ΔE{sub C}, often referred to as a “spike,” creates an absorber inversion and hence a large hole barrier adjacent to the interface. As a result, the electron-hole recombination is suppressed due to an insufficient hole supply at the interface. A large spike (ΔE{sub C} ≥ 0.4 eV), however, can impede electron transport and lead to a reduction of photocurrent and fill-factor. In contrast to the spike, a “cliff” (ΔE{sub C} < 0 eV) allows high hole concentration in the vicinity of the interface, which will assist interface recombination and result in a reduced open-circuit voltage. Another way to mitigate performance losses due to interface defects is to use a thin and highly doped emitter, which can invert the absorber and form a large hole barrier at the interface. CdS is the most common emitter material used in CdTe solar cells, but the CdS/CdTe interface is in the cliff category and is not favorable from the band-offset perspective. The ΔE{sub C} of other n-type emitter choices, such as (Mg,Zn)O, Cd(S,O), or (Cd,Mg)Te, can be tuned by varying the elemental ratio for an optimal positive value of ΔE{sub C

  6. Lanthanum hexaboride for solar energy applications.

    PubMed

    Sani, Elisa; Mercatelli, Luca; Meucci, Marco; Zoli, Luca; Sciti, Diletta

    2017-04-06

    We investigate the optical properties of LaB 6 - based materials, as possible candidates for solid absorbers in Concentrating Solar Power (CSP) systems. Bulk LaB 6 materials were thermally consolidated by hot pressing starting from commercial powders. To assess the solar absorbance and spectral selectivity properties, room-temperature hemispherical reflectance spectra were measured from the ultraviolet to the mid-infrared, considering different compositions, porosities and surface roughnesses. Thermal emittance at around 1100 K has been measured. Experimental results showed that LaB 6 can have a solar absorbance comparable to that of the most advanced solar absorber material in actual plants such as Silicon Carbide, with a higher spectral selectivity. Moreover, LaB 6 has also the appealing characteristics to be a thermionic material, so that it could act at the same time both as direct high-temperature solar absorber and as electron source, significantly reducing system complexity in future concentrating solar thermionic systems and bringing a real innovation in this field.

  7. Cu-In Halide Perovskite Solar Absorbers.

    PubMed

    Zhao, Xin-Gang; Yang, Dongwen; Sun, Yuanhui; Li, Tianshu; Zhang, Lijun; Yu, Liping; Zunger, Alex

    2017-05-17

    The long-term chemical instability and the presence of toxic Pb in otherwise stellar solar absorber APbX 3 made of organic molecules on the A site and halogens for X have hindered their large-scale commercialization. Previously explored ways to achieve Pb-free halide perovskites involved replacing Pb 2+ with other similar M 2+ cations in ns 2 electron configuration, e.g., Sn 2+ or by Bi 3+ (plus Ag + ), but unfortunately this showed either poor stability (M = Sn) or weakly absorbing oversized indirect gaps (M = Bi), prompting concerns that perhaps stability and good optoelectronic properties might be contraindicated. Herein, we exploit the electronic structure underpinning of classic Cu[In,Ga]Se 2 (CIGS) chalcopyrite solar absorbers to design Pb-free halide perovskites by transmuting 2Pb to the pair [B IB + C III ] such as [Cu + Ga] or [Ag + In] and combinations thereof. The resulting group of double perovskites with formula A 2 BCX 6 (A = K, Rb, Cs; B = Cu, Ag; C = Ga, In; X = Cl, Br, I) benefits from the ionic, yet narrow-gap character of halide perovskites, and at the same time borrows the advantage of the strong Cu(d)/Se(p) → Ga/In(s/p) valence-to-conduction-band absorption spectra known from CIGS. This constitutes a new group of CuIn-based Halide Perovskite (CIHP). Our first-principles calculations guided by such design principles indicate that the CIHPs class has members with clear thermodynamic stability, showing direct band gaps, and manifesting a wide-range of tunable gap values (from zero to about 2.5 eV) and combination of light electron and heavy-light hole effective masses. Materials screening of candidate CIHPs then identifies the best-of-class Rb 2 [CuIn]Cl 6 , Rb 2 [AgIn]Br 6 , and Cs 2 [AgIn]Br 6 , having direct band gaps of 1.36, 1.46, and 1.50 eV, and theoretical spectroscopic limited maximal efficiency comparable to chalcopyrites and CH 3 NH 3 PbI 3 . Our finding offers a new routine for designing new-type Pb-free halide perovskite solar

  8. Investigation of theoretical efficiency limit of hot carriers solar cells with a bulk indium nitride absorber

    NASA Astrophysics Data System (ADS)

    Aliberti, P.; Feng, Y.; Takeda, Y.; Shrestha, S. K.; Green, M. A.; Conibeer, G.

    2010-11-01

    Theoretical efficiencies of a hot carrier solar cell considering indium nitride as the absorber material have been calculated in this work. In a hot carrier solar cell highly energetic carriers are extracted from the device before thermalisation, allowing higher efficiencies in comparison to conventional solar cells. Previous reports on efficiency calculations approached the problem using two different theoretical frameworks, the particle conservation (PC) model or the impact ionization model, which are only valid in particular extreme conditions. In addition an ideal absorber material with the approximation of parabolic bands has always been considered in the past. Such assumptions give an overestimation of the efficiency limits and results can only be considered indicative. In this report the real properties of wurtzite bulk InN absorber have been taken into account for the calculation, including the actual dispersion relation and absorbance. A new hybrid model that considers particle balance and energy balance at the same time has been implemented. Effects of actual impact ionization (II) and Auger recombination (AR) lifetimes have been included in the calculations for the first time, considering the real InN band structure and thermalisation rates. It has been observed that II-AR mechanisms are useful for cell operation in particular conditions, allowing energy redistribution of hot carriers. A maximum efficiency of 43.6% has been found for 1000 suns, assuming thermalisation constants of 100 ps and ideal blackbody absorption. This value of efficiency is considerably lower than values previously calculated adopting PC or II-AR models.

  9. Design and proof of concept of an innovative very high temperature ceramic solar absorber

    NASA Astrophysics Data System (ADS)

    Leray, Cédric; Ferriere, Alain; Toutant, Adrien; Olalde, Gabriel; Peroy, Jean-Yves; Chéreau, Patrick; Ferrato, Marc

    2017-06-01

    Hybrid solar gas-turbine (HSGT) is an attractive technology to foster market penetration of CSP. HSGT offers some major advantages like for example high solar-to-electric conversion efficiency, reduced water requirement and low capital cost. A very high temperature solar receiver is needed when elevated solar share is claimed. A few research works, as reported by Karni et al. [8] and by Buck et al. [1], have been dedicated to solar receiver technologies able to deliver pressurized air at temperature above 750°C. The present work focuses on research aiming at developing an efficient and reliable solar absorber able to provide pressurized air at temperature up to 1000°C and more. A surface absorber technology is selected and a modular design of receiver is proposed in which each absorber module is made of BOOSTEC® SiC ceramic (silicon carbide) as bulk material with straight air channels inside. Early stage experimental works done at CNRS/PROMES on lab-scale absorbers showed that the thermo-mechanical behavior of this material is a critical issue, resulting in elevated probability of failure under severe conditions like large temperature gradient or steep variation of solar flux density in situations of cloud covering. This paper reports on recent progress made at CNRS/PROMES to address this critical issue. The design of the absorber has been revised and optimized according to thermo-mechanical numerical simulations, and an experimental proof of concept has been done on a pilot-scale absorber module at Themis solar tower facility.

  10. Paper-Thin Plastic Film Soaks Up Sun to Create Solar Energy

    NASA Technical Reports Server (NTRS)

    2006-01-01

    A non-crystallized silicon known as amorphous silicon is the semiconductor material most frequently chosen for deposition, because it is a strong absorber of light. According to the U.S. Department of Energy, amorphous silicon absorbs solar radiation 40 times more efficiently than single-crystal silicon, and a thin film only about 1-micrometer (one one-millionth of a meter) thick containing amorphous silicon can absorb 90 percent of the usable light energy shining on it. Peak efficiency and significant reduction in the use of semiconductor and thin film materials translate directly into time and money savings for manufacturers. Thanks in part to NASA, thin film solar cells derived from amorphous silicon are gaining more and more attention in a market that has otherwise been dominated by mono- and poly-crystalline silicon cells for years. At Glenn Research Center, the Photovoltaic & Space Environments Branch conducts research focused on developing this type of thin film solar cell for space applications. Placing solar cells on thin film materials provides NASA with an attractively priced solution to fabricating other types of solar cells, given that thin film solar cells require significantly less semiconductor material to generate power. Using the super-lightweight solar materials also affords NASA the opportunity to cut down on payload weight during vehicle launches, as well as the weight of spacecraft being sent into orbit.

  11. Experimental investigations of the performance of a solar air collector with latent heat thermal storage integrated with the solar absorber

    NASA Astrophysics Data System (ADS)

    Charvat, P.; Pech, O.; Hejcik, J.

    2013-04-01

    The paper deals with experimental investigations of the performance of a solar air collector with latent heat thermal storage integrated with the solarabsorber. The main purpose of heat storage in solar thermal systems is to store heat when the supply of solar heat exceeds demand and release it when otherwise. A number of heat storage materials can be used for this purpose; the phase change materials among them. Short-term latent heat thermal storage integrated with the solar absorber can stabilize the air temperature at the outlet of the collector on cloudy days when solar radiation intensity incident on a solar collector fluctuates significantly. Two experimental front-and-back pass solar air collectors of the same dimensions have been built for the experimental investigations. One collector had a "conventional" solar absorber made of a metal sheet while the solar absorber of the other collector consisted of containers filled with organic phase change material. The experimental collectors were positioned side by side during the investigations to ensure the same operating conditions (incident solar radiation, outdoor temperature).

  12. Radiation energy receiver for laser and solar propulsion systems

    NASA Technical Reports Server (NTRS)

    Rault, D. F. G.; Hertzberg, A.

    1983-01-01

    The concept of remotely heating a rocket propellant with a high intensity radiant energy flux is especially attractive due to its high specific impulse and large payload mass capabilities. In this paper, a radiation receiver-thruster which is especially suited to the particular thermodynamic and spectral characteristics of highly concentrated solar energy is proposed. In this receiver, radiant energy is volumetrically absorbed within a hydrogen gas seeded with alkali metal vapors. The alkali atoms and molecules absorb the radiant flux and, subsequently, transfer their internal excitation to hydrogen molecules through collisional quenching. It is shown that such a radiation receiver would outperform a blackbody cavity type receiver in both efficiency and maximum operating temperatures. A solar rocket equipped with such a receiver-thruster would deliver thrusts of several hundred newtons at a specific impulse of 1000 seconds.

  13. Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody.

    PubMed

    Zhu, Linxiao; Raman, Aaswath P; Fan, Shanhui

    2015-10-06

    A solar absorber, under the sun, is heated up by sunlight. In many applications, including solar cells and outdoor structures, the absorption of sunlight is intrinsic for either operational or aesthetic considerations, but the resulting heating is undesirable. Because a solar absorber by necessity faces the sky, it also naturally has radiative access to the coldness of the universe. Therefore, in these applications it would be very attractive to directly use the sky as a heat sink while preserving solar absorption properties. Here we experimentally demonstrate a visibly transparent thermal blackbody, based on a silica photonic crystal. When placed on a silicon absorber under sunlight, such a blackbody preserves or even slightly enhances sunlight absorption, but reduces the temperature of the underlying silicon absorber by as much as 13 °C due to radiative cooling. Our work shows that the concept of radiative cooling can be used in combination with the utilization of sunlight, enabling new technological capabilities.

  14. Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody

    PubMed Central

    Zhu, Linxiao; Raman, Aaswath P.; Fan, Shanhui

    2015-01-01

    A solar absorber, under the sun, is heated up by sunlight. In many applications, including solar cells and outdoor structures, the absorption of sunlight is intrinsic for either operational or aesthetic considerations, but the resulting heating is undesirable. Because a solar absorber by necessity faces the sky, it also naturally has radiative access to the coldness of the universe. Therefore, in these applications it would be very attractive to directly use the sky as a heat sink while preserving solar absorption properties. Here we experimentally demonstrate a visibly transparent thermal blackbody, based on a silica photonic crystal. When placed on a silicon absorber under sunlight, such a blackbody preserves or even slightly enhances sunlight absorption, but reduces the temperature of the underlying silicon absorber by as much as 13 °C due to radiative cooling. Our work shows that the concept of radiative cooling can be used in combination with the utilization of sunlight, enabling new technological capabilities. PMID:26392542

  15. Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody

    DOE PAGES

    Zhu, Linxiao; Raman, Aaswath P.; Fan, Shanhui

    2015-09-21

    A solar absorber, under the sun, is heated up by sunlight. In many applications, including solar cells and outdoor structures, the absorption of sunlight is intrinsic for either operational or aesthetic considerations, but the resulting heating is undesirable. Because a solar absorber by necessity faces the sky, it also naturally has radiative access to the coldness of the universe. Therefore, in these applications it would be very attractive to directly use the sky as a heat sink while preserving solar absorption properties. In this paper, we experimentally demonstrate a visibly transparent thermal blackbody, based on a silica photonic crystal. Whenmore » placed on a silicon absorber under sunlight, such a blackbody preserves or even slightly enhances sunlight absorption, but reduces the temperature of the underlying silicon absorber by as much as 13 °C due to radiative cooling. Lastly, our work shows that the concept of radiative cooling can be used in combination with the utilization of sunlight, enabling new technological capabilities.« less

  16. Semi-transparent solar energy thermal storage device

    DOEpatents

    McClelland, John F.

    1986-04-08

    A visually transmitting solar energy absorbing thermal storage module includes a thermal storage liquid containment chamber defined by an interior solar absorber panel, an exterior transparent panel having a heat mirror surface substantially covering the exterior surface thereof and associated top, bottom and side walls. Evaporation of the thermal storage liquid is controlled by a low vapor pressure liquid layer that floats on and seals the top surface of the liquid. Porous filter plugs are placed in filler holes of the module. An algicide and a chelating compound are added to the liquid to control biological and chemical activity while retaining visual clarity. A plurality of modules may be supported in stacked relation by a support frame to form a thermal storage wall structure.

  17. Semi-transparent solar energy thermal storage device

    DOEpatents

    McClelland, John F.

    1985-06-18

    A visually transmitting solar energy absorbing thermal storage module includes a thermal storage liquid containment chamber defined by an interior solar absorber panel, an exterior transparent panel having a heat mirror surface substantially covering the exterior surface thereof and associated top, bottom and side walls, Evaporation of the thermal storage liquid is controlled by a low vapor pressure liquid layer that floats on and seals the top surface of the liquid. Porous filter plugs are placed in filler holes of the module. An algicide and a chelating compound are added to the liquid to control biological and chemical activity while retaining visual clarity. A plurality of modules may be supported in stacked relation by a support frame to form a thermal storage wall structure.

  18. Super-hydrophilic copper sulfide films as light absorbers for efficient solar steam generation under one sun illumination

    NASA Astrophysics Data System (ADS)

    Guo, Zhenzhen; Ming, Xin; Wang, Gang; Hou, Baofei; Liu, Xinghang; Mei, Tao; Li, Jinhua; Wang, Jianying; Wang, Xianbao

    2018-02-01

    Solar steam technology is one of the simplest, most direct and effective ways to harness solar energy through water evaporation. Here, we report the development using super-hydrophilic copper sulfide (CuS) films with double-layer structures as light absorbers for solar steam generation. In the double-layer structure system, a porous mixed cellulose ester (MCE) membrane is used as a supporting layer, which enables water to get into the CuS light absorbers through a capillary action to provide continuous water during solar steam generation. The super-hydrophilic property of the double-layer system (CuS/MCE) leads to a thinner water film close to the air-water interface where the surface temperature is sufficiently high, leading to more efficient evaporation (˜80 ± 2.5%) under one sun illumination. Furthermore, the evaporation efficiencies still keep a steady value after 15 cycles of testing. The super-hydrophilic CuS film is promising for practical application in water purification and evaporation as a light absorption material.

  19. Absorption of solar radiation by alkali vapors. [for efficient high temperature energy converters

    NASA Technical Reports Server (NTRS)

    Mattick, A. T.

    1978-01-01

    A theoretical study of the direct absorption of solar radiation by the working fluid of high temperature, high efficiency energy converters has been carried out. Alkali vapors and potassium vapor in particular were found to be very effective solar absorbers and suitable thermodynamically for practical high temperature cycles. Energy loss via reradiation from a solar boiler was shown to reduce the overall efficiency of radiation-heated energy converters, although a simple model of radiation transfer in a potassium vapor solar boiler revealed that self-trapping of the reradiation may reduce this loss considerably. A study was also made of the requirements for a radiation boiler window. It was found that for sapphire, one of the best solar transmitting materials, the severe environment in conjunction with high radiation densities will require some form of window protection. An aerodynamic shield is particularly advantageous in this capacity, separating the window from the absorbing vapor to prevent condensation and window corrosion and to reduce the radiation density at the window.

  20. Fundamentals and applications of solar energy. Part 2

    NASA Astrophysics Data System (ADS)

    Faraq, I. H.; Melsheimer, S. S.

    Applications of techniques of chemical engineering to the development of materials, production methods, and performance optimization and evaluation of solar energy systems are discussed. Solar thermal storage systems using phase change materials, liquid phase Diels-Alder reactions, aquifers, and hydrocarbon oil were examined. Solar electric systems were explored in terms of a chlorophyll solar cell, the nonequilibrium electric field effects developed at photoelectrode/electrolyte interfaces, and designs for commercial scale processing of solar cells using continuous thin-film coating production methods. Solar coal gasification processes were considered, along with multilayer absorber coatings for solar concentrator receivers, solar thermal industrial applications, the kinetics of anaerobic digestion of crop residues to produce methane, and a procedure for developing a computer simulation of a solar cooling system.

  1. Metal-shearing energy absorber

    NASA Technical Reports Server (NTRS)

    Fay, R. J.; Wittrock, E. P.

    1971-01-01

    Device, consisting of tongue of thin aluminum alloy strip, pull tab, slotted steel plate which serves as cutter, and steel buckle, absorbs mechanical energy when its ends are subjected to tensile loading. Device is applicable as auxiliary shock absorbing anchor for automobile and airplane safety belts.

  2. Solar Thermal Energy Storage in a Photochromic Macrocycle.

    PubMed

    Vlasceanu, Alexandru; Broman, Søren L; Hansen, Anne S; Skov, Anders B; Cacciarini, Martina; Kadziola, Anders; Kjaergaard, Henrik G; Mikkelsen, Kurt V; Nielsen, Mogens Brøndsted

    2016-07-25

    The conversion and efficient storage of solar energy is recognized to hold significant potential with regard to future energy solutions. Molecular solar thermal batteries based on photochromic systems exemplify one possible technology able to harness and apply this potential. Herein is described the synthesis of a macrocycle based on a dimer of the dihydroazulene/vinylheptafulvene (DHA/VHF) photo/thermal couple. By taking advantage of conformational strain, this DHA-DHA macrocycle presents an improved ability to absorb and store incident light energy in chemical bonds (VHF-VHF). A stepwise energy release over two sequential ring-closing reactions (VHF→DHA) combines the advantages of an initially fast discharge, hypothetically addressing immediate energy consumption needs, followed by a slow process for consistent, long-term use. This exemplifies another step forward in the molecular engineering and design of functional organic materials towards solar thermal energy storage and release. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Energy absorber for the CETA

    NASA Technical Reports Server (NTRS)

    Wesselski, Clarence J.

    1994-01-01

    The energy absorber that was developed for the CETA (Crew Equipment and Translation Aid) on Space Station Freedom is a metal on metal frictional type and has a load regulating feature that prevents excessive stroking loads from occurring while in operation. This paper highlights some of the design and operating aspects and the testing of this energy absorber.

  4. Spectrally-engineered solar thermal photovoltaic devices

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lenert, Andrej; Bierman, David; Chan, Walker

    A solar thermal photovoltaic device, and method of forming same, includes a solar absorber and a spectrally selective emitter formed on either side of a thermally conductive substrate. The solar absorber is configured to absorb incident solar radiation. The solar absorber and the spectrally selective emitter are configured with an optimized emitter-to-absorber area ratio. The solar thermal photovoltaic device also includes a photovoltaic cell in thermal communication with the spectrally selective emitter. The spectrally selective emitter is configured to permit high emittance for energies above a bandgap of the photovoltaic cell and configured to permit low emittance for energies belowmore » the bandgap.« less

  5. Hybrid sunlight/LED illumination and renewable solar energy saving concepts for indoor lighting.

    PubMed

    Tsuei, Chih-Hsuan; Sun, Wen-Shing; Kuo, Chien-Cheng

    2010-11-08

    A hybrid method for using sunlight and light-emitting diode (LED) illumination powered by renewable solar energy for indoor lighting is simulated and presented in this study. We can illuminate an indoor space and collect the solar energy using an optical switching system. When the system is turned off, the full spectrum of the sunlight is concentrated by a concentrator, to be absorbed by solar photovoltaic devices that provide the electricity to power the LEDs. When the system is turned on, the sunlight collected by the concentrator is split into visible and non-visible rays by a beam splitter. The visible rays pass through the light guide into a light box where it is mixed with LED light to ultimately provide uniform illumination by a diffuser. The non-visible rays are absorbed by the solar photovoltaic devices to provide electrical power for the LEDs. Simulation results show that the efficiency of the hybrid sunlight/LED illumination with the renewable solar energy saving design is better than that of LED and traditional lighting systems.

  6. Solar collector apparatus having increased energy rejection during stagnation

    DOEpatents

    Moore, S.W.

    1981-01-16

    An active solar collector having increased energy rejection during stagnation is disclosed. The collector's glazing is brought into substantial contact with absorber during stagnation to increase re-emittance and thereby to maintan lower temperatures when the collector is not in operation.

  7. Collecting Solar Energy. Solar Energy Education Project.

    ERIC Educational Resources Information Center

    O'Brien, Alexander

    This solar energy learning module for use with junior high school students offers a list of activities, a pre-post test, job titles, basic solar energy vocabulary, and diagrams of solar energy collectors and installations. The purpose is to familiarize students with applications of solar energy and titles of jobs where this knowledge could be…

  8. Solar-pumped electronic-to-vibrational energy transfer lasers

    NASA Technical Reports Server (NTRS)

    Harries, W. L.; Wilson, J. W.

    1981-01-01

    The possibility of using solar-pumped lasers as solar energy converters is examined. The absorbing media considered are halogens or halogen compounds, which are dissociated to yield excited atoms, which then hand over energy to a molecular lasing medium. Estimates of the temperature effects for a Br2-CO2-He system with He as the cooling gas are given. High temperatures can cause the lower energy levels of the CO2 laser transition to be filled. The inverted populations are calculated and lasing should be possible. However, the efficiency is less than 0.001. Examination of other halogen-molecular lasant combinations (where the rate coefficients are known) indicate efficiencies in all cases of less than 0.005.

  9. Solar collector apparatus having increased energy rejection during stagnation

    DOEpatents

    Moore, Stanley W.

    1983-07-12

    The disclosure relates to an active solar collector having increased energy rejection during stagnation. The collector's glazing is brought into substantial contact with absorber during stagnation to increase re-emittance and thereby to maintain lower temperatures when the collector is not in operation.

  10. Metasurfaces Leveraging Solar Energy for Icephobicity.

    PubMed

    Mitridis, Efstratios; Schutzius, Thomas M; Sicher, Alba; Hail, Claudio U; Eghlidi, Hadi; Poulikakos, Dimos

    2018-06-29

    Inhibiting ice accumulation on surfaces is an energy-intensive task and is of significant importance in nature and technology where it has found applications in windshields, automobiles, aviation, renewable energy generation, and infrastructure. Existing methods rely on on-site electrical heat generation, chemicals, or mechanical removal, with drawbacks ranging from financial costs to disruptive technical interventions and environmental incompatibility. Here we focus on applications where surface transparency is desirable and propose metasurfaces with embedded plasmonically enhanced light absorption heating, using ultrathin hybrid metal-dielectric coatings, as a passive, viable approach for de-icing and anti-icing, in which the sole heat source is renewable solar energy. The balancing of transparency and absorption is achieved with rationally nanoengineered coatings consisting of gold nanoparticle inclusions in a dielectric (titanium dioxide), concentrating broadband absorbed solar energy into a small volume. This causes a > 10 °C temperature increase with respect to ambient at the air-solid interface, where ice is most likely to form, delaying freezing, reducing ice adhesion, when it occurs, to negligible levels (de-icing) and inhibiting frost formation (anti-icing). Our results illustrate an effective unexplored pathway toward environmentally compatible, solar-energy-driven icephobicity, enabled by respectively tailored plasmonic metasurfaces, with the ability to design the balance of transparency and light absorption.

  11. Building-Integrated Solar Energy Devices based on Wavelength Selective Films

    NASA Astrophysics Data System (ADS)

    Ulavi, Tejas

    A potentially attractive option for building integrated solar is to employ hybrid solar collectors which serve dual purposes, combining solar thermal technology with either thin film photovoltaics or daylighting. In this study, two hybrid concepts, a hybrid photovoltaic/thermal (PV/T) collector and a hybrid 'solar window', are presented and analyzed to evaluate technical performance. In both concepts, a wavelength selective film is coupled with a compound parabolic concentrator (CPC) to reflect and concentrate the infrared portion of the solar spectrum onto a tubular absorber. The visible portion of the spectrum is transmitted through the concentrator to either a thin film Cadmium Telluride (CdTe) solar panel for electricity generation or into the interior space for daylighting. Special attention is given to the design of the hybrid devices for aesthetic building integration. An adaptive concentrator design based on asymmetrical truncation of CPCs is presented for the hybrid solar window concept. The energetic and spectral split between the solar thermal module and the PV or daylighting module are functions of the optical properties of the wavelength selective film and the concentrator geometry, and are determined using a Monte Carlo Ray-Tracing (MCRT) model. Results obtained from the MCRT can be used in conjugation with meteorological data for specific applications to study the impact of CPC design parameters including the half-acceptance angle thetac, absorber diameter D and truncation on the annual thermal and PV/daylighting efficiencies. The hybrid PV/T system is analyzed for a rooftop application in Phoenix, AZ. Compared to a system of the same area with independent solar thermal and PV modules, the hybrid PV/T provides 20% more energy, annually. However, the increase in total delivered energy is due solely to the addition of the thermal module and is achieved at an expense of a decrease in the annual electrical efficiency from 8.8% to 5.8% due to shading by

  12. Interfacial Engineering and Charge Carrier Dynamics in Extremely Thin Absorber Solar Cells

    NASA Astrophysics Data System (ADS)

    Edley, Michael

    Photovoltaic energy is a clean and renewable source of electricity; however, it faces resistance to widespread use due to cost. Nanostructuring decouples constraints related to light absorption and charge separation, potentially reducing cost by allowing a wider variety of processing techniques and materials to be used. However, the large interfacial areas also cause an increased dark current which negatively affects cell efficiency. This work focuses on extremely thin absorber (ETA) solar cells that used a ZnO nanowire array as a scaffold for an extremely thin CdSe absorber layer. Photoexcited electrons generated in the CdSe absorber are transferred to the ZnO layer, while photogenerated holes are transferred to the liquid electrolyte. The transfer of photoexcited carriers to their transport layer competes with bulk recombination in the absorber layer. After charge separation, transport of charge carriers to their respective contacts must occur faster than interfacial recombination for efficient collection. Charge separation and collection depend sensitively on the dimensions of the materials as well as their interfaces. We demonstrated that an optimal absorber thickness can balance light absorption and charge separation. By treating the ZnO/CdSe interface with a CdS buffer layer, we were able to improve the Voc and fill factor, increasing the ETA cell's efficiency from 0.53% to 1.34%, which is higher than that achievable using planar films of the same material. We have gained additional insight into designing ETA cells through the use of dynamic measurements. Ultrafast transient absorption spectroscopy revealed that characteristic times for electron injection from CdSe to ZnO are less than 1 ps. Electron injection is rapid compared to the 2 ns bulk lifetime in CdSe. Optoelectronic measurements such as transient photocurrent/photovoltage and electrochemical impedance spectroscopy were applied to study the processes of charge transport and interfacial recombination

  13. Solar Energy.

    ERIC Educational Resources Information Center

    Eaton, William W.

    Presented is the utilization of solar radiation as an energy resource principally for the production of electricity. Included are discussions of solar thermal conversion, photovoltic conversion, wind energy, and energy from ocean temperature differences. Future solar energy plans, the role of solar energy in plant and fossil fuel production, and…

  14. An Energy Absorber for the International Space Station

    NASA Technical Reports Server (NTRS)

    Wilkes, Bob; Laurence, Lora

    2000-01-01

    The energy absorber described herein is similar in size and shape to an automotive shock absorber, requiring a constant, high load to compress over the stroke, and self-resetting with a small load. The differences in these loads over the stroke represent the energy absorbed by the device, which is dissipated as friction. This paper describes the evolution of the energy absorber, presents the results of testing performed, and shows the sensitivity of this device to several key design variables.

  15. Solar energy

    NASA Technical Reports Server (NTRS)

    Rapp, D.

    1981-01-01

    The book opens with a review of the patterns of energy use and resources in the United States, and an exploration of the potential of solar energy to supply some of this energy in the future. This is followed by background material on solar geometry, solar intensities, flat plate collectors, and economics. Detailed attention is then given to a variety of solar units and systems, including domestic hot water systems, space heating systems, solar-assisted heat pumps, intermediate temperature collectors, space heating/cooling systems, concentrating collectors for high temperatures, storage systems, and solar total energy systems. Finally, rights to solar access are discussed.

  16. Solar energy apparatus with apertured shield

    NASA Technical Reports Server (NTRS)

    Collings, Roger J. (Inventor); Bannon, David G. (Inventor)

    1989-01-01

    A protective apertured shield for use about an inlet to a solar apparatus which includesd a cavity receiver for absorbing concentrated solar energy. A rigid support truss assembly is fixed to the periphery of the inlet and projects radially inwardly therefrom to define a generally central aperture area through which solar radiation can pass into the cavity receiver. A non-structural, laminated blanket is spread over the rigid support truss in such a manner as to define an outer surface area and an inner surface area diverging radially outwardly from the central aperture area toward the periphery of the inlet. The outer surface area faces away from the inlet and the inner surface area faces toward the cavity receiver. The laminated blanket includes at least one layer of material, such as ceramic fiber fabric, having high infra-red emittance and low solar absorption properties, and another layer, such as metallic foil, of low infra-red emittance properties.

  17. Design and cost analysis for an ammonia-based solar thermochemical cavity absorber

    NASA Astrophysics Data System (ADS)

    Williams, O. M.

    1980-01-01

    A design and cost analysis is introduced for a solar thermochemical cavity absorber operated at the focus of a tracking paraboloidal concentrator and based on the ammonia dissociation reaction. The absorber design consists of a catalyst-filled nickel alloy tube wound into a spiral forming the inner cavity wall and shaped to match the incident power density profile to the reactor heat requirements. The reactor tube is welded to a coaxial counterflow heat exchanger. The relationships among the power density profile, the reaction thermodynamics and kinetics, and the heat transfer characteristics are examined in detail and it is shown that an installed cost goal of typically 10 U.S. dollars per square meter of solar collector area can be achieved through use of high activity ammonia dissociation catalyst. The optimum absorber size for a given paraboloidal dish area is calculated for a system pressure of 20 MPa and it is shown that a cost effective absorber suitable for 100,000-hr operation would operate at 90% efficiency at 750 C wall temperature.

  18. Polymers in solar energy utilization

    NASA Technical Reports Server (NTRS)

    Liang, R. H.; Coulter, D. R.; Dao, C.; Gupta, A.

    1983-01-01

    A laser photoacoustic technique (LPAT) has been verified for performing accelerated life testing of outdoor photooxidation of polymeric materials used in solar energy applications. Samples of the material under test are placed in a chamber with a sensitive microphone, then exposed to chopped laser radiation. The sample absorbs the light and converts it to heat by a nonradiative deexcitation process, thereby reducing pressure fluctuations within the cell. The acoustic signal detected by the microphone is directly proportional to the amount of light absorbed by the specimen. Tests were performed with samples of ethylene/methylacrylate copolymer (EMA) reprecipitated from hot cyclohexane, compressed, and molded into thin (25-50 microns) films. The films were exposed outdoors and sampled by LPAT weekly. The linearity of the light absorbed with respect to the acoustic signal was verified.Correlations were established between the photoacoustic behavior of the materials aged outdoors and the same kinds of samples cooled and heated in a controlled environment reactor. The reactor tests were validated for predicting outdoor exosures up to 55 days.

  19. Experimental indication for band gap widening of chalcopyrite solar cell absorbers after potassium fluoride treatment

    NASA Astrophysics Data System (ADS)

    Pistor, P.; Greiner, D.; Kaufmann, C. A.; Brunken, S.; Gorgoi, M.; Steigert, A.; Calvet, W.; Lauermann, I.; Klenk, R.; Unold, T.; Lux-Steiner, M.-C.

    2014-08-01

    The implementation of potassium fluoride treatments as a doping and surface modification procedure in chalcopyrite absorber preparation has recently gained much interest since it led to new record efficiencies for this kind of solar cells. In the present work, Cu(In,Ga)Se2 absorbers have been evaporated on alkali containing Mo/soda-lime glass substrates. We report on compositional and electronic changes of the Cu(In,Ga)Se2 absorber surface as a result of a post deposition treatment with KF (KF PDT). In particular, by comparing standard X-ray photoelectron spectroscopy and synchrotron-based hard X-ray photoelectron spectroscopy (HAXPES), we are able to confirm a strong Cu depletion in the absorbers after the KF PDT which is limited to the very near surface region. As a result of the Cu depletion, we find a change of the valence band structure and a shift of the valence band onset by approximately 0.4 eV to lower binding energies which is tentatively explained by a band gap widening as expected for Cu deficient compounds. The KF PDT increased the open circuit voltage by 60-70 mV compared to the untreated absorbers, while the fill factor deteriorated.

  20. 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.

  1. Impedance approach to designing efficient vibration energy absorbers

    NASA Astrophysics Data System (ADS)

    Bobrovnitskii, Y. I.; Morozov, K. D.; Tomilina, T. M.

    2017-03-01

    The concept introduced previously by the authors on the best sound absorber having the maximum allowable efficiency in absorbing the energy of an incident sound field has been extended to arbitrary linear elastic media and structures. Analytic relations have been found for the input impedance characteristics that the best vibrational energy absorber should have. The implementation of these relations is the basis of the proposed impedance method of designing efficient vibration and noise absorbers. We present the results of a laboratory experiment that confirms the validity of the obtained theoretical relations, and we construct the simplest best vibration absorber. We also calculate the parameters and demonstrate the efficiency of a dynamic vibration absorber as the best absorber.

  2. Deep absorbing porphyrin small molecule for high-performance organic solar cells with very low energy losses.

    PubMed

    Gao, Ke; Li, Lisheng; Lai, Tianqi; Xiao, Liangang; Huang, Yuan; Huang, Fei; Peng, Junbiao; Cao, Yong; Liu, Feng; Russell, Thomas P; Janssen, René A J; Peng, Xiaobin

    2015-06-17

    We designed and synthesized the DPPEZnP-TEH molecule, with a porphyrin ring linked to two diketopyrrolopyrrole units by ethynylene bridges. The resulting material exhibits a very low energy band gap of 1.37 eV and a broad light absorption to 907 nm. An open-circuit voltage of 0.78 V was obtained in bulk heterojunction (BHJ) organic solar cells, showing a low energy loss of only 0.59 eV, which is the first report that small molecule solar cells show energy losses <0.6 eV. The optimized solar cells show remarkable external quantum efficiency, short circuit current, and power conversion efficiency up to 65%, 16.76 mA/cm(2), and 8.08%, respectively, which are the best values for BHJ solar cells with very low energy losses. Additionally, the morphology of DPPEZnP-TEH neat and blend films with PC61BM was studied thoroughly by grazing incidence X-ray diffraction, resonant soft X-ray scattering, and transmission electron microscopy under different fabrication conditions.

  3. Energy-Absorbing, Lightweight Wheels

    NASA Technical Reports Server (NTRS)

    Waydo, Peter

    2003-01-01

    Improved energy-absorbing wheels are under development for use on special-purpose vehicles that must traverse rough terrain under conditions (e.g., extreme cold) in which rubber pneumatic tires would fail. The designs of these wheels differ from those of prior non-pneumatic energy-absorbing wheels in ways that result in lighter weights and more effective reduction of stresses generated by ground/wheel contact forces. These wheels could be made of metals and/or composite materials to withstand the expected extreme operating conditions. As shown in the figure, a wheel according to this concept would include an isogrid tire connected to a hub via spring rods. The isogrid tire would be a stiff, lightweight structure typically made of aluminum. The isogrid aspect of the structure would both impart stiffness and act as a traction surface. The hub would be a thin-walled body of revolution having a simple or compound conical or other shape chosen for structural efficiency. The spring rods would absorb energy and partially isolate the hub and the supported vehicle from impact loads. The general spring-rod configuration shown in the figure was chosen because it would distribute contact and impact loads nearly evenly around the periphery of the hub, thereby helping to protect the hub against damage that would otherwise be caused by large loads concentrated onto small portions of the hub.

  4. Luminescent solar concentrators and all-inorganic nanoparticle solar cells for solar energy harvesting

    NASA Astrophysics Data System (ADS)

    Sholin, Veronica

    Increasing energy demand and the parallel increase of greenhouse gas emissions are challenging researchers to find new and cleaner energy sources. Solar energy harvesting is arguably the most promising candidate for replacing fossil-fuel power generation. Photovoltaics are the most direct way of collecting solar energy; cost continues to hinder large-scale implementation of photovoltaics, however. Therefore, alternative technologies that will allow the extraction of solar power, while maintaining the overall costs of fabrication, installation, collection, and distribution low, must be explored. This thesis focuses on the fabrication and testing of two types of devices that step up to this challenge: the luminescent solar concentrator (LSC) and all-inorganic nanoparticle solar cells. In these devices I make use of novel materials, semiconducting polymers and inorganic nanoparticles, both of which have lower costs than the crystalline materials used in the fabrication of traditional photovoltaics. Furthermore, the cost of manufacturing LSCs and the nanoparticle solar cells is lower than the manufacturing cost of traditional optics-based concentrators and crystalline solar cells. An LSC is essentially a slab of luminescent material that acts as a planar light pipe. The LSC absorbs incoming photons and channels fluoresced photons toward appropriately located solar cells, which perform the photovoltaic conversion. By covering large areas with relatively inexpensive fluorescing organic dyes or semiconducting polymers, the area of solar cell needed is greatly reduced. Because semiconducting polymers and quantum dots may have small absorption/emission band overlaps, tunable absorption, and longer lifetimes, they are good candidates for LSC fabrication, promising improvement with respect to laser dyes traditionally used to fabricate LSCs. Here the efficiency of LSCs consisting of liquid solutions of semiconducting polymers encased in glass was measured and compared to the

  5. Porphyrin Based Near Infrared-Absorbing Materials for Organic Photovoltaics

    NASA Astrophysics Data System (ADS)

    Zhong, Qiwen

    The conservation and transformation of energy is essential to the survival of mankind, and thus concerns every modern society. Solar energy, as an everlasting source of energy, holds one of the key solutions to some of the most urgent problems the world now faces, such as global warming and the oil crisis. Advances in technologies utilizing clean, abundant solar energy, could be the steering wheel of our societies. Solar cells, one of the major advances in converting solar energy into electricity, are now capturing people's interest all over the globe. While solar cells have been commercially available for many years, the manufacturing of solar cells is quite expensive, limiting their broad based implementation. The cost of solar cell based electricity is 15-50 cents per kilowatt hour (¢/kwh), depending on the type of solar cell, compared to 0.7 ¢/kwh for fossil fuel based electricity. Clearly, decreasing the cost of electricity from solar cells is critical for their wide spread deployment. This will require a decrease in the cost of light absorbing materials and material processing used in fabricating the cells. Organic photovoltaics (OPVs) utilize organic materials such as polymers and small molecules. These devices have the advantage of being flexible and lower cost than conventional solar cells built from inorganic semiconductors (e.g. silicon). The low cost of OPVs is tied to lower materials and fabrication costs of organic cells. However, the current power conversion efficiencies of OPVs are still below 15%, while convention crystalline Si cells have efficiencies of 20-25%. A key limitation in OPVs today is their inability to utilize the near infrared (NIR) portion of the solar spectrum. This part of the spectrum comprises nearly half of the energy in sunlight that could be used to make electricity. The first and foremost step in conversion solar energy conversion is the absorption of light, which nature has provided us optimal model of, which is

  6. Metamaterial Receivers for High Efficiency Concentrated Solar Energy Conversion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yellowhair, Julius E.; Kwon, Hoyeong; Alu, Andrea

    Operation of concentrated solar power receivers at higher temperatures (>700°C) would enable supercritical carbon dioxide (sCO 2) power cycles for improved power cycle efficiencies (>50%) and cost-effective solar thermal power. Unfortunately, radiative losses at higher temperatures in conventional receivers can negatively impact the system efficiency gains. One approach to improve receiver thermal efficiency is to utilize selective coatings that enhance absorption across the visible solar spectrum while minimizing emission in the infrared to reduce radiative losses. Existing coatings, however, tend to degrade rapidly at elevated temperatures. In this report, we report on the initial designs and fabrication of spectrally selectivemore » metamaterial-based absorbers for high-temperature, high-thermal flux environments important for solarized sCO 2 power cycles. Metamaterials are structured media whose optical properties are determined by sub-wavelength structural features instead of bulk material properties, providing unique solutions by decoupling the optical absorption spectrum from thermal stability requirements. The key enabling innovative concept proposed is the use of structured surfaces with spectral responses that can be tailored to optimize the absorption and retention of solar energy for a given temperature range. In this initial study through the Academic Alliance partnership with University of Texas at Austin, we use Tungsten for its stability in expected harsh environments, compatibility with microfabrication techniques, and required optical performance. Our goal is to tailor the optical properties for high (near unity) absorptivity across the majority of the solar spectrum and over a broad range of incidence angles, and at the same time achieve negligible absorptivity in the near infrared to optimize the energy absorbed and retained. To this goal, we apply the recently developed concept of plasmonic Brewster angle to suitably designed nanostructured

  7. Nonimaging concentrators for solar thermal energy

    NASA Astrophysics Data System (ADS)

    Winston, R.; Gallagher, J. J.

    1980-03-01

    A small experimental solar collector test facility was used to explore applications of nonimaging optics for solar thermal concentration in three substantially different configurations: a single stage system with moderate concentration on an evacuated absorber (a 5.25X evacuated tube Compound Parabolic Concentrator or CPC), a two stage system with high concentration and a non-evacuated absorber (a 16X Fresnel lens/CPC type mirror) and moderate concentration single stage systems with non-evacuated absorbers for lower temperature (a 3X and a 6.5X CPC). Prototypes of each of these systems were designed, built and tested. The performance characteristics are presented.

  8. Solar Energy: Solar System Economics.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on solar system economics 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 technologies.…

  9. Photovoltaic and photoelectrochemical conversion of solar energy.

    PubMed

    Grätzel, Michael

    2007-04-15

    The Sun provides approximately 100,000 terawatts to the Earth which is about 10000 times more than the present rate of the world's present energy consumption. Photovoltaic cells are being increasingly used to tap into this huge resource and will play a key role in future sustainable energy systems. So far, solid-state junction devices, usually made of silicon, crystalline or amorphous, and profiting from the experience and material availability resulting from the semiconductor industry, have dominated photovoltaic solar energy converters. These systems have by now attained a mature state serving a rapidly growing market, expected to rise to 300 GW by 2030. However, the cost of photovoltaic electricity production is still too high to be competitive with nuclear or fossil energy. Thin film photovoltaic cells made of CuInSe or CdTe are being increasingly employed along with amorphous silicon. The recently discovered cells based on mesoscopic inorganic or organic semiconductors commonly referred to as 'bulk' junctions due to their three-dimensional structure are very attractive alternatives which offer the prospect of very low cost fabrication. The prototype of this family of devices is the dye-sensitized solar cell (DSC), which accomplishes the optical absorption and the charge separation processes by the association of a sensitizer as light-absorbing material with a wide band gap semiconductor of mesoporous or nanocrystalline morphology. Research is booming also in the area of third generation photovoltaic cells where multi-junction devices and a recent breakthrough concerning multiple carrier generation in quantum dot absorbers offer promising perspectives.

  10. Remote sensing of solar radiation absorbed and reflected by vegetated land surfaces

    NASA Technical Reports Server (NTRS)

    Myneni, Ranga B.; Asrar, Ghassem; Tanre, Didier; Choudhury, Bhaskar J.

    1992-01-01

    1D and 3D radiative-transfer models have been used to investigate the problem of remotely sensed determination of vegetated land surface-absorbed and reflected solar radiation. Calculations were conducted for various illumination conditions to determine surface albedo, soil- and canopy-absorbed photosynthetically active and nonactive radiation, and normalized difference vegetation index. Simple predictive models are developed on the basis of the relationships among these parameters.

  11. Apollo couch energy absorbers

    NASA Technical Reports Server (NTRS)

    Wesselski, C. J.; Drexel, R. E.

    1972-01-01

    Load attenuators for the Apollo spacecraft crew couch and its potential applications are described. Energy absorption is achieved through friction and cyclic deformation of material. In one concept, energy absorption is accomplished by rolling a compressed ring of metal between two surfaces. In another concept, energy is absorbed by forcing a plastically deformed washer along a rod. Among the design problems that had to be solved were material selection, fatigue life, ring slippage, lubrication, and friction loading.

  12. Experimental indication for band gap widening of chalcopyrite solar cell absorbers after potassium fluoride treatment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pistor, P., E-mail: paul.pistor@physik.uni-halle.de; Greiner, D.; Kaufmann, C. A.

    2014-08-11

    The implementation of potassium fluoride treatments as a doping and surface modification procedure in chalcopyrite absorber preparation has recently gained much interest since it led to new record efficiencies for this kind of solar cells. In the present work, Cu(In,Ga)Se{sub 2} absorbers have been evaporated on alkali containing Mo/soda-lime glass substrates. We report on compositional and electronic changes of the Cu(In,Ga)Se{sub 2} absorber surface as a result of a post deposition treatment with KF (KF PDT). In particular, by comparing standard X-ray photoelectron spectroscopy and synchrotron-based hard X-ray photoelectron spectroscopy (HAXPES), we are able to confirm a strong Cu depletionmore » in the absorbers after the KF PDT which is limited to the very near surface region. As a result of the Cu depletion, we find a change of the valence band structure and a shift of the valence band onset by approximately 0.4 eV to lower binding energies which is tentatively explained by a band gap widening as expected for Cu deficient compounds. The KF PDT increased the open circuit voltage by 60–70 mV compared to the untreated absorbers, while the fill factor deteriorated.« less

  13. One-dimension-based spatially ordered architectures for solar energy conversion.

    PubMed

    Liu, Siqi; Tang, Zi-Rong; Sun, Yugang; Colmenares, Juan Carlos; Xu, Yi-Jun

    2015-08-07

    The severe consequences of fossil fuel consumption have resulted in a need for alternative sustainable sources of energy. Conversion and storage of solar energy via a renewable method, such as photocatalysis, holds great promise as such an alternative. One-dimensional (1D) nanostructures have gained attention in solar energy conversion because they have a long axis to absorb incident sunlight yet a short radial distance for separation of photogenerated charge carriers. In particular, well-ordered spatially high dimensional architectures based on 1D nanostructures with well-defined facets or anisotropic shapes offer an exciting opportunity for bridging the gap between 1D nanostructures and the micro and macro world, providing a platform for integration of nanostructures on a larger and more manageable scale into high-performance solar energy conversion applications. In this review, we focus on the progress of photocatalytic solar energy conversion over controlled one-dimension-based spatially ordered architecture hybrids. Assembly and classification of these novel architectures are summarized, and we discuss the opportunity and future direction of integration of 1D materials into high-dimensional, spatially organized architectures, with a perspective toward improved collective performance in various artificial photoredox applications.

  14. Solar Energy Systems

    NASA Astrophysics Data System (ADS)

    1984-01-01

    Calibrated in kilowatt hours per square meter, the solar counter produced by Dodge Products, Inc. provides a numerical count of the solar energy that has accumulated on a surface. Solar energy sensing, measuring and recording devices in corporate solar cell technology developed by Lewis Research Center. Customers for their various devices include architects, engineers and others engaged in construction and operation of solar energy facilities; manufacturers of solar systems or solar related products, such as glare reducing windows; and solar energy planners in federal and state government agencies.

  15. High temperature solar energy absorbing surfaces

    DOEpatents

    Schreyer, J.M.; Schmitt, C.R.; Abbatiello, L.A.

    A solar collector having an improved coating is provided. The coating is a plasma-sprayed coating comprising a material having a melting point above 500/sup 0/C at which it is stable and selected from the group of boron carbide, boron nitride, metals and metal oxides, nitrides, carbides, borides, and silicates. The coatings preferably have a porosity of about 15 to 25% and a thickness of less than 200 micrometers. The coatings can be provided by plasma-spraying particles having a mean diameter of about 10 to 200 micrometers.

  16. Compositionally Graded Absorber for Efficient and Stable Near‐Infrared‐Transparent Perovskite Solar Cells

    PubMed Central

    Pisoni, Stefano; Weiss, Thomas P.; Feurer, Thomas; Wäckerlin, Aneliia; Fuchs, Peter; Nishiwaki, Shiro; Zortea, Lukas; Tiwari, Ayodhya N.

    2018-01-01

    Abstract Compositional grading has been widely exploited in highly efficient Cu(In,Ga)Se2, CdTe, GaAs, quantum dot solar cells, and this strategy has the potential to improve the performance of emerging perovskite solar cells. However, realizing and maintaining compositionally graded perovskite absorber from solution processing is challenging. Moreover, the operational stability of graded perovskite solar cells under long‐term heat/light soaking has not been demonstrated. In this study, a facile partial ion‐exchange approach is reported to achieve compositionally graded perovskite absorber layers. Incorporating compositional grading improves charge collection and suppresses interface recombination, enabling to fabricate near‐infrared‐transparent perovskite solar cells with power conversion efficiency of 16.8% in substrate configuration, and demonstrate 22.7% tandem efficiency with 3.3% absolute gain when mechanically stacked on a Cu(In,Ga)Se2 bottom cell. Non‐encapsulated graded perovskite device retains over 93% of its initial efficiency after 1000 h operation at maximum power point at 60 °C under equivalent 1 sun illumination. The results open an avenue in exploring partial ion‐exchange to design graded perovskite solar cells with improved efficiency and stability. PMID:29593970

  17. Compositionally Graded Absorber for Efficient and Stable Near-Infrared-Transparent Perovskite Solar Cells.

    PubMed

    Fu, Fan; Pisoni, Stefano; Weiss, Thomas P; Feurer, Thomas; Wäckerlin, Aneliia; Fuchs, Peter; Nishiwaki, Shiro; Zortea, Lukas; Tiwari, Ayodhya N; Buecheler, Stephan

    2018-03-01

    Compositional grading has been widely exploited in highly efficient Cu(In,Ga)Se 2 , CdTe, GaAs, quantum dot solar cells, and this strategy has the potential to improve the performance of emerging perovskite solar cells. However, realizing and maintaining compositionally graded perovskite absorber from solution processing is challenging. Moreover, the operational stability of graded perovskite solar cells under long-term heat/light soaking has not been demonstrated. In this study, a facile partial ion-exchange approach is reported to achieve compositionally graded perovskite absorber layers. Incorporating compositional grading improves charge collection and suppresses interface recombination, enabling to fabricate near-infrared-transparent perovskite solar cells with power conversion efficiency of 16.8% in substrate configuration, and demonstrate 22.7% tandem efficiency with 3.3% absolute gain when mechanically stacked on a Cu(In,Ga)Se 2 bottom cell. Non-encapsulated graded perovskite device retains over 93% of its initial efficiency after 1000 h operation at maximum power point at 60 °C under equivalent 1 sun illumination. The results open an avenue in exploring partial ion-exchange to design graded perovskite solar cells with improved efficiency and stability.

  18. Optimal nonimaging integrated evacuated solar collector

    NASA Astrophysics Data System (ADS)

    Garrison, John D.; Duff, W. S.; O'Gallagher, Joseph J.; Winston, Roland

    1993-11-01

    A non imaging integrated evacuated solar collector for solar thermal energy collection is discussed which has the lower portion of the tubular glass vacuum enveloped shaped and inside surface mirrored to optimally concentrate sunlight onto an absorber tube in the vacuum. This design uses vacuum to eliminate heat loss from the absorber surface by conduction and convection of air, soda lime glass for the vacuum envelope material to lower cost, optimal non imaging concentration integrated with the glass vacuum envelope to lower cost and improve solar energy collection, and a selective absorber for the absorbing surface which has high absorptance and low emittance to lower heat loss by radiation and improve energy collection efficiency. This leads to a very low heat loss collector with high optical collection efficiency, which can operate at temperatures up to the order of 250 degree(s)C with good efficiency while being lower in cost than current evacuated solar collectors. Cost estimates are presented which indicate a cost for this solar collector system which can be competitive with the cost of fossil fuel heat energy sources when the collector system is produced in sufficient volume. Non imaging concentration, which reduces cost while improving performance, and which allows efficient solar energy collection without tracking the sun, is a key element in this solar collector design.

  19. Design and Development of Variable-Load Energy Absorbers

    DTIC Science & Technology

    1981-06-16

    Three concepts were developed and/or tested: a wire - bending mechanism, a tube-constricting mechanism, and a hydraulic energy absorber. Preliminary full...scale working models of the wire - bending mechanism and the tube-constricting mechanisms were built and tested. The hydraulic energy absorber was

  20. A nanophotonic solar thermophotovoltaic device.

    PubMed

    Lenert, Andrej; Bierman, David M; Nam, Youngsuk; Chan, Walker R; Celanović, Ivan; Soljačić, Marin; Wang, Evelyn N

    2014-02-01

    The most common approaches to generating power from sunlight are either photovoltaic, in which sunlight directly excites electron-hole pairs in a semiconductor, or solar-thermal, in which sunlight drives a mechanical heat engine. Photovoltaic power generation is intermittent and typically only exploits a portion of the solar spectrum efficiently, whereas the intrinsic irreversibilities of small heat engines make the solar-thermal approach best suited for utility-scale power plants. There is, therefore, an increasing need for hybrid technologies for solar power generation. By converting sunlight into thermal emission tuned to energies directly above the photovoltaic bandgap using a hot absorber-emitter, solar thermophotovoltaics promise to leverage the benefits of both approaches: high efficiency, by harnessing the entire solar spectrum; scalability and compactness, because of their solid-state nature; and dispatchablility, owing to the ability to store energy using thermal or chemical means. However, efficient collection of sunlight in the absorber and spectral control in the emitter are particularly challenging at high operating temperatures. This drawback has limited previous experimental demonstrations of this approach to conversion efficiencies around or below 1% (refs 9, 10, 11). Here, we report on a full solar thermophotovoltaic device, which, thanks to the nanophotonic properties of the absorber-emitter surface, reaches experimental efficiencies of 3.2%. The device integrates a multiwalled carbon nanotube absorber and a one-dimensional Si/SiO2 photonic-crystal emitter on the same substrate, with the absorber-emitter areas optimized to tune the energy balance of the device. Our device is planar and compact and could become a viable option for high-performance solar thermophotovoltaic energy conversion.

  1. Development of selective solar absorbers on the basis of aluminum roll-bond heat exchangers

    NASA Astrophysics Data System (ADS)

    Moeller, M.

    1981-11-01

    A deposition technique comparable to two-stage anodizing and especially suited for solar absorber panels, using roll-bond Al 99.5 and AlMnZr alloys as a substrate, was developed. The coating is of the nickel structure filter type and provides average solar absorptivity values of 94% and thermal emission values of 14%. The setup of a production plant capable of coating surfaces up to 2 sq m is described as well as the development of corrosion resistent hermetically sealed collectors. By means of an appropriate surface treatment the same corrosion resistance was achieved for absorbers mounted in ventilated collectors.

  2. Progress In The Commercialization Of A Carbonaceous Solar Selective Absorber On A Glass Substrate

    NASA Astrophysics Data System (ADS)

    Garrison, John D.; Haiad, J. Carlos; Averett, Anthony J.

    1987-11-01

    A carbonaceous solar selective absorber is formed on a glass substrate by coating the glass with a silver infrared reflecting layer, electroplating a thin nickel catalyst coating on the silver using very special plating conditions, and then exposing the nickel coated, silvered glass substrate to acetylene at a temperature of about 400 - 500°C for about five minutes. A fairly large plater and conveyor oven have been constructed and operated for the formation of these solar selective absorbers in order to study the formation of this absorber by a process which might be used commercially. Samples of this selective absorber on a glass substrate have been formed using the plater and conveyor oven. The samples, which have the best optical properties, have an absorptance of about 0.9 and an emittance of about 0.03. Excessive decomposition of the acetylene by the walls of the oven at higher temperatures with certain wall materials and oven geometries can prevent the formation of good selective absorbers. Procedures for preventing excessive decomposition of the acetylene and the knowledge gained so far by these studies is discussed.

  3. Energy Conversion: Nano Solar Cell

    NASA Astrophysics Data System (ADS)

    Yahaya, Muhammad; Yap, Chi Chin; Mat Salleh, Muhamad

    2009-09-01

    Problems of fossil-fuel-induced climate change have sparked a demand for sustainable energy supply for all sectors of economy. Most laboratories continue to search for new materials and new technique to generate clean energy at affordable cost. Nanotechnology can play a major role in solving the energy problem. The prospect for solar energy using Si-based technology is not encouraging. Si photovoltaics can produce electricity at 20-30 c//kWhr with about 25% efficiency. Nanoparticles have a strong capacity to absorb light and generate more electrons for current as discovered in the recent work of organic and dye-sensitized cell. Using cheap preparation technique such as screen-printing and self-assembly growth, organic cells shows a strong potential for commercialization. Thin Films research group at National University Malaysia has been actively involved in these areas, and in this seminar, we will present a review works on nanomaterials for solar cells and particularly on hybrid organic solar cell based on ZnO nanorod arrays. The organic layer consisting of poly[2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEHPPV) and [6, 6]-phenyl C61-butyric acid 3-ethylthiophene ester (PCBE) was spin-coated on ZnO nanorod arrays. ZnO nanorod arrays were grown on FTO glass substrates which were pre-coated with ZnO nanoparticles using a low temperature chemical solution method. A gold electrode was used as the top contact. The device gave a short circuit current density of 2.49×10-4 mA/cm2 and an open circuit voltage of 0.45 V under illumination of a projector halogen light at 100 mW/cm2.

  4. The Spectrophotometric Method of Determining the Transmission of Solar Energy in Salt Gradient Solar Ponds

    NASA Technical Reports Server (NTRS)

    Giulianelli, J.

    1984-01-01

    In order to predict the thermal efficiency of a solar pond it is necessary to know total average solar energy reaching the storage layer. One method for determining this energy for water containing dissolved colored species is based upon spectral transmission measurements using a laboratory spectrophotometer. This method is examined and some of the theoretical ground work needed to discuss the measurement of transmission of light water. Results of in situ irradiance measurements from oceanography research are presented and the difficulties inherent in extrapolating laboratory data obtained with ten centimeter cells to real three dimensional pond situations is discussed. Particular emphasis is put on the need to account for molecular and particulate scattering in measurements done on low absorbing solutions. Despite these considerations it is expected that attenuation calculations based upon careful measurements using a dual beam spectrophotometer technique combined with known attenuation coefficients will be useful in solar pond modeling and monitoring for color buildup. Preliminary results using the CSM method are presented.

  5. Failure mechanisms in energy-absorbing composite structures

    NASA Astrophysics Data System (ADS)

    Johnson, Alastair F.; David, Matthew

    2010-11-01

    Quasi-static tests are described for determination of the energy-absorption properties of composite crash energy-absorbing segment elements under axial loads. Detailed computer tomography scans of failed specimens were used to identify local compression crush failure mechanisms at the crush front. These mechanisms are important for selecting composite materials for energy-absorbing structures, such as helicopter and aircraft sub-floors. Finite element models of the failure processes are described that could be the basis for materials selection and future design procedures for crashworthy structures.

  6. Synthesis and characterizations of Cu2ZnSnS4 nanoparticles/carbon nanotube composite as an efficient absorber material for solar cell application

    NASA Astrophysics Data System (ADS)

    Das, S.; Sa, K.; Alam, I.; Mahakul, P. C.; Raiguru, J.; Subramanyam, B. V. R. S.; Mahanandia, P.

    2018-05-01

    In this energy crisis era, the urgent calls for clean energy converter realizes the importance of photovoltaic device, which offers the highest probability of delivering a sustainable way of harvesting solar energy. The active absorber layer has its significance towards the performance of photovoltaic device by absorbing solar light and creating electron-hole pair inside layer. Being a direct p-type semiconductor, Cu2ZnSnS4 generally referred as CZTS has emerged as potential absorber towards photovoltaics application in recent decades as it offers the advantage of tunable band gap near optimal region ˜1.45-1.65 eV favorably match the solar spectrum and a high absorption coefficient ˜104 cm-1. The further improvement in the performance of CZTS based photovoltaics has involved the use of carbon nanotubes (CNTs). Semiconductors hybridized with carbonaceous materials (CNTs) have been the center of attraction in the scientific community with beneficial contribution in enhancing optoelectronic properties. The incorporation of CNTs shows effectiveness in charge carrier transfer pathways which ultimately could enhance the photo conversion efficiency (PCE) of photovoltaic device cell (PVC). Here, a facile hydrothermal one-pot synthesis of CZTS nanoparticles and MWCNTs composite towards photovoltaics application is reported. The phase and structural analysis of CZTS nanoparticles as well as CZTS/MWCNTs composite is done by XRD. From FERSEM and TEM (LRTEM & HRTEM) analysis the CZTS nanoparticles decorated over the surface of MWCNTs is confirmed. The optical band gap of CZTS/MWCNTs composite is estimated to be 1.62 eV from UV-Visible spectra.

  7. Solar energy modulator

    NASA Technical Reports Server (NTRS)

    Hale, R. R. (Inventor); Mcdougal, A. R.

    1984-01-01

    A module is described with a receiver having a solar energy acceptance opening and supported by a mounting ring along the optic axis of a parabolic mirror in coaxial alignment for receiving solar energy from the mirror, and a solar flux modulator plate for varying the quantity of solar energy flux received by the acceptance opening of the module. The modulator plate is characterized by an annular, plate-like body, the internal diameter of which is equal to or slightly greater than the diameter of the solar energy acceptance opening of the receiver. Slave cylinders are connected to the modulator plate for supporting the plate for axial displacement along the axis of the mirror, therby shading the opening with respect to solar energy flux reflected from the surface of the mirror to the solar energy acceptance opening.

  8. Research Update: Emerging chalcostibite absorbers for thin-film solar cells

    DOE PAGES

    de Souza Lucas, Francisco Willian; Zakutayev, Andriy

    2018-06-04

    Copper antimony chalcogenides CuSbCh 2 (Ch=S, Se) are an emerging family of absorbers studied for thin-film solar cells. These non-toxic and Earth-abundant materials show a layered low-dimensional chalcostibite crystal structure, leading to interesting optoelectronic properties for applications in photovoltaic (PV) devices. This research update describes the CuSbCh 2 crystallographic structures, synthesis methods, competing phases, band structures, optoelectronic properties, point defects, carrier dynamics, and interface band offsets, based on experimental and theoretical data. Correlations between these absorber properties and PV device performance are discussed, and opportunities for further increase in the efficiency of the chalcostibite PV devices are highlighted.

  9. Research Update: Emerging chalcostibite absorbers for thin-film solar cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    de Souza Lucas, Francisco Willian; Zakutayev, Andriy

    Copper antimony chalcogenides CuSbCh 2 (Ch=S, Se) are an emerging family of absorbers studied for thin-film solar cells. These non-toxic and Earth-abundant materials show a layered low-dimensional chalcostibite crystal structure, leading to interesting optoelectronic properties for applications in photovoltaic (PV) devices. This research update describes the CuSbCh 2 crystallographic structures, synthesis methods, competing phases, band structures, optoelectronic properties, point defects, carrier dynamics, and interface band offsets, based on experimental and theoretical data. Correlations between these absorber properties and PV device performance are discussed, and opportunities for further increase in the efficiency of the chalcostibite PV devices are highlighted.

  10. Flower garden trees' ability to absorb solar radiation heat for local heat reduction

    NASA Astrophysics Data System (ADS)

    Maulana, Muhammad Ilham; Syuhada, Ahmad; Hamdani

    2017-06-01

    Banda Aceh as an urban area tends to have a high air temperature than its rural surroundings. A simple way to cool Banda Aceh city is by planting urban vegetation such as home gardens or parks. In addition to aesthetics, urban vegetation plays an important role as a reducer of air pollution, oxygen producer, and reducer of the heat of the environment. To create an ideal combination of plants, knowledge about the ability of plants to absorb solar radiation heat is necessary. In this study, some types of flowers commonly grown by communities around the house, such as Michelia Champaka, Saraca Asoka, Oliander, Adenium, Codiaeum Variegatum, Jas Minum Sambac, Pisonia Alba, Variegata, Apium Graveolens, Elephantopus Scaber, Randia, Cordylin.Sp, Hibiscus Rosasinensis, Agave, Lili, Amarilis, and Sesamum Indicum, were examined. The expected benefit of this research is to provide information for people, especially in Banda Aceh, on the ability of each plant relationship in absorbing heat for thermal comfort in residential environments. The flower plant which absorbs most of the sun's heat energy is Hibiscus Rosasinensis (kembang sepatu) 6.2 Joule, Elephantopus Scaber.L (tapak leman) 4.l Joule. On the other hand, the lowest heat absorption is Oliander (sakura) 0.9 Joule.

  11. The CVD ZrB2 as a selective solar absorber

    NASA Astrophysics Data System (ADS)

    Randich, E.; Allred, D. D.

    Coatings of ZrB2 and TiB2 for photothermal solar absorber applications were prepared using chemical vapor deposition (CVD) techniques. Oxidation tests suggest a maximum temperature limit for air exposure of 600 K for TiB2 and 800 K for Z4B2. Both materials exhibit innate spectral selectivity with emittance at 375 K ranging from 0.06 to 0.09 and solar absorptance for ZrB2 ranging from 0.67 to 0.77 and solar absorptance for TiB2 ranging from 0.46 to 0.58. ZrB2 has better solar selectivity and more desirable oxidation behavior than TiB2. A 0.071 micrometer antireflection coating of Si3N4 deposited on the ZrB2 coating leads to an increase in absorptance from 0.77 to 0.93, while the emittance remains unchanged.

  12. Solar Photothermal Disinfection using Broadband-Light Absorbing Gold Nanoparticles and Carbon Black.

    PubMed

    Loeb, Stephanie; Li, Chuanhao; Kim, Jae-Hong

    2018-01-02

    A simple heat treatment, perhaps the most globally recognized point-of-use water sterilization method, is seemingly effective against all major pathogens of concern, but bulk water boiling is not energy efficient or sustainable. Herein, we present the first application of solar-to-thermal converting nanomaterials for the direct inactivation of bacteria and viruses in drinking water through the application of Au nanorods, carbon black, and Au nanorod-carbon black composite materials as light absorbers. With broad absorption bands spanning the visible and near-infrared wavelengths, at sufficient concentrations, these nanoparticles induce multiple scattering events, increasing photon absorption probability and concentrating the light within a small spatial domain, leading to localized, intense heating that inactivates microorganisms in close proximity. Moving toward practical device design, we have developed a facile silane immobilization approach to fabricate films with densely packed layers of photothermal nanomaterials. Our results suggest that upon irraditaion with simulated solar light, these films can thermally inactivate bacteria and viruses, as demonstrated through the inactivation of surrogate organisms Escherichia coli K-12, and bacteriophages MS2 and PR772.

  13. Synthesis of chemicals using solar energy with stable photoelectrochemically active heterostructures.

    PubMed

    Mubeen, Syed; Singh, Nirala; Lee, Joun; Stucky, Galen D; Moskovits, Martin; McFarland, Eric W

    2013-05-08

    Efficient and cost-effective conversion of solar energy to useful chemicals and fuels could lead to a significant reduction in fossil hydrocarbon use. Artificial systems that use solar energy to produce chemicals have been reported for more than a century. However the most efficient devices demonstrated, based on traditionally fabricated compound semiconductors, have extremely short working lifetimes due to photocorrosion by the electrolyte. Here we report a stable, scalable design and molecular level fabrication strategy to create photoelectrochemically active heterostructure (PAH) units consisting of an efficient semiconductor light absorber in contact with oxidation and reduction electrocatalysts and otherwise protected by alumina. The functional heterostructures are fabricated by layer-by-layer, template-directed, electrochemical synthesis in porous anodic aluminum oxide membranes to produce high density arrays of electronically autonomous, nanostructured, corrosion resistant, photoactive units (~10(9)-10(10) PAHs per cm(2)). Each PAH unit is isolated from its neighbor by the transparent electrically insulating oxide cellular enclosure that makes the overall assembly fault tolerant. When illuminated with visible light, the free floating devices have been demonstrated to produce hydrogen at a stable rate for over 24 h in corrosive hydroiodic acid electrolyte with light as the only input. The quantum efficiency (averaged over the solar spectrum) for absorbed photons-to-hydrogen conversion was 7.4% and solar-to-hydrogen energy efficiency of incident light was 0.9%. The fabrication approach is scalable for commercial manufacturing and readily adaptable to a variety of earth abundant semiconductors which might otherwise be unstable as photoelectrocatalysts.

  14. Solar Energy: Solar and the Weather.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on solar and the weather 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 technologies.…

  15. Chalcogenide Perovskites for Solar Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Perera, Samanthe

    Methylammonium Lead halide perovskites have recently emerged as a promising candidate for realizing high efficient low cost photovoltaic modules. Charge transport properties of the solution processed halide perovskites are comparable to some of the existing absorbers used in the current PV industry which require sophisticated processing techniques. Due to this simple processing required to achieve high efficiencies, halide perovskites have become an active field of research. As a result, perovskite solar cells are rapidly reaching towards theoretical efficiency limit of close to 30%. It's believed that ionicity inherent to perovskite materials is one of the contributing factors for the excellent charge transport properties of perovskites. Despite the growing interest for solar energy harvesting purposes, these halide perovskites have serious limitations such as toxicity and instability that need to be addressed in order to commercialize the solar cells incorporating them. This dissertation focuses on a new class of ionic semiconductors, chalcogenide perovskites for solar energy harvesting purposes. Coming from the family perovskites they are expected to have same excellent charge transport properties inherent to perovskites due to the ionicity. Inspired by few theoretical studies on chalcogenide perovskites, BaZrS3 and its Ti alloys were synthesized by sulfurizing the oxide counterpart. Structural characterizations have confirmed the predicted distorted perovskite phase. Optical characterizations have verified the direct band gap suitable for thin film single junction solar cells. Anion alloying was demonstrated by synthesizing oxysulfides with widely tunable band gap suitable for applications such as solid state lighting and sensing.

  16. Quantum design of photosynthesis for bio-inspired solar-energy conversion.

    PubMed

    Romero, Elisabet; Novoderezhkin, Vladimir I; van Grondelle, Rienk

    2017-03-15

    Photosynthesis is the natural process that converts solar photons into energy-rich products that are needed to drive the biochemistry of life. Two ultrafast processes form the basis of photosynthesis: excitation energy transfer and charge separation. Under optimal conditions, every photon that is absorbed is used by the photosynthetic organism. Fundamental quantum mechanics phenomena, including delocalization, underlie the speed, efficiency and directionality of the charge-separation process. At least four design principles are active in natural photosynthesis, and these can be applied practically to stimulate the development of bio-inspired, human-made energy conversion systems.

  17. 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…

  18. High-efficiency solar-thermophotovoltaic system equipped with a monolithic planar selective absorber/emitter

    NASA Astrophysics Data System (ADS)

    Shimizu, Makoto; Kohiyama, Asaka; Yugami, Hiroo

    2015-01-01

    We demonstrate a high-efficiency solar-thermophotovoltaic system (STPV) using a monolithic, planar, and spectrally selective absorber/emitter. A complete STPV system using gallium antimonide (GaSb) cells was designed and fabricated to conduct power generation tests. To produce a high-efficiency STPV, it is important to match the thermal radiation spectrum with the sensitive region of the GaSb cells. Therefore, to reach high temperatures with low incident power, a planar absorber/emitter is incorporated for controlling the thermal radiation spectrum. This multilayer coating consists of thin-film tungsten sandwiched by yttria-stabilized zirconia. The system efficiency is estimated to be 16% when accounting for the optical properties of the fabricated absorber/emitter. Power generation tests using a high-concentration solar simulator show that the absorber/emitter temperature peaks at 1640 K with an incident power density of 45 W/cm2, which can be easily obtained by low-cost optics such as Fresnel lenses. The conversion efficiency became 23%, exceeding the Shockley-Queisser limit for GaSb, with a bandgap of 0.67 eV. Furthermore, a total system efficiency of 8% was obtained with the view factor between the emitter and the cell assumed to be 1.

  19. Thin films with disordered nanohole patterns for solar radiation absorbers

    NASA Astrophysics Data System (ADS)

    Fang, Xing; Lou, Minhan; Bao, Hua; Zhao, C. Y.

    2015-06-01

    The radiation absorption in thin films with three disordered nanohole patterns, i.e., random position, non-uniform radius, and amorphous pattern, are numerically investigated by finite-difference time-domain (FDTD) simulations. Disorder can alter the absorption spectra and has an impact on the broadband absorption performance. Compared to random position and non-uniform radius nanoholes, amorphous pattern can induce a much better integrated absorption. The power density spectra indicate that amorphous pattern nanoholes reduce the symmetry and provide more resonance modes that are desired for the broadband absorption. The application condition for amorphous pattern nanoholes shows that they are much more appropriate in absorption enhancement for weak absorption materials. Amorphous silicon thin films with disordered nanohole patterns are applied in solar radiation absorbers. Four configurations of thin films with different nanohole patterns show that interference between layers in absorbers will change the absorption performance. Therefore, it is necessary to optimize the whole radiation absorbers although single thin film with amorphous pattern nanohole has reached optimal absorption.

  20. Integration of Semiconducting Sulfides for Full-Spectrum Solar Energy Absorption and Efficient Charge Separation.

    PubMed

    Zhuang, Tao-Tao; Liu, Yan; Li, Yi; Zhao, Yuan; Wu, Liang; Jiang, Jun; Yu, Shu-Hong

    2016-05-23

    The full harvest of solar energy by semiconductors requires a material that simultaneously absorbs across the whole solar spectrum and collects photogenerated electrons and holes separately. The stepwise integration of three semiconducting sulfides, namely ZnS, CdS, and Cu2-x S, into a single nanocrystal, led to a unique ternary multi-node sheath ZnS-CdS-Cu2-x S heteronanorod for full-spectrum solar energy absorption. Localized surface plasmon resonance (LSPR) in the nonstoichiometric copper sulfide nanostructures enables effective NIR absorption. More significantly, the construction of pn heterojunctions between Cu2-x S and CdS leads to staggered gaps, as confirmed by first-principles simulations. This band alignment causes effective electron-hole separation in the ternary system and hence enables efficient solar energy conversion. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Brief review of emerging photovoltaic absorbers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zakutayev, Andriy

    Photovoltaic solar cells have recently made significant commercial progress and are on track toward meeting more than 1% of global energy demand. However, further research is needed on photovoltaic technologies that face no scalability constraints in generating more than 10% of the world's electricity. This 2017 article briefly reviews emerging photovoltaic absorber materials, focusing on research progress over the past 2-3 years. Particular emphasis is given to emerging solar cell absorbers -- for example, SnS, Sb 2Se 3, Cu 2SnS 3, and CuSbSe 2 -- related to established solar cell technologies such as CdTe, Cu(In,Ga)Se 2, and CH 3NH 3PbImore » 3. Lastly, the general publication and performance trends are discussed, and the promising future research directions are pointed out.« less

  2. Brief review of emerging photovoltaic absorbers

    DOE PAGES

    Zakutayev, Andriy

    2017-02-08

    Photovoltaic solar cells have recently made significant commercial progress and are on track toward meeting more than 1% of global energy demand. However, further research is needed on photovoltaic technologies that face no scalability constraints in generating more than 10% of the world's electricity. This 2017 article briefly reviews emerging photovoltaic absorber materials, focusing on research progress over the past 2-3 years. Particular emphasis is given to emerging solar cell absorbers -- for example, SnS, Sb 2Se 3, Cu 2SnS 3, and CuSbSe 2 -- related to established solar cell technologies such as CdTe, Cu(In,Ga)Se 2, and CH 3NH 3PbImore » 3. Lastly, the general publication and performance trends are discussed, and the promising future research directions are pointed out.« less

  3. Solar Energy and You.

    ERIC Educational Resources Information Center

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

    This booklet provides an introduction to solar energy by discussing: (1) how a home is heated; (2) how solar energy can help in the heating process; (3) the characteristics of passive solar houses; (4) the characteristics of active solar houses; (5) how solar heat is stored; and (6) other uses of solar energy. Also provided are 10 questions to…

  4. New challenges in solar energy resource and forecasting in Greece

    NASA Astrophysics Data System (ADS)

    Kazantzidis, A.; Nikitidou, E.; Salamalikis, V.; Tzoumanikas, P.; Zagouras, A.

    2018-05-01

    Aerosols and clouds are the most important constituents in the atmosphere that affect the incoming solar radiation, either directly through absorbing and scattering processes or indirectly by changing the optical properties and lifetime of clouds. Under clear skies, aerosols become the dominant factor that affect the intensity of solar irradiance reaching the ground. Under cloudy skies, the high temporal and spatial variability of cloudiness is the key factor for the estimation of solar irradiance. In this study, recent research activities related to the climatology and the prediction of solar energy in Greece are presented with emphasis on new challenges in the climatology of global horizontal irradiance (GHI) and direct normal irradiance (DNI), the changes of DNI due to the decreasing aerosol optical depth and the short-term (15-240 min) forecasts of solar irradiance with the collaborative use of neural networks and satellite images.

  5. Investigation into the energy-absorbing properties of multilayered circular thin-walled tube

    NASA Astrophysics Data System (ADS)

    Qi, Aidong; Liu, Chuanhua; Hu, Gongli; Gu, Hongjun

    2002-05-01

    With the rise in collision accident and the increase in requirement for resistance of blastproof structures in recent years, people attach much importance to the research and application of energy-absorbing device. In this paper the author calculates the specific strength, the specific hardness and ultimate internal force of a circular thin-walled tube by theoretic calculations, discusses the feasibility of using circular thin-walled tube as an energy-absorbing element, analyzes the energy-absorbing properties and the energy-absorbing mechanism through the energy-absorbing experiments using various materials and forms of arrangement, reaches the conclusion that the load-bearing capacity and energy-absorbing properties of multilayered tubes are superior to that of single tube, and puts forward the concept of 'grading tube'.

  6. Solar energy panel

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hyman, M.

    1980-03-04

    A light-weight, low-cost and high efficiency solar panel includes a light-weight rectangular wood frame which surrounds and houses a copper absorber plate. A pair of spaced glazings, formed from plastic film materials, are disposed above the absorber to define a pair of enclosed air spaces. The lower glazing is capable of withstanding high temperatures and the upper glazing material is capable of providing good weather resistance. The material of the upper glazing extends fully about the frame to protect the entire frame from weathering. Insulation is provided beneath the absorber plate. The frame rests on top of a bottom sheetmore » of insulative foam plastic which is wrapped in a plastic envelope. The surrounding film of the outer glazing is bonded securely to the envelope to encase the entire panel within a protective sealed envelope of weather-resistant plastic film.« less

  7. 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

  8. Energy absorber for sodium-heated heat exchanger

    DOEpatents

    Essebaggers, J.

    1975-12-01

    A heat exchanger is described in which water-carrying tubes are heated by liquid sodium and in which the results of accidental contact between the water and the sodium caused by failure of one or more of the water tubes is minimized. An energy absorbing chamber contains a compressible gas and is connected to the body of flowing sodium by a channel so that, in the event of a sodium-water reaction, products of the reaction will partially fill the energy absorbing chamber to attenuate the rise in pressure within the heat exchanger.

  9. Self-Alining End Supports for Energy Absorber

    NASA Technical Reports Server (NTRS)

    Alfaro-Bou, E.; Eichelberger, C. P.; Fasanella, E.

    1986-01-01

    Simple devices stabilize axially-loaded compressive members. Energyabsorbing column held by two end supports, which stabilize column and tolerate misalinement. Column absorbs excess load by collapsing lengthwise. Self-alining supports small, lightweight, and almost maintenance-free. Their use eliminates alinement problem, opening up more applications and providing higher reliability for compressively-loaded energy absorbers.

  10. A Solar Volumetric Receiver: Influence of Absorbing Cells Configuration on Device Thermal Performance

    NASA Astrophysics Data System (ADS)

    Yilbas, B. S.; Shuja, S. Z.

    2017-01-01

    Thermal performance of a solar volumetric receiver incorporating the different cell geometric configurations is investigated. Triangular, hexagonal, and rectangular absorbing cells are incorporated in the analysis. The fluid volume fraction, which is the ratio of the volume of the working fluid over the total volume of solar volumetric receiver, is introduced to assess the effect of cell size on the heat transfer rates in the receiver. In this case, reducing the fluid volume fraction corresponds to increasing cell size in the receiver. SiC is considered as the cell material, and air is used as the working fluid in the receiver. The Lambert's Beer law is incorporated to account for the solar absorption in the receiver. A finite element method is used to solve the governing equation of flow and heat transfer. It is found that the fluid volume fraction has significant effect on the flow field in the solar volumetric receiver, which also modifies thermal field in the working fluid. The triangular absorbing cell gives rise to improved effectiveness of the receiver and then follows the hexagonal and rectangular cells. The second law efficiency of the receiver remains high when hexagonal cells are used. This occurs for the fluid volume fraction ratio of 0.5.

  11. Practical considerations for solar energy thermally enhanced photo-luminescence (TEPL) (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kruger, Nimrod; Manor, Assaf; Kurtulik, Matej; Sabapathy, Tamilarasan; Rotschild, Carmel

    2017-04-01

    While single-junction photovoltaics (PV's) are considered limited in conversion efficiency according to the Shockley-Queisser limit, concepts such as solar thermo-photovoltaics aim to harness lost heat and overcome this barrier. We claim the novel concept of Thermally Enhanced Photoluminescence (TEPL) as an easier route to achieve this goal. Here we present a practical TEPL device where a thermally insulated photo-luminescent (PL) absorber, acts as a mediator between a photovoltaic cell and the sun. This high temperature absorber emits blue-shifted PL at constant flux, then coupled to a high band gap PV cell. This scheme promotes PV conversion efficiencies, under ideal conditions, higher than 62% at temperatures lower than 1300K. Moreover, for a PV and absorber band-gaps of 1.45eV (GaAs PV's) and 1.1eV respectively, under practical conditions, solar concentration of 1000 suns, and moderate thermal insulation; the conversion efficiencies potentially exceed 46%. Some of these practical conditions belong to the realm of optical design; including high photon recycling (PR) and absorber external quantum efficiency (EQE). High EQE values, a product of the internal QE of the active PL materials and the extraction efficiency of each photon (determined by the absorber geometry and interfaces), have successfully been reached by experts in laser cooling technology. PR is the part of emitted low energy photons (in relation to the PV band-gap) that are reabsorbed and consequently reemitted with above band-gap energies. PV back-reflector reflectivity, also successfully achieved by those who design the cutting edge high efficiency PV cells, plays a major role here.

  12. High-Temperature Tolerance in Multi-Scale Cermet Solar-Selective Absorbing Coatings Prepared by Laser Cladding.

    PubMed

    Pang, Xuming; Wei, Qian; Zhou, Jianxin; Ma, Huiyang

    2018-06-19

    In order to achieve cermet-based solar absorber coatings with long-term thermal stability at high temperatures, a novel single-layer, multi-scale TiC-Ni/Mo cermet coating was first prepared using laser cladding technology in atmosphere. The results show that the optical properties of the cermet coatings using laser cladding were much better than the preplaced coating. In addition, the thermal stability of the optical properties for the laser cladding coating were excellent after annealing at 650 °C for 200 h. The solar absorptance and thermal emittance of multi-scale cermet coating were 85% and 4.7% at 650 °C. The results show that multi-scale cermet materials are more suitable for solar-selective absorbing coating. In addition, laser cladding is a new technology that can be used for the preparation of spectrally-selective coatings.

  13. Solar energy: Technology and applications

    NASA Technical Reports Server (NTRS)

    Williams, J. R.

    1974-01-01

    It is pointed out that in 1970 the total energy consumed in the U.S. was equal to the energy of sunlight received by only 0.15% of the land area of the continental U.S. The utilization of solar energy might, therefore, provide an approach for solving the energy crisis produced by the consumption of irreplaceable fossil fuels at a steadily increasing rate. Questions regarding the availability of solar energy are discussed along with the design of solar energy collectors and various approaches for heating houses and buildings by utilizing solar radiation. Other subjects considered are related to the heating of water partly or entirely with solar energy, the design of air conditioning systems based on the use of solar energy, electric power generation by a solar thermal and a photovoltaic approach, solar total energy systems, industrial and agricultural applications of solar energy, solar stills, the utilization of ocean thermal power, power systems based on the use of wind, and solar-energy power systems making use of geosynchronous power plants.

  14. The Energy Crisis and Solar Energy

    ERIC Educational Resources Information Center

    Bockris, J. O'M.

    1974-01-01

    Examines the status of the energy crisis in Australia. Outlines energy alternatives for the 1990's and describes the present status of solar energy research and the economics of solar energy systems. (GS)

  15. 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.

  16. Comparative evaluation of solar, fission, fusion, and fossil energy resources. Part 1: Solar energy

    NASA Technical Reports Server (NTRS)

    Williams, J. R.

    1974-01-01

    The utilization of solar energy to meet the energy needs of the U.S. is discussed. Topics discussed include: availability of solar energy, solar energy collectors, heating for houses and buildings, solar water heater, electric power generation, and ocean thermal power.

  17. Light harvesting for quantum solar energy conversion

    NASA Astrophysics Data System (ADS)

    Markvart, Tomas

    2000-05-01

    Despite wide structural and functional differences, the laws that govern quantum solar energy conversion to chemical energy or electricity share many similarities. In the photosynthetic membrane, in common with semiconductor solar cells, the conversion process proceeds from the creation of electron-hole pairs by a photon of light, followed by charge separation to produce the required high-energy product. In many cases, however, mechanisms are needed to enhance the optical absorption cross-section and extend the spectral range of operation. A common way of achieving this is by light harvesting: light absorption by a specialised unit which transfers the energy to the conversion apparatus. This paper considers two examples of light harvesting - semiconductor solar cells and the photosynthetic apparatus - to illustrate the basic operation and principles that apply. The existence of a light harvesting unit in photosynthesis has been known since the early 1930's but details of the process - relating, in particular, to the relationship between the structure and spectral properties - are still being unravelled. The excitation energy carriers are excitons but the precise nature of the transport - via the solid state Frenkel-Peierls variety or by Förster's resonant energy transfer - is still subject to debate. In semiconductor solar cells, the energy of the absorbed photon is collected by minority carriers but the broad principles remain the same. In both cases it is shown that the rate of energy conversion is described by a law which parallels the Shockley's solar cell equation, and the light harvesting energy collection is subject to reciprocity relations which resemble Onsager's reciprocity relations between coefficients which couple appropriate forces and flows in non-equilibrium thermodynamics. Differences in the basic atomic make-up in the two systems lead to different energy transport equations. In both cases, however, similar mathematical techniques based on Green

  18. 8.4% efficient fullerene-free organic solar cells exploiting long-range exciton energy transfer.

    PubMed

    Cnops, Kjell; Rand, Barry P; Cheyns, David; Verreet, Bregt; Empl, Max A; Heremans, Paul

    2014-03-07

    In order to increase the power conversion efficiency of organic solar cells, their absorption spectrum should be broadened while maintaining efficient exciton harvesting. This requires the use of multiple complementary absorbers, usually incorporated in tandem cells or in cascaded exciton-dissociating heterojunctions. Here we present a simple three-layer architecture comprising two non-fullerene acceptors and a donor, in which an energy-relay cascade enables an efficient two-step exciton dissociation process. Excitons generated in the remote wide-bandgap acceptor are transferred by long-range Förster energy transfer to the smaller-bandgap acceptor, and subsequently dissociate at the donor interface. The photocurrent originates from all three complementary absorbing materials, resulting in a quantum efficiency above 75% between 400 and 720 nm. With an open-circuit voltage close to 1 V, this leads to a remarkable power conversion efficiency of 8.4%. These results confirm that multilayer cascade structures are a promising alternative to conventional donor-fullerene organic solar cells.

  19. Defect Tolerant Semiconductors for Solar Energy Conversion.

    PubMed

    Zakutayev, Andriy; Caskey, Christopher M; Fioretti, Angela N; Ginley, David S; Vidal, Julien; Stevanovic, Vladan; Tea, Eric; Lany, Stephan

    2014-04-03

    Defect tolerance is the tendency of a semiconductor to keep its properties despite the presence of crystallographic defects. Scientific understanding of the origin of defect tolerance is currently missing. Here we show that semiconductors with antibonding states at the top of the valence band are likely to be tolerant to defects. Theoretical calculations demonstrate that Cu3N with antibonding valence band maximum has shallow intrinsic defects and no surface states, in contrast to GaN with bonding valence band maximum. Experimental measurements indicate shallow native donors and acceptors in Cu3N thin films, leading to 10(16)-10(17) cm(-3) doping with either electrons or holes depending on the growth conditions. The experimentally measured bipolar doping and the solar-matched optical absorption onset (1.4 eV) make Cu3N a promising candidate absorber for photovoltaic and photoelectrochemical solar cells, despite the calculated indirect fundamental band gap (1.0 eV). These conclusions can be extended to other materials with antibonding character of the valence band, defining a class of defect-tolerant semiconductors for solar energy conversion applications.

  20. Triplet-triplet energy transfer from a UV-A absorber butylmethoxydibenzoylmethane to UV-B absorbers.

    PubMed

    Kikuchi, Azusa; Oguchi-Fujiyama, Nozomi; Miyazawa, Kazuyuki; Yagi, Mikio

    2014-01-01

    The phosphorescence decay of a UV-A absorber, 4-tert-butyl-4'-methoxydibenzolymethane (BMDBM) has been observed following a 355 nm laser excitation in the absence and presence of UV-B absorbers, 2-ethylhexyl 4-methoxycinnamate (octyl methoxycinnamate, OMC) and octocrylene (OCR) in ethanol at 77 K. The lifetime of the lowest excited triplet (T1) state of BMDBM is significantly reduced in the presence of OMC and OCR. The observed quenching of BMDBM triplet by OMC and OCR suggests that the intermolecular triplet-triplet energy transfer occurs from BMDBM to OMC and OCR. The T1 state of OCR is nonphosphorescent or very weakly phosphorescent. However, we have shown that the energy level of the T1 state of OCR is lower than that of the enol form of BMDBM. Our methodology of energy-donor phosphorescence decay measurements can be applied to the study of the triplet-triplet energy transfer between UV absorbers even if the energy acceptor is nonphosphorescent. In addition, the delayed fluorescence of BMDBM due to triplet-triplet annihilation was observed in the BMDBM-OMC and BMDBM-OCR mixtures in ethanol at 77 K. Delayed fluorescence is one of the deactivation processes of the excited states of BMDBM under our experimental conditions. © 2013 The American Society of Photobiology.

  1. Alternatives in solar energy

    NASA Technical Reports Server (NTRS)

    Schueler, D. G.

    1978-01-01

    Although solar energy has the potential of providing a significant source of clean and renewable energy for a variety of applications, it is expected to penetrate the nation's energy economy very slowly. The alternative solar energy technologies which employ direct collection and conversion of solar radiation as briefly described.

  2. Solar Renewable Energy. Teaching Unit.

    ERIC Educational Resources Information Center

    Buchanan, Marion; And Others

    This unit develops the concept of solar energy as a renewable resource. It includes: (1) an introductory section (developing understandings of photosynthesis and impact of solar energy); (2) information on solar energy use (including applications and geographic limitations of solar energy use); and (3) future considerations of solar energy…

  3. Contactless efficient two-stage solar concentrator for tubular absorber.

    PubMed

    Benítez, P; García, R; Miñano, J C

    1997-10-01

    The design of a new type of two-mirror solar concentrator for a tubular receiver, the XX concentrator, is presented. The main feature of the XX is that it has a sizable gap between the secondary mirror and the absorber and it still achieves concentrations close to the thermodynamic limit with high collection efficiencies. This characteristic makes the XX unique and, contrary to current two-stage designs, allows for the location of the secondary outside the evacuated tube. One of the XX concentrators presented achieves an average flux concentration within +/-0.73 deg of 91.1% of the thermodynamic limit with a collection efficiency of 96.8% (i.e., 3.2% of the rays incident on the primary mirror within +/-0.73 deg are rejected). Another XX design is 92.5% efficient and receives 95.1% of the maximum concentration. These values are the highest reported for practical concentrators, to our knowledge. The gap between the absorber and the secondary mirror is 6.8 and 10.5 times the absorber radius for each concentrator. Moreover the rim angle of the primary mirror is 98.8 and 104.4 deg in each case, which is of interest for the collector's good mechanical stability.

  4. Impact resistance of fiber composites - Energy-absorbing mechanisms and environmental effects

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Sinclair, J. H.

    1985-01-01

    Energy absorbing mechanisms were identified by several approaches. The energy absorbing mechanisms considered are those in unidirectional composite beams subjected to impact. The approaches used include: mechanic models, statistical models, transient finite element analysis, and simple beam theory. Predicted results are correlated with experimental data from Charpy impact tests. The environmental effects on impact resistance are evaluated. Working definitions for energy absorbing and energy releasing mechanisms are proposed and a dynamic fracture progression is outlined. Possible generalizations to angle-plied laminates are described.

  5. Impact resistance of fiber composites: Energy absorbing mechanisms and environmental effects

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Sinclair, J. H.

    1983-01-01

    Energy absorbing mechanisms were identified by several approaches. The energy absorbing mechanisms considered are those in unidirectional composite beams subjected to impact. The approaches used include: mechanic models, statistical models, transient finite element analysis, and simple beam theory. Predicted results are correlated with experimental data from Charpy impact tests. The environmental effects on impact resistance are evaluated. Working definitions for energy absorbing and energy releasing mechanisms are proposed and a dynamic fracture progression is outlined. Possible generalizations to angle-plied laminates are described.

  6. Molecular approaches to solar energy conversion: the energetic cost of charge separation from molecular-excited states.

    PubMed

    Durrant, James R

    2013-08-13

    This review starts with a brief overview of the technological potential of molecular-based solar cell technologies. It then goes on to focus on the core scientific challenge associated with using molecular light-absorbing materials for solar energy conversion, namely the separation of short-lived, molecular-excited states into sufficiently long-lived, energetic, separated charges capable of generating an external photocurrent. Comparisons are made between different molecular-based solar cell technologies, with particular focus on the function of dye-sensitized photoelectrochemical solar cells as well as parallels with the function of photosynthetic reaction centres. The core theme of this review is that generating charge carriers with sufficient lifetime and a high quantum yield from molecular-excited states comes at a significant energetic cost-such that the energy stored in these charge-separated states is typically substantially less than the energy of the initially generated excited state. The role of this energetic loss in limiting the efficiency of solar energy conversion by such devices is emphasized, and strategies to minimize this energy loss are compared and contrasted.

  7. Research progress about chemical energy storage of solar energy

    NASA Astrophysics Data System (ADS)

    Wu, Haifeng; Xie, Gengxin; Jie, Zheng; Hui, Xiong; Yang, Duan; Du, Chaojun

    2018-01-01

    In recent years, the application of solar energy has been shown obvious advantages. Solar energy is being discontinuity and inhomogeneity, so energy storage technology becomes the key to the popularization and utilization of solar energy. Chemical storage is the most efficient way to store and transport solar energy. In the first and the second section of this paper, we discuss two aspects about the solar energy collector / reactor, and solar energy storage technology by hydrogen production, respectively. The third section describes the basic application of solar energy storage system, and proposes an association system by combining solar energy storage and power equipment. The fourth section briefly describes several research directions which need to be strengthened.

  8. Solar Energy Basics | NREL

    Science.gov Websites

    Solar Energy Basics Solar Energy Basics Solar is the Latin word for sun-a powerful source of energy sun falls on the earth in one hour than is used by everyone in the world in one year. A variety of heat from the sun to provide electricity for large power stations. Solar Process Heat These

  9. Organic Solar Cells: Understanding the Role of Förster Resonance Energy Transfer

    PubMed Central

    Feron, Krishna; Belcher, Warwick J.; Fell, Christopher J.; Dastoor, Paul C.

    2012-01-01

    Organic solar cells have the potential to become a low-cost sustainable energy source. Understanding the photoconversion mechanism is key to the design of efficient organic solar cells. In this review, we discuss the processes involved in the photo-electron conversion mechanism, which may be subdivided into exciton harvesting, exciton transport, exciton dissociation, charge transport and extraction stages. In particular, we focus on the role of energy transfer as described by Förster resonance energy transfer (FRET) theory in the photoconversion mechanism. FRET plays a major role in exciton transport, harvesting and dissociation. The spectral absorption range of organic solar cells may be extended using sensitizers that efficiently transfer absorbed energy to the photoactive materials. The limitations of Förster theory to accurately calculate energy transfer rates are discussed. Energy transfer is the first step of an efficient two-step exciton dissociation process and may also be used to preferentially transport excitons to the heterointerface, where efficient exciton dissociation may occur. However, FRET also competes with charge transfer at the heterointerface turning it in a potential loss mechanism. An energy cascade comprising both energy transfer and charge transfer may aid in separating charges and is briefly discussed. Considering the extent to which the photo-electron conversion efficiency is governed by energy transfer, optimisation of this process offers the prospect of improved organic photovoltaic performance and thus aids in realising the potential of organic solar cells. PMID:23235328

  10. Organic solar cells: understanding the role of Förster resonance energy transfer.

    PubMed

    Feron, Krishna; Belcher, Warwick J; Fell, Christopher J; Dastoor, Paul C

    2012-12-12

    Organic solar cells have the potential to become a low-cost sustainable energy source. Understanding the photoconversion mechanism is key to the design of efficient organic solar cells. In this review, we discuss the processes involved in the photo-electron conversion mechanism, which may be subdivided into exciton harvesting, exciton transport, exciton dissociation, charge transport and extraction stages. In particular, we focus on the role of energy transfer as described by F¨orster resonance energy transfer (FRET) theory in the photoconversion mechanism. FRET plays a major role in exciton transport, harvesting and dissociation. The spectral absorption range of organic solar cells may be extended using sensitizers that efficiently transfer absorbed energy to the photoactive materials. The limitations of F¨orster theory to accurately calculate energy transfer rates are discussed. Energy transfer is the first step of an efficient two-step exciton dissociation process and may also be used to preferentially transport excitons to the heterointerface, where efficient exciton dissociation may occur. However, FRET also competes with charge transfer at the heterointerface turning it in a potential loss mechanism. An energy cascade comprising both energy transfer and charge transfer may aid in separating charges and is briefly discussed. Considering the extent to which the photo-electron conversion efficiency is governed by energy transfer, optimisation of this process offers the prospect of improved organic photovoltaic performance and thus aids in realising the potential of organic solar cells.

  11. Large-scale broadband absorber based on metallic tungsten nanocone structure

    NASA Astrophysics Data System (ADS)

    Wang, Jiaxing; Liang, Yuzhang; Huo, Pengcheng; Wang, Daopeng; Tan, Jun; Xu, Ting

    2017-12-01

    We report a broadband tungsten absorber based on a nanocone metallic resonant structure fabricated by self-assembly nanosphere lithography. In experimental demonstration, the fabricated absorber has more than 90% average absorption efficiency and shows superior angular tolerance in the entire visible and near-infrared spectral region. We envision that this large-scale nanostructured broadband optical absorber would find great potential in the applications of high performance optoelectronic platforms and solar-thermal energy harvesting systems.

  12. Solar energy research and utilization

    NASA Technical Reports Server (NTRS)

    Cherry, W. R.

    1974-01-01

    The role of solar energy is visualized in the heating and cooling of buildings, in the production of renewable gaseous, liquid and solid fuels, and in the production of electric power over the next 45 years. Potential impacts of solar energy on various energy markets, and estimated costs of such solar energy systems are discussed. Some typical solar energy utilization processes are described in detail. It is expected that at least 20% of the U.S. total energy requirements by 2020 will be delivered from solar energy.

  13. Innovative energy absorbing devices based on composite tubes

    NASA Astrophysics Data System (ADS)

    Tiwari, Chandrashekhar

    Analytical and experimental study of innovative load limiting and energy absorbing devices are presented here. The devices are based on composite tubes and can be categorized in to two groups based upon the energy absorbing mechanisms exhibited by them, namely: foam crushing and foam fracturing. The device based on foam crushing as the energy absorbing mechanism is composed of light weight elastic-plastic foam filling inside an angle ply composite tube. The tube is tailored to have a high Poisson’s ratio (>20). Upon being loaded the device experiences large transverse contraction resulting in rapid decrease in diameter. At a certain axial load the foam core begins to crush and energy is dissipated. This device is termed as crush tube device. The device based upon foam shear fracture as the energy absorbing mechanism involves an elastic-plastic core foam in annulus of two concentric extension-twist coupled composite tubes with opposite angles of fibers. The core foam is bonded to the inner and outer tube walls. Upon being loaded axially, the tubes twist in opposite directions and fracture the core foam in out of plane shear and thus dissipate the energy stored. The device is termed as sandwich core device (SCD). The devices exhibit variations in force-displacement characteristics with changes in design and material parameters, resulting in wide range of energy absorption capabilities. A flexible matrix composite system was selected, which was composed of high stiffness carbon fibers as reinforcements in relatively low stiffness polyurethane matrix, based upon large strain to failure capabilities and large beneficial elastic couplings. Linear and non-linear analytical models were developed encapsulating large deformation theory of the laminated composite shells (using non-linear strain energy formulation) to the fracture mechanics of core foam and elastic-plastic deformation theory of the foam filling. The non-linear model is capable of including material and

  14. Efficient conversion of solar energy to biomass and electricity

    PubMed Central

    2014-01-01

    The Earth receives around 1000 W.m−2 of power from the Sun and only a fraction of this light energy is able to be converted to biomass (chemical energy) via the process of photosynthesis. Out of all photosynthetic organisms, microalgae, due to their fast growth rates and their ability to grow on non-arable land using saline water, have been identified as potential source of raw material for chemical energy production. Electrical energy can also be produced from this same solar resource via the use of photovoltaic modules. In this work we propose a novel method of combining both of these energy production processes to make full utilisation of the solar spectrum and increase the productivity of light-limited microalgae systems. These two methods of energy production would appear to compete for use of the same energy resource (sunlight) to produce either chemical or electrical energy. However, some groups of microalgae (i.e. Chlorophyta) only require the blue and red portions of the spectrum whereas photovoltaic devices can absorb strongly over the full range of visible light. This suggests that a combination of the two energy production systems would allow for a full utilization of the solar spectrum allowing both the production of chemical and electrical energy from the one facility making efficient use of available land and solar energy. In this work we propose to introduce a filter above the algae culture to modify the spectrum of light received by the algae and redirect parts of the spectrum to generate electricity. The electrical energy generated by this approach can then be directed to running ancillary systems or producing extra illumination for the growth of microalgae. We have modelled an approach whereby the productivity of light-limited microalgae systems can be improved by at least 4% through using an LED array to increase the total amount of illumination on the microalgae culture. PMID:24976951

  15. Efficient conversion of solar energy to biomass and electricity.

    PubMed

    Parlevliet, David; Moheimani, Navid Reza

    2014-01-01

    The Earth receives around 1000 W.m(-2) of power from the Sun and only a fraction of this light energy is able to be converted to biomass (chemical energy) via the process of photosynthesis. Out of all photosynthetic organisms, microalgae, due to their fast growth rates and their ability to grow on non-arable land using saline water, have been identified as potential source of raw material for chemical energy production. Electrical energy can also be produced from this same solar resource via the use of photovoltaic modules. In this work we propose a novel method of combining both of these energy production processes to make full utilisation of the solar spectrum and increase the productivity of light-limited microalgae systems. These two methods of energy production would appear to compete for use of the same energy resource (sunlight) to produce either chemical or electrical energy. However, some groups of microalgae (i.e. Chlorophyta) only require the blue and red portions of the spectrum whereas photovoltaic devices can absorb strongly over the full range of visible light. This suggests that a combination of the two energy production systems would allow for a full utilization of the solar spectrum allowing both the production of chemical and electrical energy from the one facility making efficient use of available land and solar energy. In this work we propose to introduce a filter above the algae culture to modify the spectrum of light received by the algae and redirect parts of the spectrum to generate electricity. The electrical energy generated by this approach can then be directed to running ancillary systems or producing extra illumination for the growth of microalgae. We have modelled an approach whereby the productivity of light-limited microalgae systems can be improved by at least 4% through using an LED array to increase the total amount of illumination on the microalgae culture.

  16. From Anti-greenhouse Effect of Solar Absorbers to Cooling Effect of Greenhouse Gases: A 1-D Radiative Convective Model Study

    NASA Astrophysics Data System (ADS)

    Shia, R.

    2012-12-01

    The haze layer in Titan's upper atmosphere absorbs 90% of the solar radiation, but is inefficient for trapping infrared radiation generated by the surface. Its existence partially compensates for the greenhouse warming and keeps the surface approximately 9°C cooler than would otherwise be expected from the greenhouse effect alone. This is the so called anti-greenhouse effect (McKay et al., 1991). This effect can be used to alleviate the warming caused by the increasing level of greenhouse gases in the Earth's atmosphere. A one-dimensional radiative convective model (Kasting et al., 2009 and references listed there) is used to investigate the anti-greenhouse effect in the Earth atmosphere. Increasing of solar absorbers, e.g. aerosols and ozone, in the stratosphere reduces the surface solar flux and cool the surface. However, the absorption of the solar flux also increases the temperature in the upper atmosphere, while reduces the temperature at the surface. Thus, the temperature profile of the atmosphere changes and the regions with positive vertical temperature gradient are expanded. According to Shia (2010) the radiative forcing of greenhouse gases is directly related to the vertical temperature gradient. Under the new temperature profile increases of greenhouse gases should have less warming effect. When the solar absorbers keep increasing, eventually most of the atmosphere has positive temperature gradient and increasing greenhouse gases would cool the surface (Shia, 2011). The doubling CO2 scenario in the Earth atmosphere is simulated for different levels of solar absorbers using the 1-D RC model. The model results show that if the solar absorber increases to a certain level that less than 50% solar flux reaching the surface, doubling CO2 cools the surface by about 2 C. This means if the snowball Earth is generated by solar absorbers in the stratosphere, increasing greenhouse gases would make it freeze even more (Shia, 2011). References: Kasting, J. et al

  17. From sunlight to phytomass: on the potential efficiency of converting solar radiation to phyto-energy.

    PubMed

    Amthor, Jeffrey S

    2010-12-01

    The relationship between solar radiation capture and potential plant growth is of theoretical and practical importance. The key processes constraining the transduction of solar radiation into phyto-energy (i.e. free energy in phytomass) were reviewed to estimate potential solar-energy-use efficiency. Specifically, the out-put:input stoichiometries of photosynthesis and photorespiration in C(3) and C(4) systems, mobilization and translocation of photosynthate, and biosynthesis of major plant biochemical constituents were evaluated. The maintenance requirement, an area of important uncertainty, was also considered. For a hypothetical C(3) grain crop with a full canopy at 30°C and 350 ppm atmospheric [CO(2) ], theoretically potential efficiencies (based on extant plant metabolic reactions and pathways) were estimated at c. 0.041 J J(-1) incident total solar radiation, and c. 0.092 J J(-1) absorbed photosynthetically active radiation (PAR). At 20°C, the calculated potential efficiencies increased to 0.053 and 0.118 J J(-1) (incident total radiation and absorbed PAR, respectively). Estimates for a hypothetical C(4) cereal were c. 0.051 and c. 0.114 J J(-1), respectively. These values, which cannot be considered as precise, are less than some previous estimates, and the reasons for the differences are considered. Field-based data indicate that exceptional crops may attain a significant fraction of potential efficiency. © The Author (2010). Journal compilation © New Phytologist Trust (2010).

  18. Layer-by-Layer Assembled Films of Perylene Diimide- and Squaraine-Containing Metal-Organic Frameworks- like Materials: Solar Energy Capture and Directional Energy Transfer

    DOE PAGES

    Park, Hea Jung; So, Monica C.; Gosztola, David J.

    2016-09-28

    We demonstrate that thin films of metal organic framework (MOF)-like materials, containing two perylenedlimides (PDICl4, PDIOPh2) and a squaraine dye (S1); can be fabricated by, layer-by-layer assembly (LbL). Interestingly, these LbL films absorb across the visible light region (400-750 nm) and facilitate directional energy transfer. Due to the high spectral overlap and oriented transition dipole moments of the donor (PDICl4 and PDIOPh2) and acceptor (S1) components, directional long-range energy transfer from the bluest to reddest absorber was successfully demonstrated in the multicomponent MOF-like films. These findings have significant implications for the development of solar energy conversion devices based on MOFs.

  19. Assessing the role of hydrogen in Fermi-level pinning in chalcopyrite and kesterite solar absorbers from first-principles calculations

    NASA Astrophysics Data System (ADS)

    Varley, J. B.; Lordi, V.; Ogitsu, T.; Deangelis, A.; Horsley, K.; Gaillard, N.

    2018-04-01

    Understanding the impact of impurities in solar absorbers is critical to engineering high-performance in devices, particularly over extended periods of time. Here, we use hybrid functional calculations to explore the role of hydrogen interstitial (Hi) defects in the electronic properties of a number of attractive solar absorbers within the chalcopyrite and kesterite families to identify how this common impurity may influence device performance. Our results identify that Hi can inhibit the highly p-type conditions desirable for several higher-band gap absorbers and that H incorporation could detrimentally affect the open-circuit voltage (Voc) and limit device efficiencies. Additionally, we find that Hi can drive the Fermi level away from the valence band edge enough to lead to n-type conductivity in a number of chalcopyrite and kesterite absorbers, particularly those containing Ag rather than Cu. We find that these effects can lead to interfacial Fermi-level pinning that can qualitatively explain the observed performance in high-Ga content CIGSe solar cells that exhibit saturation in the Voc with increasing band gap. Our results suggest that compositional grading rather than bulk alloying, such as by creating In-rich surfaces, may be a better strategy to favorably engineering improved thin-film photovoltaics with larger-band gap absorbers.

  20. Pilot solar power plant

    NASA Astrophysics Data System (ADS)

    Wolf, D.

    A fully functionally efficient solar-thermal power plant (10 kW electric) was built. The operating principle of thermomechanical conversion of solar energy into mechanical or electrical energy is presented. The equipment is completely automatic. Flat plate collectors absorb solar energy and convert it into heat which is transmitted by water to a heat exchanger. A closed cycle machine uses the heat to boil a working fluid (C2C12F4). A screw, powered by gas expansion in the working fluid, converts mechanical energy into electrical energy.

  1. Effect of core quantum-dot size on power-conversion-efficiency for silicon solar-cells implementing energy-down-shift using CdSe/ZnS core/shell quantum dots.

    PubMed

    Baek, Seung-Wook; Shim, Jae-Hyoung; Seung, Hyun-Min; Lee, Gon-Sub; Hong, Jin-Pyo; Lee, Kwang-Sup; Park, Jea-Gun

    2014-11-07

    Silicon solar cells mainly absorb visible light, although the sun emits ultraviolet (UV), visible, and infrared light. Because the surface reflectance of a textured surface with SiNX film on a silicon solar cell in the UV wavelength region (250-450 nm) is higher than ∼27%, silicon solar-cells cannot effectively convert UV light into photo-voltaic power. We implemented the concept of energy-down-shift using CdSe/ZnS core/shell quantum-dots (QDs) on p-type silicon solar-cells to absorb more UV light. CdSe/ZnS core/shell QDs demonstrated clear evidence of energy-down-shift, which absorbed UV light and emitted green-light photoluminescence signals at a wavelength of 542 nm. The implementation of 0.2 wt% (8.8 nm QDs layer) green-light emitting CdSe/ZnS core/shell QDs reduced the surface reflectance of the textured surface with SiNX film on a silicon solar-cell from 27% to 15% and enhanced the external quantum efficiency (EQE) of silicon solar-cells to around 30% in the UV wavelength region, thereby enhancing the power conversion efficiency (PCE) for p-type silicon solar-cells by 5.5%.

  2. Glass heat pipe evacuated tube solar collector

    DOEpatents

    McConnell, Robert D.; Vansant, James H.

    1984-01-01

    A glass heat pipe is adapted for use as a solar energy absorber in an evacuated tube solar collector and for transferring the absorbed solar energy to a working fluid medium or heat sink for storage or practical use. A capillary wick is formed of granular glass particles fused together by heat on the inside surface of the heat pipe with a water glass binder solution to enhance capillary drive distribution of the thermal transfer fluid in the heat pipe throughout the entire inside surface of the evaporator portion of the heat pipe. Selective coatings are used on the heat pipe surface to maximize solar absorption and minimize energy radiation, and the glass wick can alternatively be fabricated with granular particles of black glass or obsidian.

  3. Reconstructing the energy band electronic structure of pulsed laser deposited CZTS thin films intended for solar cell absorber applications

    NASA Astrophysics Data System (ADS)

    Pandiyan, Rajesh; Oulad Elhmaidi, Zakaria; Sekkat, Zouheir; Abd-lefdil, Mohammed; El Khakani, My Ali

    2017-02-01

    We report here on the use of pulsed KrF-laser deposition (PLD) technique for the growth of high-quality Cu2ZnSnS4 (CZTS) thin films onto Si, and glass substrates without resorting to any post sulfurization process. The PLD-CZTS films were deposited at room temperature (RT) and then subjected to post annealing at different temperatures ranging from 200 to 500 °C in Argon atmosphere. The X-ray diffraction and Raman spectroscopy confirmed that the PLD films crystallize in the characteristic kesterite CZTS structure regardless of their annealing temperature (Ta), but their crystallinity is much improved for Ta ≥ 400 °C. The PLD-CZTS films were found to exhibit a relatively dense morphology with a surface roughness (RMS) that increases with Ta (from ∼14 nm at RT to 70 nm at Ta = 500 °C with a value around 40 nm for Ta = 300-400 °C). The optical bandgap of the PLD-CZTS films, was derived from UV-vis transmission spectra analysis, and found to decrease from 1.73 eV for non-annealed films to ∼1.58 eV for those annealed at Ta = 300 °C. These band gap values are very close to the optimum value needed for an ideal solar cell absorber. In order to achieve a complete reconstruction of the one-dimensional energy band structure of these PLD-CZTS absorbers, we have combined both XPS and UPS spectroscopies to determine their chemical bondings, the position of their valence band maximum (relative to Fermi level), and their work function values. This enabled us to sketch out, as accurately as possible, the band alignment of the heterojunction interface formed between CZTS and both CdS and ZnS buffer layer materials.

  4. Energy absorber uses expanded coiled tube

    NASA Technical Reports Server (NTRS)

    Johnson, E. F.

    1972-01-01

    Mechanical shock mitigating device, based on working material to its failure point, absorbs mechanical energy by bending or twisting tubing. It functions under axial or tangential loading, has no rebound, is area independent, and is easy and inexpensive to build.

  5. Energy Absorbing Seat System for an Agricultural Aircraft

    NASA Technical Reports Server (NTRS)

    Kellas, Sotiris; Jones, Lisa E. (Technical Monitor)

    2002-01-01

    A task was initiated to improve the energy absorption capability of an existing aircraft seat through cost-effective retrofitting, while keeping seat-weight increase to a minimum. This task was undertaken as an extension of NASA ongoing safety research and commitment to general aviation customer needs. Only vertical crash scenarios have been considered in this task which required the energy absorbing system to protect the seat occupant in a range of crash speeds up to 31 ft/sec. It was anticipated that, the forward and/or side crash accelerations could be attenuated with the aid of airbags, the technology of which is currently available in automobiles and military helicopters. Steps which were followed include, preliminary crush load determination, conceptual design of cost effective energy absorbers, fabrication and testing (static and dynamic) of energy absorbers, system analysis, design and fabrication of dummy seat/rail assembly, dynamic testing of dummy seat/rail assembly, and finally, testing of actual modified seat system with a dummy occupant. A total of ten full scale tests have been performed including three of the actual aircraft seat. Results from full-scale tests indicated that occupant loads were attenuated successfully to survivable levels.

  6. Solar converter system with thermal overload protection

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Popovich, J.M.; Thornbury, T.R.

    1979-10-02

    A solar energy conversion system comprises: (a) a solar converter in which liquid absorbs solar radiation, the liquid being solar energy absorptive; (b) first means to circulate said liquid for flow through the converter; and (c) means to effect removal of liquid from the converter in response to an undesirable operation condition in said system. 12 claims.

  7. Solar Energy Reporting

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Last year the people of Cleveland, Ohio were troubled by natural gas shortages during one of the coldest winters on record. The severe winter generated a great deal of interest in solar energy as an alternative source of heat. Home owners, home builders and civic officials wanted to know just how much solar energy is available in Cleveland. Now they get a daily report through the city's news media, from information supplied as a community service by NASA's Lewis Research Center. Lewis routinely makes daily measurements of solar energy as part of its continuing research in behalf of the Department of Energy. The measuring device is a sun sensor called a pyranometer (upper photo) located atop a building at the NASA Center. To make the information conveniently available to news media, Lewis developed a Voice Output Integrating Insolometer, an automated system that acquires information from the sun sensor and translates it into a recorded telephone message. The Lewis pyranometer collects sun data for 15 hours daily and measures the total solar energy yield. For reporting to the public, the information is electronically converted to a specific reading. A media representative calling in gets a voice-synthesized announcement of a two or three digit number; the number corresponds to the kilowatt-hours of solar energy that would be available to a typical 500-square-foot solar collector system. Response in Cleveland has been favorable and interest is developing in other parts of the country.

  8. Concentrating Solar Power Projects - Genesis Solar Energy Project |

    Science.gov Websites

    Concentrating Solar Power | NREL Genesis Solar Energy Project This page provides information on the Genesis Solar Energy Project, a concentrating solar power (CSP) project, with data organized by background, participants, and power plant configuration. The Project includes two 125-MW units incorporating

  9. An advanced plasmonic cermet solar absorber for high temperature solar energy conversion applications

    NASA Astrophysics Data System (ADS)

    Bilokur, M.; Gentle, A.; Arnold, M.; Cortie, M.; Smith, G.

    2017-08-01

    Cermet coatings based on nanoparticles of Au or Ag in a stable dielectric matrix provide a combination of spectral-selectivity and microstructural stability at elevated temperatures. The nanoparticles provide an absorption peak due to their localized surface plasmon resonance and the dielectric matrix provides red-shifting and intrinsic absorption from defects. The matrix and two separated cermet layers combined add mechanical support, greater thermal stability and extra absorptance. The coatings may be prepared by magnetron sputtering. They have solar absorptance ranging between 91% and 97% with low thermal emittance making them suitable for application in solar thermal conversion installations.

  10. Toward a High-Efficient Utilization of Solar Radiation by Quad-Band Solar Spectral Splitting.

    PubMed

    Cao, Feng; Huang, Yi; Tang, Lu; Sun, Tianyi; Boriskina, Svetlana V; Chen, Gang; Ren, Zhifeng

    2016-12-01

    The promising quad-band solar spectral splitter incorporates the properties of the optical filter and the spectrally selective solar thermal absorber can direct PV band to PV modules and absorb thermal band energy for thermal process with low thermal losses. It provides a new strategy for spectral splitting and offers potential ways for hybrid PVT system design. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Solar energy emplacement developer

    NASA Technical Reports Server (NTRS)

    Mortensen, Michael; Sauls, Bob

    1991-01-01

    A preliminary design was developed for a Lunar Power System (LPS) composed of photovoltaic arrays and microwave reflectors fabricated from lunar materials. The LPS will collect solar energy on the surface of the Moon, transform it into microwave energy, and beam it back to Earth where it will be converted into usable energy. The Solar Energy Emplacement Developer (SEED) proposed will use a similar sort of solar energy collection and dispersement to power the systems that will construct the LPS.

  12. Bright Idea: Solar Energy Primer.

    ERIC Educational Resources Information Center

    Missouri State Dept. of Natural Resources, Jefferson City.

    This booklet is intended to address questions most frequently asked about solar energy. It provides basic information and a starting point for prospective solar energy users. Information includes discussion of solar space heating, solar water heating, and solar greenhouses. (Author/RE)

  13. The World's Largest Experiment Manipulating Solar Energy Input To Earth Resumed In 2003

    NASA Astrophysics Data System (ADS)

    Ward, P. L.

    2010-12-01

    Small amounts of solar-ultraviolet-energy absorbing gases such as ozone, SO2, and NO2 play an unusually large role warming the atmosphere. A mere 3 to 8 ppmv ozone at elevations of 15 to 50 km and associated exothermic chemical reactions warm the atmosphere >50oC, forming the stratosphere. All three molecules have an asymmetric top shape that, unlike linear molecules of CO2, forms a permanent electromagnetic dipole enhancing interaction with electromagnetic radiation. Planck’s postulate (Energy = a constant times frequency) implies that solar ultraviolet energy strongly absorbed by SO2 is 43 times greater than infrared energy radiated by earth and strongly absorbed by CO2. Solar energy in the blue visible spectrum and ultraviolet causes electronic transitions and an absorption spectrum that is a continuum, absorbing far more energy per unit gas than spectral line absorption of infrared energy caused by rotational and vibrational transitions. Absorption of electromagnetic energy by atmospheric gases increases rapidly with increasing frequency, an observation not accounted for by the use of specific heat in atmospheric models to link energy flux with temperature. While SO2 in the stratosphere is oxidized to a sulfuric acid aerosol that reflects sunlight, cooling the earth, SO2 in the troposphere is oxidized much more slowly than commonly assumed. Well-documented concentrations of tens of ppbv SO2 emitted by humans burning fossil fuels, especially coal, in northern mid-latitudes are contemporaneous, with suitable time delays for warming the ocean, with increased global warming during the 20th century, greatest by nearly a factor of two in the northern hemisphere. A decrease by 18% of anthropogenic SO2 emissions between 1979 and 2000 aimed at reducing acid rain had the unintended effect of reducing the global mean rate of temperature increase to zero by 1998. By 2003, global SO2 emissions began to rise sharply due to the rapid increase in number of new coal

  14. Solar energy in buildings: Implications for California energy policy

    NASA Technical Reports Server (NTRS)

    Hirshberg, A. S.; Davis, E. S.

    1977-01-01

    An assessment of the potential of active solar energy systems for buildings in California is summarized. The technology used for solar heating, cooling, and water heating in buildings is discussed. The major California weather zones and the solar energy designs are described, as well as the sizing of solar energy systems and their performance. The cost of solar energy systems is given both at current prices and at prices consistent with optimistic estimates for the cost of collectors. The main institutional barriers to the wide spread use of solar energy are summarized.

  15. Evaluation of energy absorbers for use in a roadside/median barrier.

    DOT National Transportation Integrated Search

    2014-02-01

    Several types of elastomeric energy absorbers were evaluated for use in a Manual for Assessing Safety Hardware (MASH) : Test Level 4 (TL-4) energy-absorbing, urban roadside/median barrier. Twelve dynamic bogie tests were conducted on 60- : and 80-dur...

  16. An Overview on Impact Behaviour and Energy Absorption of Collapsible Metallic and Non-Metallic Energy Absorbers used in Automotive Applications

    NASA Astrophysics Data System (ADS)

    Shinde, R. B.; Mali, K. D.

    2018-04-01

    Collapsible impact energy absorbers play an important role of protecting automotive components from damage during collision. Collision of the two objects results into the damage to one or both of them. Damage may be in the form of crack, fracture and scratch. Designers must know about how the material and object behave under impact event. Owing to above reasons different types of collapsible impact energy absorbers are developed. In the past different studies were undertaken to improve such collapsible impact energy absorbers. This article highlights such studies on common shapes of collapsible impact energy absorber and their impact behaviour under the axial compression. The literature based on studies and analyses of effects of different geometrical parameters on the crushing behaviour of impact energy absorbers is presented in detail. The energy absorber can be of different shape such as circular tube, square tube, and frustums of cone and pyramids. The crushing behaviour of energy absorbers includes studies on crushing mechanics, modes of deformation, energy absorbing capacity, effect on peak and mean crushing load. In this work efforts are made to cover major outcomes from past studies on such behavioural parameters. Even though the major literature reviewed is related to metallic energy absorbers, emphasis is also laid on covering literature on use of composite tube, fiber metal lamination (FML) member, honeycomb plate and functionally graded thickness (FGT) tube as a collapsible impact energy absorber.

  17. Energy-harvesting shock absorber with a mechanical motion rectifier

    NASA Astrophysics Data System (ADS)

    Li, Zhongjie; Zuo, Lei; Kuang, Jian; Luhrs, George

    2013-02-01

    Energy-harvesting shock absorbers are able to recover the energy otherwise dissipated in the suspension vibration while simultaneously suppressing the vibration induced by road roughness. They can work as a controllable damper as well as an energy generator. An innovative design of regenerative shock absorbers is proposed in this paper, with the advantage of significantly improving the energy harvesting efficiency and reducing the impact forces caused by oscillation. The key component is a unique motion mechanism, which we called ‘mechanical motion rectifier (MMR)’, to convert the oscillatory vibration into unidirectional rotation of the generator. An implementation of a MMR-based harvester with high compactness is introduced and prototyped. A dynamic model is created to analyze the general properties of the motion rectifier by making an analogy between mechanical systems and electrical circuits. The model is capable of analyzing electrical and mechanical components at the same time. Both simulation and experiments are carried out to verify the modeling and the advantages. The prototype achieved over 60% efficiency at high frequency, much better than conventional regenerative shock absorbers in oscillatory motion. Furthermore, road tests are done to demonstrate the feasibility of the MMR shock absorber, in which more than 15 Watts of electricity is harvested while driving at 15 mph on a smooth paved road. The MMR-based design can also be used for other applications of vibration energy harvesting, such as from tall buildings or long bridges.

  18. Solar electricity and solar fuels

    NASA Astrophysics Data System (ADS)

    Spiers, David J.

    1989-04-01

    The nature of solar radiation and its variation with location is described. The distribution of energy in the solar spectrum places immediate limits on the theoretical efficiency of conversion processes, since practical absorbers cannot convert all wavelengths received to useful energy. The principles of solar energy conversion methods are described. Absorption of solar energy can give rise to direct electrical generation, heating, or chemical change. Electrical generation from sunlight can be achieved by photovoltaic systems directly or by thermal systems which use solar heat to drive a heat engine and generator. The technology used and under research for promising ways of producing electricity or fuel from solar energy is described. Photovoltaic technology is established today for remote area, small power applications, and photovoltaic module sales alone are over 100 million dollars per year at present. The photovoltaic market has grown steadily since the mid-1970's, as prices have fallen continuously. Future energy options are briefly described. The merits of a sustainable energy economy, based on renewable energy resources, including solar energy, are emphasized, as this seems to provide the only hope of eliminating the problems caused by the build-up of atmospheric carbon dioxide, acid rain pollution and nuclear waste disposal. There is no doubt that clean fuels which were derived from solar energy and either did not involve carbon dioxide and used atmospheric carbon dioxide as the source dioxide as the source of carbon would be a worthy ideal. Methods described could one day achieve this.

  19. Energy 101: Concentrating Solar Power

    ScienceCinema

    None

    2018-02-07

    From towers to dishes to linear mirrors to troughs, concentrating solar power (CSP) technologies reflect and collect solar heat to generate electricity. A single CSP plant can generate enough power for about 90,000 homes. This video explains what CSP is, how it works, and how systems like parabolic troughs produce renewable power. For more information on the Office of Energy Efficiency and Renewable Energy's CSP research, see the Solar Energy Technology Program's Concentrating Solar Power Web page at http://www1.eere.energy.gov/solar/csp_program.html.

  20. Methylammonium Bismuth Iodide as a Lead-Free, Stable Hybrid Organic-Inorganic Solar Absorber.

    PubMed

    Hoye, Robert L Z; Brandt, Riley E; Osherov, Anna; Stevanović, Vladan; Stranks, Samuel D; Wilson, Mark W B; Kim, Hyunho; Akey, Austin J; Perkins, John D; Kurchin, Rachel C; Poindexter, Jeremy R; Wang, Evelyn N; Bawendi, Moungi G; Bulović, Vladimir; Buonassisi, Tonio

    2016-02-18

    Methylammonium lead halide (MAPbX3 ) perovskites exhibit exceptional carrier transport properties. But their commercial deployment as solar absorbers is currently limited by their intrinsic instability in the presence of humidity and their lead content. Guided by our theoretical predictions, we explored the potential of methylammonium bismuth iodide (MBI) as a solar absorber through detailed materials characterization. We synthesized phase-pure MBI by solution and vapor processing. In contrast to MAPbX3, MBI is air stable, forming a surface layer that does not increase the recombination rate. We found that MBI luminesces at room temperature, with the vapor-processed films exhibiting superior photoluminescence (PL) decay times that are promising for photovoltaic applications. The thermodynamic, electronic, and structural features of MBI that are amenable to these properties are also present in other hybrid ternary bismuth halide compounds. Through MBI, we demonstrate a lead-free and stable alternative to MAPbX3 that has a similar electronic structure and nanosecond lifetimes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Optimization by simulation of the nature of the buffer, the gap profile of the absorber and the thickness of the various layers in CZTSSe solar cells

    NASA Astrophysics Data System (ADS)

    Chadel, Meriem; Chadel, Asma; Moustafa Bouzaki, Mohammed; Aillerie, Michel; Benyoucef, Boumediene; Charles, Jean-Pierre

    2017-11-01

    Performances of ZnO/ZnS/CZTSSe polycrystalline thin film solar cells (Copper Zinc Tin Sulphur Selenium-solar cell) were simulated for different thicknesses of the absorber and ZnS buffer layers. Simulations were performed with SCAPS (Solar Cell Capacitance Simulator) software, starting with actual parameters available from industrial data for commercial cells processing. The influences of the thickness of the various layers in the structure of the solar cell and the gap profile of the CZTSSe absorber layer on the performance of the solar cell were studied in detail. Through considerations of recent works, we discuss possible routes to enhance the performance of CZTSSe solar cells towards a higher efficiency level. Thus, we found that for one specific thickness of the absorber layer, the efficiency of the CZTSSe solar cell can be increased when a ZnS layer replaces the usual CdS buffer layer. On the other hand, the efficiency of the solar cell can be also improved when the absorber layer presents a grad-gap. In this case, the maximum efficiency for the CZTSSe cell was found equal to 13.73%.

  2. Solar Energy Technologies Office Fact Sheet

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Solar Energy Technologies Office

    The U.S. Department of Energy Solar Energy Technologies Office (SETO) supports early-stage research and development to improve the affordability, reliability, and performance of solar technologies on the grid. The office invests in innovative research efforts that securely integrate more solar energy into the grid, enhance the use and storage of solar energy, and lower solar electricity costs.

  3. Northeast Solar Energy Market Coalition (NESEMC)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rabago, Karl R.

    The Northeast Solar Energy Market Coalition (NESEMC) brought together solar energy business associations and other stakeholders in the Northeast to harmonize regional solar energy policy and advance the solar energy market. The Coalition was managed by the Pace Energy and Climate Center, a project of the Pace University Elisabeth Haub School of Law. The NESEMC was funded by the U.S. Department of Energy SunShot Initiative as a cooperative agreement through 2017 as part of Solar Market Pathways.

  4. Solar Energy: Heat Transfer.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on heat transfer 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 technologies. The…

  5. Copper and Zinc Oxide Composite Nanostructures for Solar Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Wu, Fei

    Solar energy is a clean and sustainable energy source to counter global environmental issues of rising atmospheric CO2 levels and depletion of natural resources. To extract useful work from solar energy, silicon-based photovoltaic devices are extensively used. The technological maturity and the high quality of silicon (Si) make it a material of choice. However limitations in Si exist, ranging from its indirect band gap to low light absorption coefficient and energy and capital intensive crystal growth schemes. Therefore, alternate materials that are earth-abundant, benign and simpler to process are needed for developing new platforms for solar energy harvesting applications. In this study, we explore oxides of copper (CuO and Cu2O) in a nanowire morphology as alternate energy harvesting materials. CuO has a bandgap of 1.2 eV whereas Cu2O has a bandgap of 2.1 eV making them ideally suited for absorbing solar radiation. First, we develop a method to synthesize vertical, single crystalline CuO and Cu2O nanowires of ~50 microm length and aspect ratios of ~200. CuO nanowire arrays are synthesized by thermal oxidation of Cu foils. Cu2O nanowire arrays are synthesized by thermal reduction of CuO nanowires. Next, surface engineering of these nanowires is achieved using atomic layer deposition (ALD) of ZnO. By depositing 1.4 nm of ZnO, a highly defective surface is produced on the CuO nanowires. These defects are capable of trapping charge as is evident through persistent photoconductivity measurements of ZnO coated CuO nanowires. The same nanowires serve as efficient photocatalysts reducing CO2 to CO with a yield of 1.98 mmol/g-cat/hr. Finally, to develop a robust platform for flexible solar cells, a protocol to transfer vertical CuO nanowires inside flexible polydimethylsiloxane (PDMS) is demonstrated. Embedded CuO nanowires-ZnO pn junctions show a VOC of 0.4 V and a JSC of 10.4 microA/cm2 under white light illumination of 5.7 mW/cm2. Thus, this research provides broad

  6. Sea shell solar collector

    DOEpatents

    Rabl, Ari

    1976-01-01

    A device is provided for the collection and concentration of solar radiant energy including a longitudinally extending structure having a wall for directing radiant energy. The wall is parabolic with its focus along a line parallel to an extreme ray of the sun at one solstice and with its axis along a line parallel to an extreme ray of the sun at the other solstice. An energy absorber is positioned to receive the solar energy thereby collected.

  7. Solar thermophotovoltaic system using nanostructures

    DOE PAGES

    Ungaro, Craig; Gray, Stephen K.; Gupta, Mool C.

    2015-08-20

    This paper presents results on a highly efficient experimental solar thermophotovoltaic (STPV) system using simulated solar energy. An overall power conversion efficiency of 6.2% was recorded under solar simulation. This was matched with a thermodynamic model, and the losses within the system, as well as a path forward to mitigate these losses, have been investigated. The system consists of a planar, tungsten absorbing/emitting structure with an anti-reflection layer coated laser-microtextured absorbing surface and single-layer dielectric coated emitting surface. A GaSb PV cell was used to capture the emitted radiation and convert it into electrical energy. This simple structure is bothmore » easy to fabricate and temperature stable, and contains no moving parts or heat exchange fluids.« less

  8. Solar thermophotovoltaic system using nanostructures.

    PubMed

    Ungaro, Craig; Gray, Stephen K; Gupta, Mool C

    2015-09-21

    This paper presents results on a highly efficient experimental solar thermophotovoltaic (STPV) system using simulated solar energy. An overall power conversion efficiency of 6.2% was recorded under solar simulation. This was matched with a thermodynamic model, and the losses within the system, as well as a path forward to mitigate these losses, have been investigated. The system consists of a planar, tungsten absorbing/emitting structure with an anti-reflection layer coated laser-microtextured absorbing surface and single-layer dielectric coated emitting surface. A GaSb PV cell was used to capture the emitted radiation and convert it into electrical energy. This simple structure is both easy to fabricate and temperature stable, and contains no moving parts or heat exchange fluids.

  9. Solar Energy: Heat Storage.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on heat storage 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 technologies. The module…

  10. Solar Energy: Home Heating.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on home heating 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 technologies. The module…

  11. Non-tracking solar concentrator with a high concentration ratio

    DOEpatents

    Hinterberger, Henry

    1977-01-01

    A nontracking solar concentrator with a high concentration ratio is provided. The concentrator includes a plurality of energy absorbers which communicate with a main header by which absorbed heat is removed. Undesired heat flow of those absorbers not being heated by radiant energy at a particular instant is impeded, improving the efficiency of the concentrator.

  12. Hydrogen production from solar energy

    NASA Technical Reports Server (NTRS)

    Eisenstadt, M. M.; Cox, K. E.

    1975-01-01

    Three alternatives for hydrogen production from solar energy have been analyzed on both efficiency and economic grounds. The analysis shows that the alternative using solar energy followed by thermochemical decomposition of water to produce hydrogen is the optimum one. The other schemes considered were the direct conversion of solar energy to electricity by silicon cells and water electrolysis, and the use of solar energy to power a vapor cycle followed by electrical generation and electrolysis. The capital cost of hydrogen via the thermochemical alternative was estimated at $575/kW of hydrogen output or $3.15/million Btu. Although this cost appears high when compared with hydrogen from other primary energy sources or from fossil fuel, environmental and social costs which favor solar energy may prove this scheme feasible in the future.

  13. Moving core beam energy absorber and converter

    DOEpatents

    Degtiarenko, Pavel V.

    2012-12-18

    A method and apparatus for the prevention of overheating of laser or particle beam impact zones through the use of a moving-in-the-coolant-flow arrangement for the energy absorbing core of the device. Moving of the core spreads the energy deposition in it in 1, 2, or 3 dimensions, thus increasing the effective cooling area of the device.

  14. Solar energy, its conversion and utilization

    NASA Technical Reports Server (NTRS)

    Farber, E. A.

    1972-01-01

    The work being carried out at the University of Florida Solar Energy and Energy Conversion Laboratory in converting solar energy, our only income, into other needed and useful forms of energy is described. A treatment such as this demonstrates, in proper perspective, how solar energy can benefit mankind with its many problems of shortages and pollution. Descriptions were given of the conversion processes, equipment, and performance. The testing of materials, solar water heating, space heating, cooking and baking, solar distillation, refrigeration and air-conditioning, work with the solar furnace, conversion to mechanical power, hot air engines, solar-heated sewage digestion, conversion to electricity, and other devices will be discussed.

  15. Solar Energy Development PEIS Information Center

    Science.gov Websites

    skip navigation Solar Energy Development Programmatic EIS Home About the EIS Public Involvement Solar Energy Solar Energy Zones Maps Documents secondary menu News Frequently Asked Questions Glossary E the Programmatic Environmental Impact Statement for Solar Energy Development in Six Southwestern

  16. Energy level alignment in TiO2/metal sulfide/polymer interfaces for solar cell applications.

    PubMed

    Lindblad, Rebecka; Cappel, Ute B; O'Mahony, Flannan T F; Siegbahn, Hans; Johansson, Erik M J; Haque, Saif A; Rensmo, Håkan

    2014-08-28

    Semiconductor sensitized solar cell interfaces have been studied with photoelectron spectroscopy to understand the interfacial electronic structures. In particular, the experimental energy level alignment has been determined for complete TiO2/metal sulfide/polymer interfaces. For the metal sulfides CdS, Sb2S3 and Bi2S3 deposited from single source metal xanthate precursors, it was shown that both driving forces for electron injection into TiO2 and hole transfer to the polymer decrease for narrower bandgaps. The energy level alignment results were used in the discussion of the function of solar cells with the same metal sulfides as light absorbers. For example Sb2S3 showed the most favourable energy level alignment with 0.3 eV driving force for electron injection and 0.4 eV driving force for hole transfer and also the most efficient solar cells due to high photocurrent generation. The energy level alignment of the TiO2/Bi2S3 interface on the other hand showed no driving force for electron injection to TiO2, and the performance of the corresponding solar cell was very low.

  17. Organic solar cells with graded absorber layers processed from nanoparticle dispersions.

    PubMed

    Gärtner, Stefan; Reich, Stefan; Bruns, Michael; Czolk, Jens; Colsmann, Alexander

    2016-03-28

    The fabrication of organic solar cells with advanced multi-layer architectures from solution is often limited by the choice of solvents since most organic semiconductors dissolve in the same aromatic agents. In this work, we investigate multi-pass deposition of organic semiconductors from eco-friendly ethanol dispersion. Once applied, the nanoparticles are insoluble in the deposition agent, allowing for the application of further nanoparticulate layers and hence for building poly(3-hexylthiophene-2,5-diyl):indene-C60 bisadduct absorber layers with vertically graded polymer and conversely graded fullerene concentration. Upon thermal annealing, we observe some degrees of polymer/fullerene interdiffusion by means of X-ray photoelectron spectroscopy and Kelvin probe force microscopy. Replacing the common bulk-heterojunction by such a graded photo-active layer yields an enhanced fill factor of the solar cell due to an improved charge carrier extraction, and consequently an overall power conversion efficiency beyond 4%. Wet processing of such advanced device architectures paves the way for a versatile, eco-friendly and industrially feasible future fabrication of organic solar cells with advanced multi-layer architectures.

  18. Solar Energy Education. Renewable energy: a background text. [Includes glossary

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1985-01-01

    Some of the most common forms of renewable energy are presented in this textbook for students. The topics include solar energy, wind power hydroelectric power, biomass ocean thermal energy, and tidal and geothermal energy. The main emphasis of the text is on the sun and the solar energy that it yields. Discussions on the sun's composition and the relationship between the earth, sun and atmosphere are provided. Insolation, active and passive solar systems, and solar collectors are the subtopics included under solar energy. (BCS)

  19. Survey of selective solar absorbers and their limitations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mattox, D.M.; Sowell, R.R.

    1980-01-01

    A number of selective absorber coating systems with high solar absorptance exist which may be used in the mid-temperature range. Some of the systems are more chemically and thermally stable than others. Unfortunately, there are large gaps in the stability data for a large number of the systems. In an inert environment, the principle degradation mechanisms are interdiffusion between the layers or phases and changes in surface morphology. These degradation mechanisms would be minimized by using refractory metals and compounds for the absorbing layer and using refractory materials or diffusion barriers for the underlayer. For use in a reactive environment,more » the choice of materials is much more restrictive since internal chemical reactions can change phase compositions and interfacial reactions can lead to loss of adhesion. For a coating process to be useful, it is necessary to determine what parameters influence the performance of the coating and the limits to these parameters. This process sensitivity has a direct influence on the production process controls necessary to produce a good product. Experience with electroplated black chrome has been rather disappointing. Electroplating should be a low cost deposition process but the extensive bath analysis and optical monitoring necessary to produce a thermally stable produce for use to 320/sup 0/C has increased cost signficantly. 49 references.« less

  20. Multi-Level Experimental and Analytical Evaluation of Two Composite Energy Absorbers

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Littell, Justin D.; Fasanella, Edwin L.; Annett, Martin S.; Seal, Michael D., II

    2015-01-01

    Two composite energy absorbers were developed and evaluated at NASA Langley Research Center through multi-level testing and simulation performed under the Transport Rotorcraft Airframe Crash Testbed (TRACT) research program. A conical-shaped energy absorber, designated the conusoid, was evaluated that consisted of four layers of hybrid carbon-Kevlar plain weave fabric oriented at [+45 deg/-45 deg/-45 deg/+45 deg] with respect to the vertical, or crush, direction. A sinusoidal-shaped energy absorber, designated the sinusoid, was developed that consisted of hybrid carbon-Kevlar plain weave fabric face sheets, two layers for each face sheet oriented at +/-45deg with respect to the vertical direction and a closed-cell ELFOAM P200 polyisocyanurate (2.0-lb/cu ft) foam core. The design goal for the energy absorbers was to achieve average floor-level accelerations of between 25- and 40-g during the full-scale crash test of a retrofitted CH-46E helicopter airframe, designated TRACT 2. Variations in both designs were assessed through dynamic crush testing of component specimens. Once the designs were finalized, subfloor beams of each configuration were fabricated and retrofitted into a barrel section of a CH-46E helicopter. A vertical drop test of the barrel section was conducted onto concrete to evaluate the performance of the energy absorbers prior to retrofit into TRACT 2. The retrofitted airframe was crash tested under combined forward and vertical velocity conditions onto soil, which is characterized as a sand/clay mixture. Finite element models were developed of all test articles and simulations were performed using LS-DYNA, a commercial nonlinear explicit transient dynamic finite element code. Test-analysis results are presented for each energy absorber as comparisons of time-history responses, as well as predicted and experimental structural deformations and progressive damage under impact loading for each evaluation level.

  1. Enabling iron pyrite (FeS2) and related ternary pyrite compounds for high-performance solar energy applications

    NASA Astrophysics Data System (ADS)

    Caban Acevedo, Miguel

    The success of solar energy technologies depends not only on highly efficient solar-to-electrical energy conversion, charge storage or chemical fuel production, but also on dramatically reduced cost, to meet the future terawatt energy challenges we face. The enormous scale involved in the development of impactful solar energy technologies demand abundant and inexpensive materials, as well as energy-efficient and cost-effective processes. As a result, the investigation of semiconductor, catalyst and electrode materials made of earth-abundant and sustainable elements may prove to be of significant importance for the long-term adaptation of solar energy technologies on a larger scale. Among earth-abundant semiconductors, iron pyrite (cubic FeS2) has been considered the most promising solar energy absorber with the potential to achieve terawatt energy-scale deployment. Despite extensive synthetic progress and device efforts, the solar conversion efficiency of iron pyrite has remained below 3% since the 1990s, primarily due to a low open circuit voltage (V oc). The low photovoltage (Voc) of iron pyrite has puzzled scientists for decades and limited the development of cost-effective solar energy technologies based on this otherwise promising semiconductor. Here I report a comprehensive investigation of the syntheses and properties of iron pyrite materials, which reveals that the Voc of iron pyrite is limited by the ionization of a high density of intrinsic bulk defect states despite high density surface states and strong surface Fermi level pinning. Contrary to popular belief, bulk defects most-likely caused by intrinsic sulfur vacancies in iron pyrite must be controlled in order to enable this earth-abundant semiconductor for cost-effective and sustainable solar energy conversion. Lastly, the investigation of iron pyrite presented here lead to the discovery of ternary pyrite-type cobalt phosphosulfide (CoPS) as a highly-efficient earth-abundant catalyst material for

  2. Experimenting with Solar Energy

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2004-01-01

    Over the past 25 years, the author has had the opportunity to study the subject of solar energy and to get involved with the installation, operation, and testing of solar energy systems. His work has taken him all over the United States and put him in contact with solar experts from around the world. He has also had the good fortune of seeing some…

  3. Nanomorphology of P3HT:PCBM-based absorber layers of organic solar cells after different processing conditions analyzed by low-energy scanning transmission electron microscopy.

    PubMed

    Pfaff, Marina; Klein, Michael F G; Müller, Erich; Müller, Philipp; Colsmann, Alexander; Lemmer, Uli; Gerthsen, Dagmar

    2012-12-01

    In this study the nanomorphology of P3HT:PC61BM absorber layers of organic solar cells was studied as a function of the processing parameters and for P3HT with different molecular weight. For this purpose we apply scanning transmission electron microscopy (STEM) at low electron energies in a scanning electron microscope. This method exhibits sensitive material contrast in the high-angle annular dark-field (HAADF) mode, which is well suited to distinguish materials with similar densities and mean atomic numbers. The images taken with low-energy HAADF STEM are compared with conventional transmission electron microscopy and atomic force microscopy images to illustrate the capabilities of the different techniques. For the interpretation of the low-energy HAADF STEM images, a semiempirical equation is used to calculate the image intensities. The experiments show that the nanomorphology of the P3HT:PC61BM blends depends strongly on the molecular weight of the P3HT. Low-molecular-weight P3HT forms rod-like domains during annealing. In contrast, only small globular features are visible in samples containing high-molecular-weight P3HT, which do not change significantly after annealing at 150°C up to 30 min.

  4. Optimization of Perfect Absorbers with Multilayer Structures

    NASA Astrophysics Data System (ADS)

    Li Voti, Roberto

    2018-02-01

    We study wide-angle and broadband perfect absorbers with compact multilayer structures made of a sequence of ITO and TiN layers deposited onto a silver thick layer. An optimization procedure is introduced for searching the optimal thicknesses of the layers so as to design a perfect broadband absorber from 400 nm to 750 nm, for a wide range of angles of incidence from 0{°} to 50{°}, for both polarizations and with a low emissivity in the mid-infrared. We eventually compare the performances of several optimal structures that can be very promising for solar thermal energy harvesting and collectors.

  5. Moving body velocity arresting line. [stainless steel cables with energy absorbing sleeves

    NASA Technical Reports Server (NTRS)

    Hull, R. A. (Inventor)

    1981-01-01

    The arresting of a moving body is improved through the use of steel cables that elongate to absorb the kinetic energy of the body. A sleeve surrounds the cables, protecting them from chafing and providing a failsafe energy absorbing system should the cables fail.

  6. Atlas of albedo and absorbed solar radiation derived from Nimbus 7 earth radiation budget data set, November 1985 to October 1987

    NASA Technical Reports Server (NTRS)

    Smith, G. Louis; Rutan, David; Bess, T. Dale

    1992-01-01

    An atlas of monthly mean global contour maps of albedo and absorbed solar radiation is presented for 21 months from Nov. 1985 to Oct. 1987. These data were retrieved from measurements made by the shortwave wide-field-of-view radiometer of the Earth Radiation Budget (ERB) instrument aboard the Nimbus 7 spacecraft. Profiles of zonal mean albedos and absorbed solar radiation were tabulated. These geographical distributions are provided as a resource for researchers studying the radiation budget of the Earth. The El Nino/Southern Oscillation event of 1986-1987 is included in this data set. This atlas of albedo and absorbed solar radiation extends to 12 years the period covered by two similar atlases: NASA RP-1230 (Jul. 1975 - Oct. 1978) and NASA RP-1231 (Nov. 1978 - Oct. 1985). These three compilations complement the atlases of outgoing longwave radiation by Bess and Smith in NASA RP-1185, RP-1186, and RP-1261, which were also based on the Nimbus 6 and 7 ERB data.

  7. Solar Program Assessment: Environmental Factors - Solar Total Energy Systems.

    ERIC Educational Resources Information Center

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    The purpose of this report is to present and prioritize the major environmental, safety, and social/institutional issues associated with the further development of Solar Total Energy Systems (STES). Solar total energy systems represent a specific application of the Federally-funded solar technologies. To provide a background for this analysis, the…

  8. Support for solar energy collectors

    DOEpatents

    Cole, Corey; Ardell-Smith, Zachary; Ciasulli, John; Jensen, Soren

    2016-11-01

    A solar energy collection system can include support devices configured to accommodate misalignment of components during assembly. For example, the system can include piles fixed to the earth and an adjustable bearing assembly at the upper end of the pile. The adjustable bearing assembly can include at least one of a vertical adjustment device, a lateral adjustment device and an angular adjustment device. The solar energy collection system can also include a plurality of solar energy collection device pre-wired together and mounted to a support member so as to form modular units. The system can also include enhanced supports for wire trays extending between rows of solar energy collection devices.

  9. Solar Energy-An Everyday Occurrence

    ERIC Educational Resources Information Center

    Keister, Carole; Cornell, Lu Beth

    1978-01-01

    Describes a solar energy research project sponsored by the Energy Research and Development Administration and conducted at Timonium School in Maryland. Elementary student involvement in solar energy studies resulting from the project is noted. (MDR)

  10. More Efficient Solar Thermal-Energy Receiver

    NASA Technical Reports Server (NTRS)

    Dustin, M. O.

    1987-01-01

    Thermal stresses and reradiation reduced. Improved design for solar thermal-energy receiver overcomes three major deficiencies of solar dynamic receivers described in literature. Concentrator and receiver part of solar-thermal-energy system. Receiver divided into radiation section and storage section. Concentrated solar radiation falls on boiling ends of heat pipes, which transmit heat to thermal-energy-storage medium. Receiver used in number of applications to produce thermal energy directly for use or to store thermal energy for subsequent use in heat engine.

  11. The Energy Under Our Feet: A Study of Solar Radiation

    NASA Astrophysics Data System (ADS)

    Weiss, I.

    2016-12-01

    In this experiment I tested if asphalt pavement can produce enough solar heat to produce energy through a system that uses water, solar energy and heat. A setup that can conserve the water and prevent it from evaporating, as well as measuring the energy production is required to run this experiment. I have done a lot of research on this experiment and found that there are several variables that impact the results of this experiment. 1. The surface temperature compared to the air temperature 2. The Geographical location of the pavement 3. The time of the year 4. Cloud coverage for the day Overall there will be many variables I will have to keep out of the experiment such as temperature ranges, season changes and geographical location. My constant will be my location at 33.7086o North and 117.9564o West. Asphalt pavements do not reflect the sunlight and hence heat up faster than a light surface that would reflect the sunlight. This means the Asphalt absorbs the solar radiation, which increases the temperature of the air around the asphalt contributing to what is known as the urban heat island effect. This heating in turn contributes to the formation of smog and ozone products. With the population still growing this would also mean an increase in this temperature and hence an increase in smog and ozone, creating a significant health concern. Cities need to start looking at ways to cool their pavement and find ways to harvest the energy created by their streets. Installing pipes with water can provide that solution and not only reduce the heat reflected from the pavement but also harvest energy from this setup, and decrease the smog production and maintain a balance in ozone levels. As well as the asphalt needed to run the testing, a Stirling engine is required. A Stirling Engine is a highly efficient engine that can run on a variety of heat sources. Because it is highly compatible with alternative energy and renewable energy sources it could become increasingly

  12. Fixture for assembling solar panels

    NASA Technical Reports Server (NTRS)

    Dillard, P. A.; Fritz, W. M.

    1979-01-01

    Vacuum fixture attaches array of silicon solar cells to mounting plate made of clear glass which holds and protects cells. Glass plate transmits, rather than absorbs, solar energy thus cooling cells for efficient operation. Device therefore reduces handling of cells and interconnecting conductors to one operation.

  13. The energy impacts of solar heating.

    PubMed

    Whipple, C

    1980-04-18

    The energy required to build and install solar space- and water-heating equipment is compared to the energy it saves under two solar growth paths corresponding to high and low rates of implementation projected by the Domestic Policy Review of Solar Energy. For the rapid growth case, the cumulative energy invested to the year 2000 is calculated to be (1/2) to 1(1/2) times the amount saved. An impact of rapid solar heating implementation is to shift energy demand from premium heating fuels (natural gas and oil) to coal and nuclear power use in the industries that provide materials for solar equipment.

  14. Research on temperature characteristics of laser energy meter absorber irradiated by ms magnitude long pulse laser

    NASA Astrophysics Data System (ADS)

    Li, Nan; Qiao, Chunhong; Fan, Chengyu; Zhang, Jinghui; Yang, Gaochao

    2017-10-01

    The research on temperature characteristics for large-energy laser energy meter absorber is about continuous wave (CW) laser before. For the measuring requirements of millisecond magnitude long pulse laser energy, the temperature characteristics for absorber are numerically calculated and analyzed. In calculation, the temperature field distributions are described by heat conduction equations, and the metal cylinder cavity is used for absorber model. The results show that, the temperature of absorber inwall appears periodic oscillation with pulse structure, the oscillation period and amplitude respectively relate to the pulse repetition frequency and single pulse energy. With the wall deep increasing, the oscillation amplitude decreases rapidly. The temperature of absorber outerwall is without periodism, and rises gradually with time. The factors to affect the temperature rise of absorber are single pulse energy, pulse width and repetition frequency. When the laser irradiation stops, the temperature between absorber inwall and outerwall will reach agreement rapidly. After special technology processing to enhance the capacity of resisting laser damage for absorber inwall, the ms magnitude long pulse laser energy can be obtained with the method of measuring the temperature of absorber outerwall. Meanwhile, by optimization design of absorber structure, when the repetition frequency of ms magnitude pulse laser is less than 10Hz, the energy of every pulse for low repetition frequency pulse sequence can be measured. The work offers valuable references for the design of ms magnitude large-energy pulse laser energy meter.

  15. Impact Testing and Simulation of a Sinusoid Foam Sandwich Energy Absorber

    NASA Technical Reports Server (NTRS)

    Jackson, Karen E.; Fasanella, Edwin L; Littell, Justin D.

    2015-01-01

    A sinusoidal-shaped foam sandwich energy absorber was developed and evaluated at NASA Langley Research Center through multi-level testing and simulation performed under the Transport Rotorcraft Airframe Crash Testbed (TRACT) research project. The energy absorber, designated the "sinusoid," consisted of hybrid carbon- Kevlar® plain weave fabric face sheets, two layers for each face sheet oriented at +/-45deg with respect to the vertical or crush direction, and a closed-cell ELFOAM(TradeMark) P200 polyisocyanurate (2.0-lb/ft3) foam core. The design goal for the energy absorber was to achieve an average floor-level acceleration of between 25- and 40-g during the full-scale crash test of a retrofitted CH-46E helicopter airframe, designated TRACT 2. Variations in the design were assessed through quasi-static and dynamic crush testing of component specimens. Once the design was finalized, a 5-ft-long subfloor beam was fabricated and retrofitted into a barrel section of a CH-46E helicopter. A vertical drop test of the barrel section was conducted onto concrete to evaluate the performance of the energy absorber prior to retrofit into TRACT 2. Finite element models were developed of all test articles and simulations were performed using LSDYNA ®, a commercial nonlinear explicit transient dynamic finite element code. Test analysis results are presented for the sinusoid foam sandwich energy absorber as comparisons of load-displacement and acceleration-time-history responses, as well as predicted and experimental structural deformations and progressive damage for each evaluation level (component testing through barrel section drop testing).

  16. Solar '80s: A Teacher's Handbook for Solar Energy Education.

    ERIC Educational Resources Information Center

    LaHart, David E.

    This guide is intended to assist the teacher in exploring energy issues and the technology of solar energy conversion and associated technologies. Sections of the guide include: (1) Rationale; (2) Technology Overview; (3) Sun Day Suggestions for School; (4) Backyard Solar Water Heater; (5) Solar Tea; (6) Biogas; (7) Solar Cells; (8) Economics; (9)…

  17. Solar America: A Solar Energy Tour of the United States (Revised)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    2003-06-01

    This CDROM contains nearly 500 photos and captions of solar energy technologies at work throughout the United States. Every state of the union is represented, as well as Puerto Rico, the U.S. Virgin Islands, the District of Columbia, and U.S. outposts in Antarctica. The technologies represented are photovoltaics, solar thermal, solar hot water, and concentrating solar power. The CD promotes solar energy as a wise energy choice for America's present and future.

  18. Solar energy and the aeronautics industry. Thesis

    NASA Technical Reports Server (NTRS)

    Benedek, L.

    1985-01-01

    An introduction to the physical aspects of solar energy, incidental energy and variations in solar flux is presented, along with an explanation of the physical principles of obtaining solar energy. The history of the application of solar energy to aeronautics, including the Gossamer Penguin and the Solar Challenger is given. Finally, an analysis of the possibilities of using a reaction motor with hybrid propulsion combining solar energy with traditional fuels as well as calculations of the proposed cycle and its mode of operation are given.

  19. Tech Transfer Webinar: Energy Absorbing Materials

    ScienceCinema

    Duoss, Eric

    2018-01-16

    A new material has been designed and manufactured at LLNL that can absorb mechanical energy--a cushion--while also providing protection against sheering. This ordered cellular material is 3D printed using direct ink writing techniques under development at LLNL. It is expected to find utility in application spaces that currently use unordered foams, such as sporting and consumer goods as well as defense and aerospace.

  20. High spectral selectivity for solar absorbers using a monolayer transparent conductive oxide coated on a metal substrate

    NASA Astrophysics Data System (ADS)

    Shimizu, Makoto; Suzuki, Mari; Iguchi, Fumitada; Yugami, Hiroo

    2017-05-01

    A spectrally selective absorber composed of a monolayer transparent conductive oxide (TCO) coated on a metal substrate is investigated for use in solar systems operating at temperatures higher (>973 K) than the operation temperature of conventional systems ( ˜ 673 K). This method is different from the currently used solar-selective coating technologies, such as those using multilayered and cermet materials. The spectral selective absorption property can be attributed to the inherent optical property of TCO owing to the plasma frequency and interferences between the substrates. Since spectral selectivity can be achieved using monolayered materials, the effect of atomic diffusion occurring at each layer boundary in a multilayer or cermet coatings under high-temperature conditions can be reduced. In addition, since this property is attributed to the inherent property of TCO, the precise control of the layer thickness can be omitted if the layer is sufficiently thick (>0.5 μm). The optimum TCO properties, namely, carrier density and mobility, required for solar-selective absorbers are analyzed to determine the cutoff wavelength and emittance in the infrared range. A solar absorptance of 0.95 and hemispherical emittance of 0.10 at 973 K are needed for achieving the optimum TCO properties, i.e., a carrier density of 5.5 × 1020 cm-3 and mobility of 90 cm2 V-1 s-1 are required. Optical simulations indicate that the spectrally selective absorption weakly depends on the incident angle and film thickness. The thermal stability of the fabricated absorber treated at temperatures up to 973 K for 10 h is verified in vacuum by introducing a SiO2 interlayer, which plays an important role as a diffusion barrier.

  1. GPP Webinar: The Solar Roadmap—Navigating the Evolving Solar Energy Market

    EPA Pesticide Factsheets

    GPP and State & Local Climate and Energy Branch webinar on the Solar Roadmap and the evolving solar energy market. This webinar discussed local and state government’s success stories and opportunities for progress in renewable energy goals using the Solar

  2. Solar thermal energy receiver

    NASA Technical Reports Server (NTRS)

    Baker, Karl W. (Inventor); Dustin, Miles O. (Inventor)

    1992-01-01

    A plurality of heat pipes in a shell receive concentrated solar energy and transfer the energy to a heat activated system. To provide for even distribution of the energy despite uneven impingement of solar energy on the heat pipes, absence of solar energy at times, or failure of one or more of the heat pipes, energy storage means are disposed on the heat pipes which extend through a heat pipe thermal coupling means into the heat activated device. To enhance energy transfer to the heat activated device, the heat pipe coupling cavity means may be provided with extensions into the device. For use with a Stirling engine having passages for working gas, heat transfer members may be positioned to contact the gas and the heat pipes. The shell may be divided into sections by transverse walls. To prevent cavity working fluid from collecting in the extensions, a porous body is positioned in the cavity.

  3. Solar energy collection system

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K. (Inventor)

    1977-01-01

    An improved solar energy collection system, having enhanced energy collection and conversion capabilities, is delineated. The system is characterized by a plurality of receivers suspended above a heliostat field comprising a multiplicity of reflector surfaces, each being adapted to direct a concentrated beam of solar energy to illuminate a target surface for a given receiver. A magnitude of efficiency, suitable for effectively competing with systems employed in collecting and converting energy extracted from fossil fuels, is indicated.

  4. Chemistry of personalized solar energy.

    PubMed

    Nocera, Daniel G

    2009-11-02

    Personalized energy (PE) is a transformative idea that provides a new modality for the planet's energy future. By providing solar energy to the individual, an energy supply becomes secure and available to people of both legacy and nonlegacy worlds and minimally contributes to an increase in the anthropogenic level of carbon dioxide. Because PE will be possible only if solar energy is available 24 h a day, 7 days a week, the key enabler for solar PE is an inexpensive storage mechanism. HY (Y = halide or OH(-)) splitting is a fuel-forming reaction of sufficient energy density for large-scale solar storage, but the reaction relies on chemical transformations that are not understood at the most basic science level. Critical among these are multielectron transfers that are proton-coupled and involve the activation of bonds in energy-poor substrates. The chemistry of these three italicized areas is developed, and from this platform, discovery paths leading to new hydrohalic acid- and water-splitting catalysts are delineated. The latter water-splitting catalyst captures many of the functional elements of photosynthesis. In doing so, a highly manufacturable and inexpensive method for solar PE storage has been discovered.

  5. Toward cost-effective solar energy use.

    PubMed

    Lewis, Nathan S

    2007-02-09

    At present, solar energy conversion technologies face cost and scalability hurdles in the technologies required for a complete energy system. To provide a truly widespread primary energy source, solar energy must be captured, converted, and stored in a cost-effective fashion. New developments in nanotechnology, biotechnology, and the materials and physical sciences may enable step-change approaches to cost-effective, globally scalable systems for solar energy use.

  6. Solar energy conversion with photon-enhanced thermionic emission

    NASA Astrophysics Data System (ADS)

    Kribus, Abraham; Segev, Gideon

    2016-07-01

    Photon-enhanced thermionic emission (PETE) converts sunlight to electricity with the combined photonic and thermal excitation of charge carriers in a semiconductor, leading to electron emission over a vacuum gap. Theoretical analyses predict conversion efficiency that can match, or even exceed, the efficiency of traditional solar thermal and photovoltaic converters. Several materials have been examined as candidates for radiation absorbers and electron emitters, with no conclusion yet on the best set of materials to achieve high efficiency. Analyses have shown the complexity of the energy conversion and transport processes, and the significance of several loss mechanisms, requiring careful control of material properties and optimization of the device structure. Here we survey current research on PETE modeling, materials, and device configurations, outline the advances made, and stress the open issues and future research needed. Based on the substantial progress already made in this young topic, and the potential of high conversion efficiency based on theoretical performance limits, continued research in this direction is very promising and may yield a competitive technology for solar electricity generation.

  7. Power efficiency for very high temperature solar thermal cavity receivers

    DOEpatents

    McDougal, Allan R.; Hale, Robert R.

    1984-01-01

    This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positioned in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts infrared radiation from the front of the absorber. With this arrangement, a high percentage of the solar power input is retained in the cavity; thus, high internal temperatures are attained.

  8. Solar Energy a Path to India's Prosperity

    NASA Astrophysics Data System (ADS)

    Chandra, Yogender Pal; Singh, Arashdeep; Kannojiya, Vikas; Kesari, J. P.

    2018-05-01

    Solar energy technology has grabbed a worldwide interest and attention these days. India also, having a huge solar influx and potential, is not falling back to feed its energy demand through non-conventional energy sources such as concentrating solar power (CSP) and photovoltaic (PV). This work will try to add some comprehensive insight on solar energy framework, policy, outlook and socio-economic challenges of India. This includes its prominent areas of working such as grid independent and `utility-scale' power production using CSP or PV power plants, rural as well as urban electrification using PV, solar powered public transportation systems, solar power in agrarian society—water pumping, irrigation, waste management and so on and so forth. Despite the fact that, a vast legion of furtherance and advancement has been done during the last decade of solar energy maturation and proliferation, improvements could be suggested so as to augment the solar energy usage in contrast to conventional energy sources in India.

  9. The SERI solar energy storage program

    NASA Technical Reports Server (NTRS)

    Copeland, R. J.; Wright, J. D.; Wyman, C. E.

    1980-01-01

    In support of the DOE thermal and chemical energy storage program, the solar energy storage program (SERI) provides research on advanced technologies, systems analyses, and assessments of thermal energy storage for solar applications in support of the Thermal and Chemical Energy Storage Program of the DOE Division of Energy Storage Systems. Currently, research is in progress on direct contact latent heat storage and thermochemical energy storage and transport. Systems analyses are being performed of thermal energy storage for solar thermal applications, and surveys and assessments are being prepared of thermal energy storage in solar applications. A ranking methodology for comparing thermal storage systems (performance and cost) is presented. Research in latent heat storage and thermochemical storage and transport is reported.

  10. Lightweight Energy Absorbers for Blast Containers

    NASA Technical Reports Server (NTRS)

    Balles, Donald L.; Ingram, Thomas M.; Novak, Howard L.; Schricker, Albert F.

    2003-01-01

    Kinetic-energy-absorbing liners made of aluminum foam have been developed to replace solid lead liners in blast containers on the aft skirt of the solid rocket booster of the space shuttle. The blast containers are used to safely trap the debris from small explosions that are initiated at liftoff to sever frangible nuts on hold-down studs that secure the spacecraft to a mobile launch platform until liftoff.

  11. Solar energy to meet the nation's energy needs

    NASA Technical Reports Server (NTRS)

    Rom, F. E.; Thomas, R. L.

    1973-01-01

    Discussion of the possibilities afforded by solar energy as one of the alternative energy sources capable to take the place of the dwindling oil and gas reserves. Solar energy, being a nondepleting clean source of energy, is shown to be capable of providing energy in all the forms in which it is used today. Steps taken toward providing innovative solutions that are economically competitive with other systems are briefly reviewed.

  12. 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.

  13. IPR 1.0: an efficient method for calculating solar radiation absorbed by individual plants in sparse heterogeneous woody plant communities

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Chen, W.; Li, J.

    2013-12-01

    Climate change may alter the spatial distribution, composition, structure, and functions of plant communities. Transitional zones between biomes, or ecotones, are particularly sensitive to climate change. Ecotones are usually heterogeneous with sparse trees. The dynamics of ecotones are mainly determined by the growth and competition of individual plants in the communities. Therefore it is necessary to calculate solar radiation absorbed by individual plants for understanding and predicting their responses to climate change. In this study, we developed an individual plant radiation model, IPR (version 1.0), to calculate solar radiation absorbed by individual plants in sparse heterogeneous woody plant communities. The model is developed based on geometrical optical relationships assuming crowns of woody plants are rectangular boxes with uniform leaf area density. The model calculates the fractions of sunlit and shaded leaf classes and the solar radiation absorbed by each class, including direct radiation from the sun, diffuse radiation from the sky, and scattered radiation from the plant community. The solar radiation received on the ground is also calculated. We tested the model by comparing with the analytical solutions of random distributions of plants. The tests show that the model results are very close to the averages of the random distributions. This model is efficient in computation, and is suitable for ecological models to simulate long-term transient responses of plant communities to climate change.

  14. Can industry afford solar energy

    NASA Astrophysics Data System (ADS)

    Kreith, F.; Bezdek, R.

    1983-03-01

    Falling oil prices and conservation measures have reduced the economic impetus to develop new energy sources, thus decreasing the urgency for bringing solar conversion technologies to commercial readiness at an early date. However, the capability for solar to deliver thermal energy for industrial uses is proven. A year-round operation would be three times as effective as home heating, which is necessary only part of the year. Flat plate, parabolic trough, and solar tower power plant demonstration projects, though uneconomically operated, have revealed engineering factors necessary for successful use of solar-derived heat for industrial applications. Areas of concern have been categorized as technology comparisons, load temperatures, plant size, location, end-use, backup requirements, and storage costs. Tax incentives have, however, supported home heating and not industrial uses, and government subsidies have historically gone to conventional energy sources. Tax credit programs which could lead to a 20% market penetration by solar energy in the industrial sector by the year 2000 are presented.

  15. Efficiency enhancement of perovskite solar cells using structural and morphological improvement of CH3NH3PbI3 absorber layers

    NASA Astrophysics Data System (ADS)

    Alidaei, Maryam; Izadifard, Morteza; Ghazi, Mohammad E.; Ahmadi, Vahid

    2018-01-01

    Perovskite solar cells have been heavily investigated due to their unique properties such as high power conversion efficiency (PCE), low-cost fabrication by solution processes, high diffusion length, large absorption coefficient, and direct and tunable band gap. PCE of perovskite devices is strongly dependent on the absorber layer properties such as morphology, crystallinity, and compactness, which are required to be optimized. In this work, the CH3NH3PbI3 (170-480 nm) absorber layers with various methylammonium iodine (MAI) concentrations (7, 10, 20 and 40 mg ml-1) and perovskite solar cells with the fluorine-doped tin oxide (400 nm)/C-TiO2 (30 nm)/Meso-TiO2 (400 nm)/CH3NH3PbI3 (170-480 nm)/P3HT (30 nm)/Au (100 nm) structure were fabricated. A two-step solution process was used for deposition of the CH3NH3PbI3 absorber layers. The morphology, crystal structure, and optical properties of the perovskite layer grown on glass and also the photovoltaic properties of the fabricated solar cells were studied. The results obtained showed that by controlling the deposition conditions, due to the reduction in charge recombination, PCE enhancement of the perovskite solar cell (up to 11.6%) was accessible.

  16. Solar Energy: Its Technologies and Applications

    DOE R&D Accomplishments Database

    Auh, P. C.

    1978-06-01

    Solar heat, as a potential source of clean energy, is available to all of us. Extensive R and D efforts are being made to effectively utilize this renewable energy source. A variety of different technologies for utilizing solar energy have been proven to be technically feasible. Here, some of the most promising technologies and their applications are briefly described. These are: Solar Heating and Cooling of Buildings (SHACOB), Solar Thermal Energy Conversion (STC), Wind Energy Conversion (WECS), Bioconversion to Fuels (BCF), Ocean Thermal Energy Conversion (OTEC), and Photovoltaic Electric Power Systems (PEPS). Special emphasis is placed on the discussion of the SHACOB technologies, since the technologies are being expeditiously developed for the near commercialization.

  17. Nanofluid Types, Their Synthesis, Properties and Incorporation in Direct Solar Thermal Collectors: A Review.

    PubMed

    Chamsa-Ard, Wisut; Brundavanam, Sridevi; Fung, Chun Che; Fawcett, Derek; Poinern, Gerrard

    2017-05-31

    The global demand for energy is increasing and the detrimental consequences of rising greenhouse gas emissions, global warming and environmental degradation present major challenges. Solar energy offers a clean and viable renewable energy source with the potential to alleviate the detrimental consequences normally associated with fossil fuel-based energy generation. However, there are two inherent problems associated with conventional solar thermal energy conversion systems. The first involves low thermal conductivity values of heat transfer fluids, and the second involves the poor optical properties of many absorbers and their coating. Hence, there is an imperative need to improve both thermal and optical properties of current solar conversion systems. Direct solar thermal absorption collectors incorporating a nanofluid offers the opportunity to achieve significant improvements in both optical and thermal performance. Since nanofluids offer much greater heat absorbing and heat transfer properties compared to traditional working fluids. The review summarizes current research in this innovative field. It discusses direct solar absorber collectors and methods for improving their performance. This is followed by a discussion of the various types of nanofluids available and the synthesis techniques used to manufacture them. In closing, a brief discussion of nanofluid property modelling is also presented.

  18. Modeling and Simulation of Turbulent Flows through a Solar Air Heater Having Square-Sectioned Transverse Rib Roughness on the Absorber Plate

    PubMed Central

    Yadav, Anil Singh; Bhagoria, J. L.

    2013-01-01

    Solar air heater is a type of heat exchanger which transforms solar radiation into heat energy. The thermal performance of conventional solar air heater has been found to be poor because of the low convective heat transfer coefficient from the absorber plate to the air. Use of artificial roughness on a surface is an effective technique to enhance the rate of heat transfer. A CFD-based investigation of turbulent flow through a solar air heater roughened with square-sectioned transverse rib roughness has been performed. Three different values of rib-pitch (P) and rib-height (e) have been taken such that the relative roughness pitch (P/e = 14.29) remains constant. The relative roughness height, e/D, varies from 0.021 to 0.06, and the Reynolds number, Re, varies from 3800 to 18,000. The results predicted by CFD show that the average heat transfer, average flow friction, and thermohydraulic performance parameter are strongly dependent on the relative roughness height. A maximum value of thermohydraulic performance parameter has been found to be 1.8 for the range of parameters investigated. Comparisons with previously published work have been performed and found to be in excellent agreement. PMID:24222752

  19. Modeling and simulation of turbulent flows through a solar air heater having square-sectioned transverse rib roughness on the absorber plate.

    PubMed

    Yadav, Anil Singh; Bhagoria, J L

    2013-01-01

    Solar air heater is a type of heat exchanger which transforms solar radiation into heat energy. The thermal performance of conventional solar air heater has been found to be poor because of the low convective heat transfer coefficient from the absorber plate to the air. Use of artificial roughness on a surface is an effective technique to enhance the rate of heat transfer. A CFD-based investigation of turbulent flow through a solar air heater roughened with square-sectioned transverse rib roughness has been performed. Three different values of rib-pitch (P) and rib-height (e) have been taken such that the relative roughness pitch (P/e = 14.29) remains constant. The relative roughness height, e/D, varies from 0.021 to 0.06, and the Reynolds number, Re, varies from 3800 to 18,000. The results predicted by CFD show that the average heat transfer, average flow friction, and thermohydraulic performance parameter are strongly dependent on the relative roughness height. A maximum value of thermohydraulic performance parameter has been found to be 1.8 for the range of parameters investigated. Comparisons with previously published work have been performed and found to be in excellent agreement.

  20. Solar Flares and the High Energy Solar Spectroscopic Imager (HESSI)

    NASA Technical Reports Server (NTRS)

    Holman, Gordon D.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    Solar flares are the biggest explosions in the solar system. They are important both for understanding explosive events in the Universe and for their impact on human technology and communications. The satellite-based HESSI is designed to study the explosive release of energy and the acceleration of electrons, protons, and other charged particles to high energies in solar flares. HESSI produces "color" movies of the Sun in high-energy X rays and gamma rays radiated by these energetic particles. HESSI's X-ray and gamma-ray images of flares are obtained using techniques similar to those used in radio interferometry. Ground-based radio observations of the Sun provide an important complement to the HESSI observations of solar flares. I will describe the HESSI Project and the high-energy aspects of solar flares, and how these relate to radio astronomy techniques and observations.

  1. The Energy Impacts of Solar Heating.

    ERIC Educational Resources Information Center

    Whipple, Chris

    1980-01-01

    The energy required to build and install solar space- and water-heating equipment is compared to the energy saved under two solar growth paths corresponding to high and low rates of solar technology implementation. (Author/RE)

  2. Solar applications analysis for energy storage

    NASA Technical Reports Server (NTRS)

    Blanchard, T.

    1980-01-01

    The role of energy storage as it relates to solar energy systems is considered. Storage technologies to support solar energy applications, the status of storage technologies, requirements and specifications for storage technologies, and the adequacy of the current storage research and development program to meet these requirements are among the factors discussed. Emphasis is placed on identification of where the greatest potential exists for energy storage in support of those solar energy systems which could have a significant impact on the U.S. energy mix.

  3. Effects of weld damage on the dynamics of energy-absorbing lanyards.

    PubMed

    Katona, David N; Bennett, Charlie R; McKoryk, Michael; Brisson, Andre L; Sparrey, Carolyn J

    2017-12-01

    Manufacturers recommend removing fall protection system components from service for any indication of weld spatter or tool damage; however, little is known about the specific effects of lanyard damage on fall arrest dynamics. Thirty-two energy-absorbing lanyards were drop tested after being damaged with weld spatter, plasma torches and cutting tools and compared with new, undamaged lanyards. Two lanyards damaged with a plasma torch failed completely without deploying the energy absorber while weld spatter damage and tool cuts, up to two-thirds through the width of the webbing, had no effect on fall arrest dynamics. The results highlight the catastrophic implications of high-temperature damage to lanyard webbing resulting from plasma torches - which require immediate removal from service. In addition, the integrated energy absorber design in bungee-style lanyards makes them more susceptible to damage anywhere along the length. We therefore recommended against bungee lanyards for ironworkers and welders.

  4. Non-tracking solar energy collector system

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K. (Inventor)

    1978-01-01

    A solar energy collector system is described characterized by an improved concentrator for directing incident rays of solar energy on parallel strip-like segments of a flatplate receiver. Individually mounted reflector modules of a common asymmetrical triangular cross-sectional configuration supported for independent orientation are asymmetric included with vee-trough concentrators for deflecting incident solar energy toward the receiver.

  5. Solar Energy in the Home. Revised.

    ERIC Educational Resources Information Center

    Roeder, Allen A.; Woodland, James A.

    Recommended for grades 10-12 physical, earth, or general science classes, this 5-7 day unit is designed to give students a general understanding of solar energy and its use as a viable alternative to present energy sources. Along with this technology, students examine several factors of solar energy which influence the choice of solar home site…

  6. Principles, efficiency, and blueprint character of solar-energy conversion in photosynthetic water oxidation.

    PubMed

    Dau, Holger; Zaharieva, Ivelina

    2009-12-21

    Photosynthesis in plants and cyanobacteria involves two protein-cofactor complexes which are denoted as photosystems (PS), PSII and PSI. These solar-energy converters have powered life on earth for approximately 3 billion years. They facilitate light-driven carbohydrate formation from H(2)O and CO(2), by oxidizing the former and reducing the latter. PSII splits water in a process driven by light. Because all attractive technologies for fuel production driven by solar energy involve water oxidation, recent interest in this process carried out by PSII has increased. In this Account, we describe and apply a rationale for estimating the solar-energy conversion efficiency (eta(SOLAR)) of PSII: the fraction of the incident solar energy absorbed by the antenna pigments and eventually stored in form of chemical products. For PSII at high concentrations, approximately 34% of the incident solar energy is used for creation of the photochemistry-driving excited state, P680*, with an excited-state energy of 1.83 eV. Subsequent electron transfer results in the reduction of a bound quinone (Q(A)) and oxidation of the Tyr(Z) within 1 micros. This radical-pair state is stable against recombination losses for approximately 1 ms. At this level, the maximal eta(SOLAR) is 23%. After the essentially irreversible steps of quinone reduction and water oxidation (the final steps catalyzed by the PSII complex), a maximum of 50% of the excited-state energy is stored in chemical form; eta(SOLAR) can be as high as 16%. Extending our considerations to a photosynthetic organism optimized to use PSII and PSI to drive H(2) production, the theoretical maximum of the solar-energy conversion efficiency would be as high as 10.5%, if all electrons and protons derived from water oxidation were used for H(2) formation. The above performance figures are impressive, but they represent theoretical maxima and do not account for processes in an intact organism that lower these yields, such as light saturation

  7. United States Department of Energy solar receiver technology development

    NASA Astrophysics Data System (ADS)

    Klimas, P. C.; Diver, R. B.; Chavez, J. M.

    The United States Department of Energy (DOE), through Sandia National Laboratories, has been conducting a Solar Thermal Receiver Technology Development Program, which maintains a balance between analytical modeling, bench and small scale testing, and experimentation conducted at scales representative of commercially-sized equipment. Central receiver activities emphasize molten salt-based systems on large scales and volumetric devices in the modeling and small scale testing. These receivers are expected to be utilized in solar power plants rated between 100 and 200 MW. Distributed receiver research focuses on liquid metal refluxing devices. These are intended to mate parabolic dish concentrators with Stirling cycle engines in the 5 to 25 kW(sub e) power range. The effort in the area of volumetric receivers is less intensive and highly cooperative in nature. A ceramic foam absorber of Sandia design was successfully tested on the 200 kW(sub t) test bed at Plataforma Solar during 1989. Material integrity during the approximately 90-test series was excellent. Significant progress has been made with parabolic dish concentrator-mounted receivers using liquid metals (sodium or a potassium/sodium mixture) as heat transport media. Sandia has successfully solar-tested a pool boiling reflux receiver sized to power a 25 kW Stirling engine. Boiling stability and transient operation were both excellent. This document describes these activities in detail and will outline plans for future development.

  8. Solar America: A Solar Energy Tour of the United States (CD-ROM)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    2001-12-01

    This CDROM contains nearly 500 photos and captions of solar energy technologies at work throughout the United States. Every state of the union is represented, as well as Puerto Rico, the U.S. Virgin Islands, the District of Columbia, and U.S. outposts in Antarctica. The technologies represented are photovoltaics, solar thermal, solar hot water, and concentrating solar power. The CD promotes solar energy as a wise energy choice for America's present and future.

  9. Improved power efficiency for very-high-temperature solar-thermal-cavity receivers

    DOEpatents

    McDougal, A.R.; Hale, R.R.

    1982-04-14

    This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positiond in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts radiation from the front of the absorber. With this arrangement, a high percentage of the solar power input is retained in the cavity; thus, high internal temperatues are attained.

  10. Solar Energy Educational Material, Activities and Science Projects

    Science.gov Websites

    ;The sun has produced energy for billions of years. Solar energy is the solar radiation that reaches Energy - Energy from the Sun DOE Documents with Activities/Projects: Web Pages Solar Energy Education , Part I. Energy, Society, and the Sun Solar Energy Education. Reader, Part II. Sun Story. [Includes

  11. Crush Can Behaviour as an Energy Absorber in a Frontal Impact

    NASA Astrophysics Data System (ADS)

    Bhuyan, Atanu; Ganilova, Olga

    2012-08-01

    The work presented is devoted to the investigation of a state-of-the-art technological solution for the design of a crush-can characterized by optimal energy absorbing properties. The work is focused on the theoretical background of the square tubes, circular tubes and inverbucktube performance under impact with the purpose of design of a novel optimized structure. The main system under consideration is based on the patent US 2008/0185851 A1 and includes a base flange with elongated crush boxes and back straps for stabilization of the crush boxes with the purpose of improvement of the energy-absorbing functionality. The modelling of this system is carried out applying both a theoretical approach and finite element analysis concentrating on the energy absorbing abilities of the crumple zones. The optimization process is validated under dynamic and quasi-static loading conditions whilst considering various modes of deformation and stress distribution along the tubular components. Energy absorbing behaviour of the crush-cans is studied concentrating on their geometrical properties and their diamond or concertina modes of deformation. Moreover, structures made of different materials, steel, aluminium and polymer composites are considered for the material effect analysis and optimization through their combination. Optimization of the crush-can behaviour is done within the limits of the frontal impact scenario with the purpose of improvement of the structural performance in the Euro NCAP tests.

  12. Basic Research Needs for Solar Energy Utilization. Report of the Basic Energy Sciences Workshop on Solar Energy Utilization, April 18-21, 2005

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lewis, N. S.; Crabtree, G.; Nozik, A. J.

    2005-04-21

    World demand for energy is projected to more than double by 2050 and to more than triple by the end of the century. Incremental improvements in existing energy networks will not be adequate to supply this demand in a sustainable way. Finding sufficient supplies of clean energy for the future is one of society?s most daunting challenges. Sunlight provides by far the largest of all carbon-neutral energy sources. More energy from sunlight strikes the Earth in one hour (4.3 ? 1020 J) than all the energy consumed on the planet in a year (4.1 ? 1020 J). We currently exploitmore » this solar resource through solar electricity ? a $7.5 billion industry growing at a rate of 35?40% per annum ? and solar-derived fuel from biomass, which provides the primary energy source for over a billion people. Yet, in 2001, solar electricity provided less than 0.1% of the world's electricity, and solar fuel from modern (sustainable) biomass provided less than 1.5% of the world's energy. The huge gap between our present use of solar energy and its enormous undeveloped potential defines a grand challenge in energy research. Sunlight is a compelling solution to our need for clean, abundant sources of energy in the future. It is readily available, secure from geopolitical tension, and poses no threat to our environment through pollution or to our climate through greenhouse gases. This report of the Basic Energy Sciences Workshop on Solar Energy Utilization identifies the key scientific challenges and research directions that will enable efficient and economic use of the solar resource to provide a significant fraction of global primary energy by the mid 21st century. The report reflects the collective output of the workshop attendees, which included 200 scientists representing academia, national laboratories, and industry in the United States and abroad, and the U.S. Department of Energy?s Office of Basic Energy Sciences and Office of Energy Efficiency and Renewable Energy.« less

  13. High flux solar energy transformation

    DOEpatents

    Winston, Roland; Gleckman, Philip L.; O'Gallagher, Joseph J.

    1991-04-09

    Disclosed are multi-stage systems for high flux transformation of solar energy allowing for uniform solar intensification by a factor of 60,000 suns or more. Preferred systems employ a focusing mirror as a primary concentrative device and a non-imaging concentrator as a secondary concentrative device with concentrative capacities of primary and secondary stages selected to provide for net solar flux intensification of greater than 2000 over 95 percent of the concentration area. Systems of the invention are readily applied as energy sources for laser pumping and in other photothermal energy utilization processes.

  14. Ply-tear webbing energy absorber

    NASA Technical Reports Server (NTRS)

    Stevens, G. W. H.

    1972-01-01

    Ply-tear webbing is essentially two plain webbings that are bound together by a portion of the warps and that can be torn apart and do work by breaking the binders. Nylon webbing were woven to range in tear force from 1 to 10 kilonewtons. This force is substantially independent of speed, which was as high as 100 m/sec in some cases. A specific energy absorption of 90 J/g was achieved in the dry state. However, lower rated webbings that absorb approximately 40 J/g are recommended for use in practice where it is acceptable.

  15. Online National Solar Energy Directory and 2005 Solar Decathlon Product Directory. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hamm, Julia; Taylor, Mike

    2008-12-31

    The Solar Electric Power Association (SEPA), in partnership with the American Solar Energy Society, developed an online National Solar Energy Directory with clear, comprehensive information on suppliers and purchasing options. The site was originally located at FindSolar.com, but has recently been moved to Find-Solar.org. The original FindSolar.com domain name has been taken by the American Solar Energy Society (a partner in this project) and utilized for a similar but different project. This Find-Solar.org directory offers the rapidly growing base of potential solar customers a simple, straightforward destination to learn about their solar options. Members of the public are able tomore » easily locate contractors in their geographic area and verify companies' qualifications with accurate third-party information. It allows consumers to obtain key information on the economics, incentives, desirability, and workings of a solar energy system, as well as competing quotes from different contractors and reviews from customers they have worked with previously. Find-Solar.org is a means of facilitating the growing public interest in solar power and overcoming a major barrier to widespread development of U.S. solar markets. In addition to the development of Find-Solar.org, SEPA developed a separate online product directory for the 2005 DOE Solar Decathlon to facilitate the communication of information about the energy efficiency and renewable energy products used in each university team's home.« less

  16. The possibility of developing hybrid PV/T solar system

    NASA Astrophysics Data System (ADS)

    Dobrnjac, M.; Zivkovic, P.; Babic, V.

    2017-05-01

    An alternative and cost-effective solution to developing integrated PV system is to use hybrid photovoltaic/thermal (PV/T) solar system. The temperature of PV modules increases due to the absorbed solar radiation that is not converted into electricity, causing a decrease in their efficiency. In hybrid PV/T solar systems the reduction of PV module temperature can be combined with a useful fluid heating. In this paper we present the possibility of developing a new hybrid PV/T solar system. Hybrid PV/T system can provide electrical and thermal energy, thus achieving a higher energy conversion rate of the absorbed solar radiation. We developed PV/T prototype consisted of commercial PV module and thermal panel with our original solution of aluminium absorber with special geometric shapes. The main advantages of our combined PV/T system are: removing of heat from the PV panel; extending the lifetime of photovoltaic cells; excess of the removing heat from PV part is used to heat the fluid in the thermal part of the panel; the possibility of using on the roof and facade constructions because less weight.

  17. Proposed electromagnetic wave energy converter

    NASA Technical Reports Server (NTRS)

    Bailey, R. L.

    1973-01-01

    Device converts wave energy into electric power through array of insulated absorber elements responsive to field of impinging electromagnetic radiation. Device could also serve as solar energy converter that is potentially less expensive and fragile than solar cells, yet substantially more efficient.

  18. Ultrafast Electron Dynamics in Solar Energy Conversion.

    PubMed

    Ponseca, Carlito S; Chábera, Pavel; Uhlig, Jens; Persson, Petter; Sundström, Villy

    2017-08-23

    Electrons are the workhorses of solar energy conversion. Conversion of the energy of light to electricity in photovoltaics, or to energy-rich molecules (solar fuel) through photocatalytic processes, invariably starts with photoinduced generation of energy-rich electrons. The harvesting of these electrons in practical devices rests on a series of electron transfer processes whose dynamics and efficiencies determine the function of materials and devices. To capture the energy of a photogenerated electron-hole pair in a solar cell material, charges of opposite sign have to be separated against electrostatic attractions, prevented from recombining and being transported through the active material to electrodes where they can be extracted. In photocatalytic solar fuel production, these electron processes are coupled to chemical reactions leading to storage of the energy of light in chemical bonds. With the focus on the ultrafast time scale, we here discuss the light-induced electron processes underlying the function of several molecular and hybrid materials currently under development for solar energy applications in dye or quantum dot-sensitized solar cells, polymer-fullerene polymer solar cells, organometal halide perovskite solar cells, and finally some photocatalytic systems.

  19. Solar-Terrestrial Coupling Evidenced by Periodic Behavior in Geomagnetic Indexes and the Infrared Energy Budget of the Thermosphere

    NASA Technical Reports Server (NTRS)

    Mlynczak, Martin G.; Martin-Torres, F. Javier; Mertens, Christopher J.; Marshall, B. Thomas; Thompson, R. Earl; Kozyra, Janet U.; Remsberg, Ellis E.; Gordley, Larry L.; Russell, James M.; Woods, Thomas

    2008-01-01

    We examine time series of the daily global power (W) radiated by carbon dioxide (at 15 microns) and by nitric oxide (at 5.3 microns) from the Earth s thermosphere between 100 km and 200 km altitude. Also examined is a time series of the daily absorbed solar ultraviolet power in the same altitude region in the wavelength span 0 to 175 nm. The infrared data are derived from the SABER instrument and the solar data are derived from the SEE instrument, both on the NASA TIMED satellite. The time series cover nearly 5 years from 2002 through 2006. The infrared and solar time series exhibit a decrease in radiated and absorbed power consistent with the declining phase of the current 11-year solar cycle. The infrared time series also exhibits high frequency variations that are not evident in the solar power time series. Spectral analysis shows a statistically significant 9-day periodicity in the infrared data but not in the solar data. A very strong 9-day periodicity is also found to exist in the time series of daily A(sub p) and K(sub p) geomagnetic indexes. These 9-day periodicities are linked to the recurrence of coronal holes on the Sun. These results demonstrate a direct coupling between the upper atmosphere of the Sun and the infrared energy budget of the thermosphere.

  20. Solar Energy Systems for Ohioan Residential Homeowners

    NASA Astrophysics Data System (ADS)

    Luckett, Rickey D.

    Dwindling nonrenewable energy resources and rising energy costs have forced the United States to develop alternative renewable energy sources. The United States' solar energy industry has seen an upsurge in recent years, and photovoltaic holds considerable promise as a renewable energy technology. The purpose of this case study was to explore homeowner's awareness of the benefits of solar energy. Disruptive-innovation theory was used to explore marketing strategies for conveying information to homeowners about access to new solar energy products and services. Twenty residential homeowners were interviewed face-to-face to explore (a) perceived benefits of solar energy in their county in Ohio, and (b) perceptions on the rationale behind the marketing strategy of solar energy systems sold for residential use. The study findings used inductive analyses and coding interpretation to explore the participants' responses that revealed 3 themes: the existence of environmental benefits for using solar energy systems, the expensive cost of equipment associated with government incentives, and the lack of marketing information that is available for consumer use. The implications for positive social change include the potential to enable corporate leaders, small business owners, and entrepreneurs to develop marketing strategies for renewable energy systems. These strategies may promote use of solar energy systems as a clean, renewable, and affordable alternative electricity energy source for the 21st century.

  1. Solar Energy Monitor In Space (SEMIS)

    NASA Technical Reports Server (NTRS)

    Thekaekara, M. P.

    1974-01-01

    Measurements made at high altitudes from aircraft have resulted in the establishment of standard values of the solar constant and extraterrestrial solar spectral irradiance. These standard values and other solar spectral curves are described. The problem of possible variations of the solar constant and solar spectrum and their influence on the earth-atmosphere system and weather related phenomena is examined. It is shown that the solar energy input parameters should be determined with considerably greater accuracy and precision than has been possible. An instrument package designed as a compact, low weight solar energy monitor in space (SEMIS) is described.

  2. A new laboratory-scale experimental facility for detailed aerothermal characterizations of volumetric absorbers

    NASA Astrophysics Data System (ADS)

    Gomez-Garcia, Fabrisio; Santiago, Sergio; Luque, Salvador; Romero, Manuel; Gonzalez-Aguilar, Jose

    2016-05-01

    This paper describes a new modular laboratory-scale experimental facility that was designed to conduct detailed aerothermal characterizations of volumetric absorbers for use in concentrating solar power plants. Absorbers are generally considered to be the element with the highest potential for efficiency gains in solar thermal energy systems. The configu-ration of volumetric absorbers enables concentrated solar radiation to penetrate deep into their solid structure, where it is progressively absorbed, prior to being transferred by convection to a working fluid flowing through the structure. Current design trends towards higher absorber outlet temperatures have led to the use of complex intricate geometries in novel ceramic and metallic elements to maximize the temperature deep inside the structure (thus reducing thermal emission losses at the front surface and increasing efficiency). Although numerical models simulate the conjugate heat transfer mechanisms along volumetric absorbers, they lack, in many cases, the accuracy that is required for precise aerothermal validations. The present work aims to aid this objective by the design, development, commissioning and operation of a new experimental facility which consists of a 7 kWe (1.2 kWth) high flux solar simulator, a radiation homogenizer, inlet and outlet collector modules and a working section that can accommodate volumetric absorbers up to 80 mm × 80 mm in cross-sectional area. Experimental measurements conducted in the facility include absorber solid temperature distributions along its depth, inlet and outlet air temperatures, air mass flow rate and pressure drop, incident radiative heat flux, and overall thermal efficiency. In addition, two windows allow for the direct visualization of the front and rear absorber surfaces, thus enabling full-coverage surface temperature measurements by thermal imaging cameras. This paper presents the results from the aerothermal characterization of a siliconized silicon

  3. Science Activities in Energy: Solar Energy II.

    ERIC Educational Resources Information Center

    Oak Ridge Associated Universities, TN.

    Included in this science activities energy package are 14 activities related to solar energy for secondary students. Each activity is outlined on a single card and is introduced by a question such as: (1) how much solar heat comes from the sun? or (2) how many times do you have to run water through a flat-plate collector to get a 10 degree rise in…

  4. TiAlN/TiAlON/Si{sub 3}N{sub 4} tandem absorber for high temperature solar selective applications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Barshilia, Harish C.; Selvakumar, N.; Rajam, K. S.

    2006-11-06

    A tandem absorber of TiAlN/TiAlON/Si{sub 3}N{sub 4} is prepared using a magnetron sputtering process. The graded composition of the individual component layers of the tandem absorber produces a film with a refractive index increasing from the surface to the substrate, which exhibits a high absorptance (0.95) and a low emittance (0.07). The tandem absorber is stable in air up to 600 deg. C for 2 h, indicating its importance for high temperature solar selective applications. The thermal stability of the tandem absorber is attributed to high oxidation resistance and microstructural stability of the component materials at higher temperatures.

  5. Reversible electron-hole separation in a hot carrier solar cell

    NASA Astrophysics Data System (ADS)

    Limpert, S.; Bremner, S.; Linke, H.

    2015-09-01

    Hot-carrier solar cells are envisioned to utilize energy filtering to extract power from photogenerated electron-hole pairs before they thermalize with the lattice, and thus potentially offer higher power conversion efficiency compared to conventional, single absorber solar cells. The efficiency of hot-carrier solar cells can be expected to strongly depend on the details of the energy filtering process, a relationship which to date has not been satisfactorily explored. Here, we establish the conditions under which electron-hole separation in hot-carrier solar cells can occur reversibly, that is, at maximum energy conversion efficiency. We thus focus our analysis on the internal operation of the hot-carrier solar cell itself, and in this work do not consider the photon-mediated coupling to the Sun. After deriving an expression for the voltage of a hot-carrier solar cell valid under conditions of both reversible and irreversible electrical operation, we identify separate contributions to the voltage from the thermoelectric effect and the photovoltaic effect. We find that, under specific conditions, the energy conversion efficiency of a hot-carrier solar cell can exceed the Carnot limit set by the intra-device temperature gradient alone, due to the additional contribution of the quasi-Fermi level splitting in the absorber. We also establish that the open-circuit voltage of a hot-carrier solar cell is not limited by the band gap of the absorber, due to the additional thermoelectric contribution to the voltage. Additionally, we find that a hot-carrier solar cell can be operated in reverse as a thermally driven solid-state light emitter. Our results help explore the fundamental limitations of hot-carrier solar cells, and provide a first step towards providing experimentalists with a guide to the optimal configuration of devices.

  6. IPR 1.0: an efficient method for calculating solar radiation absorbed by individual plants in sparse heterogeneous woody plant communities

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Chen, W.; Li, J.

    2014-07-01

    Climate change may alter the spatial distribution, composition, structure and functions of plant communities. Transitional zones between biomes, or ecotones, are particularly sensitive to climate change. Ecotones are usually heterogeneous with sparse trees. The dynamics of ecotones are mainly determined by the growth and competition of individual plants in the communities. Therefore it is necessary to calculate the solar radiation absorbed by individual plants in order to understand and predict their responses to climate change. In this study, we developed an individual plant radiation model, IPR (version 1.0), to calculate solar radiation absorbed by individual plants in sparse heterogeneous woody plant communities. The model is developed based on geometrical optical relationships assuming that crowns of woody plants are rectangular boxes with uniform leaf area density. The model calculates the fractions of sunlit and shaded leaf classes and the solar radiation absorbed by each class, including direct radiation from the sun, diffuse radiation from the sky, and scattered radiation from the plant community. The solar radiation received on the ground is also calculated. We tested the model by comparing with the results of random distribution of plants. The tests show that the model results are very close to the averages of the random distributions. This model is efficient in computation, and can be included in vegetation models to simulate long-term transient responses of plant communities to climate change. The code and a user's manual are provided as Supplement of the paper.

  7. Solar power conversion system with directionally- and spectrally-selective properties based on a reflective cavity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Boriskina, Svetlana; Kraemer, Daniel; McEnaney, Kenneth

    Solar power conversion system. The system includes a cavity formed within an enclosure having highly specularly reflecting in the IR spectrum inside walls, the enclosure having an opening to receive solar radiation. An absorber is positioned within the cavity for receiving the solar radiation resulting in heating of the absorber structure. In a preferred embodiment, the system further contains an energy conversion and storage devices thermally-linked to the absorber by heat conduction, convection, far-field or near-field thermal radiation.

  8. Publications | Concentrating Solar Power | NREL

    Science.gov Websites

    -including technical reports, journal articles, and conference papers-about its research and development (R Block and Balance of Plant R&D Supercritical CO2 Water Cooling Wet Dry Solar Field R&D Reflector Absorber Receivers Durability Solar field Thermal Energy Storage and Heat Transfer Fluids R&D Storage

  9. Solar energy to meet the nation's energy needs

    NASA Technical Reports Server (NTRS)

    Rom, F. E.; Thomas, R. L.

    1973-01-01

    Solar energy, being a non-depleting clean source of energy, is shown to be capable of providing energy in all the forms in which it is used today. It can be used to generate electricity, for heating and cooling buildings, and for producing clean renewable gaseous, liquid and solid fuel. There is little question of the technical feasibility for utilizing solar energy. The chief problem is rapidly providing innovative solutions that are economically competititive with other systems.

  10. Activities for Teaching Solar Energy.

    ERIC Educational Resources Information Center

    Mason, Jack Lee; Cantrell, Joseph S.

    1980-01-01

    Plans and activities are suggested for teaching elementary children about solar energy. Directions are included for constructing a flat plate collector and a solar oven. Activities for a solar field day are given. (SA)

  11. The Global Energy Balance of Titan

    NASA Technical Reports Server (NTRS)

    Li, Liming; Nixon, Conor A.; Achterberg, Richard K.; Smith, Mark A.; Gorius, Nicolas J. P.; Jiang, Xun; Conrath, Barney J.; Gierasch, Peter J.; Simon-Miller, Amy A.; Flasar, F. Michael; hide

    2011-01-01

    We report the first measurement of the global emitted power of Titan. Longterm (2004-2010) observations conducted by the Composite Infrared Spectrometer (CIRS) onboard Cassini reveal that the total emitted power by Titan is (2.84 plus or minus 0.01) x 10(exp 8) watts. Together with previous measurements of the global absorbed solar power of Titan, the CIRS measurements indicate that the global energy budget of Titan is in equilibrium within measurement error. The uncertainty in the absorbed solar energy places an upper limit on the energy imbalance of 5.3%.

  12. High flux solar energy transformation

    DOEpatents

    Winston, R.; Gleckman, P.L.; O'Gallagher, J.J.

    1991-04-09

    Disclosed are multi-stage systems for high flux transformation of solar energy allowing for uniform solar intensification by a factor of 60,000 suns or more. Preferred systems employ a focusing mirror as a primary concentrative device and a non-imaging concentrator as a secondary concentrative device with concentrative capacities of primary and secondary stages selected to provide for net solar flux intensification of greater than 2000 over 95 percent of the concentration area. Systems of the invention are readily applied as energy sources for laser pumping and in other photothermal energy utilization processes. 7 figures.

  13. Immersible solar heater for fluids

    DOEpatents

    Kronberg, James W.

    1995-01-01

    An immersible solar heater comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater.

  14. Solar Energy

    ERIC Educational Resources Information Center

    Building Design and Construction, 1977

    1977-01-01

    Describes 21 completed projects now using solar energy for heating, cooling, or electricity. Included are elementary schools in Atlanta and San Diego, a technical school in Detroit, and Trinity University in San Antonio, Texas. (MLF)

  15. Solar flare particles - Energy-dependent composition and relationship to solar composition

    NASA Technical Reports Server (NTRS)

    Crawford, H. J.; Price, P. B.; Cartwright, B. G.; Sullivan, J. D.

    1975-01-01

    Plastic and glass track detectors on rockets and Apollo spacecraft have been used to determine the composition of particles from He to Ni at energies from 0.1 to 50 MeV per nucleon in several solar flares of widely varying intensities. At low energies the composition of solar particles is enriched in heavy elements by an amount, relative to the asymptotic high-energy composition, that increases with atomic number from Z = 2 up to at least Z = 50, that decreases with energy, and that varies from flare to flare. At high energies (usually beyond an energy of 5 to 20 MeV per nucleon) the composition becomes independent of energy and, though somewhat variable from flare to flare, approximates the composition of the solar atmosphere. A table of abundances of the even-Z elements from He to Ni (plus N) in solar particles is constructed by averaging the asymptotic high-energy abundances in several flares.

  16. Nanofluid Types, Their Synthesis, Properties and Incorporation in Direct Solar Thermal Collectors: A Review

    PubMed Central

    Chamsa-ard, Wisut; Brundavanam, Sridevi; Fung, Chun Che; Fawcett, Derek; Poinern, Gerrard

    2017-01-01

    The global demand for energy is increasing and the detrimental consequences of rising greenhouse gas emissions, global warming and environmental degradation present major challenges. Solar energy offers a clean and viable renewable energy source with the potential to alleviate the detrimental consequences normally associated with fossil fuel-based energy generation. However, there are two inherent problems associated with conventional solar thermal energy conversion systems. The first involves low thermal conductivity values of heat transfer fluids, and the second involves the poor optical properties of many absorbers and their coating. Hence, there is an imperative need to improve both thermal and optical properties of current solar conversion systems. Direct solar thermal absorption collectors incorporating a nanofluid offers the opportunity to achieve significant improvements in both optical and thermal performance. Since nanofluids offer much greater heat absorbing and heat transfer properties compared to traditional working fluids. The review summarizes current research in this innovative field. It discusses direct solar absorber collectors and methods for improving their performance. This is followed by a discussion of the various types of nanofluids available and the synthesis techniques used to manufacture them. In closing, a brief discussion of nanofluid property modelling is also presented. PMID:28561802

  17. Solar energy innovation and Silicon Valley

    NASA Astrophysics Data System (ADS)

    Kammen, Daniel M.

    2015-03-01

    The growth of the U. S. and global solar energy industry depends on a strong relationship between science and engineering innovation, manufacturing, and cycles of policy design and advancement. The mixture of the academic and industrial engine of innovation that is Silicon Valley, and the strong suite of environmental policies for which California is a leader work together to both drive the solar energy industry, and keep Silicon Valley competitive as China, Europe and other area of solar energy strength continue to build their clean energy sectors.

  18. Design of a Conceptual Bumper Energy Absorber Coupling Pedestrian Safety and Low-Speed Impact Requirements

    PubMed Central

    Mo, Fuhao; Zhao, Siqi; Yu, Chuanhui; Duan, Shuyong

    2018-01-01

    The car front bumper system needs to meet the requirements of both pedestrian safety and low-speed impact which are somewhat contradicting. This study aims to design a new kind of modular self-adaptive energy absorber of the front bumper system which can balance the two performances. The X-shaped energy-absorbing structure was proposed which can enhance the energy absorption capacity during impact by changing its deformation mode based on the amount of external collision energy. Then, finite element simulations with a realistic vehicle bumper system are performed to demonstrate its crashworthiness in comparison with the traditional foam energy absorber, which presents a significant improvement of the two performances. Furthermore, the structural parameters of the X-shaped energy-absorbing structure including thickness (t u), side arc radius (R), and clamping boost beam thickness (t b) are analyzed using a full factorial method, and a multiobjective optimization is implemented regarding evaluation indexes of both pedestrian safety and low-speed impact. The optimal parameters are then verified, and the feasibility of the optimal results is confirmed. In conclusion, the new X-shaped energy absorber can meet both pedestrian safety and low-speed impact requirements well by altering the main deformation modes according to different impact energy levels. PMID:29581728

  19. Design of a Conceptual Bumper Energy Absorber Coupling Pedestrian Safety and Low-Speed Impact Requirements.

    PubMed

    Mo, Fuhao; Zhao, Siqi; Yu, Chuanhui; Xiao, Zhi; Duan, Shuyong

    2018-01-01

    The car front bumper system needs to meet the requirements of both pedestrian safety and low-speed impact which are somewhat contradicting. This study aims to design a new kind of modular self-adaptive energy absorber of the front bumper system which can balance the two performances. The X-shaped energy-absorbing structure was proposed which can enhance the energy absorption capacity during impact by changing its deformation mode based on the amount of external collision energy. Then, finite element simulations with a realistic vehicle bumper system are performed to demonstrate its crashworthiness in comparison with the traditional foam energy absorber, which presents a significant improvement of the two performances. Furthermore, the structural parameters of the X-shaped energy-absorbing structure including thickness ( t u ), side arc radius ( R ), and clamping boost beam thickness ( t b ) are analyzed using a full factorial method, and a multiobjective optimization is implemented regarding evaluation indexes of both pedestrian safety and low-speed impact. The optimal parameters are then verified, and the feasibility of the optimal results is confirmed. In conclusion, the new X-shaped energy absorber can meet both pedestrian safety and low-speed impact requirements well by altering the main deformation modes according to different impact energy levels.

  20. Solar energy in the context of energy use, energy transportation and energy storage.

    PubMed

    MacKay, David J C

    2013-08-13

    Taking the UK as a case study, this paper describes current energy use and a range of sustainable energy options for the future, including solar power and other renewables. I focus on the area involved in collecting, converting and delivering sustainable energy, looking in particular detail at the potential role of solar power. Britain consumes energy at a rate of about 5000 watts per person, and its population density is about 250 people per square kilometre. If we multiply the per capita energy consumption by the population density, then we obtain the average primary energy consumption per unit area, which for the UK is 1.25 watts per square metre. This areal power density is uncomfortably similar to the average power density that could be supplied by many renewables: the gravitational potential energy of rainfall in the Scottish highlands has a raw power per unit area of roughly 0.24 watts per square metre; energy crops in Europe deliver about 0.5 watts per square metre; wind farms deliver roughly 2.5 watts per square metre; solar photovoltaic farms in Bavaria, Germany, and Vermont, USA, deliver 4 watts per square metre; in sunnier locations, solar photovoltaic farms can deliver 10 watts per square metre; concentrating solar power stations in deserts might deliver 20 watts per square metre. In a decarbonized world that is renewable-powered, the land area required to maintain today's British energy consumption would have to be similar to the area of Britain. Several other high-density, high-consuming countries are in the same boat as Britain, and many other countries are rushing to join us. Decarbonizing such countries will only be possible through some combination of the following options: the embracing of country-sized renewable power-generation facilities; large-scale energy imports from country-sized renewable facilities in other countries; population reduction; radical efficiency improvements and lifestyle changes; and the growth of non-renewable low

  1. Solar Energy Systems

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A waste water treatment plant in Wilton, Maine, where sludge is converted to methane gas, and Monsanto Company's Environmental Health Laboratory in St. Louis Missouri, where more than 200 solar collectors provide preheating of boiler feed water for laboratory use are representative of Grumman's Sunstream line of solar energy equipment. This equipment was developed with technology from NASA's Apollo lunar module program.

  2. Correlation of energy disorder and open-circuit voltage in hybrid perovskite solar cells

    DOE PAGES

    Shao, Yuchuan; Yuan, Yongbo; Huang, Jinsong

    2016-01-11

    Organometal trihalide perovskites have been demonstrated as excellent light absorbers for high efficiency photovoltaic applications. Previous approaches to increasing the solar cell efficiency have focussed on optimisation of the grain morphology of perovskite thin films. Here, we show that the structural order of the electron-transport layers also has a significant impact on solar cell performance. We demonstrate that the power conversion efficiency of CH 3NH 3PbI 3 planar-heterojunction photovoltaic cells increases from 17.1% to 19.4% when the energy disorder in the fullerene electron-transport layer is reduced by a simple solvent annealing process. The increase in efficiency is the result ofmore » the enhancement in open-circuit voltage from 1.04 V to 1.13 V without sacrificing the short-circuit current and fill factor. Finally, these results shed light on the origin of open-circuit voltage in perovskite solar cells, and provide a new path to further increase their efficiency« less

  3. Environmental Co-Benefit Opportunities of Solar Energy

    NASA Astrophysics Data System (ADS)

    Hernandez, R. R.; Armstrong, A.; Burney, J. A.; Easter, S. B.; Hoffacker, M. K.; Moore, K. A.

    2015-12-01

    Solar energy reduces greenhouse gas emissions by an order of magnitude when substituted for fossil fuels. Nonetheless, the strategic deployment of solar energy—from single, rooftop modules to utility-scale solar energy power plants—can confer additional environmental co-benefits beyond its immediate use as a low carbon energy source. In this study, we identify a diverse portfolio of environmental co-benefit opportunities of solar energy technologies resulting from synergistic innovations in land, food, energy, and water systems. For each opportunity, we provide a demonstrative, quantitative framework for environmental co-benefit valuation—including, equations, models, or case studies for estimating carbon dioxide equivalent (CO2-eq) and cost savings ($US) averted by environmental co-benefit opportunities of solar energy—and imminent research questions to improve certainty of valuations. As land-energy-food-water nexus issues are increasingly exigent in 21st century, we show that environmental co-benefit opportunities of solar energy are feasible in numerous environments and at a wide range of spatial scales thereby able to contribute to local and regional environmental goals and for the mitigation of climate change.

  4. Surface meteorology and Solar Energy

    NASA Technical Reports Server (NTRS)

    Stackhouse, Paul W. (Principal Investigator)

    The Release 5.1 Surface meteorology and Solar Energy (SSE) data contains parameters formulated for assessing and designing renewable energy systems. Parameters fall under 11 categories including: Solar cooking, solar thermal applications, solar geometry, tilted solar panels, energy storage systems, surplus product storage systems, cloud information, temperature, wind, other meteorological factors, and supporting information. This latest release contains new parameters based on recommendations by the renewable energy industry and it is more accurate than previous releases. On-line plotting capabilities allow quick evaluation of potential renewable energy projects for any region of the world. The SSE data set is formulated from NASA satellite- and reanalysis-derived insolation and meteorological data for the 10-year period July 1983 through June 1993. Results are provided for 1 degree latitude by 1 degree longitude grid cells over the globe. Average daily and monthly measurements for 1195 World Radiation Data Centre ground sites are also available. [Mission Objectives] The SSE project contains insolation and meteorology data intended to aid in the development of renewable energy systems. Collaboration between SSE and technology industries such as the Hybrid Optimization Model for Electric Renewables ( HOMER ) may aid in designing electric power systems that employ some combination of wind turbines, photovoltaic panels, or diesel generators to produce electricity. [Temporal_Coverage: Start_Date=1983-07-01; Stop_Date=1993-06-30] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180].

  5. 24 CFR 203.18a - Solar energy system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 2 2013-04-01 2013-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by up... to the installation of a solar energy system. (b) Solar energy system is defined as any addition...

  6. 24 CFR 203.18a - Solar energy system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 2 2014-04-01 2014-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by up... to the installation of a solar energy system. (b) Solar energy system is defined as any addition...

  7. 24 CFR 203.18a - Solar energy system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 2 2012-04-01 2012-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by up... to the installation of a solar energy system. (b) Solar energy system is defined as any addition...

  8. 24 CFR 203.18a - Solar energy system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by up... to the installation of a solar energy system. (b) Solar energy system is defined as any addition...

  9. 24 CFR 203.18a - Solar energy system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by up... to the installation of a solar energy system. (b) Solar energy system is defined as any addition...

  10. Solar cooling in Madrid: Available solar energy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Izquierdo, M.; Hernandez, F.; Martin, E.

    1994-11-01

    This paper analyzes the behaviour of an absorption chiller lithium bromide installation fed by a field of flat-plate solar collectors and condensed by swimming pool water. A method of calculation in a variable regime is developed in terms of the obtained experimental results. Starting from the meteorological variables of a clear summer day and from the project data (collector normalization curve, collector and installation mass), the minimum solar radiation level necessary to initiate the process, I[sub min], and the instantaneous available solar energy, Q[sub u] + W[sub 1] is determined. The solar radiation threshold, I[sub min], necessary to obtain themore » process temperature, t[sub ave], in each instant, is obtained by adding to the corrected Klein radiation threshold, I[sub k,c], the heat capacity effects of the collector, HCE[sub CO], and of the installation, HCE[sub ins], as well as the losses of heat of the pipes to the surroundings, Q[sub 1]. The instantaneous available solar energy, available useful heat, in addition to the wind collector losses to the surroundings, Q[sub u] + W[sub 1], is the difference, in each instant, between the radiation, I[sub g1T], and the radiation threshold, I[sub min].The integration during the day of the instantaneous available solar energy allows us to calculate the daily available function, H[sub T]. The value of H[sub T], measured in the swimming-pool water condensation installation reached 6.92 MJ/(m[sup 2] day ). The calculated values of H[sub T] for a conventional installation condensed by tower water, or air, have been 6.35 and 0.56 MJ/(m[sup 2] day). respectively.« less

  11. Organometallic photovoltaics: a new and versatile approach for harvesting solar energy using conjugated polymetallaynes.

    PubMed

    Wong, Wai-Yeung; Ho, Cheuk-Lam

    2010-09-21

    Energy remains one of the world's great challenges. Growing concerns about limited fossil fuel resources and the accumulation of CO(2) in the atmosphere from burning those fuels have stimulated tremendous academic and industrial interest. Researchers are focusing both on developing inexpensive renewable energy resources and on improving the technologies for energy conversion. Solar energy has the capacity to meet increasing global energy needs. Harvesting energy directly from sunlight using photovoltaic technology significantly reduces atmospheric emissions, avoiding the detrimental effects of these gases on the environment. Currently inorganic semiconductors dominate the solar cell production market, but these materials require high technology production and expensive materials, making electricity produced in this manner too costly to compete with conventional sources of electricity. Researchers have successfully fabricated efficient organic-based polymer solar cells (PSCs) as a lower cost alternative. Recently, metalated conjugated polymers have shown exceptional promise as donor materials in bulk-heterojunction solar cells and are emerging as viable alternatives to the all-organic congeners currently in use. Among these metalated conjugated polymers, soluble platinum(II)-containing poly(arylene ethynylene)s of variable bandgaps (∼1.4-3.0 eV) represent attractive candidates for a cost-effective, lightweight solar-energy conversion platform. This Account highlights and discusses the recent advances of this research frontier in organometallic photovoltaics. The emerging use of low-bandgap soluble platinum-acetylide polymers in PSCs offers a new and versatile strategy to capture sunlight for efficient solar power generation. Properties of these polyplatinynes--including their chemical structures, absorption coefficients, bandgaps, charge mobilities, accessibility of triplet excitons, molecular weights, and blend film morphologies--critically influence the device

  12. Energy-Absorbing Beam Member

    NASA Technical Reports Server (NTRS)

    Littell, Justin D. (Inventor)

    2017-01-01

    An energy-absorbing (EA) beam member and having a cell core structure is positioned in an aircraft fuselage proximate to the floor of the aircraft. The cell core structure has a length oriented along a width of the fuselage, a width oriented along a length of the fuselage, and a depth extending away from the floor. The cell core structure also includes cell walls that collectively define a repeating conusoidal pattern of alternating respective larger and smaller first and second radii along the length of the cell core structure. The cell walls slope away from a direction of flight of the aircraft at a calibrated lean angle. An EA beam member may include the cell core structure and first and second plates along the length of the cell core structure on opposite edges of the cell material.

  13. Simple Experiments on the Use of Solar Energy

    ERIC Educational Resources Information Center

    Vella, G. J.; Goldsmid, H. J.

    1976-01-01

    Describes 5 solar energy experiments that can be used in secondary school: flat-plate collector, solar thermoelectric generator, simple concentrators, solar cell, and natural storage of solar energy. (MLH)

  14. Solar Energy Employment and Requirements, 1978-1985.

    ERIC Educational Resources Information Center

    Levy, Girard W.; Field, Jennifer

    Based on data collected from a mailed survey of 2800 employers engaged in solar energy activities, a study identified the characteristics of establishments engaged in solar work and the number and occupational distribution of persons working in solar energy activities in 1978, and projected solar labor requirements through 1983. The scope of the…

  15. Solar Energy - It's Growth, Development, and Use

    Science.gov Websites

    Report, June 1978 Solar Energy and Your Home: Questions and Answers, DOE Technical Report, January 1984 Solar Air Collectors: How Much Can You Save?, DOE Technical Report, April 1985 Building Design Guidelines for Solar Energy Technologies, DOE Technical Report, January 1989 OUT Success Stories: Solar

  16. Solar pond

    NASA Technical Reports Server (NTRS)

    Miller, C. G.; Stephens, J. B. (Inventor)

    1978-01-01

    Shallow pools of liquid to collect low-temperature solar generated thermal energy are described. Narrow elongated trenches, grouped together over a wide area, are lined with a heat-absorbing black liner. The heat-absorbing liquid is kept separate from the thermal energy removing fluid by means such as clear polyethylene material. The covering for the pond may be a fluid or solid. If the covering is a fluid, fire fighting foam, continuously generated, or siloons are used to keep the surface covering clean and insulated. If the thermal energy removing fluid is a gas, a fluid insulation layer contained in a flat polyethlene tubing is used to cover the pond. The side of the tube directed towards the sun is treated to block out ultraviolet radiation and trap in infrared radiation.

  17. The HESP (High Energy Solar Physics) project

    NASA Technical Reports Server (NTRS)

    Kai, K.

    1986-01-01

    A project for space observations of solar flares for the coming solar maximum phase is briefly described. The main objective is to make a comprehensive study of high energy phenomena of flares through simultaneous imagings in both hard and soft X-rays. The project will be performed with collaboration from US scientists. The HESP (High Energy Solar Physics) WG of ISAS (Institute of Space and Astronautical Sciences) has extensively discussed future aspects of space observations of high energy phenomena of solar flares based on successful results of the Hinotori mission, and proposed a comprehensive research program for the next solar maximum, called the HESP (SOLAR-A) project. The objective of the HESP project is to make a comprehensive study of both high energy phenomena of flares and quiet structures including pre-flare states, which have been left uncovered by SMM and Hinotori. For such a study simultaneous imagings with better resolutions in space and time in a wide range of energy will be extremely important.

  18. Solar energy for electricity and fuels.

    PubMed

    Inganäs, Olle; Sundström, Villy

    2016-01-01

    Solar energy conversion into electricity by photovoltaic modules is now a mature technology. We discuss the need for materials and device developments using conventional silicon and other materials, pointing to the need to use scalable materials and to reduce the energy payback time. Storage of solar energy can be achieved using the energy of light to produce a fuel. We discuss how this can be achieved in a direct process mimicking the photosynthetic processes, using synthetic organic, inorganic, or hybrid materials for light collection and catalysis. We also briefly discuss challenges and needs for large-scale implementation of direct solar fuel technologies.

  19. Spectral sensitization of nanocrystalline solar cells

    DOEpatents

    Spitler, Mark T.; Ehret, Anne; Stuhl, Louis S.

    2002-01-01

    This invention relates to dye sensitized polycrystalline photoelectrochemical solar cells for use in energy transduction from light to electricity. It concerns the utility of highly absorbing organic chromophores as sensitizers in such cells and the degree to which they may be utilized alone and in combination to produce an efficient photoelectrochemical cell, e.g., a regenerative solar cell.

  20. Solar Energy and the Western Asian Countries

    NASA Astrophysics Data System (ADS)

    De Morais Mendonca Teles, Antonio

    2016-07-01

    The Western Asian countries receive the most abundant solar radiation of the world. They also have enormous reserves of oil and natural gas. But the world reserves of those fuels will certainly diminish greatly as the worldwide demand for energy will increase steadily in the coming decades. And the suppliers of energy will have to contend with public concerns about the polluting effects of those fuels and the possible dangers of nuclear energy. Clearly a power source based on an non exhaustible and non-polluting fuel could be expected to find a role. It now appears that such a source is at hand in the solar energy. Here in this paper, under the principles in the United Nations' Agenda 21, we suggest to Western Asian countries, the study and own development of the following technologies based on solar energy; and comment about them: *photo-voltaic solar cell power plants - in the future, its cost per kilowatt-hour will probably be competitive as to other sources of electrical energy. A new technique, the solar non-imaging concentrator, with amorphous silicon-based thin films solar cells at the focus of the concentrators, can collect and intensify solar radiation far better than conventional concentrators do, thus reducing much more the cost; *bio-gas - using biological gas to produce energy and for heating/cooling purposes; *wind generation of electricity - it's nowadays, a non-expensive technique; *water pump for irrigation and human consuming, driving their power from photovoltaic cells; *and the study and own development of solar lasers for peaceful scientific studies. In this new kind of laser, the external necessary pumping energy comes from the high intensity of sunlight, produced with non-imaging concentrators. Solar lasers can give unexpected new great uses for mankind. Those achievements will require international cooperation and transfer of information, sustained research and development work, and some initial subsides by independent governments. Solar

  1. Black Liquid Solar Collector Demonstrator.

    ERIC Educational Resources Information Center

    Weichman, F. L.; Austen, D. J.

    1979-01-01

    Describes the details of constructing, and use of, a solar collector. Uses a black liquid to absorb the energy, the thermosyphon effect to drive the liquid through the collector, and a floodlamp as a surrogate sun. (GA)

  2. Solar steam generation by heat localization.

    PubMed

    Ghasemi, Hadi; Ni, George; Marconnet, Amy Marie; Loomis, James; Yerci, Selcuk; Miljkovic, Nenad; Chen, Gang

    2014-07-21

    Currently, steam generation using solar energy is based on heating bulk liquid to high temperatures. This approach requires either costly high optical concentrations leading to heat loss by the hot bulk liquid and heated surfaces or vacuum. New solar receiver concepts such as porous volumetric receivers or nanofluids have been proposed to decrease these losses. Here we report development of an approach and corresponding material structure for solar steam generation while maintaining low optical concentration and keeping the bulk liquid at low temperature with no vacuum. We achieve solar thermal efficiency up to 85% at only 10 kW m(-2). This high performance results from four structure characteristics: absorbing in the solar spectrum, thermally insulating, hydrophilic and interconnected pores. The structure concentrates thermal energy and fluid flow where needed for phase change and minimizes dissipated energy. This new structure provides a novel approach to harvesting solar energy for a broad range of phase-change applications.

  3. Impedance matched thin metamaterials make metals absorbing.

    PubMed

    Mattiucci, N; Bloemer, M J; Aközbek, N; D'Aguanno, G

    2013-11-13

    Metals are generally considered good reflectors over the entire electromagnetic spectrum up to their plasma frequency. Here we demonstrate an approach to tailor their absorbing characteristics based on the effective metamaterial properties of thin, periodic metallo-dielectric multilayers by exploiting a broadband, inherently non-resonant, surface impedance matching mechanism. Based on this mechanism, we design, fabricate and test omnidirectional, thin (<1 micron), polarization independent, extremely efficient absorbers (in principle being capable to reach A > 99%) over a frequency range spanning from the UV to the IR. Our approach opens new venues to design cost effective materials for many applications such as thermo-photovoltaic energy conversion devices, light harvesting for solar cells, flat panel display, infrared detectors, stray light reduction, stealth and others.

  4. Impact of natural photosensitizer extraction solvent upon light absorbance in dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Suhaimi, Suriati; Mohamed Siddick, Siti Zubaidah; Ahmad Hambali, Nor Azura Malini; Retnasamy, Vithyacharan; Abdul Wahid, Mohamad Halim; Mohamad Shahimin, Mukhzeer

    2017-02-01

    Natural pigmentations of Ardisia, Bawang Sabrang, Harum Manis mango, Oxalis Triangularis and Rosella were used to study the general trend in performance of dyes as a photosensitizer in the application of dye-sensitized solar cells (DSSCs) based on optical light absorbance and photoelectrochemical characteristics. From the Ultraviolet-Visible Spectrophotometer with the recorded absorption measurements in the range between 400 nm to 800 nm, the dyes extracted from Rosella and Oxalis Triangularis in water solvent exhibited the conversion efficiency up to 0.68% and 0.67%, respectively. The light absorbance peak for dye extracted from Ardisia, Bawang Sabrang, Oxalis Triangularis and Rosella in water and ethanol solvent resulted in the range between 500 nm to 650 nm, while the Harum Manis mango resulted in the broader spectra in both water and ethanol solvent. The light absorbance spectra of each the dyes shows shifted wavelength spectrum when the extracted dye is adsorbed onto TiO2 film surface that might influenced the absorption of light by TiO2 particle in the visible region. The capabilities of the dyes to absorb light when bonded onto the TiO2 photoanode was found to be significant with the current-voltage conversion of the cell. The results demonstrates just the tip of the vastness of natural dyes' (native to tropical region) feasibility and applicability as a photosensitizer.

  5. High performance and thermally stable tandem solar selective absorber coating for concentrated solar thermal power (CSP) application

    NASA Astrophysics Data System (ADS)

    Prasad, M. Shiva; Kumar, K. K. Phani; Atchuta, S. R.; Sobha, B.; Sakthivel, S.

    2018-05-01

    A novel tandem absorber system (Mn-Cu-Co-Ox-ZrO2/SiO2) developed on an austenitic stainless steel (SS-304) substrate to show an excellent optical performance (αsol: 0.96; ɛ: 0.23@500 °C). In order to achieve this durable tandem, we experimented with two antireflective layers such as ZrO2-SiO2 and nano SiO2 layer on top of Mn-Cu-Co-Ox-ZrO2 layer. We optimized the thickness of antireflective layers to get good tandem system in terms of solar absorptance and emittance. Field emission scanning electron microscopy (FESEM), UV-Vis-NIR and Fourier transform infrared spectroscopy (FTIR) were used to characterize the developed coatings. Finally, the Mn-Cu-Co-Ox-ZrO2/SiO2 exhibits high temperature resistance up to 800 °C, thus allow an increase in the operating temperature of CSP which may lead to high efficiency. We successfully developed a high temperature resistant tandem layer with easy manufacturability at low cost which is an attractive candidate for concentrated solar power generation (CSP).

  6. Kinetic-energy absorber employs frictional force between mating cylinders

    NASA Technical Reports Server (NTRS)

    Conrad, E. W.

    1964-01-01

    A kinetic energy absorbing device uses a series of coaxial, mating cylindrical surfaces. These surfaces have high frictional resistance to relative motion when axial impact forces are applied. The device is designed for safe deceleration of vehicles impacting on landing surfaces.

  7. Immersible solar heater for fluids

    DOEpatents

    Hazen, T.C.; Fliermans, C.B.

    1994-01-01

    An immersible solar heater is described comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater.

  8. Immersible solar heater for fluids

    DOEpatents

    Kronberg, J.W.

    1995-07-11

    An immersible solar heater is described comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater. 11 figs.

  9. Passive solar energy information user study

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Belew, W.W.; Wood, B.L.; Marle, T.L.

    1980-11-01

    The results of a series of telephone interviews with groups of users of information on passive solar heating and cooling are described. These results, part of a larger study on many different solar technologies, identify types of information each group needed and the best ways to get information to each group. The overall study provides baseline data about information needs in the solar community. An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Resultsmore » from seven passive groups respondents are analyzed in this report: Federally Funded Researchers, Manufacturer Representatives, Architects, Builders, Educators, Cooperative Extension Service County Agents, and Homeowners. The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.« less

  10. Two alternative solar energy scenarios for Western Europe

    NASA Astrophysics Data System (ADS)

    Nakicenovic, N.

    1982-11-01

    Two limiting scenarios that lead to a sustainable energy system in Western Europe toward the end of the next century are described. The scenarios consider exclusively solar energy futures: one based on centralized solar technologies (hard scenario) and the other on decentralized user-oriented technologies (soft scenario). While both scenarios eliminate Western Europe's dependence on domestic and foreign fossil energy sources, the hard solar scenario requires substantial imports of solar produced hydrogen. Fundamental but different changes of the whole energy system, economic structure and lifestyles are necessary in order to achieve sustainable solar energy futures in the scenarios.

  11. Teaching Children to Value Solar Energy

    ERIC Educational Resources Information Center

    Hugerat, Muhamad; Saker, Salem; Odeh, Saeed; Agbaria, Adnan

    2011-01-01

    In this educational initiative, we suggest to build a real model of solar village inside the school, which uses only solar energy. These educational initiatives emphasize the importance of energy for a technological society and the advantage of alternative energy sources. In this scientific educational initiative, the pupils in three elementary…

  12. Solar Energy for Rural Egypt

    NASA Astrophysics Data System (ADS)

    Abdelsalam, Tarek I.; Darwish, Ziad; Hatem, Tarek M.

    Egypt is currently experiencing the symptoms of an energy crisis, such as electricity outage and high deficit, due to increasing rates of fossil fuels consumption. Conversely, Egypt has a high solar availability of more than 18.5 MJ daily. Additionally, Egypt has large uninhabited deserts on both sides of the Nile valley and Sinai Peninsula, which both represent more than 96.5 % of the nation's total land area. Therefore, solar energy is one of the promising solutions for the energy shortage in Egypt. Furthermore, these vast lands are advantageous for commissioning large-scaled solar power projects, not only in terms of space availability, but also of availability of high quality silicon (sand) required for manufacturing silicon wafers used in photovoltaic (PV) modules. Also, rural Egypt is considered market a gap for investors, due to low local competition, and numerous remote areas that are not connected to the national electricity grid. Nevertheless, there are some obstacles that hinder the progress of solar energy in Egypt; for instance, the lack of local manufacturing capabilities, security, and turbulent market in addition to other challenges. This paper exhibits an experience of the authors designing and installing decentralized PV solar systems, with a total rated power of about 11 kW, installed at two rural villages in at the suburbs of Fayoum city, in addition to a conceptual design of a utility scale, 2 MW, PV power plant to be installed in Kuraymat. The outcomes of this experience asserted that solar PV systems can be a more technically and economically feasible solution for the energy problem in rural villages.

  13. High efficiency carrier multiplication in PbSe nanocrystals: implications for solar energy conversion.

    PubMed

    Schaller, R D; Klimov, V I

    2004-05-07

    We demonstrate for the first time that impact ionization (II) (the inverse of Auger recombination) occurs with very high efficiency in semiconductor nanocrystals (NCs). Interband optical excitation of PbSe NCs at low pump intensities, for which less than one exciton is initially generated per NC on average, results in the formation of two or more excitons (carrier multiplication) when pump photon energies are more than 3 times the NC band gap energy. The generation of multiexcitons from a single photon absorption event is observed to take place on an ultrafast (picosecond) time scale and occurs with up to 100% efficiency depending upon the excess energy of the absorbed photon. Efficient II in NCs can be used to considerably increase the power conversion efficiency of NC-based solar cells.

  14. Carbon nanostructures for solar energy conversion schemes.

    PubMed

    Guldi, Dirk M; Sgobba, Vito

    2011-01-14

    Developing environmentally friendly, renewable energy is one of the challenges to society in the 21st century. One of the renewable energy technologies is solar energy conversion--a technology that directly converts daylight into electricity. This highlight surveys recent breakthroughs in the field of implementing carbon nanostructures--fullerenes (0D), carbon nanotubes (1D), carbon nanohorns, and graphene (2D)--into solar energy conversion schemes, that is, bulk heterojunction and dye-sensitized solar cells.

  15. Performance study of a laboratory model shallow solar pond with and without single transparent glass cover for solar thermal energy conversion applications.

    PubMed

    Ganesh, S; Arumugam, S

    2016-12-01

    The thermal performance of a shallow solar pond with and without the single transparent glass cover has been investigated experimentally. This experiment has been performed during the summer season of 2014 under the operational condition for five different storage volumes of water upto a maximum of 10liter. The pond performance is investigated in terms of the rate of energy collected and its collection efficiency. A Low Density Polyethylene (LDPE) black sheet liner of 200μm thickness was laid on all the interior sides of the pond for solar energy absorption. A clear transparent PVC plastic sheet of 150μm thickness was laid over the water surface as evaporation suppressing membrane. Calibrated Copper constantan thermocouples were used to measure the temperatures of the system. A highest temperature of 81.5°C has been achieved for the stored volume of 2liter of water, when the pond was used with a single transparent glass cover of 5mm thickness. When the shallow solar pond was used without the transparent glass cover the system attained a maximum temperature of 62°C for the same stored volume of 2liter. A comparison between the two conditions of with and without the transparent glass cover, on the thermal performance of the SSP has been reported. A shallow solar pond system of the present type could be used us a source of warm water, of desired temperature, below 10°C which are required for the domestic and industrial utilities. The global warming is increased day by day; inorder to reduce global warming a typical method of small scale shallow solar pond has been used to absorb the radiation from the sun to convert it to useful heat energy by the source of water. The SSP is an eco friendly way to generate energy without polluting our environment and in an environment safety manner. Based on environmental safety this study has experimentally investigated the thermal performance of the shallow solar pond. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Candidate chemical systems for air cooled solar powered, absorption air conditioner design. Part I. Organic absorbent systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Biermann, W. J.

    1978-01-01

    All the available experimental evidence suggests that the optimum ''organic'' absorbent/refrigerant combination would be a methane derivative with a single hydrogen atom with chlorine and fluorine atoms in the other sites, as refrigerant. This would be hydrogen bonded to an absorbent molecule containing the group =NC/sup -/O, with the substituent groups being such that no steric hindrance took place. Cycle analyses showed that the ratio of internal heat transfer to cooling would be large, probably impractically so in view of the high coefficient of performance needed for solar driven cooling and the additional handicap of heat rejection to the atmosphere.more » A more promising approach would be to reduce the internal heat transfer per unit of space cooling by selecting a refrigerant with a high latent heat of vaporization and selecting an absorbent with suitable properties.« less

  17. Design and Manufacture of Energy Absorbing Materials

    ScienceCinema

    Duoss, Eric

    2018-01-16

    Learn about an ordered cellular material that has been designed and manufactured using direct ink writing (DIW), a 3-D printing technology being developed at LLNL. The new material is a patterned cellular material that can absorb mechanical energy-a cushion-while also providing protection against sheering. This material is expected to find utility in application spaces that currently use unordered foams, such as sporting and consumer goods as well as defense and aerospace.

  18. Design principles for morphologies of antireflection patterns for solar absorbing applications.

    PubMed

    Moon, Yoon-Jong; Na, Jin-Young; Kim, Sun-Kyung

    2015-07-01

    Two-dimensional surface texturing is a widespread technology for imparting broadband antireflection, yet its design rules are not completely understood. The dependence of the reflectance spectrum of a periodically patterned glass film on various structural parameters (e.g., pitch, height, shape, and fill factor) has been investigated by means of full-vectorial numerical simulations. An average weighted reflectivity accounting for the AM1.5G solar spectrum (λ=300-1000  nm) was sinusoidally modulated by a rod pattern's height, and was minimized for pitches of 400-600 nm. When a rationally optimized cone pattern was used, the average weighted reflectivity was less than 0.5%, for incident angles of up to 40° off normal. The broadband antireflection of a cone pattern was reproduced well by a graded refractive index film model corresponding to its geometry, with the addition of a diffraction effect resulting from its periodicity. The broadband antireflection ability of optimized cone patterns is not limited to the glass material, but rather is generically applicable to other semiconductor materials, including Si and GaAs. The design rules developed herein represent a key step in the development of light-absorbing devices, such as solar cells.

  19. Thermo-hydraulic actuator as a new way for conversion of solar energy in space

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sukhodolsky, A.T.

    1998-07-01

    A thermo-hydraulic actuator (THA) to directly convert the energy of continuous radiation into mechanical energy of vibration for use in power or propulsive systems in space is described. A THA consists of a chamber with an active liquid and optical fibers to deliver light energy inside. Power input comes from either argon laser or a solar concentrator 300 mm. in diameter. The principle of THA function is self-organization of a heat cycle that takes place by using a state of liquid (inversion) powered by light up to a temperature much higher than the temperature of boiling. As a result, anmore » excited state of liquid is able to form a single cavity to absorb thermal energy that is available to be converted by the non-equilibrium phase transition of first order into mechanical energy. This work stroke of a THA to form a hydraulic shock has been stimulated by non-linear mechanical motion of a single cavity and non-equilibrium phase transition of first order. The main feature of THA to accumulate energy of light in form of heat between sequential mechanical impulses gives the unique possibility to reach the motive forces induced by solar light by many order of the magnitude greater than the forces available by equilibrium radiation pressure. The first free-piston actuator (FPA) powered by solar light is also described. The construction consists of parabolic collector of diameter of 300mm and a transparent window with mounted actuator that has of a hollow piston with active liquid. Direct generation of hydraulic shocks by THA and preliminary experiments on generation of vibrations within a construction (FPA) has been proposed to be a new subject of interdisciplinary research to go from physical phenomenon observed in laser experiments to engineering development of new vibration machines powered by solar light. To conclude, a project to apply THA in new solar cosmic propulsive systems is discussed.« less

  20. Solar Energy Demonstrations

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Solar energy furnishes all of the heating and hot water needs, plus 80 percent of the air conditioning, for the two-story Reedy Creek building. A unique feature of this installation is that the 16 semi-cylindrical solar collectors (center photo on opposite page with closeup of a single collector below it) are not mounted atop the roof as is customary, they actually are the roof. This arrangement eliminates the usual trusses, corrugated decking and insulating concrete in roof construction; that, in turn, reduces overall building costs and makes the solar installation more attractive economically. The Reedy Creek collectors were designed and manufactured by AAI Corporation of Baltimore, Maryland.

  1. Plasmonic near-touching titanium oxide nanoparticles to realize solar energy harvesting and effective local heating.

    PubMed

    Yan, Jiahao; Liu, Pu; Ma, Churong; Lin, Zhaoyong; Yang, Guowei

    2016-04-28

    Through the excitation of plasmon resonance, the energy of plasmonic nanoparticles either reradiates through light scattering or decays into energetic electrons (absorption). The plasmon-induced absorption can greatly enhance the efficiency of solar energy harvesting, local heating, photodetection and photocatalysis. Here, we demonstrate that heavily self-doped titanium oxide nanoparticles (TiO1.67 analogue arising from oxygen vacancies in rutile TiO2) with the plasmon resonance dominated by an interband transition shows strong absorption to build a broadband perfect absorber in the wavelength range from 300 to 2000 nm covering the solar irradiation spectrum completely. The absorptivity of the fabricated array is greater than 90% in the whole spectral range. And the broadband and strong absorption is due to the plasmon hybridization and hot spot generation from near-touching TiO1.67 nanoparticles with different sizes. What is more, the local heating of a TiO1.67 nanoparticle layer is fast and effective. The temperature increases quickly from 30 °C to 80 °C within 200 seconds. This local heating can realize rapid solar-enabled evaporation which can find applications in large-scale distillation and seawater desalination. These findings actually open a pathway for applications of these newly developed plasmonic materials in the energy and environment fields.

  2. Availability of solar energy reports from the National Solar Data Program

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1981-07-01

    This booklet discusses the various types of reports published by the National Solar Data Program, lists the reports issued prior to July 15, 1981, and provides order blanks for obtaining copies of reports. The reports identified in the following pages are segmented into nine types: monthly performance reports; solar energy performance evaluation reports; solar performance bulletins;environmental data reports;solar project description reports;solar project cost reports;program information reports;comparative reports; and reliability and material assessment reports. For convenience, available site-specific reports are listed alphabetically by site name, solar system type, and by state. These reports are disseminated through the US Department of Energy,more » Technical Information Center, P.O. Box 62, Oak Ridge, Tennessee 37830.« less

  3. Energy scavenging strain absorber: application to kinetic dielectric elastomer generator

    NASA Astrophysics Data System (ADS)

    Jean-Mistral, C.; Beaune, M.; Vu-Cong, T.; Sylvestre, A.

    2014-03-01

    Dielectric elastomer generators (DEGs) are light, compliant, silent energy scavengers. They can easily be incorporated into clothing where they could scavenge energy from the human kinetic movements for biomedical applications. Nevertheless, scavengers based on dielectric elastomers are soft electrostatic generators requiring a high voltage source to polarize them and high external strain, which constitutes the two major disadvantages of these transducers. We propose here a complete structure made up of a strain absorber, a DEG and a simple electronic power circuit. This new structure looks like a patch, can be attached on human's wear and located on the chest, knee, elbow… Our original strain absorber, inspired from a sailing boat winch, is able to heighten the external available strain with a minimal factor of 2. The DEG is made of silicone Danfoss Polypower and it has a total area of 6cm per 2.5cm sustaining a maximal strain of 50% at 1Hz. A complete electromechanical analytical model was developed for the DEG associated to this strain absorber. With a poling voltage of 800V, a scavenged energy of 0.57mJ per cycle is achieved with our complete structure. The performance of the DEG can further be improved by enhancing the imposed strain, by designing a stack structure, by using a dielectric elastomer with high dielectric permittivity.

  4. Space satellite power system. [conversion of solar energy by photovoltaic solar cell arrays

    NASA Technical Reports Server (NTRS)

    Glaser, P. E.

    1974-01-01

    The concept of a satellite solar power station was studied. It is shown that it offers the potential to meet a significant portion of future energy needs, is pollution free, and is sparing of irreplaceable earth resources. Solar energy is converted by photovoltaic solar cell arrays to dc energy which in turn is converted into microwave energy in a large active phased array. The microwave energy is beamed to earth with little attenuation and is converted back to dc energy on the earth. Economic factors are considered.

  5. EVALUATING AND DESIGNING ULTRA-LOW-COST SOLAR WATER HEATING SYSTEMS

    EPA Science Inventory

    This project will have three key outputs:

    1. an evaluation of the thermal performance of ultra-low-cost solar components, with components being characterized by their absorbed solar energy per cost;
    2. a built demonstration prototype of...

    3. Solar Energy: Potential Powerhouse for Jobs

      ERIC Educational Resources Information Center

      McCallion, Tom

      1976-01-01

      Components of solar energy systems are described, the development of the solar industry discussed, and implications are drawn for employment opportunities in industries (which may expand into new, solar-related areas) and in the professions, from law to sales, upon the advent of solar heating. (AJ)

    4. High Efficiency Multijunction Solar Cells with Finely-Tuned Quantum Wells

      NASA Astrophysics Data System (ADS)

      Varonides, Argyrios C.

      The field of high efficiency (inorganic) photovoltaics (PV) is rapidly maturing in both efficiency goals and cover all cost reduction of fabrication. On one hand, know-how from space industry in new solar cell design configurations and on the other, fabrication cost reduction challenges for terrestrial uses of solar energy, have paved the way to a new generation of PV devices, capable of capturing most of the solar spectrum. For quite a while now, the goal of inorganic solar cell design has been the total (if possible) capture-absorption of the solar spectrum from a single solar cell, designed in such a way that a multiple of incident wavelengths could be simultaneously absorbed. Multi-absorption in device physics indicates parallel existence of different materials that absorb solar photons of different energies. Bulk solid state devices absorb at specific energy thresholds, depending on their respective energy gap (EG). More than one energy gaps would on principle offer new ways of photon absorption: if such a structure could be fabricated, two or more groups of photons could be absorbed simultaneously. The point became then what lattice-matched semiconductor materials could offer such multiple levels of absorption without much recombination losses. It was soon realized that such layer multiplicity combined with quantum size effects could lead to higher efficiency collection of photo-excited carriers. At the moment, the main reason that slows down quantum effect solar cell production is high fabrication cost, since it involves primarily expensive methods of multilayer growth. Existing multi-layer cells are fabricated in the bulk, with three (mostly) layers of lattice-matched and non-lattice-matched (pseudo-morphic) semiconductor materials (GaInP/InGaN etc), where photo-carrier collection occurs in the bulk of the base (coming from the emitter which lies right under the window layer). These carriers are given excess to conduction via tunnel junction (grown between

    5. Nanofluid heat transfer under mixed convection flow in a tube for solar thermal energy applications.

      PubMed

      Sekhar, Y Raja; Sharma, K V; Kamal, Subhash

      2016-05-01

      The solar flat plate collector operating under different convective modes has low efficiency for energy conversion. The energy absorbed by the working fluid in the collector system and its heat transfer characteristics vary with solar insolation and mass flow rate. The performance of the system is improved by reducing the losses from the collector. Various passive methods have been devised to aid energy absorption by the working fluid. Also, working fluids are modified using nanoparticles to improve the thermal properties of the fluid. In the present work, simulation and experimental studies are undertaken for pipe flow at constant heat flux boundary condition in the mixed convection mode. The working fluid at low Reynolds number in the mixed laminar flow range is undertaken with water in thermosyphon mode for different inclination angles of the tube. Local and average coefficients are determined experimentally and compared with theoretical values for water-based Al2O3 nanofluids. The results show an enhancement in heat transfer in the experimental range with Rayleigh number at higher inclinations of the collector tube for water and nanofluids.

    6. Conversion of magnetic field energy into kinetic energy in the solar wind

      NASA Technical Reports Server (NTRS)

      Whang, Y. C.

      1972-01-01

      The outflow of the solar magnetic field energy (the radial component of the Poynting vector) per steradian is inversely proportional to the solar wind velocity. It is a decreasing function of the heliocentric distance. When the magnetic field effect is included in the one-fluid model of the solar wind, the transformation of magnetic field energy into kinetic energy during the expansion process increases the solar wind velocity at 1 AU by 17 percent.

    7. Solar Spots - Activities to Introduce Solar Energy into the K-8 Curricula.

      ERIC Educational Resources Information Center

      Longe, Karen M.; McClelland, Michael J.

      Following an introduction to solar technology which reviews solar heating and cooling, passive solar systems (direct gain systems, thermal storage walls, sun spaces, roof ponds, and convection loops), active solar systems, solar electricity (photovoltaic and solar thermal conversion systems), wind energy, and biomass, activities to introduce solar…

    8. Near-infrared absorbing squarylium dyes with linearly extended π-conjugated structure for dye-sensitized solar cell applications.

      PubMed

      Maeda, Takeshi; Hamamura, Yuuto; Miyanaga, Kyohei; Shima, Naoki; Yagi, Shigeyuki; Nakazumi, Hiroyuki

      2011-11-18

      A novel class of near-infrared absorbing squarylium sensitizers with linearly extended π-conjugated structures, which were obtained by Pd-catalyzed cross-coupling reactions with stannylcyclobutenediones, has been developed for dye-sensitized solar cells. The cells based on these dyes exhibited a significant spectral response in the near-infrared region over 750 nm in addition to the visible region.

    9. Production of crystalline refractory metal oxides containing colloidal metal precipitates and useful as solar-effective absorbers

      DOEpatents

      Narayan, Jagdish; Chen, Yok

      1983-01-01

      This invention is a new process for producing refractory crystalline oxides having improved or unusual properties. The process comprises the steps of forming a doped-metal crystal of the oxide; exposing the doped crystal in a bomb to a reducing atmosphere at superatmospheric pressure and a temperature effecting precipitation of the dopant metal in the crystal lattice of the oxide but insufficient to effect net diffusion of the metal out of the lattice; and then cooling the crystal. Preferably, the cooling step is effected by quenching. The process forms colloidal precipitates of the metal in the oxide lattice. The process may be used, for example, to produce thermally stable black MgO crystalline bodies containing magnetic colloidal precipitates consisting of about 99% Ni. The Ni-containing bodies are solar-selective absorbers, having a room-temperature absorptivity of about 0.96 over virtually all of the solar-energy spectrum and exhibiting an absorption edge in the region of 2 .mu.m. The process parameters can be varied to control the average size of the precipitates. The process can produce a black MgO crystalline body containing colloidal Ni precipitates, some of which have the face-centered-cubic structure and others of which have the body-centered cubic structure. The products of the process are metal-precipitate-containing refractory crystalline oxides which have improved or unique optical, mechanical, magnetic, and/or electronic properties.

    10. Triplet-triplet annihilation photon-upconversion: towards solar energy applications.

      PubMed

      Gray, Victor; Dzebo, Damir; Abrahamsson, Maria; Albinsson, Bo; Moth-Poulsen, Kasper

      2014-06-14

      Solar power production and solar energy storage are important research areas for development of technologies that can facilitate a transition to a future society independent of fossil fuel based energy sources. Devices for direct conversion of solar photons suffer from poor efficiencies due to spectrum losses, which are caused by energy mismatch between the optical absorption of the devices and the broadband irradiation provided by the sun. In this context, photon-upconversion technologies are becoming increasingly interesting since they might offer an efficient way of converting low energy solar energy photons into higher energy photons, ideal for solar power production and solar energy storage. This perspective discusses recent progress in triplet-triplet annihilation (TTA) photon-upconversion systems and devices for solar energy applications. Furthermore, challenges with evaluation of the efficiency of TTA-photon-upconversion systems are discussed and a general approach for evaluation and comparison of existing systems is suggested.

    11. The Solar Energy Notebook.

      ERIC Educational Resources Information Center

      Rankins, William H., III; Wilson, David A.

      This publication is a handbook for the do-it-yourselfer or anyone else interested in solar space and water heating. Described are methods for calculating sun angles, available energy, heating requirements, and solar heat storage. Also described are collector and system designs with mention of some design problems to avoid. Climatological data for…

    12. Flexible hybrid energy cell for simultaneously harvesting thermal, mechanical, and solar energies.

      PubMed

      Yang, Ya; Zhang, Hulin; Zhu, Guang; Lee, Sangmin; Lin, Zong-Hong; Wang, Zhong Lin

      2013-01-22

      We report the first flexible hybrid energy cell that is capable of simultaneously or individually harvesting thermal, mechanical, and solar energies to power some electronic devices. For having both the pyroelectric and piezoelectric properties, a polarized poly(vinylidene fluoride) (PVDF) film-based nanogenerator (NG) was used to harvest thermal and mechanical energies. Using aligned ZnO nanowire arrays grown on the flexible polyester (PET) substrate, a ZnO-poly(3-hexylthiophene) (P3HT) heterojunction solar cell was designed for harvesting solar energy. By integrating the NGs and the solar cells, a hybrid energy cell was fabricated to simultaneously harvest three different types of energies. With the use of a Li-ion battery as the energy storage, the harvested energy can drive four red light-emitting diodes (LEDs).

    13. Design and testing of an energy-absorbing crewseat for the F/FB-111 aircraft, volume 1

      NASA Technical Reports Server (NTRS)

      Shane, S. J.

      1985-01-01

      A program to determine if the injury potential could be reduced by replacing the existing crewseats with energy absorbing crewseats is explored. An energy-absorbing test seat was designed using much of the existing seat hardware. An extensive dynamic seat test series, designed to duplicate various crew module ground impact conditions, was conducted at a sled test facility. Comparative tests with operational F-111 crewseats were also conducted. After successful dynamic testing of the seat, more testing was conducted with the seats mounted in an F-111 crew module. Both swing tests and vertical drop tests were conducted. The vertical drop tests were used to obtain comparative data between the energy-absorbing and operational seats. Volume 1 describes the energy absorbing test seat and testing conducted, and evaluates the data from both test series.

    14. Design and fabrication of an energy-harvesting device using vibration absorber

      NASA Astrophysics Data System (ADS)

      Heidari, Hamidreza; Afifi, Arash

      2017-05-01

      Energy-harvesting devices collect energy that is being wasted and convert to the electrical energy. For this reason, this type of devices is considered as a convenient alternative to traditional batteries. In this paper, experimental examinations were performed to investigate the application of harvesting device for the reduction of the vibration amplitude in a vibration system and also increase the efficiency of energy-harvesting device. This study focuses on the energy-harvesting device as both producing electrical device and a vibration disabled absorber. In this regard, a motion-based energy-harvesting device is designed to produce electrical energy and also eliminate vibrations of a two joint-end beam which is located under the harmonic excitation force. Then, the governing equations of the forced motion on the main beam are derived and energy-harvesting system are simulated. In addition, the system designed by MATLAB simulation is explained and its results are expressed. Finally, a prototype of the system was made and the ability of the energy-harvesting device to absorb the original system vibrations, as well as parameters impact on the efficiency of energy harvesting is investigated. Experimental results show that the energy-harvesting device, in addition to producing electric current with a maximum value of 1.5V, reduces 94% of the original system vibrations.

    15. Solar Hot Water Heater

      NASA Technical Reports Server (NTRS)

      1978-01-01

      The solar panels pictured below, mounted on a Moscow, Idaho home, are part of a domestic hot water heating system capable of providing up to 100 percent of home or small business hot water needs. Produced by Lennox Industries Inc., Marshalltown, Iowa, the panels are commercial versions of a collector co-developed by NASA. In an effort to conserve energy, NASA has installed solar collectors at a number of its own facilities and is conducting research to develop the most efficient systems. Lewis Research Center teamed with Honeywell Inc., Minneapolis, Minnesota to develop the flat plate collector shown. Key to the collector's efficiency is black chrome coating on the plate developed for use on spacecraft solar cells, the coating prevents sun heat from "reradiating," or escaping outward. The design proved the most effective heat absorber among 23 different types of collectors evaluated in a Lewis test program. The Lennox solar domestic hot water heating system has three main components: the array of collectors, a "solar module" (blue unit pictured) and a conventional water heater. A fluid-ethylene glycol and water-is circulated through the collectors to absorb solar heat. The fluid is then piped to a double-walled jacket around a water tank within the solar module.

    16. Finite Element Analysis of an Energy Absorbing Sub-floor Structure

      NASA Technical Reports Server (NTRS)

      Moore, Scott C.

      1995-01-01

      As part of the Advanced General Aviation Transportation Experiments program, the National Aeronautics and Space Administration's Langley Research Center is conducting tests to design energy absorbing structures to improve occupant survivability in aircraft crashes. An effort is currently underway to design an Energy Absorbing (EA) sub-floor structure which will reduce occupant loads in an aircraft crash. However, a recent drop test of a fuselage specimen with a proposed EA sub-floor structure demonstrated that the effects of sectioning the fuselage on both the fuselage section's stiffness and the performance of the EA structure were not fully understood. Therefore, attempts are underway to model the proposed sub-floor structure on computers using the DYCAST finite element code to provide a better understanding of the structure's behavior in testing, and in an actual crash.

    17. Material Model Evaluation of a Composite Honeycomb Energy Absorber

      NASA Technical Reports Server (NTRS)

      Jackson, Karen E.; Annett, Martin S.; Fasanella, Edwin L.; Polanco, Michael A.

      2012-01-01

      A study was conducted to evaluate four different material models in predicting the dynamic crushing response of solid-element-based models of a composite honeycomb energy absorber, designated the Deployable Energy Absorber (DEA). Dynamic crush tests of three DEA components were simulated using the nonlinear, explicit transient dynamic code, LS-DYNA . In addition, a full-scale crash test of an MD-500 helicopter, retrofitted with DEA blocks, was simulated. The four material models used to represent the DEA included: *MAT_CRUSHABLE_FOAM (Mat 63), *MAT_HONEYCOMB (Mat 26), *MAT_SIMPLIFIED_RUBBER/FOAM (Mat 181), and *MAT_TRANSVERSELY_ANISOTROPIC_CRUSHABLE_FOAM (Mat 142). Test-analysis calibration metrics included simple percentage error comparisons of initial peak acceleration, sustained crush stress, and peak compaction acceleration of the DEA components. In addition, the Roadside Safety Verification and Validation Program (RSVVP) was used to assess similarities and differences between the experimental and analytical curves for the full-scale crash test.

  1. Integrated solar energy system optimization

    NASA Astrophysics Data System (ADS)

    Young, S. K.

    1982-11-01

    The computer program SYSOPT, intended as a tool for optimizing the subsystem sizing, performance, and economics of integrated wind and solar energy systems, is presented. The modular structure of the methodology additionally allows simulations when the solar subsystems are combined with conventional technologies, e.g., a utility grid. Hourly energy/mass flow balances are computed for interconnection points, yielding optimized sizing and time-dependent operation of various subsystems. The program requires meteorological data, such as insolation, diurnal and seasonal variations, and wind speed at the hub height of a wind turbine, all of which can be taken from simulations like the TRNSYS program. Examples are provided for optimization of a solar-powered (wind turbine and parabolic trough-Rankine generator) desalinization plant, and a design analysis for a solar powered greenhouse.

  2. Metal Nanoshells for Plasmonically Enhanced Solar-to-Fuel Photocatalytic Conversion

    DTIC Science & Technology

    2014-05-09

    Final 3. DATES COVERED (From - To) 04/16/2013 – 04/15/2014 4. TITLE AND SUBTITLE Metal Nanoshells for Plasmonically Enhanced Solar -to...following experiments, the core-shell of nanoshell@SiO2, as well as the nanostructure of photocatalyst, were further investigated. Solar energy in the...nanoshells as the core can absorb the solar energy in the IR and visible-light region ranging from 500 nm to 900 nm. Our data showed that the plasmonic

  3. Solar energy for industrial process heat

    NASA Technical Reports Server (NTRS)

    Barbieri, R. H.; Pivirotto, D. L.

    1979-01-01

    Findings of study of potential use for solar energy utilization by California dairy industry, prove that applicable solar energy system furnish much of heat needed for milk processing with large savings in expenditures for oil and gas and ensurance of adequate readily available sources of process heat.

  4. Nanoimprinted backside reflectors for a-Si:H thin-film solar cells: critical role of absorber front textures.

    PubMed

    Tsao, Yao-Chung; Fisker, Christian; Pedersen, Thomas Garm

    2014-05-05

    The development of optimal backside reflectors (BSRs) is crucial for future low cost and high efficiency silicon (Si) thin-film solar cells. In this work, nanostructured polymer substrates with aluminum coatings intended as BSRs were produced by positive and negative nanoimprint lithography (NIL) techniques, and hydrogenated amorphous silicon (a-Si:H) was deposited hereon as absorbing layers. The relationship between optical properties and geometry of front textures was studied by combining experimental reflectance spectra and theoretical simulations. It was found that a significant height variation on front textures plays a critical role for light-trapping enhancement in solar cell applications. As a part of sample preparation, a transfer NIL process was developed to overcome the problem of low heat deflection temperature of polymer substrates during solar cell fabrication.

  5. Biotechnological storage and utilization of entrapped solar energy.

    PubMed

    Bhattacharya, Sumana; Schiavone, Marc; Nayak, Amiya; Bhattacharya, Sanjoy K

    2005-03-01

    Our laboratory has recently developed a device employing immobilized F0F1 adenosine triphosphatase (ATPase) that allows synthesis of adenosine triphosphate (ATP) from adenosine 5'-diphosphate and inorganic phosphate using solar energy. We present estimates of total solar energy received by Earth's land area and demonstrate that its efficient capture may allow conversion of solar energy and storage into bonds of biochemicals using devices harboring either immobilized ATPase or NADH dehydrogenase. Capture and storage of solar energy into biochemicals may also enable fixation of CO2 emanating from polluting units. The cofactors ATP and NADH synthesized using solar energy could be used for regeneration of acceptor D-ribulose-1,5-bisphosphate from 3-phosphoglycerate formed during CO2 fixation.

  6. Bioinspired fractal electrodes for solar energy storages.

    PubMed

    Thekkekara, Litty V; Gu, Min

    2017-03-31

    Solar energy storage is an emerging technology which can promote the solar energy as the primary source of electricity. Recent development of laser scribed graphene electrodes exhibiting a high electrical conductivity have enabled a green technology platform for supercapacitor-based energy storage, resulting in cost-effective, environment-friendly features, and consequent readiness for on-chip integration. Due to the limitation of the ion-accessible active porous surface area, the energy densities of these supercapacitors are restricted below ~3 × 10 -3  Whcm -3 . In this paper, we demonstrate a new design of biomimetic laser scribed graphene electrodes for solar energy storage, which embraces the structure of Fern leaves characterized by the geometric family of space filling curves of fractals. This new conceptual design removes the limit of the conventional planar supercapacitors by significantly increasing the ratio of active surface area to volume of the new electrodes and reducing the electrolyte ionic path. The attained energy density is thus significantly increased to ~10 -1  Whcm -3 - more than 30 times higher than that achievable by the planar electrodes with ~95% coulombic efficiency of the solar energy storage. The energy storages with these novel electrodes open the prospects of efficient self-powered and solar-powered wearable, flexible and portable applications.

  7. A concentrated solar cavity absorber with direct heat transfer through recirculating metallic particles

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sarker, M. R. I., E-mail: islamrabiul@yahoo.com; Saha, Manabendra, E-mail: manabendra.saha@adelaide.edu.au, E-mail: manab04me@gmail.com; Beg, R. A.

    A recirculating flow solar particle cavity absorber (receiver) is modeled to investigate the flow behavior and heat transfer characteristics of a novel developing concept. It features a continuous recirculating flow of non-reacting metallic particles (black silicon carbide) with air which are used as a thermal enhancement medium. The aim of the present study is to numerically investigate the thermal behavior and flow characteristics of the proposed concept. The proposed solar particle receiver is modeled using two phase discrete particle model (DPM), RNG k-flow model and discrete ordinate (DO) radiation model. Numerical analysis is carried out considering a solar receiver withmore » only air and the mixture of non-reacting particles and air as a heat transfer as well as heat carrying medium. The parametric investigation is conducted considering the incident solar flux on the receiver aperture and changing air flow rate and recirculation rate inside the receiver. A stand-alone feature of the recirculating flow solar particle receiver concept is that the particles are directly exposed to concentrated solar radiation monotonously through recirculating flow inside the receiver and results in efficient irradiation absorption and convective heat transfer to air that help to achieve high temperature air and consequently increase in thermal efficiency. This paper presents, results from the developed concept and highlights its flow behavior and potential to enhance the heat transfer from metallic particles to air by maximizing heat carrying capacity of the heat transfer medium. The imposed milestones for the present system will be helpful to understand the radiation absorption mechanism of the particles in a recirculating flow based receiver, the thermal transport between the particles, the air and the cavity, and the fluid dynamics of the air and particle in the cavity.« less

  8. Photochemical conversion of solar energy.

    PubMed

    Balzani, Vincenzo; Credi, Alberto; Venturi, Margherita

    2008-01-01

    Energy is the most important issue of the 21st century. About 85% of our energy comes from fossil fuels, a finite resource unevenly distributed beneath the Earth's surface. Reserves of fossil fuels are progressively decreasing, and their continued use produces harmful effects such as pollution that threatens human health and greenhouse gases associated with global warming. Prompt global action to solve the energy crisis is therefore needed. To pursue such an action, we are urged to save energy and to use energy in more efficient ways, but we are also forced to find alternative energy sources, the most convenient of which is solar energy for several reasons. The sun continuously provides the Earth with a huge amount of energy, fairly distributed all over the world. Its enormous potential as a clean, abundant, and economical energy source, however, cannot be exploited unless it is converted into useful forms of energy. This Review starts with a brief description of the mechanism at the basis of the natural photosynthesis and, then, reports the results obtained so far in the field of photochemical conversion of solar energy. The "grand challenge" for chemists is to find a convenient means for artificial conversion of solar energy into fuels. If chemists succeed to create an artificial photosynthetic process, "... life and civilization will continue as long as the sun shines!", as the Italian scientist Giacomo Ciamician forecast almost one hundred years ago.

  9. Development of 2 underseat energy absorbers for application to crashworthy passenger seats for general aviation aircraft

    NASA Technical Reports Server (NTRS)

    Warrick, J. C.; Desjardins, S. P.

    1979-01-01

    This report presents the methodology and results of a program conducted to develop two underseat energy absorber (E/A) concepts for application to nonadjustable crashworthy passenger seats for general aviation aircraft. One concept utilizes an inflated air bag, and the other, a convoluted sheet metal bellows. Prototypes of both were designed, built, and tested. Both concepts demonstrated the necessary features of an energy absorber (load-limiter); however, the air bag concept is particularly encouraging because of its light weight. Several seat frame concepts also were investigated as a means of resisting longitudinal and lateral loads and of guiding the primary vertical stroke of the underseat energy absorber. Further development of a seat system design using the underseat energy absorbers is recommended because they provide greatly enhanced crash survivability as compared with existing general aviation aircraft seats.

  10. Techno-Economic Analysis of Solar Water Heating Systems inTurkey.

    PubMed

    Ertekin, Can; Kulcu, Recep; Evrendilek, Fatih

    2008-02-25

    In this study, solar water heater was investigated using meteorological and geographical data of 129 sites over Turkey. Three different collector types were compared in terms of absorber material (copper, galvanized sheet and selective absorber). Energy requirement for water heating, collector performances, and economical indicators were calculated with formulations using observed data. Results showed that selective absorbers were most appropriate in terms of coverage rate of energy requirement for water-heating all over Turkey. The prices of selective, copper and galvanized absorber type's heating systems in Turkey were 740.49, 615.69 and 490.89 USD, respectively. While payback periods (PBPs) of the galvanized absorber were lower, net present values (NPVs) of the selective absorber were higher than the rest. Copper absorber type collectors did not appear to be appropriate based on economical indicators.

  11. MHD conversion of solar energy. [space electric power system

    NASA Technical Reports Server (NTRS)

    Lau, C. V.; Decher, R.

    1978-01-01

    Low temperature plasmas wherein an alkali metal vapor is a component are uniquely suited to simultaneously absorb solar radiation by coupling to the resonance lines and produce electrical power by the MHD interaction. This work is an examination of the possibility of developing space power systems which take advantage of concentrated solar power to produce electricity. It is shown that efficient cycles in which expansion work takes place at nearly constant top cycle temperature can be devised. The power density of the solar MHD generator is lower than that of conventional MHD generators because of the relatively high seed concentration required for radiation absorption and the lower flow velocity permitted to avoid total pressure losses due to heating.

  12. Solar solids reactor

    DOEpatents

    Yudow, B.D.

    1986-02-24

    A solar powered kiln is provided, that is of relatively simple design and which efficiently uses solar energy. The kiln or solids reactor includes a stationary chamber with a rearward end which receives solid material to be reacted and a forward end through which reacted material is disposed of, and a screw conveyor extending along the bottom of the chamber for slowly advancing the material between the chamber ends. Concentrated solar energy is directed to an aperture at the forward end of the chamber to heat the solid material moving along the bottom of the chamber. The solar energy can be reflected from a mirror facing at an upward incline, through the aperture and against a heat-absorbing material near the top of the chamber, which moves towards the rear of the chamber to distribute heat throughout the chamber. Pumps at the forward and rearward ends of the chamber pump heated sweep gas through the length of the chamber, while minimizing the flow of gas through an open aperture through which concentrated sunlight is received.

  13. Solar solids reactor

    DOEpatents

    Yudow, Bernard D.

    1987-01-01

    A solar powered kiln is provided, that is of relatively simple design and which efficiently uses solar energy. The kiln or solids reactor includes a stationary chamber with a rearward end which receives solid material to be reacted and a forward end through which reacted material is disposed of, and a screw conveyor extending along the bottom of the chamber for slowly advancing the material between the chamber ends. Concentrated solar energy is directed to an aperture at the forward end of the chamber to heat the solid material moving along the bottom of the chamber. The solar energy can be reflected from a mirror facing at an upward incline, through the aperture and against a heat-absorbing material near the top of the chamber, which moves towards the rear of the chamber to distribute heat throughout the chamber. Pumps at the forward and rearward ends of the chamber pump heated sweep gas through the length of the chamber, while minimizing the flow of gas through an open aperture through which concentrated sunlight is received.

  14. Space solar power - An energy alternative

    NASA Technical Reports Server (NTRS)

    Johnson, R. W.

    1978-01-01

    The space solar power concept is concerned with the use of a Space Power Satellite (SPS) which orbits the earth at geostationary altitude. Two large symmetrical solar collectors convert solar energy directly to electricity using photovoltaic cells woven into blankets. The dc electricity is directed to microwave generators incorporated in a transmitting antenna located between the solar collectors. The antenna directs the microwave beam to a receiving antenna on earth where the microwave energy is efficiently converted back to dc electricity. The SPS design promises 30-year and beyond lifetimes. The SPS is relatively pollution free as it promises earth-equivalence of 80-85% efficient ground-based thermal power plant.

  15. Constraining Aggregate-Scale Solar Energy Partitioning in Arctic Sea Ice Through Synthesis of Remote Sensing and Autonomous In-Situ Observations.

    NASA Astrophysics Data System (ADS)

    Wright, N.; Polashenski, C. M.; Deeb, E. J.; Morriss, B. F.; Song, A.; Chen, J.

    2015-12-01

    One of the key processes controlling sea ice mass balance in the Arctic is the partitioning of solar energy between reflection back to the atmosphere and absorption into the ice and upper ocean. We investigate the solar energy balance in the ice-ocean system using in-situ data collected from Arctic Observing Network (AON) sea ice sites and imagery from high resolution optical satellites. AON assets, including ice mass balance buoys and ice tethered profilers, monitor the storage and fluxes of heat in the ice-ocean system. High resolution satellite imagery, processed using object-based image classification techniques, allows us to quantify the evolution of surrounding ice conditions, including melt pond coverage and floe size distribution, at aggregate scale. We present results from regionally representative sites that constrain the partitioning of absorbed solar energy between ice melt and ocean storage, and quantify the strength of the ice-albedo feedback. We further demonstrate how the results can be used to validate model representations of the physical processes controlling ice-albedo feedbacks. The techniques can be extended to understand solar partitioning across the Arctic basin using additional sites and model based data integration.

  16. The Determinant of US Consumers Attitudes toward Solar Energy

    ERIC Educational Resources Information Center

    Lu, Chao-Lin

    2016-01-01

    Solar energy provides several significant advantages, such as reduction of the CO[subscript 2] emissions, increase of energy supply diversification, security of energy, and regional/national energy independence. Due to the reduced installation cost and the rapid advances in solar energy technology, the installed capacity of solar power has been…

  17. Solar Energy Directory: A Directory of Domestic and International Firms Involved in Solar Energy.

    ERIC Educational Resources Information Center

    Centerline Co., Phoenix, AZ.

    This directory is intended to provide a link between suppliers of solar energy technology and information and potential users of these products. Included are over 1400 national and international entries. These listings include architects, associations, education sources, wind power technology and information sources, solar research organizations,…

  18. Projects in a Solar Energy Course.

    ERIC Educational Resources Information Center

    Lindsay, Richard H.

    1983-01-01

    Describes student projects on applications of solar energy optics to home design. Project criterion (requiring sketches and detailed calculations of time rate of energy flow/production) is that half the heat for the heating season be taken from the solar resource; calculations must be based on meteorological data for a specific location. (JM)

  19. Argonne OutLoud presents: The Solar Energy Challenge

    ScienceCinema

    Darling, Seth

    2018-02-19

    To better understand the current and future role of solar energy, Argonne's Seth Darling framed the global energy supply and demand outlook over the next 40 years while examining potential energy sources from a feasibility and sustainability perspective. He also discussed the promise and challenges of solar energy while providing a broad overview of related research taking place at Argonne as well as his group's work on organic solar cells.

  20. Argonne OutLoud presents: The Solar Energy Challenge

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Darling, Seth

    To better understand the current and future role of solar energy, Argonne's Seth Darling framed the global energy supply and demand outlook over the next 40 years while examining potential energy sources from a feasibility and sustainability perspective. He also discussed the promise and challenges of solar energy while providing a broad overview of related research taking place at Argonne as well as his group's work on organic solar cells.

  1. Comparing solar energy alternatives

    NASA Astrophysics Data System (ADS)

    White, J. R.

    1984-03-01

    This paper outlines a computational procedure for comparing the merits of alternative processes to convert solar radiation to heat, electrical power, or chemical energy. The procedure uses the ratio of equipment investment to useful work as an index. Comparisons with conversion counterparts based on conventional fuels are also facilitated by examining this index. The procedure is illustrated by comparisons of (1) photovoltaic converters of differing efficiencies; (2) photovoltaic converters with and without focusing concentrators; (3) photovoltaic conversion plus electrolysis vs photocatalysis for the production of hydrogen; (4) photovoltaic conversion plus plasma arcs vs photocatalysis for nitrogen fixation. Estimates for conventionally-fuelled processes are included for comparison. The reasons why solar-based concepts fare poorly in such comparisons are traced to the low energy density of solar radiation and its low stream time factor resulting from the limited number of daylight hours available and clouds obscuring the sun.

  2. Bioinspired fractal electrodes for solar energy storages

    PubMed Central

    Thekkekara, Litty V.; Gu, Min

    2017-01-01

    Solar energy storage is an emerging technology which can promote the solar energy as the primary source of electricity. Recent development of laser scribed graphene electrodes exhibiting a high electrical conductivity have enabled a green technology platform for supercapacitor-based energy storage, resulting in cost-effective, environment-friendly features, and consequent readiness for on-chip integration. Due to the limitation of the ion-accessible active porous surface area, the energy densities of these supercapacitors are restricted below ~3 × 10−3 Whcm−3. In this paper, we demonstrate a new design of biomimetic laser scribed graphene electrodes for solar energy storage, which embraces the structure of Fern leaves characterized by the geometric family of space filling curves of fractals. This new conceptual design removes the limit of the conventional planar supercapacitors by significantly increasing the ratio of active surface area to volume of the new electrodes and reducing the electrolyte ionic path. The attained energy density is thus significantly increased to ~10−1 Whcm−3- more than 30 times higher than that achievable by the planar electrodes with ~95% coulombic efficiency of the solar energy storage. The energy storages with these novel electrodes open the prospects of efficient self-powered and solar-powered wearable, flexible and portable applications. PMID:28361924

  3. Solar energy utilization by physical methods.

    PubMed

    Wolf, M

    1974-04-19

    On the basis of the estimated contributions of these differing methods of the utilization of solar energy, their total energy delivery impact on the projected U.S. energy economy (9) can be evaluated (Fig. 5). Despite this late energy impact, the actual sales of solar energy utilization equipment will be significant at an early date. Potential sales in photovoltaic arrays alone could exceed $400 million by 1980, in order to meet the projected capacity buildup (10). Ultimately, the total energy utilization equipment industry should attain an annual sales volume of several tens of billion dollars in the United States, comparable to that of several other energy related industries. Varying amounts of technology development are required to assure the technical and economic feasibility of the different solar energy utilization methods. Several of these developments are far enough along that the paths can be analyzed from the present time to the time of demonstration of technical and economic feasibility, and from there to production and marketing readiness. After that point, a period of market introduction will follow, which will differ in duration according to the type of market addressed. It may be noted that the present rush to find relief from the current energy problem, or to be an early leader in entering a new market, can entail shortcuts in sound engineering practice, particularly in the areas of design for durability and easy maintenance, or of proper application engineering. The result can be loss of customer acceptance, as has been experienced in the past with various products, including solar water heaters. Since this could cause considerable delay in achieving the expected total energy impact, it will be important to spend adequate time at this stage for thorough development. Two other aspects are worth mentioning. The first is concerned with the economic impacts. Upon reflection on this point, one will observe that largescale solar energy utilization will

  4. Solar energy research and utilization

    NASA Technical Reports Server (NTRS)

    Cherry, W. R.

    1974-01-01

    The role is described that solar energy will play in the heating and cooling of buildings, the production of renewable gaseous, liquid and solid fuels, and the production of electric power over the next 45 years. Potential impacts on the various energy markets and estimated costs of such systems are discussed along with illustrations of some of the processes to accomplish the goals. The conclusions of the NSF/NASA Solar Energy Panel (1972) are given along with the estimated costs to accomplish the 15 year recommended program and also the recent and near future budget appropriations and recommendations are included.

  5. Fundamental Studies of Hydroporphyrin Architectures for Solar-Energy Applications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lindsey, Jonathan S.; Bocian, David F.; Holten, Dewey

    2013-10-30

    The long-term objective of the Bocian/Holten&Kirmaier/Lindsey research program is to design, synthesize, and characterize tetrapyrrole-based molecular architectures that absorb sunlight, funnel energy, and separate charge with high efficiency and in a manner compatible with current and future solar-energy conversion schemes. The synthetic tetrapyrroles include porphyrins and hydroporphyrins; the latter classes of molecules encompass analogues of the naturally occurring chlorophylls and bacteriochlorophylls (e.g., chlorins, bacteriochlorins, and their derivatives). The attainment of the goals of the research program requires the close interplay of molecular design and synthesis (Lindsey group), static and time-resolved optical spectroscopic measurements (Holten&Kirmaier group), and electrochemical, electron paramagnetic resonance,more » resonance Raman, and infrared studies, as well as density functional theory calculations (Bocian Group). The proposed research encompasses four interrelated themes: (i) Gain a deeper understanding of the spectral and electronic properties of bacteriochlorins, with a subsidiary aim of learning how to shift the long-wavelength absorption band deeper into the NIR region. Bacteriochlorins bearing diverse substituents, including annulated rings, will be prepared and examined. A set of bacteriochlorins with site-specific isotopic (13C, 2H) substitution patterns about the macrocycle perimeter will be prepared for studies of vibrational and electronic properties. (ii) Examine the underlying electronic origin of panchromatic absorption and excited-state behavior of strongly coupled rylene–tetrapyrrole arrays. The rylene constituents include a perylene-monoimide and a terrylene-monoimide. The tetrapyrroles include porphyrins (meso- or β-linked) and bacteriochlorins (β-linked). The objective is to achieve panchromatic absorption while preserving a viable, long-lived excited singlet state. (iii) Determine the rates of ground-state hole

  6. Community Solar Program Final Report for Austin Energy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None, None

    Austin Energy seeks to expand its portfolio of renewable programs with an innovative community solar program. The program provides an opportunity for Austin Energy's customers, who are unable or uninterested in installing solar on their own premises, to purchase solar power.

  7. Solar energy in California industry - Applications, characteristics and potential

    NASA Technical Reports Server (NTRS)

    Barbieri, R. H.; Pivirotto, D. S.

    1978-01-01

    Results of a survey to determine the potential applicability of solar thermal energy to industrial processes in California are presented. It is found that if the heat for all industrial processes at temperatures below 212 F were supplied by solar energy, total state energy consumption could be reduced by 100 trillion Btus (2%), while the use of solar energy in processes between 212 and 350 F could displace 500 trillion Btus. The issues and problems with which solar energy must contend are illustrated by a description of fluid milk processing operations. Solar energy application is found to be technically feasible for processes with thermal energy requirements below 212 F, with design, and degree of technical, economic and management feasibility being site specific. It is recommended that the state provide support for federal and industrial research, development and demonstration programs in order to stimulate acceptance of solar process heat application by industry.

  8. The Case for the Large Scale Development of Solar Energy

    ERIC Educational Resources Information Center

    O'Reilly, S. A.

    1977-01-01

    Traces the history of solar energy development. Discusses global effects (temperature, particle and other pollution) of burning fossil fuels. Provides energy balance equations for solar energy distribution and discusses flat plate collectors, solar cells, photochemical and photobiological conversion of solar energy, heat pumps. (CS)

  9. Dormitory Solar-Energy-System Economics

    NASA Technical Reports Server (NTRS)

    1982-01-01

    102-page report analyzes long-term economic performance of a prepackaged solar energy assembly system at a dormitory installation and extrapolates to four additional sites about the U.S. Method of evaluation is f-chart procedure for solar-heating and domestic hotwater systems.

  10. Pinning down high-performance Cu-chalcogenides as thin-film solar cell absorbers: A successive screening approach

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, Yubo; Zhang, Wenqing, E-mail: wqzhang@mail.sic.ac.cn, E-mail: pzhang3@buffalo.edu; State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050

    2016-05-21

    Photovoltaic performances of Cu-chalcogenides solar cells are strongly correlated with the absorber fundamental properties such as optimal bandgap, desired band alignment with window material, and high photon absorption ability. According to these criteria, we carry out a successive screening for 90 Cu-chalcogenides using efficient theoretical approaches. Besides the well-recognized CuInSe{sub 2} and Cu{sub 2}ZnSnSe{sub 4} materials, several novel candidates are identified to have optimal bandgaps of around 1.0–1.5 eV, spike-like band alignments with CdS window layer, sharp photon absorption edges, and high absorption coefficients. These new systems have great potential to be superior absorbers for photovolatic applications if their carrriermore » transport and defect properties are properly optimized.« less

  11. Lumbar load attenuation for rotorcraft occupants using a design methodology for the seat impact energy-absorbing system

    NASA Astrophysics Data System (ADS)

    Moradi, Rasoul; Beheshti, Hamid K.; Lankarani, Hamid M.

    2012-12-01

    Aircraft occupant crash-safety considerations require a minimum cushion thickness to limit the relative vertical motion of the seat-pelvis during high vertical impact loadings in crash landings or accidents. In military aircraft and helicopter seat design, due to the potential for high vertical accelerations in crash scenarios, the seat system must be provided with an energy absorber to attenuate the acceleration level sustained by the occupants. Because of the limited stroke available for the seat structure, the design of the energy absorber becomes a trade-off problem between minimizing the stroke and maximizing the energy absorption. The available stroke must be used to prevent bottoming out of the seat as well as to absorb maximum impact energy to protect the occupant. In this study, the energy-absorbing system in a rotorcraft seat design is investigated using a mathematical model of the occupant/seat system. Impact theories between interconnected bodies in multibody mechanical systems are utilized to study the impact between the seat pan and the occupant. Experimental responses of the seat system and the occupant are utilized to validate the results from this study for civil and military helicopters according to FAR 23 and 25 and MIL-S-58095 requirements. A model for the load limiter is proposed to minimize the lumbar load for the occupant by minimizing the relative velocity between the seat pan and the occupant's pelvis. The modified energy absorber/load limiter is then implemented for the seat structure so that it absorbs the energy of impact in an effective manner and below the tolerable limit for the occupant in a minimum stroke. Results show that for a designed stroke, the level of occupant lumbar spine injury would be significantly attenuated using this modified energy-absorber system.

  12. Performance evaluation and parameter sensitivity of energy-harvesting shock absorbers on different vehicles

    NASA Astrophysics Data System (ADS)

    Guo, Sijing; Liu, Yilun; Xu, Lin; Guo, Xuexun; Zuo, Lei

    2016-07-01

    Traditional shock absorbers provide favourable ride comfort and road handling by dissipating the suspension vibration energy into heat waste. In order to harvest this dissipated energy and improve the vehicle fuel efficiency, many energy-harvesting shock absorbers (EHSAs) have been proposed in recent years. Among them, two types of EHSAs have attracted much attention. One is a traditional EHSA which converts the oscillatory vibration into bidirectional rotation using rack-pinion, ball-screw or other mechanisms. The other EHSA is equipped with a mechanical motion rectifier (MMR) that transforms the bidirectional vibration into unidirectional rotation. Hereinafter, they are referred to as NonMMR-EHSA and MMR-EHSA, respectively. This paper compares their performances with the corresponding traditional shock absorber by using closed-form analysis and numerical simulations on various types of vehicles, including passenger cars, buses and trucks. Results suggest that MMR-EHSA provides better ride performances than NonMMR-EHSA, and that MMR-EHSA is able to improve both the ride comfort and road handling simultaneously over the traditional shock absorber when installed on light-damped, heavy-duty vehicles. Additionally, the optimal parameters of MMR-EHSA are obtained for ride comfort. The optimal solutions ('Pareto-optimal solutions') are also obtained by considering the trade-off between ride comfort and road handling.

  13. Solar power satellite—Life-cycle energy recovery considerations

    NASA Astrophysics Data System (ADS)

    Weingartner, S.; Blumenberg, J.

    1995-05-01

    The construction, in-orbit installation and maintenance of a solar power satellite (SPS) will demand large amounts of energy. As a minimum requirement for an energy effective power satellite it is asked that this amount of energy be recovered. The energy effectiveness in this sense resulting in a positive net energy balance is a prerequisite for a cost-effective power satellite. This paper concentrates on life-cycle energy recovery instead of monetary aspects. The trade-offs between various power generation systems (different types of solar cells, solar dynamic), various construction and installation strategies (using terrestrial or extra-terrestrial resources) and the expected/required lifetime of the SPS are reviewed. The presented work is based on a 2-year study performed at the Technical University of Munich. The study showed that the main energy which is needed to make a solar power satellite a reality is required for the production of the solar power plant components (up to 65%), especially for the solar cell production. Whereas transport into orbit accounts in the order of 20% and the receiving station on Earth (rectenna) requires in the order of 15% of the total energy investment. The energetic amortization time, i.e. the time the SPS has to be operational to give back the amount of energy which was needed for its production, installation and operation, is in the order of two years.

  14. Solar power satellite life-cycle energy recovery consideration

    NASA Astrophysics Data System (ADS)

    Weingartner, S.; Blumenberg, J.

    The construction, in-orbit installation and maintenance of a solar power satellite (SPS) will demand large amounts of energy. As a minimum requirement for an energy effective power satellite it is asked that this amount of energy be recovered. The energy effectiveness in this sense resulting in a positive net energy balance is a prerequisite for cost-effective power satellite. This paper concentrates on life-cycle energy recovery instead on monetary aspects. The trade-offs between various power generation systems (different types of solar cells, solar dynamic), various construction and installation strategies (using terrestrial or extra-terrestrial resources) and the expected/required lifetime of the SPS are reviewed. The presented work is based on a 2-year study performed at the Technical University of Munich. The study showed that the main energy which is needed to make a solar power satellite a reality is required for the production of the solar power components (up to 65%), especially for the solar cell production. Whereas transport into orbit accounts in the order of 20% and the receiving station on earth (rectenna) requires about 15% of the total energy investment. The energetic amortization time, i.e. the time the SPS has to be operational to give back the amount of energy which was needed for its production installation and operation, is about two years.

  15. The Prospects of Solar Energy for Developing Nations.

    ERIC Educational Resources Information Center

    Ramachandran, A.; Gururaja, J.

    1979-01-01

    Discussed are the potential application of solar energy and its possible benefits to developing countries. Various energy needs, including domestic, agricultural, and household, that could be met by using solar energy are discussed. (BT)

  16. Techno-Economic Analysis of Solar Water Heating Systems in Turkey

    PubMed Central

    Ertekin, Can; Kulcu, Recep; Evrendilek, Fatih

    2008-01-01

    In this study, solar water heater was investigated using meteorological and geographical data of 129 sites over Turkey. Three different collector types were compared in terms of absorber material (copper, galvanized sheet and selective absorber). Energy requirement for water heating, collector performances, and economical indicators were calculated with formulations using observed data. Results showed that selective absorbers were most appropriate in terms of coverage rate of energy requirement for water-heating all over Turkey. The prices of selective, copper and galvanized absorber type's heating systems in Turkey were 740.49, 615.69 and 490.89 USD, respectively. While payback periods (PBPs) of the galvanized absorber were lower, net present values (NPVs) of the selective absorber were higher than the rest. Copper absorber type collectors did not appear to be appropriate based on economical indicators. PMID:27879764

  17. Application of solar energy to air-conditioning

    NASA Technical Reports Server (NTRS)

    Harstad, A. J.; Nash, J. M.

    1978-01-01

    Results of survey of application of solar energy to air-conditioning systems are summarized in report. Survey reviewed air-conditioning techniques that are most likely to find residential applications and that are compatible with solar-energy systems being developed.

  18. Solar energy storage and utilization

    NASA Technical Reports Server (NTRS)

    Yuan, S. W.; Bloom, A. M.

    1976-01-01

    A method of storing solar energy in the ground for heating residential buildings is described. The method would utilize heat exchanger pipes with a circulating fluid to transfer the energy beneath the surface as well as to extract the stored energy.

  19. The Solar Constant: A Take Home Lab

    ERIC Educational Resources Information Center

    Eaton, B. G.; And Others

    1977-01-01

    Describes a method that uses energy from the sun, absorbed by aluminum discs, to melt ice, and allows the determination of the solar constant. The take-home equipment includes Styrofoam cups, a plastic syringe, and aluminum discs. (MLH)

  20. Solar optics-based active panel for solar energy storage and disinfection of greywater.

    PubMed

    Lee, W; Song, J; Son, J H; Gutierrez, M P; Kang, T; Kim, D; Lee, L P

    2016-09-01

    Smart city and innovative building strategies are becoming increasingly more necessary because advancing a sustainable building system is regarded as a promising solution to overcome the depleting water and energy. However, current sustainable building systems mainly focus on energy saving and miss a holistic integration of water regeneration and energy generation. Here, we present a theoretical study of a solar optics-based active panel (SOAP) that enables both solar energy storage and photothermal disinfection of greywater simultaneously. Solar collector efficiency of energy storage and disinfection rate of greywater have been investigated. Due to the light focusing by microlens, the solar collector efficiency is enhanced from 25% to 65%, compared to that without the microlens. The simulation of greywater sterilization shows that 100% disinfection can be accomplished by our SOAP for different types of bacteria including Escherichia coli . Numerical simulation reveals that our SOAP as a lab-on-a-wall system can resolve the water and energy problem in future sustainable building systems.

  1. Solar optics-based active panel for solar energy storage and disinfection of greywater

    PubMed Central

    Lee, W.; Song, J.; Son, J. H.; Gutierrez, M. P.; Kang, T.; Kim, D.; Lee, L. P.

    2016-01-01

    Smart city and innovative building strategies are becoming increasingly more necessary because advancing a sustainable building system is regarded as a promising solution to overcome the depleting water and energy. However, current sustainable building systems mainly focus on energy saving and miss a holistic integration of water regeneration and energy generation. Here, we present a theoretical study of a solar optics-based active panel (SOAP) that enables both solar energy storage and photothermal disinfection of greywater simultaneously. Solar collector efficiency of energy storage and disinfection rate of greywater have been investigated. Due to the light focusing by microlens, the solar collector efficiency is enhanced from 25% to 65%, compared to that without the microlens. The simulation of greywater sterilization shows that 100% disinfection can be accomplished by our SOAP for different types of bacteria including Escherichia coli. Numerical simulation reveals that our SOAP as a lab-on-a-wall system can resolve the water and energy problem in future sustainable building systems. PMID:27822328

  2. The Geography of Solar Energy.

    ERIC Educational Resources Information Center

    LaHart, David E.; Allen, Rodney F.

    1984-01-01

    After learning about two promising techniques for generating electricity--photovoltaic cells and wind energy conversion systems--secondary students analyze two maps of the United States showing solar radiation and available wind power to determine which U.S. regions have potential for these solar electric systems. (RM)

  3. Solar energy to biofuels.

    PubMed

    Agrawal, Rakesh; Singh, Navneet R

    2010-01-01

    In a solar economy, sustainably available biomass holds the potential to be an excellent nonfossil source of high energy density transportation fuel. However, if sustainably available biomass cannot supply the liquid fuel need for the entire transport sector, alternatives must be sought. This article reviews biomass to liquid fuel conversion processes that treat biomass primarily as a carbon source and boost liquid fuel production substantially by using supplementary energy that is recovered from solar energy at much higher efficiencies than the biomass itself. The need to develop technologies for an energy-efficient future sustainable transport sector infrastructure that will use different forms of energy, such as electricity, H(2), and heat, in a synergistic interaction with each other is emphasized. An enabling template for such a future transport infrastructure is presented. An advantage of the use of such a template is that it reduces the land area needed to propel an entire transport sector. Also, some solutions for the transition period that synergistically combine biomass with fossil fuels are briefly discussed.

  4. Key techniques for space-based solar pumped semiconductor lasers

    NASA Astrophysics Data System (ADS)

    He, Yang; Xiong, Sheng-jun; Liu, Xiao-long; Han, Wei-hua

    2014-12-01

    In space, the absence of atmospheric turbulence, absorption, dispersion and aerosol factors on laser transmission. Therefore, space-based laser has important values in satellite communication, satellite attitude controlling, space debris clearing, and long distance energy transmission, etc. On the other hand, solar energy is a kind of clean and renewable resources, the average intensity of solar irradiation on the earth is 1353W/m2, and it is even higher in space. Therefore, the space-based solar pumped lasers has attracted much research in recent years, most research focuses on solar pumped solid state lasers and solar pumped fiber lasers. The two lasing principle is based on stimulated emission of the rare earth ions such as Nd, Yb, Cr. The rare earth ions absorb light only in narrow bands. This leads to inefficient absorption of the broad-band solar spectrum, and increases the system heating load, which make the system solar to laser power conversion efficiency very low. As a solar pumped semiconductor lasers could absorb all photons with energy greater than the bandgap. Thus, solar pumped semiconductor lasers could have considerably higher efficiencies than other solar pumped lasers. Besides, solar pumped semiconductor lasers has smaller volume chip, simpler structure and better heat dissipation, it can be mounted on a small satellite platform, can compose satellite array, which can greatly improve the output power of the system, and have flexible character. This paper summarizes the research progress of space-based solar pumped semiconductor lasers, analyses of the key technologies based on several application areas, including the processing of semiconductor chip, the design of small and efficient solar condenser, and the cooling system of lasers, etc. We conclude that the solar pumped vertical cavity surface-emitting semiconductor lasers will have a wide application prospects in the space.

  5. Solar Thermal Energy Storage Device: Hybrid Nanostructures for High-Energy-Density Solar Thermal Fuels

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    2012-01-09

    HEATS Project: MIT is developing a thermal energy storage device that captures energy from the sun; this energy can be stored and released at a later time when it is needed most. Within the device, the absorption of sunlight causes the solar thermal fuel’s photoactive molecules to change shape, which allows energy to be stored within their chemical bonds. A trigger is applied to release the stored energy as heat, where it can be converted into electricity or used directly as heat. The molecules would then revert to their original shape, and can be recharged using sunlight to begin themore » process anew. MIT’s technology would be 100% renewable, rechargeable like a battery, and emissions-free. Devices using these solar thermal fuels—called Hybrisol—can also be used without a grid infrastructure for applications such as de-icing, heating, cooking, and water purification.« less

  6. Temperature effect of natural organic extraction upon light absorbance in dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Suhaimi, Suriati; Mohamed Siddick, Siti Zubaidah; Retnasamy, Vithyacharan; Abdul Wahid, Mohamad Halim; Ahmad Hambali, Nor Azura Malini; Mohamad Shahimin, Mukhzeer

    2017-02-01

    Natural organic dyes contain pigments which when safely extracted from plants have the potential to be used as a sensitizer while promising a low-cost fabrication, environmental friendly dye-sensitized solar cells (DSSCs). Ardisia, Bawang Sabrang, Harum Manis mango, Oxalis Triangularis and Rosella showed different absorption peaks when the extraction process were carried out at different temperatures. Hence, these were used as the basis to determine the conversion efficiency against the dyes extracting temperature. In this study, all dyes extracted in water have shown the best performance at a temperature of 100°C except for Harum Manis mango, while in ethanol, the optimum temperature was obtained between the room temperature, 25°C and 50°C. The absorption spectrum in water showed a broader absorption wavelength vis-à-vis ethanol solvent that resulted in the absorption peak for Ardisia, Harum Manis mango and Rosella between 450 nm and 550 nm. The highest conversion efficiency is observed to be achieved by Oxalis Triangularis extracted in water solution at 100°C, which was approximately 0.96% which corresponds to the broader absorbance trends in the literature. Thus, the optimum condition for extracting temperature for dyes in water and ethanol is room temperature and boiling points of water. Hence, Ardisia, Bawang Sabrang, Harum Manis mango, Oxalis Triangularis and Rosella can be an as alternative source for photosensitizer, and the impacts of temperature upon the light absorbance can be further investigated to produce the ultimate natural dye based solar cells.

  7. Solar energy: An investment in our nation`s energy and economic security

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    NONE

    1995-08-01

    The Solar Energy Industries Association (SEIA) is the national trade organization of the photovoltaics and solar thermal manufacturers and component suppliers. The solar energy industries are engaged in aggressive efforts to develop, validate, and deploy solar energy systems for a wide variety of applications in every sector of our economy. In many cases. these efforts are being implemented in partnership with the US DOE and its laboratories. These partnerships are heavily cost-shared by industry and were entered into in good faith by companies and corporations willing to include their significant cost-share in their multi-year budget planning. The result is amore » set of highly leveraged programs that are on-budget, on-time, and are working. The authors feel confident that those who take the time to look will see the compelling benefits of continued investment in solar energy.« less

  8. Electrodeposited Ni nanowires-track etched P.E.T. composites as selective solar absorbers

    NASA Astrophysics Data System (ADS)

    Lukhwa, R.; Sone, B.; Kotsedi, L.; Madjoe, R.; Maaza, M.

    2018-05-01

    This contribution reports on the structural, optical and morphological properties of nanostructured flexible solar-thermal selective absorber composites for low temperature applications. The candidate material in the system is consisting of electrodeposited nickel nano-cylinders embedded in track-etched polyethylene terephthalate (PET) host membrane of pore sizes ranging between 0.3-0.8µm supported by conductive nickel thin film of about 0.5µm. PET were irradiated with 11MeV/u high charged xenon (Xe) ions at normal incidence. The tubular and metallic structure of the nickel nano-cylinders within the insulator polymeric host forms a typical ceramic-metal nano-composite "Cermet". The produced material was characterized by the following techniques: X-ray diffraction (XRD) for structural characterization to determine preferred crystallographic structure, and grain size of the materials; Scanning electron microscopy (SEM) to determine surface morphology, particle size, and visual imaging of distribution of structures on the surface of the substrate; Atomic force microscopy (AFM) to characterize surface roughness, surface morphology, and film thickness, and UV-Vis-NIR spectrophotometer to measure the reflectance, then to determine solar absorption

  9. Adaptive, full-spectrum solar energy system

    DOEpatents

    Muhs, Jeffrey D.; Earl, Dennis D.

    2003-08-05

    An adaptive full spectrum solar energy system having at least one hybrid solar concentrator, at least one hybrid luminaire, at least one hybrid photobioreactor, and a light distribution system operably connected to each hybrid solar concentrator, each hybrid luminaire, and each hybrid photobioreactor. A lighting control system operates each component.

  10. Advanced solar energy conversion. [solar pumped gas lasers

    NASA Technical Reports Server (NTRS)

    Lee, J. H.

    1981-01-01

    An atomic iodine laser, a candidate for the direct solar pumped lasers, was successfully excited with a 4 kW beam from a xenon arc solar simulator, thus proving the feasibility of the concept. The experimental set up and the laser output as functions of operating conditions are presented. The preliminary results of the iodine laser amplifier pumped with the HCP array to which a Q switch for giant pulse production was coupled are included. Two invention disclosures - a laser driven magnetohydrodynamic generator for conversion of laser energy to electricity and solar pumped gas lasers - are also included.

  11. Absorber for solar power.

    PubMed

    Powell, W R

    1974-10-01

    A simple, economical absorber utilizing a new principle of operation to achieve very low reradiation losses while generating temperatures limited by material properties of quartz is described. Its performance is analyzed and indicates approximately 90% thermal efficiency and 73% conversion efficiency for an earth based unit with moderately concentrated (~tenfold) sunlight incident. It is consequently compatible with the most economic of concentrator mirrors (stamped) or mirrors deployable in space. Space applications are particularly attractive, as temperatures significantly below 300 K are possible and permit even higher conversion efficiency.

  12. The Potential of Heat Collection from Solar Radiation in Asphalt Solar Collectors in Malaysia

    NASA Astrophysics Data System (ADS)

    Beddu, Salmia; Talib, Siti Hidayah Abdul; Itam, Zarina

    2016-03-01

    The implementation of asphalt solar collectors as a means of an energy source is being widely studied in recent years. Asphalt pavements are exposed to daily solar radiation, and are capable of reaching up to 70°C in temperature. The potential of harvesting energy from solar pavements as an alternative energy source in replace of non-renewable energy sources prone to depletion such as fuel is promising. In Malaysia, the sun intensity is quite high and for this reason, absorbing the heat from sun radiation, and then utilizing it in many other applications such as generating electricity could definitely be impressive. Previous researches on the different methods of studying the effect of heat absorption caused by solar radiation prove to be quite old and inaffective. More recent findings, on the otherhand, prove to be more informative. This paper focuses on determining the potential of heat collection from solar radiation in asphalt solar collectors using steel piping. The asphalt solar collector model constructed for this research was prepared in the civil engineering laboratory. The hot mixed asphalt (HMA) contains 10% bitumen mixed with 90% aggregates of the total size of asphalt. Three stainless steel pipes were embedded into the interior region of the model according to the design criteria, and then put to test. Results show that harvesting energy from asphalt solar collectors proves highly potential in Malaysia due its the hot climate.

  13. Theoretical studies of solar pumped lasers

    NASA Technical Reports Server (NTRS)

    Harries, Wynford L.

    1990-01-01

    One concept for collecting solar energy is to use large solar collectors and then use lasers as energy converters whose output beams act as transmission lines to deliver the energy to a destination. The efficiency of the process would be improved if the conversion could be done directly using solar pumped lasers, and the possibility of making such lasers is studied. There are many applications for such lasers, and these are examined. By including the applications first, the requirements for the lasers will be more evident. They are especially applicable to the Space program, and include cases where no other methods of delivering power seem possible. Using the lasers for conveying information and surveillance is also discussed. Many difficulties confront the designer of an efficient system for power conversion. These involve the nature of the solar spectrum, the method of absorbing the energy, the transfer of power into laser beams, and finally, the far field patterns of the beams. The requirements of the lasers are discussed. Specific laser configurations are discussed. The thrust is into gas laser systems, because for space applications, the laser could be large, and also the medium would be uniform and not subject to thermal stresses. Dye and solid lasers are treated briefly. For gas lasers, a chart of the various possibilities is shown, and the various families of gas lasers divided according to the mechanisms of absorbing solar radiation and of lasing. Several specific models are analyzed and evaluated. Overall conclusions for the program are summarized, and the performances of the lasers related to the requirements of various applications.

  14. Preparation and characterization of CuInS2 absorber layers by sol-gel method for solar cell applications

    NASA Astrophysics Data System (ADS)

    Amerioun, M. H.; Ghazi, M. E.; Izadifard, M.; Bahramian, B.

    2016-04-01

    CuInSe2 , CuInS2 ( CIS2 and CuInGaS2 alloys and their compounds with band gaps between 1.05 and 1.7eV are absorbance materials based on chalcopyrite, in which, because of their suitable direct band gap, high absorbance coefficient and short carrier diffusion are used as absorbance layers in solar cells. In this work, the effects of decrease in p H and thickness variation on characteristics of the CIS2 absorber layers, grown by spin coating on glass substrates, are investigated. Furthermore by using thiourea as a sulphur source in solvent, the sulfurization of layers was done easier than other sulfurization methods. Due to the difficulty in dissolving thiourea in the considered solvent that leads to a fast deposition during the dissolving process, precise conditions are employed in order to prepare the solution. In fact, this procedure can facilitate the sulfurization process of CuIn layers. The results obtained from this investigation indicate reductions in absorbance and band gap in the visible region of the spectrum as a result of decrease in p H. Finally, conductivity of layers is studied by the current vs. voltage curve that represents reduction of electrical resistance with decrease and increase in p H and thickness, respectively.

  15. Magnetic energy flow in the solar wind.

    NASA Technical Reports Server (NTRS)

    Modisette, J. L.

    1972-01-01

    Discussion of the effect of rotation (tangential flow) of the solar wind on the conclusions of Whang (1971) suggesting an increase in the solar wind velocity due to the conversion of magnetic energy to kinetic energy. It is shown that the effect of the rotation of the sun on the magnetic energy flow results in most of the magnetic energy being transported by magnetic shear stress near the sun.

  16. Epidermal UV-A absorbance and whole-leaf flavonoid composition in pea respond more to solar blue light than to solar UV radiation.

    PubMed

    Siipola, Sari M; Kotilainen, Titta; Sipari, Nina; Morales, Luis O; Lindfors, Anders V; Robson, T Matthew; Aphalo, Pedro J

    2015-05-01

    Plants synthesize phenolic compounds in response to certain environmental signals or stresses. One large group of phenolics, flavonoids, is considered particularly responsive to ultraviolet (UV) radiation. However, here we demonstrate that solar blue light stimulates flavonoid biosynthesis in the absence of UV-A and UV-B radiation. We grew pea plants (Pisum sativum cv. Meteor) outdoors, in Finland during the summer, under five types of filters differing in their spectral transmittance. These filters were used to (1) attenuate UV-B; (2) attenuate UV-B and UV-A < 370 nm; (3) attenuate UV-B and UV-A; (4) attenuate UV-B, UV-A and blue light; and (5) as a control not attenuating these wavebands. Attenuation of blue light significantly reduced the flavonoid content in leaf adaxial epidermis and reduced the whole-leaf concentrations of quercetin derivatives relative to kaempferol derivatives. In contrast, UV-B responses were not significant. These results show that pea plants regulate epidermal UV-A absorbance and accumulation of individual flavonoids by perceiving complex radiation signals that extend into the visible region of the solar spectrum. Furthermore, solar blue light instead of solar UV-B radiation can be the main regulator of phenolic compound accumulation in plants that germinate and develop outdoors. © 2014 John Wiley & Sons Ltd.

  17. Synergies of solar energy across a land-food-energy-water nexus

    NASA Astrophysics Data System (ADS)

    Hoffacker, M. K.; Hernandez, R. R.; Allen, M. F.

    2017-12-01

    Land-cover change from energy development, including solar energy, presents trade-offs for the production of food and the conservation of natural ecosystems. Solar energy plays a critical role in contributing to the alternative energy mix to mitigate climate change and meet policy milestones; however, the extent that solar energy development can mitigate land scarcity, water shortages, and conservation is understudied. Here, we test whether projected electricity needs for the state of California (CA, United States [US]) can be met within land-cover types that can also generate environmental, social and fiscal co-benefits (techno-ecological synergies) including: the built environment, salt-affected land, contaminated land, and water reservoirs (as floatovoltaics). Additionally, we analyze general spatial trends and patterns related to clustering and proximity of techno-ecological opportunities and land-cover types (e.g. contamination sites and cities). In total, the Central Valley, a globally significant agricultural region, encompasses 15% of CA, 8,415 km2 of which was identified as potentially synergistic land for solar energy. These areas comprise a capacity-based energy potential of 17,348 TWh y-1 for photovoltaic (PV) and 1,655 TWh y-1 for concentrating solar power (CSP). Accounting for technology efficiencies, this exceeds California's 2025 projected electricity demands up to 13 and 2 times for PV and CSP, respectively. Further, 60% of contaminated lands are clustered within and up to 10 km of the 10 most populated cities in the Central Valley, where energy is consumed. Our study underscores the potential of strategic renewable energy siting to mitigate environmental trade-offs typically coupled with energy development sprawl in landscapes characterized by complex nexus issues.

  18. Off-farm applications of solar energy in agriculture

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Berry, R.E.

    1980-01-01

    Food processing applications make up almost all present off-farm studies of solar energy in agriculture. Research, development and demonstration projects on solar food processing have shown significant progress over the past 3 years. Projects have included computer simulation and mathematical models, hardware and process development for removing moisture from horticultural or animal products, integration of energy conservation with solar energy augmentation in conventional processes, and commercial scale demonstrations. The demonstration projects include solar heated air for drying prunes and raisins, soy beans and onions/garlic; and solar generated steam for orange juice pasteurization. Several new and planned projects hold considerable promisemore » for commerical exploitation in future food processes.« less

  19. Graphene for thermoelectronic solar energy conversion

    NASA Astrophysics Data System (ADS)

    De, Dilip K.; Olukunle, Olawole C.

    2017-08-01

    Graphene is a high temperature material which can stand temperature as high as 4600 K in vacuum. Even though its work function is high (4.6 eV) the thermionic emission current density at such temperature is very high. Graphene is a wonderful material whose work function can be engineered as desired. Kwon et al41 reported a chemical approach to reduce work function of graphene using K2CO3, Li2CO3, Rb2CO3, Cs2CO3. The work functions are reported to be 3.7 eV, 3.8 eV, 3.5 eV and 3.4 eV. Even though they did not report the high temperature tolerance of such alkali metal carbonate doped graphene, their works open a great promise for use of pure graphene and doped graphene as emitter (cathode) and collector (anode) in a solar thermionic energy converter. This paper discusses the dynamics of solar energy conversion to electrical energy using thermionic energy converter with graphene as emitter and collector. We have considered parabolic mirror concentrator to focus solar energy onto the emitter to achieve temperature around 4300 K. Our theoretical calculations and the modelling show that efficiency as high as 55% can easily be achieved if space-charge problem can be reduced and the collector can be cooled to certain proper temperature. We have discussed methods of controlling the associated space-charge problems. Richardson-Dushman equation modified by the authors have been used in this modelling. Such solar energy conversion would reduce the dependence on silicon solar panel and has great potential for future applications.

  20. Self-organized porphyrin nanomaterials for solar energy harvesting

    NASA Astrophysics Data System (ADS)

    Radivojevic, Ivana

    New concepts in the design and function of organic dyes as sensitizers for solar energy harvesting are needed. Commercial viability constrains these designs: (a) cost effective synthesis, (b) long-term stability, and (c) an important goal is to reduce the environmental impact of the product at the end of its life cycle. Simple porphyrinoid dyes meet these constraints, but new modes of incorporation into devices are needed to increase the efficiency of charge separation that drives any photonic device designed to harvest light. In this thesis, we will show how complex material architectures on surfaces need not to be the result of complex molecular structures or strong intermolecular forces that form in solution and deposit intact onto surfaces. Varying environmental conditions we can dictate morphology of self-organized structures on surfaces. These studies provide further insights into the design principles, processing, and extent of electron and energy transfer in supramolecular porphyrin materials. We are also developing a new strategy to couple porphyrinoid dyes to oxide surfaces using hafnium and zirconium metalloporphyrins and metallophthalocyanines.The mode of dye attachment to oxide surfaces is a key parameter for the construction of efficient dye sensitized solar cells. Porphyrinoid dyes containing oxophylic group (IV) metal ions that protrude from on face of the macrocycle allow connections directly to oxide surfaces, wherein the metal ion serves as the conduit. Since the charge transport efficiency is mediated by appropriate matching of molecular HOMO-LUMO gaps to semiconductor band gaps, we will show characterized solution phase ground and excited redox potentials of these dyes, and also photophysical properties of dye excited state using transient absorbance spectroscopy.

  1. 76 FR 54454 - Issuance of Loan Guarantee to Genesis Solar, LLC, for the Genesis Solar Energy Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-01

    ... DEPARTMENT OF ENERGY Issuance of Loan Guarantee to Genesis Solar, LLC, for the Genesis Solar... Energy Project (GSEP), a 250-megawatt (MW) nominal capacity solar power generating facility on.../Final Environmental Impact Statement for the Genesis Solar Energy Project, Riverside County, California...

  2. Energy conservation in housing design using solar energy, mechanical system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bakir, N.M.W.

    1985-01-01

    This paper presents the first experimental full-scale house built by the Solar Energy Research Center of Baghdad to be heated and cooled by solar energy. The various architectural and environmental considerations which entered into the design process are discussed, as well as the range of passive techniques examined for their compatibility with the local climate and their ability to optimize the energy efficiency of the house. The mechanical systems which were ultimately implemented are described.

  3. Solar energy thermalization and storage device

    DOEpatents

    McClelland, John F.

    1981-09-01

    A passive solar thermalization and thermal energy storage assembly which is visually transparent. The assembly consists of two substantial parallel, transparent wall members mounted in a rectangular support frame to form a liquid-tight chamber. A semitransparent thermalization plate is located in the chamber, substantially paralled to and about equidistant from the transparent wall members to thermalize solar radiation which is stored in a transparent thermal energy storage liquid which fills the chamber. A number of the devices, as modules, can be stacked together to construct a visually transparent, thermal storage wall for passive solar-heated buildings.

  4. Solar energy thermalization and storage device

    DOEpatents

    McClelland, J.F.

    A passive solar thermalization and thermal energy storage assembly which is visually transparent is described. The assembly consists of two substantial parallel, transparent wall members mounted in a rectangular support frame to form a liquid-tight chamber. A semitransparent thermalization plate is located in the chamber, substantially paralled to and about equidistant from the transparent wall members to thermalize solar radiation which is stored in a transparent thermal energy storage liquid which fills the chamber. A number of the devices, as modules, can be stacked together to construct a visually transparent, thermal storage wall for passive solar-heated buildings.

  5. Solar energy control system. [temperature measurement

    NASA Technical Reports Server (NTRS)

    Currie, J. R. (Inventor)

    1981-01-01

    A solar energy control system for a hot air type solar energy heating system wherein thermocouples are arranged to sense the temperature of a solar collector, a space to be heated, and a top and bottom of a heat storage unit is disclosed. Pertinent thermocouples are differentially connected together, and these are employed to effect the operation of dampers, a fan, and an auxiliary heat source. In accomplishing this, the differential outputs from the thermocouples are amplified by a single amplifier by multiplexing techniques. Additionally, the amplifier is corrected as to offset by including as one multiplex channel a common reference signal.

  6. Solar applications of thermal energy storage. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, C.; Taylor, L.; DeVries, J.

    A technology assessment is presented on solar energy systems which use thermal energy storage. The study includes characterization of the current state-of-the-art of thermal energy storage, an assessment of the energy storage needs of solar energy systems, and the synthesis of this information into preliminary design criteria which would form the basis for detailed designs of thermal energy storage. (MHR)

  7. Plant engineers solar energy handbook. [Includes glossaries

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1978-01-21

    This handbook is to provide plant engineers with factual information on solar energy technology and on the various methods for assessing the future potential of this alternative energy source. The following areas are covered: solar components and systems (collectors, storage, service hot-water systems, space heating with liquid and air systems, space cooling, heat pumps and controls); computer programs for system optimization local solar and weather data; a description of buildings and plants in the San Francisco Bay Area applying solar technology; current Federal and California solar legislation; standards, codes, and performance testing information; a listing of manufacturers, distributors, and professionalmore » services that are available in Northern California; and information access. Finally, solar design checklists are provided for those engineers who wish to design their own systems. (MHR)« less

  8. Combined solar collector and energy storage system

    NASA Technical Reports Server (NTRS)

    Jensen, R. N. (Inventor)

    1980-01-01

    A combined solar energy collector, fluid chiller and energy storage system is disclosed. A movable interior insulated panel in a storage tank is positionable flush against the storage tank wall to insulate the tank for energy storage. The movable interior insulated panel is alternately positionable to form a solar collector or fluid chiller through which the fluid flows by natural circulation.

  9. Flat plate solar collector for water pre-heating using concentrated solar power (CSP)

    NASA Astrophysics Data System (ADS)

    Peris, Leonard Sunny; Shekh, Md. Al Amin; Sarker, Imran

    2017-12-01

    Numerous attempt and experimental conduction on different methods to harness energy from renewable sources are being conducted. This study is a contribution to the purpose of harnessing solar energy as a renewable source by using flat plate solar collector medium to preheat water. Basic theory of solar radiation and heat convection in water (working fluid) has been combined with heat conduction process by using copper tubes and aluminum absorber plate in a closed conduit, covered with a glazed through glass medium. By this experimental conduction, a temperature elevation of 35°C in 10 minutes duration which is of 61.58% efficiency range (maximum) has been achieved. The obtained data and experimental findings are validated with the theoretical formulation and an experimental demonstration model. A cost effective and simple form of heat energy extraction method for space heating/power generation has been thoroughly discussed with possible industrial implementation possibilities. Under-developed and developing countries can take this work as an illustration for renewable energy utilization for sustainable energy prospect. Also a full structure based data to derive concentrated solar energy in any geographical location of Bangladesh has been outlined in this study. These research findings can contribute to a large extent for setting up any solar based power plant in Bangladesh irrespective of its installation type.

  10. Dependence of lattice strain relaxation, absorbance, and sheet resistance on thickness in textured ZnO@B transparent conductive oxide for thin-film solar cell applications.

    PubMed

    Kou, Kuang-Yang; Huang, Yu-En; Chen, Chien-Hsun; Feng, Shih-Wei

    2016-01-01

    The interplay of surface texture, strain relaxation, absorbance, grain size, and sheet resistance in textured, boron-doped ZnO (ZnO@B), transparent conductive oxide (TCO) materials of different thicknesses used for thin film, solar cell applications is investigated. The residual strain induced by the lattice mismatch and the difference in the thermal expansion coefficient for thicker ZnO@B is relaxed, leading to an increased surface texture, stronger absorbance, larger grain size, and lower sheet resistance. These experimental results reveal the optical and material characteristics of the TCO layer, which could be useful for enhancing the performance of solar cells through an optimized TCO layer.

  11. Physical Limits of Solar Energy Conversion in the Earth System.

    PubMed

    Kleidon, Axel; Miller, Lee; Gans, Fabian

    2016-01-01

    Solar energy provides by far the greatest potential for energy generation among all forms of renewable energy. Yet, just as for any form of energy conversion, it is subject to physical limits. Here we review the physical limits that determine how much energy can potentially be generated out of sunlight using a combination of thermodynamics and observed climatic variables. We first explain how the first and second law of thermodynamics constrain energy conversions and thereby the generation of renewable energy, and how this applies to the conversions of solar radiation within the Earth system. These limits are applied to the conversion of direct and diffuse solar radiation - which relates to concentrated solar power (CSP) and photovoltaic (PV) technologies as well as biomass production or any other photochemical conversion - as well as solar radiative heating, which generates atmospheric motion and thus relates to wind power technologies. When these conversion limits are applied to observed data sets of solar radiation at the land surface, it is estimated that direct concentrated solar power has a potential on land of up to 11.6 PW (1 PW=10(15) W), whereas photovoltaic power has a potential of up to 16.3 PW. Both biomass and wind power operate at much lower efficiencies, so their potentials of about 0.3 and 0.1 PW are much lower. These estimates are considerably lower than the incoming flux of solar radiation of 175 PW. When compared to a 2012 primary energy demand of 17 TW, the most direct uses of solar radiation, e.g., by CSP or PV, have thus by far the greatest potential to yield renewable energy requiring the least space to satisfy the human energy demand. Further conversions into solar-based fuels would be reduced by further losses which would lower these potentials. The substantially greater potential of solar-based renewable energy compared to other forms of renewable energy simply reflects much fewer and lower unavoidable conversion losses when solar

  12. Photoswitchable Molecular Rings for Solar-Thermal Energy Storage.

    PubMed

    Durgun, E; Grossman, Jeffrey C

    2013-03-21

    Solar-thermal fuels reversibly store solar energy in the chemical bonds of molecules by photoconversion, and can release this stored energy in the form of heat upon activation. Many conventional photoswichable molecules could be considered as solar thermal fuels, although they suffer from low energy density or short lifetime in the photoinduced high-energy metastable state, rendering their practical use unfeasible. We present a new approach to the design of chemistries for solar thermal fuel applications, wherein well-known photoswitchable molecules are connected by different linker agents to form molecular rings. This approach allows for a significant increase in both the amount of stored energy per molecule and the stability of the fuels. Our results suggest a range of possibilities for tuning the energy density and thermal stability as a function of the type of the photoswitchable molecule, the ring size, or the type of linkers.

  13. A facile fabrication of chemically converted graphene oxide thin films and their uses as absorber materials for solar cells

    NASA Astrophysics Data System (ADS)

    Adelifard, Mehdi; Darudi, Hosein

    2016-07-01

    There is a great interest in the use of graphene sheets in thin film solar cells with low-cost and good-optoelectronic properties. Here, the production of absorbent conductive reduced graphene oxide (RGO) thin films was investigated. RGO thin films were prepared from spray-coated graphene oxide (GO) layers at various substrate temperature followed by a simple hydrazine-reducing method. The structural, morphological, optical, and electrical characterizations of graphene oxide (GO) and RGO thin films were investigated. X-ray diffraction analysis showed a phase shift from GO to RGO due to hydrazine treatment, in agreement with the FTIR spectra of the layers. FESEM images clearly exhibited continuous films resulting from the overlap of graphene nanosheets. The produced low-cost thin films had high absorption coefficient up to 1.0 × 105 cm-1, electrical resistance as low as 0.9 kΩ/sq, and effective optical band gap of about 1.50 eV, close to the optimum value for solar conversion. The conductive absorbent properties of the reduced graphene oxide thin films would be useful to develop photovoltaic cells.

  14. Economic Evaluation of Townhouse Solar Energy System

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Solar-energy site in Columbia, South Carolina, is comprised of four townhouse apartments. Report summarizes economic evaluation of solar--energy system and projected performance of similar systems in four other selected cities. System is designed to supply 65 percent of heating and 75 percent of hot water.

  15. Energy efficiency of a solar domestic hot water system

    NASA Astrophysics Data System (ADS)

    Zukowski, Miroslaw

    2017-11-01

    The solar domestic hot water (SDHW) system located on the campus of Bialystok University of Technology is the object of the research described in the current paper. The solar thermal system is composed of 35 flat plate collectors, 21 evacuated tube collectors and eight hot water tanks with the capacity of 1 m3 of each. Solar facility is equipped with hardware for automatic data collection. Additionally, the weather station located on the roof of the building provides measurements of basic parameters of ambient air and solar radiation. The main objective of Regional Operational Program was the assessment of the effectiveness of this solar energy technology in the climatic conditions of the north-eastern Poland. Energy efficiency of SDHW system was defined in this research as the ratio between the useful heat energy supplied to the domestic hot water system and solar energy incident on the surface of solar panels. Heat loss from water storage tanks, and from the pipe network to the surrounding air, as well as the electrical energy consumed by the pumps have been included in the calculations. The paper presents the detailed results and conclusions obtained from this energy analysis.

  16. Solar Energy for Pacific Northwest Buildings.

    ERIC Educational Resources Information Center

    Reynolds, John S.

    Data presented in this report indicate that solar space and water heating are possible in the Pacific Northwest. The first section of the report contains solar records from several stations in the region illustrating space heating needs that could be met, on an average daily basis, by solar energy. The data are summarized, and some preliminary…

  17. Battle Keeps Solar Energy in Receiver

    NASA Technical Reports Server (NTRS)

    Mcdougal, A. R.; Hale, R. R.

    1982-01-01

    Mirror structure in solar concentrator reduces heat loss by reflection and reradiation. Baffle reflects entering rays back and forth in solar-concentrator receiver until they reach heat exchanger. Similarly, infrared energy reradiated by heat exchanger is prevented from leaving receiver. Surfaces of baffle and inside wall of receiver are polished and highly reflective at solar and infrared wavelengths.

  18. Turbulent Kinetic Energy in the Energy Balance of a Solar Flare

    NASA Astrophysics Data System (ADS)

    Kontar, E. P.; Perez, J. E.; Harra, L. K.; Kuznetsov, A. A.; Emslie, A. G.; Jeffrey, N. L. S.; Bian, N. H.; Dennis, B. R.

    2017-04-01

    The energy released in solar flares derives from a reconfiguration of magnetic fields to a lower energy state, and is manifested in several forms, including bulk kinetic energy of the coronal mass ejection, acceleration of electrons and ions, and enhanced thermal energy that is ultimately radiated away across the electromagnetic spectrum from optical to x rays. Using an unprecedented set of coordinated observations, from a suite of instruments, we here report on a hitherto largely overlooked energy component—the kinetic energy associated with small-scale turbulent mass motions. We show that the spatial location of, and timing of the peak in, turbulent kinetic energy together provide persuasive evidence that turbulent energy may play a key role in the transfer of energy in solar flares. Although the kinetic energy of turbulent motions accounts, at any given time, for only ˜(0.5 - 1 )% of the energy released, its relatively rapid (˜1 - 10 s ) energization and dissipation causes the associated throughput of energy (i.e., power) to rival that of major components of the released energy in solar flares, and thus presumably in other astrophysical acceleration sites.

  19. Turbulent Kinetic Energy in the Energy Balance of a Solar Flare.

    PubMed

    Kontar, E P; Perez, J E; Harra, L K; Kuznetsov, A A; Emslie, A G; Jeffrey, N L S; Bian, N H; Dennis, B R

    2017-04-14

    The energy released in solar flares derives from a reconfiguration of magnetic fields to a lower energy state, and is manifested in several forms, including bulk kinetic energy of the coronal mass ejection, acceleration of electrons and ions, and enhanced thermal energy that is ultimately radiated away across the electromagnetic spectrum from optical to x rays. Using an unprecedented set of coordinated observations, from a suite of instruments, we here report on a hitherto largely overlooked energy component-the kinetic energy associated with small-scale turbulent mass motions. We show that the spatial location of, and timing of the peak in, turbulent kinetic energy together provide persuasive evidence that turbulent energy may play a key role in the transfer of energy in solar flares. Although the kinetic energy of turbulent motions accounts, at any given time, for only ∼(0.5-1)% of the energy released, its relatively rapid (∼1-10  s) energization and dissipation causes the associated throughput of energy (i.e., power) to rival that of major components of the released energy in solar flares, and thus presumably in other astrophysical acceleration sites.

  20. Hexagonal Hollow Tube Based Energy Absorbing Crash Buffers for Roadside Fixed Objects

    NASA Astrophysics Data System (ADS)

    Uddin, M. S.; Amirah Shafie, Nurul; Zivkovic, Grad

    2017-03-01

    The purpose of this study was to investigate the deformation of the energy absorbing hexagonal hollow tubes in a lateral compression. The aim is to design cost effective and high energy-absorbing buffer systems, which are capable of controlling out-of-control vehicles in high-speed zones. A nonlinear quasi-static finite element analysis was applied to determine the deformation and energy absorption capacity. The main parameters in the design were diameter and wall thickness of the tubes. Experimental test simulating the lateral compressive loading on a single tube was performed. Results show that as the diameter and the thickness increase, the deformation strength increases. Hexagonal tube with diameter of 219 mm and thickness of 4 mm is shown to have the highest energy absorption capability. Compared to existing cylindrical and octagonal shapes, the hexagonal tubes show the highest energy absorption capacity. Hexagonal tubes therefore can be regarded as a potential candidate for buffer designs in high speed zones. In addition, they would be compact, cost effective and facilitate ease of installation.

  1. Satellite Collectors of Solar Energy for Earth and Colonized Planet Habitats

    NASA Astrophysics Data System (ADS)

    Kusiolek, Richard

    it to absorb more energy and making the antenna collector 20 times more efficient than planar designs. A tracking pedestal powered by betavoltaics can follow the sun. With a 500-sun photovoltaic cell underneath a Fresnal lens magnifies and distributes the sun's energy at 500 times. Primary results and the main conclusions This idea is revolutionary and utilizes satellite tracking abilities to follow the sun, maintaining a constant energy source that can reach 700 to 800 degrees. This technology will have many applications, from instant fresh water in the form of steam to the use of fiber optics to filter natural light through a building. With the direction of the oil and energy costs continuing to spiral upward, there has been recent emphasis on alternative energy that is transmitted from space. Satellite antenna manufacturers can move quickly to production and create a revolution in sustainable energy that was never thought of before. The efforts of the United States, Russia, China, and India to colonize the Moon and Mars would be greatly enhanced by use of satellite solar collectors and betavoltaics electrical energy technologies for the colonies' habitats. Introduction This study was undertaken for the Global environment is in a crisis. The rich oil producing countries of Russia, Saudi Arabia, Venezuela, and Africa, have been at war to gain monopoly power and to restrict the space based explorations of the solar system. The physics of solar energy transmission to electrical mechanical energy is unique in improving the economies of the entire community of Nations. It is easy to produce satellite antennas, thus, satellite antennas can now be used as solar panels which can generate free power from the sun by converting sunlight to electricity. Solar Panels require no moving parts; have zero emissions, and no maintenance. These antennas will revolutionize the use of solar rays from the sun to benefit a global grid. These "collectors of free energy" are able to harness

  2. The utilization of solar energy to help meet our nation's energy needs

    NASA Technical Reports Server (NTRS)

    Thomas, R. L.

    1973-01-01

    The nation's energy needs, domestic energy resources, and possible future energy resources are briefly discussed in this paper. Three potential solutions, coal, nuclear and solar are compared as to benefits and problems. The paper primarily discusses the options available in using solar energy as a natural energy resource. These options are discussed under the generation of electricity, heating and cooling of buildings, and the production of clean fuel.

  3. Simulation of Solar Energy Use in Livelihood of Buildings

    NASA Astrophysics Data System (ADS)

    Lvocich, I. Ya; Preobrazhenskiy, A. P.; Choporov, O. N.

    2017-11-01

    Solar energy can be considered as the most technological and economical type of renewable energy. The purpose of the paper is to increase the efficiency of solar energy utilization on the basis of the mathematical simulation of the solar collector. A mathematical model of the radiant heat transfer vacuum solar collector is clarified. The model was based on the process of radiative heat transfer between glass and copper walls with the defined blackness degrees. A mathematical model of the ether phase transition point is developed. The dependence of the reservoir walls temperature change on the ambient temperature over time is obtained. The results of the paper can be useful for the development of prospective sources using solar energy.

  4. CNRS interdisciplinary research program for solar energy development

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    The contributions of CNRS to the French national solar energy R and D program are reviewed. The three principal processes in which solar radiation is converted into other, directly usable energy forms are discussed in detail. These include thermodynamic conversion, photovoltaic conversion, and bioconversion to produce a substitute fuel. Related research on insolation and the weather is mentioned and relations with the industrial sector are considered. French collaboration with other countries in solar energy is discussed.

  5. Research opportunities to advance solar energy utilization.

    PubMed

    Lewis, Nathan S

    2016-01-22

    Major developments, as well as remaining challenges and the associated research opportunities, are evaluated for three technologically distinct approaches to solar energy utilization: solar electricity, solar thermal, and solar fuels technologies. Much progress has been made, but research opportunities are still present for all approaches. Both evolutionary and revolutionary technology development, involving foundational research, applied research, learning by doing, demonstration projects, and deployment at scale will be needed to continue this technology-innovation ecosystem. Most of the approaches still offer the potential to provide much higher efficiencies, much lower costs, improved scalability, and new functionality, relative to the embodiments of solar energy-conversion systems that have been developed to date. Copyright © 2016, American Association for the Advancement of Science.

  6. On the radiative effects of light-absorbing impurities on snowpack evolution

    NASA Astrophysics Data System (ADS)

    Dumont, M.; Tuzet, F.; Lafaysse, M.; Arnaud, L.; Picard, G.; Lejeune, Y.; Lamare, M.; Morin, S.; Voisin, D.; Di Mauro, B.

    2017-12-01

    The presence of light absorbing impurities in snow strongly decreases snow reflectance leading to an increase in the amount of solar energy absorbed by the snowpack. This effect is also known as impurities direct radiative effect. The change in the amount of energy absorbed by the snowpack modifies the temperature profile inside the snowpack and in turn snow metamorphism (impurities indirect radiative effects). In this work, we used the detailed snowpack model SURFEX/ISBA-Crocus with an explicit representation of snow light-absorbing impurities content (Tuzet et al., 2017) fed by medium-resolution ALADIN-Climate atmospheric model to represent dust and black carbon atmospheric deposition fluxes. The model is used at two sites: Col de Porte (medium elevation site in the French Alps) and Torgnon (high elevation site in the Italian Alps). The simulations are compared to in-situ observations and used to quantify the effects of light-absorbing impurities on snow melt rate and timing. The respective parts of the direct and indirect radiative effects of light-absorbing impurities in snow are also computed for the two sites, emphasizing the need to account for the interactions between snow metamorphism and LAI radiative properties, to accurately predict the effects of light-absorbing impurities in snow. Moreover, we describe how automated hyperspectral reflectance can be used to estimate effective impurities surface content in snow. Finally we demonstrate how these reflectances measurements either from in situ or satellite data can be used via an assimilation scheme to constrain snowpack ensemble simulations and better predict the snowpack state and evolution.

  7. A survey of some solar energy retrofits.

    DOT National Transportation Integrated Search

    1981-01-01

    The report briefly describes a survey of some solar energy retrofits, such as solar heaters and Trombe walls, that can be easily adapted into existing buildings belonging to the Department. With their relatively high cost, commercial solar heaters ha...

  8. Integrated photoelectrochemical energy storage: solar hydrogen generation and supercapacitor.

    PubMed

    Xia, Xinhui; Luo, Jingshan; Zeng, Zhiyuan; Guan, Cao; Zhang, Yongqi; Tu, Jiangping; Zhang, Hua; Fan, Hong Jin

    2012-01-01

    Current solar energy harvest and storage are so far realized by independent technologies (such as solar cell and batteries), by which only a fraction of solar energy is utilized. It is highly desirable to improve the utilization efficiency of solar energy. Here, we construct an integrated photoelectrochemical device with simultaneous supercapacitor and hydrogen evolution functions based on TiO(2)/transition metal hydroxides/oxides core/shell nanorod arrays. The feasibility of solar-driven pseudocapacitance is clearly demonstrated, and the charge/discharge is indicated by reversible color changes (photochromism). In such an integrated device, the photogenerated electrons are utilized for H(2) generation and holes for pseudocapacitive charging, so that both the reductive and oxidative energies are captured and converted. Specific capacitances of 482 F g(-1) at 0.5 A g(-1) and 287 F g(-1) at 1 A g(-1) are obtained with TiO(2)/Ni(OH)(2) nanorod arrays. This study provides a new research strategy for integrated pseudocapacitor and solar energy application.

  9. Solar Energy Technologies Office FY 2017 Budget At-A-Glance

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None, None

    2016-03-01

    The Solar Energy Technologies Office supports the SunShot Initiative goal to make solar energy technologies cost competitive with conventional energy sources by 2020. Reducing the total installed cost for utility-scale solar electricity by approximately 75% (2010 baseline) to roughly $0.06 per kWh without subsidies will enable rapid, large-scale adoption of solar electricity across the United States. This investment will help re-establish American technological and market leadership in solar energy, reduce environmental impacts of electricity generation, and strengthen U.S. economic competitiveness.

  10. Optically Transparent Thermally Insulating Silica Aerogels for Solar Thermal Insulation.

    PubMed

    Günay, A Alperen; Kim, Hannah; Nagarajan, Naveen; Lopez, Mateusz; Kantharaj, Rajath; Alsaati, Albraa; Marconnet, Amy; Lenert, Andrej; Miljkovic, Nenad

    2018-04-18

    Rooftop solar thermal collectors have the potential to meet residential heating demands if deployed efficiently at low solar irradiance (i.e., 1 sun). The efficiency of solar thermal collectors depends on their ability to absorb incoming solar energy and minimize thermal losses. Most techniques utilize a vacuum gap between the solar absorber and the surroundings to eliminate conduction and convection losses, in combination with surface coatings to minimize reradiation losses. Here, we present an alternative approach that operates at atmospheric pressure with simple, black, absorbing surfaces. Silica based aerogels coated on black surfaces have the potential to act as simple and inexpensive solar thermal collectors because of their high transmission to solar radiation and low transmission to thermal radiation. To demonstrate their heat-trapping properties, we fabricated tetramethyl orthosilicate-based silica aerogels. A hydrophilic aerogel with a thickness of 1 cm exhibited a solar-averaged transmission of 76% and thermally averaged transmission of ≈1% (at 100 °C). To minimize unwanted solar absorption by O-H groups, we functionalized the aerogel to be hydrophobic, resulting in a solar-averaged transmission of 88%. To provide a deeper understanding of the link between aerogel properties and overall efficiency, we developed a coupled radiative-conductive heat transfer model and used it to predict solar thermal performance. Instantaneous solar thermal efficiencies approaching 55% at 1 sun and 80 °C were predicted. This study sheds light on the applicability of silica aerogels on black coatings for solar thermal collectors and offers design priorities for next-generation solar thermal aerogels.

  11. Support and maneuvering apparatus for solar energy receivers

    DOEpatents

    Murphy, L.M.

    1988-07-28

    A support and maneuvering apparatus is disclosed for a solar energy receiving device adapted for receiving and concentrating solar energy and having a central axis extending through the center thereof. The apparatus includes a frame for mounting the perimeter of said solar energy receiving device. A support member extends along the central axis of the receiving device and has a base end passing through the center of the receiving device and an outer distal end adapted for carrying a solar energy receiving and conversion mechanism. A variable tension mechanism interconnects the support member with the frame to provide stiffening for the support member and the frame and to assist in the alignment of the frame to optimize the optical efficiency of the solar energy receiving device. A rotatable base is provided, and connecting members extend from the base for pivotable attachment to the frame at spaced positions therealong. Finally, an elevation assembly is connected to the receiving device for selectively pivoting the receiving about an axis defined between the attachment positions of the connecting members on the frame. 4 figs.

  12. Support and maneuvering apparatus for solar energy receivers

    DOEpatents

    Murphy, Lawrence M.

    1989-01-01

    A support and maneuvering apparatus is disclosed for a solar energy receiving device adpated for receiving and concentrating solar energy and having a central axis extending through the center thereof. The apparatus includes a frame for mounting the perimeter of said solar energy receiving device. A support member extends along the central axis of the receiving device and has a base end passing through the center of the receiving device and an outer distal end adapted for carrying a solar energy receiving and conversion mechanism. A variable tension mechanism interconnects the support member with the frame to provide stiffening for the support member and the frame and to assist in the alignment of the frame to optimize the optical efficiency of the solar energy receiving device. A rotatable base is provided, and connecting members extend from the base for pivotable attachment to the frame at spaced positions therealong. Finally, an elevation assembly is connected to the receiving device for selectively pivoting the receiving device about an axis defined between the attachment positions of the connecting members on the frame.

  13. Plasmonic Enhancement Mechanisms in Solar Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Cushing, Scott K.

    Semiconductor photovoltaics (solar-to-electrical) and photocatalysis (solar-to-chemical) requires sunlight to be converted into excited charge carriers with sufficient lifetimes and mobility to drive a current or photoreaction. Thin semiconductor films are necessary to reduce the charge recombination and mobility losses, but thin films also limit light absorption, reducing the solar energy conversion efficiency. Further, in photocatalysis, the band edges of semiconductor must straddle the redox potentials of a photochemical reaction, reducing light absorption to half the solar spectrum in water splitting. Plasmonics transforms metal nanoparticles into antennas with resonances tuneable across the solar spectrum. If energy can be transferred from the plasmon to the semiconductor, light absorption in the semiconductor can be increased in thin films and occur at energies smaller than the band gap. This thesis investigates why, despite this potential, plasmonic solar energy harvesting techniques rarely appear in top performing solar architectures. To accomplish this goal, the possible plasmonic enhancement mechanisms for solar energy conversion were identified, isolated, and optimized by combining systematic sample design with transient absorption spectroscopy, photoelectrochemical and photocatalytic testing, and theoretical development. Specifically, metal semiconductor nanostructures were designed to modulate the plasmon's scattering, hot carrier, and near field interactions as well as remove heating and self-catalysis effects. Transient absorption spectroscopy then revealed how the structure design affected energy and charge carrier transfer between metal and semiconductor. Correlating this data with wavelength-dependent photoconversion efficiencies and theoretical developments regarding metal-semiconductor interactions identified the origin of the plasmonic enhancement. Using this methodology, it has first been proven that three plasmonic enhancement routes are

  14. Is Solar Energy the Fuel of the Future?

    ERIC Educational Resources Information Center

    Cetincelik, Mauammer

    1974-01-01

    Describes the present distribution of solar energy, traces its use through history, explores its potential utilization in the future, and presents the effects of the use of solar energy on pollution. (GS)

  15. False Dawn of a Solar Age: A History of Solar Heating and Power During the Energy Crisis, 1973-1986

    NASA Astrophysics Data System (ADS)

    Scavo, Jordan Michael

    The unfolding of the energy crisis in the early 1970s brought solar to the fore as a topic for national discussion. National dialogues about solar power and national energy policy were one way that Americans interpreted their present and envisioned their nation's future. Yet, policy makers and the general public considered alternative energies, including solar, largely based on the economic conditions of their eras, considerations that, at least until the Reagan era, often transcended political ideologies and parties. Energy prices and the emerging political expediency of replacing fossil fuels were the primary drivers in shaping federal energy policies and public interest during this era. Enthusiasm for solar power often corresponded to the market price of petroleum. By the late 1970s, a lot of people believed the same. Amid growing public enthusiasm, President Carter eventually came out strongly in favor of solar energy, mounting solar panels on the White House and unveiling a plan to procure 20% of the nation's energy from the sun by the year 2000. During the 1960s and 1970s, Americans changed their energy values in response to concerns over environmentalism and the antinuclear movement. Pollution, environmental disasters, and energy crises during the 1960s and 1970s brought terms like "clean energy" and "renewable energy" into the national lexicon, and solar often served as the most prominent symbol of those ideas. At the same time, advocates presented solar as a stark contrast to nuclear: solar energy made life on earth possible; nuclear energy made it perilous. Science fiction and futurism shaped the American popular imagination through its presentation of solar technology. Each genre suffused the other and ingrained in the American national consciousness a sense of grandiose wonderment about the potential for solar energy, a potential that often did not match the contemporary applications for solar technology. The emergence of solar industries alarmed oil

  16. The Energy Spectrum of Solar Energetic Electrons

    NASA Astrophysics Data System (ADS)

    Wang, L.; Yang, L.; Krucker, S.; Wimmer-Schweingruber, R. F.; Bale, S. D.

    2015-12-01

    Here we present a statistical survey of the energy spectrum of solar energetic electron events (SEEs) observed by the WIND 3DP instrument from 1995 though 2014. For SEEs with the minimum energy below 10 keV and the maximum energy above 100 keV, ~85% (~2%) have a double-power-law energy spectrum with a steepening (hardening) above the break energy, while ~13% have a single-power-law energy spectrum at all energies. The average spectral index is ~2.4 below the energy break and is ~4.0 above the energy break. For SEEs detected only at energies <10 keV (>20 keV), they generally show a single-power-law spectrum with the average index of ~3.0 (~3.3). The spectrum of SEEs detected only below 10 keV appears to get harder with increasing solar activity, but the spectrum of SEEs with higher-energy electrons shows no clear correlation with solar activity. We will also investigate whether the observed energy spectrum of SEEs at 1 AU mainly reflects the electron acceleration at the Sun or the electron transport in the interplanetary medium.

  17. Electromagnetic radiation energy arrangement. [coatings for solar energy absorption and infrared reflection

    NASA Technical Reports Server (NTRS)

    Lipkis, R. R.; Vehrencamp, J. E. (Inventor)

    1965-01-01

    A solar energy collector and infrared energy reflector is described which comprises a vacuum deposited layer of aluminum of approximately 200 to 400 Angstroms thick on one side of a substrate. An adherent layer of titanium with a thickness of between 800 and 1000 Angstroms is vacuum deposited on the aluminum substrate and is substantially opaque to solar energy and substantially transparent to infrared energy.

  18. Solar Energy Now.

    ERIC Educational Resources Information Center

    Rose, Harvey, Ed.

    Twenty articles addressing different aspects of solar energy are compiled in this book. They represent the views of different governmental and non-governmental organizations, members of congress, and other individuals including, for example, Barry Commoner and Amory Lovins. Topics discussed include the need for federal support, passive solar…

  19. Solar Photovoltaic Energy.

    ERIC Educational Resources Information Center

    Ehrenreich, Henry; Martin, John H.

    1979-01-01

    The goals of solar photovoltaic technology in contributing to America's future energy needs are presented in this study conducted by the American Physical Society. Although the time needed for photovoltaics to become popular is several decades away, according to the author, short-range applications are given. (Author/SA)

  20. Surface Plasmon-Assisted Solar Energy Conversion.

    PubMed

    Dodekatos, Georgios; Schünemann, Stefan; Tüysüz, Harun

    2016-01-01

    The utilization of localized surface plasmon resonance (LSPR) from plasmonic noble metals in combination with semiconductors promises great improvements for visible light-driven photocatalysis, in particular for energy conversion. This review summarizes the basic principles of plasmonic photocatalysis, giving a comprehensive overview about the proposed mechanisms for enhancing the performance of photocatalytically active semiconductors with plasmonic devices and their applications for surface plasmon-assisted solar energy conversion. The main focus is on gold and, to a lesser extent, silver nanoparticles in combination with titania as semiconductor and their usage as active plasmonic photocatalysts. Recent advances in water splitting, hydrogen generation with sacrificial organic compounds, and CO2 reduction to hydrocarbons for solar fuel production are highlighted. Finally, further improvements for plasmonic photocatalysts, regarding performance, stability, and economic feasibility, are discussed for surface plasmon-assisted solar energy conversion.

  1. Conservation and solar energy program: congressional budget request, FY 1982

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    None

    1981-01-01

    Funding summaries are presented for the Conservation and Solar Energy Program funding information and program overview on energy conservation (Volume 7 of 7, DOE/CR-0011/2) are included for the Buildings and Community Systems, Industrial, Transportation; State and Local, Multi-Sector, Energy Impact Assistance, and Residential/Commercial retrofit programs. Funding information and program overviews on solar technology (Volume 2 of 7, DOE/CR-011/2) are included for Active and Passive Solar Heating and Cooling, Photovoltaics Energy Systems, Solar Thermal Power Systems, Biomass Energy Systems, Wind Energy Conversion Systems, Ocean Systems, Solar International Activities, Solar Information Systems, SERI Facility, MX-RES, Program Direction, and Alcohol Fuels programs. Informationmore » and overviews on energy production, demonstration, and distribution (Volume 6 of 7, DOE/CR-0011/2) are given for the solar program. A funding summary and a program overview are included for electrochemical and physical and chemical storage systems as appearing in DOE/CR-0011/2, Volume 3 of 7. Relevant tabulated data from the FY 1981. Request to the Congress are presented for Supplementals, Rescissions, and Deferrals. (MCW)« less

  2. The Next Spaceflight Solar Irradiance Sensor: TSIS

    NASA Astrophysics Data System (ADS)

    Kopp, Greg; Pilewskie, Peter; Richard, Erik

    2016-05-01

    The Total and Spectral Solar Irradiance Sensor (TSIS) will continue measurements of the solar irradiance with improved accuracies and stabilities over extant spaceflight instruments. The two TSIS solar-observing instruments include the Total Irradiance Monitor (TIM) and the Spectral Irradiance Monitor (SIM) for measuring total- and spectral- solar-irradiance, respectively. The former provides the net energy powering the Earth’s climate system while the latter helps attribute where that energy is absorbed by the Earth’s atmosphere and surface. Both spaceflight instruments are assembled and being prepared for integration on the International Space Station. With operations commencing in late 2017, the TSIS is intended to overlap with NASA’s ongoing SOlar Radiation and Climate Experiment (SORCE) mission, which launched in 2003 and contains the first versions of both the TIM and SIM instruments, as well as with the TSI Calibration Transfer Experiment (TCTE), which began total solar irradiance measurements in 2013. We summarize the TSIS’s instrument improvements and intended solar-irradiance measurements.

  3. Advanced Cloud Forecasting for Solar Energy Production

    NASA Astrophysics Data System (ADS)

    Werth, D. W.; Parker, M. J.

    2017-12-01

    A power utility must decide days in advance how it will allocate projected loads among its various generating sources. If the latter includes solar plants, the utility must predict how much energy the plants will produce - any shortfall will have to be compensated for by purchasing power as it is needed, when it is more expensive. To avoid this, utilities often err on the side of caution and assume that a relatively small amount of solar energy will be available, and allocate correspondingly more load to coal-fired plants. If solar irradiance can be predicted more accurately, utilities can be more confident that the predicted solar energy will indeed be available when needed, and assign solar plants a larger share of the future load. Solar power production is increasing in the Southeast, but is often hampered by irregular cloud fields, especially during high-pressure periods when rapid afternoon thunderstorm development can occur during what was predicted to be a clear day. We are currently developing an analog forecasting system to predict solar irradiance at the surface at the Savannah River Site in South Carolina, with the goal of improving predictions of available solar energy. Analog forecasting is based on the assumption that similar initial conditions will lead to similar outcomes, and involves the use of an algorithm to look through the weather patterns of the past to identify previous conditions (the analogs) similar to those of today. For our application, we select three predictor variables - sea-level pressure, 700mb geopotential, and 700mb humidity. These fields for the current day are compared to those from past days, and a weighted combination of the differences (defined by a cost function) is used to select the five best analog days. The observed solar irradiance values subsequent to the dates of those analogs are then combined to represent the forecast for the next day. We will explain how we apply the analog process, and compare it to existing

  4. Evaluation of a pilot installation of an energy absorbing bridge rail.

    DOT National Transportation Integrated Search

    1978-01-01

    A newly developed bridge rail which uses steel rings that collapse or deform to absorb the energy of an impacting vehicle was retrofitted to the concrete parapet of an existing interstate highway bridge. It was planned that the installation would be ...

  5. Design and evaluation of an energy-absorbing, reusable roadside/median barrier.

    DOT National Transportation Integrated Search

    2015-07-01

    Further design and evaluation was conducted on an energy-absorbing, restorable and reusable roadside/median barrier, : designated the RESTORE barrier. A series of dynamic component tests were conducted on 11-in. (295-mm) tall x 10-in. : (254-mm) w...

  6. Control of base-excited dynamical systems through piezoelectric energy harvesting absorber

    NASA Astrophysics Data System (ADS)

    Abdelmoula, H.; Dai, H. L.; Abdelkefi, A.; Wang, L.

    2017-09-01

    The spring-mass absorber usually offers a good control to dynamical systems under direct base excitations for a specific value of the excitation frequency. As the vibrational energy of a primary dynamical system is transferred to the absorber, it gets dissipated. In this study, this energy is no longer dissipated but converted to available electrical power by designing efficient energy harvesters. A novel design of a piezoelectric beam installed inside an elastically-mounted dynamical system undergoing base excitations is considered. A design is carried out in order to determine the properties and dimensions of the energy harvester with the constraint of simultaneously decreasing the oscillating amplitudes of the primary dynamical system and increasing the harvested power of the energy harvesting absorber. An analytical model for the coupled system is constructed using Euler-Lagrange principle and Galerkin discretization. Different strategies for controlling the primary structure displacement and enhancing the harvested power as functions of the electrical load resistance and thickness of the beam substrate are performed. The linear polynomial approximation of the system’s key parameters as a function of the beam’s substrate thickness is first carried out. Then, the gradient method is applied to determine the adequate values of the electrical load resistance and thickness of the substrate under the constraints of minimizing the amplitudes of the primary structure or maximizing the levels of the harvested power. After that, an iterative strategy is considered in order to simultaneously minimize the amplitudes of the primary structure and maximize the levels of the harvested power as functions of the thickness of the substrate and electrical load resistance. In addition to harmonic excitations, the coupled system subjected to a white noise is explored. Through this analysis, the load resistance and thickness of the substrate of the piezoelectric energy harvester

  7. CaFe2O4 as a self-sufficient solar energy converter

    NASA Astrophysics Data System (ADS)

    Tablero, C.

    2017-10-01

    An ideal solar energy to electricity or fuel converter should work without the use of any external bias potential. An analysis of self-sufficiency when CaFe2O4 is used to absorb the sunlight is carried out based on the CaFe2O4 absorption coefficient. We started to obtain this coefficient theoretically within the experimental bandgap range in order to fix the interval of possible values of photocurrents, maximum absorption efficiencies, and photovoltages and thus that of self-sufficiency considering only the radiative processes. Also for single-gap CaFe2O4, we evaluate an alternative for increasing the photocurrent and maximum absorption efficiency based on inserting an intermediate band using high doping or alloying.

  8. Solar concentrator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Melchior, B.

    1984-04-03

    A solar concentrator comprises a solid block of a transparent material having a planar incident surface positioned to receive solar rays and, opposite this surface, a curved reflective surface so that the material of the block completely fills the space between these surfaces. At the incident surface an absorber is provided and the curvature of the reflective surface is such that it is at least partly parabolical and adapted to reflect solar rays traversing the body through the body again to the absorber.

  9. Relationship between open-circuit voltage in Cu(In,Ga)Se2 solar cell and peak position of (220/204) preferred orientation near its absorber surface

    NASA Astrophysics Data System (ADS)

    Chantana, J.; Watanabe, T.; Teraji, S.; Kawamura, K.; Minemoto, T.

    2013-11-01

    Cu(In,Ga)Se2 (CIGS) absorbers with various Ga/III, Ga/(In+Ga), profiles are prepared by the so-called "multi-layer precursor method" using multi-layer co-evaporation of material sources. It is revealed that open-circuit voltage (VOC) of CIGS solar cell is primarily dependent on averaged Ga/III near the surface of its absorber. This averaged Ga/III is well predicted by peak position of (220/204) preferred orientation of CIGS film near its surface investigated by glancing-incidence X-ray diffraction with 0.1° incident angle. Finally, the peak position of (220/204) preferred orientation is proposed as a measure of VOC before solar cell fabrication.

  10. Dielectric compound parabolic concentrating solar collector with frustrated total internal reflection absorber

    NASA Astrophysics Data System (ADS)

    Hull, J. R.

    Since its introduction, the concept of nonimaging solar concentrators, as exemplified by the compound parabolic concentrator (CPC) design, has greatly enhanced the ability to collect solar energy efficiently in thermal and photovoltaic devices. When used as a primary concentrator, a CPC can provide significant concentration without the complication of a tracking mechanism and its associated maintenance problems. When used as a secondary, a CPC provides higher total concentration, or for a fixed concentration, tolerates greater tracking error in the primary.

  11. Heterojunction solar cell

    DOEpatents

    Olson, Jerry M.

    1994-01-01

    A high-efficiency single heterojunction solar cell wherein a thin emitter layer (preferably Ga.sub.0.52 In.sub.0.48 P) forms a heterojunction with a GaAs absorber layer. The conversion effiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer.

  12. Bifunctional polymer hydrogel layers as forward osmosis draw agents for continuous production of fresh water using solar energy.

    PubMed

    Razmjou, Amir; Liu, Qi; Simon, George P; Wang, Huanting

    2013-11-19

    The feasibility of bilayer polymer hydrogels as draw agent in forward osmosis process has been investigated. The dual-functionality hydrogels consist of a water-absorptive layer (particles of a copolymer of sodium acrylate and N-isopropylacrylamide) to provide osmotic pressure, and a dewatering layer (particles of N-isopropylacrylamide) to allow the ready release of the water absorbed during the FO drawing process at lower critical solution temperature (32 °C). The use of solar concentrated energy as the source of heat resulted in a significant increase in the dewatering rate as the temperature of dewatering layer increased to its LSCT more rapidly. Dewatering flux rose from 10 to 25 LMH when the solar concentrator increased the input energy from 0.5 to 2 kW/m(2). Thermodynamic analysis was also performed to find out the minimum energy requirement of such a bilayer hydrogel-driven FO process. This study represents a significant step forward toward the commercial implementation of hydrogel-driven FO system for continuous production of fresh water from saline water or wastewaters.

  13. Thin film solar energy collector

    DOEpatents

    Aykan, Kamran; Farrauto, Robert J.; Jefferson, Clinton F.; Lanam, Richard D.

    1983-11-22

    A multi-layer solar energy collector of improved stability comprising: (1) a substrate of quartz, silicate glass, stainless steel or aluminum-containing ferritic alloy; (2) a solar absorptive layer comprising silver, copper oxide, rhodium/rhodium oxide and 0-15% by weight of platinum; (3) an interlayer comprising silver or silver/platinum; and (4) an optional external anti-reflective coating, plus a method for preparing a thermally stable multi-layered solar collector, in which the absorptive layer is undercoated with a thin film of silver or silver/platinum to obtain an improved conductor-dielectric tandem.

  14. Fundamentals and techniques of nonimaging optics for solar energy concentration

    NASA Astrophysics Data System (ADS)

    Winston, R.; Ogallaher, J. J.

    1980-09-01

    Recent progress in basic research into the theoretical understanding of nonimaging optical systems and their application to the design of practical solar concentration was reviewed. Work was done to extend the previously developed geometrical vector flux formalism with the goal of applying it to the analysis of nonideal concentrators. Both phase space and vector flux representation for traditional concentrators were generated. Understanding of the thermodynamically derived relationship between concentration and cavity effects led to the design of new lossless and low loss concentrators for absorbers with gaps. Quantitative measurements of the response of real collector systems and the distribution of diffuse insolation shows that in most cases performance exceeds predictions in solar applications. These developments led to improved nonimaging solar concentrator designs and applications.

  15. Integrated photoelectrochemical energy storage: solar hydrogen generation and supercapacitor

    PubMed Central

    Xia, Xinhui; Luo, Jingshan; Zeng, Zhiyuan; Guan, Cao; Zhang, Yongqi; Tu, Jiangping; Zhang, Hua; Fan, Hong Jin

    2012-01-01

    Current solar energy harvest and storage are so far realized by independent technologies (such as solar cell and batteries), by which only a fraction of solar energy is utilized. It is highly desirable to improve the utilization efficiency of solar energy. Here, we construct an integrated photoelectrochemical device with simultaneous supercapacitor and hydrogen evolution functions based on TiO2/transition metal hydroxides/oxides core/shell nanorod arrays. The feasibility of solar-driven pseudocapacitance is clearly demonstrated, and the charge/discharge is indicated by reversible color changes (photochromism). In such an integrated device, the photogenerated electrons are utilized for H2 generation and holes for pseudocapacitive charging, so that both the reductive and oxidative energies are captured and converted. Specific capacitances of 482 F g−1 at 0.5 A g−1 and 287 F g−1 at 1 A g−1 are obtained with TiO2/Ni(OH)2 nanorod arrays. This study provides a new research strategy for integrated pseudocapacitor and solar energy application. PMID:23248745

  16. Progress in passive solar energy systems. Volume 8. Part 1

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hayes, J.; Andrejko, D.A.

    1983-01-01

    This book presents the papers given at a conference sponsored by the US DOE, the Solar Energy Research Institute, SolarVision, Inc., and the Southern California Solar Energy Society. The topics considered at the conference included sizing solar energy systems for agricultural applications, a farm scale ethanol production plant, the EEC wind energy RandD program, the passive solar performance assessment of an earth-sheltered house, the ARCO 1 MW photovoltaic power plant, the performance of a dendritic web photovoltaic module, second generation point focused concentrators, linear fresnel lens concentrating photovoltaic collectors, photovoltaic conversion efficiency, amorphous silicon thin film solar cells, a photovoltaicmore » system for a shopping center, photovoltaic power generation for the utility industry, spectral solar radiation, and the analysis of insolation data.« less

  17. Near-term Forecasting of Solar Total and Direct Irradiance for Solar Energy Applications

    NASA Astrophysics Data System (ADS)

    Long, C. N.; Riihimaki, L. D.; Berg, L. K.

    2012-12-01

    Integration of solar renewable energy into the power grid, like wind energy, is hindered by the variable nature of the solar resource. One challenge of the integration problem for shorter time periods is the phenomenon of "ramping events" where the electrical output of the solar power system increases or decreases significantly and rapidly over periods of minutes or less. Advance warning, of even just a few minutes, allows power system operators to compensate for the ramping. However, the ability for short-term prediction on such local "point" scales is beyond the abilities of typical model-based weather forecasting. Use of surface-based solar radiation measurements has been recognized as a likely solution for providing input for near-term (5 to 30 minute) forecasts of solar energy availability and variability. However, it must be noted that while fixed-orientation photovoltaic panel systems use the total (global) downwelling solar radiation, tracking photovoltaic and solar concentrator systems use only the direct normal component of the solar radiation. Thus even accurate near-term forecasts of total solar radiation will under many circumstances include inherent inaccuracies with respect to tracking systems due to lack of information of the direct component of the solar radiation. We will present examples and statistical analyses of solar radiation partitioning showing the differences in the behavior of the total/direct radiation with respect to the near-term forecast issue. We will present an overview of the possibility of using a network of unique new commercially available total/diffuse radiometers in conjunction with a near-real-time adaptation of the Shortwave Radiative Flux Analysis methodology (Long and Ackerman, 2000; Long et al., 2006). The results are used, in conjunction with persistence and tendency forecast techniques, to provide more accurate near-term forecasts of cloudiness, and both total and direct normal solar irradiance availability and

  18. Competing Atmospheric and Surface-Driven Impacts of Absorbing Aerosols on the East Asian Summer Monsoon

    NASA Astrophysics Data System (ADS)

    Persad, G.; Paynter, D.; Ming, Y.; Ramaswamy, V.

    2015-12-01

    Absorbing aerosols, by attenuating shortwave radiation within the atmosphere and reemitting it as longwave radiation, redistribute energy both vertically within the surface-atmosphere column and horizontally between polluted and unpolluted regions. East Asia has the largest concentrations of anthropogenic absorbing aerosols globally, and these, along with the region's scattering aerosols, have both reduced the amount of solar radiation reaching the Earth's surface regionally ("solar dimming") and increased shortwave absorption within the atmosphere, particularly during the peak months of the East Asian Summer Monsoon (EASM). We here analyze how atmospheric absorption and surface solar dimming compete in driving the response of EASM circulation to anthropogenic absorbing aerosols, which dominates, and why—issues of particular importance for predicting how the EASM will respond to projected changes in absorbing and scattering aerosol emissions in the future. We probe these questions in a state-of-the-art general circulation model (GCM) using a combination of realistic and idealized aerosol perturbations that allow us to analyze the relative influence of absorbing aerosols' atmospheric and surface-driven impacts on EASM circulation. In combination, our results make clear that, although absorption-driven dimming has a less detrimental effect on EASM circulation than purely scattering-driven dimming, aerosol absorption is still a net impairment to EASM strength when both its atmospheric and surface effects are considered. Because atmospheric heating is not efficiently conveyed to the surface, the surface dimming and associated cooling from even a pure absorber is sufficient to counteract its atmospheric heating, resulting in a net reduction in EASM strength. These findings elevate the current understanding of the impacts of aerosol absorption on the EASM, improving our ability to diagnose EASM responses to current and future regional changes in aerosol emissions.

  19. NREL Develops Switchable Solar Window | News | NREL

    Science.gov Websites

    electricity at a high efficiency have been developed by scientists at the U.S. Department of Energy's National reversibly absorbed into the device. When solar energy heats up the device, the molecules are driven out, and the device is darkened. When the sun is not shining, the device is cooled back down, and the molecules

  20. Solar Energy for Space Heating & Hot Water.

    ERIC Educational Resources Information Center

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    This pamphlet reviews the direct transfer of solar energy into heat, particularly for the purpose of providing space and hot water heating needs. Owners of buildings and homes are provided with a basic understanding of solar heating and hot water systems: what they are, how they perform, the energy savings possible, and the cost factors involved.…

  1. An assessment of solar energy as a national energy resource

    NASA Technical Reports Server (NTRS)

    Donovan, P.; Woodward, W.; Cherry, W. E.; Morse, F. H.; Herwig, L. O.

    1972-01-01

    The applications are discussed of solar energy for thermal energy for buildings; chemical and biological conversion of organic materials to liquid, solid, and gaseous fuels; and the generation of electricity. It is concluded that if solar development programs are successful, building heating for public use is possible within 5 years, building cooling in 6 to 10 years, synthetic fuels from organic materials in 5 to 8 years, and electricity production in 10 to 15 years.

  2. Port of Galveston Solar Energy Project

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Falcioni, Diane; Cuclis, Alex; Freundlich, Alex

    This study on the performance characteristics of existing solar technologies in a maritime environment was funded by an award given to The Port of Galveston (POG) from the U.S. Department of Energy (DOE). The study includes research performed by The Center for Advanced Materials at the University of Houston (UH). The UH researchers examined how solar cell efficiencies and life spans can be improved by examining the performance of a variety of antireflective (AR) coatings mounted on the top of one of the POG’s Cruise Terminals. Supplemental supporting research was performed at the UH laboratories. An educational Kiosk was constructedmore » with a 55” display screen providing information about solar energy, the research work UH performed at POG and real time data from the solar panels located on the roof of the Cruise Terminal. The Houston Advanced Research Center (HARC) managed the project.« less

  3. Energy 101: Solar PV

    ScienceCinema

    None

    2018-01-08

    Solar photovoltaic (PV) systems can generate clean, cost-effective power anywhere the sun shines. This video shows how a PV panel converts the energy of the sun into renewable electricity to power homes and businesses.

  4. Optical Waveguide Solar Energy System for Lunar Materials Processing

    NASA Technical Reports Server (NTRS)

    Nakamura, T.; Case, J. A.; Senior, C. L.

    1997-01-01

    This paper discusses results of our work on development of the Optical Waveguide (OW) Solar Energy System for Lunar Materials Processing. In the OW system as shown, solar radiation is collected by the concentrator which transfers the concentrated solar radiation to the OW transmission line consisting of low-loss optical fibers. The OW line transmits the solar radiation to the thermal reactor of the lunar materials processing plant. The feature of the OW system are: (1) Highly concentrated solar radiation (up to 104 suns) can be transmitted via flexible OW lines directly into the thermal reactor for materials processing: (2) Solar radiation intensity or spectra can be tailored to specific materials processing steps; (3) Provide solar energy to locations or inside of enclosures that would not otherwise have an access to solar energy; and (4) The system can be modularized and can be easily transported to and deployed at the lunar base.

  5. Silicon nanowires for photovoltaic solar energy conversion.

    PubMed

    Peng, Kui-Qing; Lee, Shuit-Tong

    2011-01-11

    Semiconductor nanowires are attracting intense interest as a promising material for solar energy conversion for the new-generation photovoltaic (PV) technology. In particular, silicon nanowires (SiNWs) are under active investigation for PV applications because they offer novel approaches for solar-to-electric energy conversion leading to high-efficiency devices via simple manufacturing. This article reviews the recent developments in the utilization of SiNWs for PV applications, the relationship between SiNW-based PV device structure and performance, and the challenges to obtaining high-performance cost-effective solar cells.

  6. Solar energy an investment in our nations energy and economic security

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Barnett, A.; Sklar, A.

    1996-07-01

    The solar energy industries are engaged in aggressive efforts to develop, validate, and deploy solar energy systems for a wide variety of applications in every sector of the economy. In many cases, efforts are in partnership with the United States Departmet of Energy (DOE) and it`s laboratories. These partnerships are heavily cost shared by industry and were entered into with good faith by companies and corporations willing to include their significant cost-share in their budget planning.

  7. Solar Energy Education. Reader, Part II. Sun story. [Includes glossary

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1981-05-01

    Magazine articles which focus on the subject of solar energy are presented. The booklet prepared is the second of a four part series of the Solar Energy Reader. Excerpts from the magazines include the history of solar energy, mythology and tales, and selected poetry on the sun. A glossary of energy related terms is included. (BCS)

  8. Absorbing phase transitions in deterministic fixed-energy sandpile models

    NASA Astrophysics Data System (ADS)

    Park, Su-Chan

    2018-03-01

    We investigate the origin of the difference, which was noticed by Fey et al. [Phys. Rev. Lett. 104, 145703 (2010), 10.1103/PhysRevLett.104.145703], between the steady state density of an Abelian sandpile model (ASM) and the transition point of its corresponding deterministic fixed-energy sandpile model (DFES). Being deterministic, the configuration space of a DFES can be divided into two disjoint classes such that every configuration in one class should evolve into one of absorbing states, whereas no configurations in the other class can reach an absorbing state. Since the two classes are separated in terms of toppling dynamics, the system can be made to exhibit an absorbing phase transition (APT) at various points that depend on the initial probability distribution of the configurations. Furthermore, we show that in general the transition point also depends on whether an infinite-size limit is taken before or after the infinite-time limit. To demonstrate, we numerically study the two-dimensional DFES with Bak-Tang-Wiesenfeld toppling rule (BTW-FES). We confirm that there are indeed many thresholds. Nonetheless, the critical phenomena at various transition points are found to be universal. We furthermore discuss a microscopic absorbing phase transition, or a so-called spreading dynamics, of the BTW-FES, to find that the phase transition in this setting is related to the dynamical isotropic percolation process rather than self-organized criticality. In particular, we argue that choosing recurrent configurations of the corresponding ASM as an initial configuration does not allow for a nontrivial APT in the DFES.

  9. Absorbing phase transitions in deterministic fixed-energy sandpile models.

    PubMed

    Park, Su-Chan

    2018-03-01

    We investigate the origin of the difference, which was noticed by Fey et al. [Phys. Rev. Lett. 104, 145703 (2010)PRLTAO0031-900710.1103/PhysRevLett.104.145703], between the steady state density of an Abelian sandpile model (ASM) and the transition point of its corresponding deterministic fixed-energy sandpile model (DFES). Being deterministic, the configuration space of a DFES can be divided into two disjoint classes such that every configuration in one class should evolve into one of absorbing states, whereas no configurations in the other class can reach an absorbing state. Since the two classes are separated in terms of toppling dynamics, the system can be made to exhibit an absorbing phase transition (APT) at various points that depend on the initial probability distribution of the configurations. Furthermore, we show that in general the transition point also depends on whether an infinite-size limit is taken before or after the infinite-time limit. To demonstrate, we numerically study the two-dimensional DFES with Bak-Tang-Wiesenfeld toppling rule (BTW-FES). We confirm that there are indeed many thresholds. Nonetheless, the critical phenomena at various transition points are found to be universal. We furthermore discuss a microscopic absorbing phase transition, or a so-called spreading dynamics, of the BTW-FES, to find that the phase transition in this setting is related to the dynamical isotropic percolation process rather than self-organized criticality. In particular, we argue that choosing recurrent configurations of the corresponding ASM as an initial configuration does not allow for a nontrivial APT in the DFES.

  10. 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.

  11. Solar Energy Technologies and the Utilization on Native American Tribal Lands

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hall, Kathryn

    As an undergraduate researcher, I worked on a new technology called nanofluid-based direct absorption solar collectors (DASC) which is a type of solar water heater that has the potential to be more efficient than traditional solar water heaters. Because of my experience with this type of technology, I decided to look into other types of solar energy technologies which could be used on Native American tribal lands. Some types of solar energy technologies that I wanted to focus on are photovoltaic solar energy systems, passive solar design, and solar water heaters.

  12. SWOT analysis of the renewable energy sources in Romania - case study: solar energy

    NASA Astrophysics Data System (ADS)

    Lupu, A. G.; Dumencu, A.; Atanasiu, M. V.; Panaite, C. E.; Dumitrașcu, Gh; Popescu, A.

    2016-08-01

    The evolution of energy sector worldwide triggered intense preoccupation on both finding alternative renewable energy sources and environmental issues. Romania is considered to have technological potential and geographical location suitable to renewable energy usage for electricity generation. But this high potential is not fully exploited in the context of policies and regulations adopted globally, and more specific, European Union (EU) environmental and energy strategies and legislation related to renewable energy sources. This SWOT analysis of solar energy source presents the state of the art, potential and future prospects for development of renewable energy in Romania. The analysis concluded that the development of solar energy sector in Romania depends largely on: viability of legislative framework on renewable energy sources, increased subsidies for solar R&D, simplified methodology of green certificates, and educating the public, investors, developers and decision-makers.

  13. Energy development and environment: What about solar energy in a long term perspective?

    NASA Astrophysics Data System (ADS)

    Dessus, Benjamin; Pharabod, Francois

    After decades of strong growth, the next century might be that in which the world population is stabilized around 11 billion inhabitants. Next century's main concerns include the development hoped for the probable consequences of an increase of the greenhouse effect due to main induced emissions, and the risks posed by possible dissemination of nuclear energy to all the regions of the globe. In order to shed some light on these questions, we propose an energy scenario, based on an analysis of evolution of demographics, energy needs, renewable and fossil reserves, environmental issues, technological possibilities and regional imbalances. This scenario shows that solar energy could contribute significantly in the long term energy mix. We discuss the respective advantages and drawbacks of the different solar technologies: solar power satellites, ground solar power plants and decentralized applications, as they to the needs that must be satisfied.

  14. PVMirror: A New Concept for Tandem Solar Cells and Hybrid Solar Converters

    DOE PAGES

    Yu, Zhengshan J.; Fisher, Kathryn C.; Wheelwright, Brian M.; ...

    2015-08-25

    As the solar electricity market has matured, energy conversion efficiency and storage have joined installed system cost as significant market drivers. In response, manufacturers of flatplate silicon photovoltaic (PV) cells have pushed cell efficiencies above 25%—nearing the 29.4% detailed-balance efficiency limit— and both solar thermal and battery storage technologies have been deployed at utility scale. This paper introduces a new tandem solar collector employing a “PVMirror” that has the potential to both increase energy conversion efficiency and provide thermal storage. A PVMirror is a concentrating mirror, spectrum splitter, and light-to-electricity converter all in one: It consists of a curved arrangementmore » of PV cells that absorb part of the solar spectrum and reflect the remainder to their shared focus, at which a second solar converter is placed. A strength of the design is that the solar converter at the focus can be of a radically different technology than the PV cells in the PVMirror; another is that the PVMirror converts a portion of the diffuse light to electricity in addition to the direct light. Here, we consider two case studies—a PV cell located at the focus of the PVMirror to form a four-terminal PV–PV tandem, and a thermal receiver located at the focus to form a PV–CSP (concentrating solar thermal power) tandem—and compare the outdoor energy outputs to those of competing technologies. PVMirrors can outperform (idealized) monolithic PV–PV tandems that are under concentration, and they can also generate nearly as much energy as silicon flat-plate PV while simultaneously providing the full energy storage benefit of CSP.« less

  15. Heterojunction solar cell

    DOEpatents

    Olson, J.M.

    1994-08-30

    A high-efficiency single heterojunction solar cell is described wherein a thin emitter layer (preferably Ga[sub 0.52]In[sub 0.48]P) forms a heterojunction with a GaAs absorber layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer. 1 fig.

  16. Improving Air Quality with Solar Energy

    DOE R&D Accomplishments Database

    2008-04-01

    This fact sheet series highlights how renewable energy and energy efficiency technologies can and are being used to reduce air emissions and meet environmental goals, showcasing case studies and technology-specific topics. This one focus on solar energy technologies.

  17. Development of a Conceptual Structure for Architectural Solar Energy Systems.

    ERIC Educational Resources Information Center

    Ringel, Robert F.

    Solar subsystems and components were identified and conceptual structure was developed for architectural solar energy heating and cooling systems. Recent literature related to solar energy systems was reviewed and analyzed. Solar heating and cooling system, subsystem, and component data were compared for agreement and completeness. Significant…

  18. Measuring Solar Radiation Incident on Earth: Solar Constant-3 (SOLCON-3)

    NASA Technical Reports Server (NTRS)

    Crommelynck, Dominique; Joukoff, Alexandre; Dewitte, Steven

    2002-01-01

    Life on Earth is possible because the climate conditions on Earth are relatively mild. One element of the climate on Earth, the temperature, is determined by the heat exchanges between the Earth and its surroundings, outer space. The heat exchanges take place in the form of electromagnetic radiation. The Earth gains energy because it absorbs solar radiation, and it loses energy because it emits thermal infrared radiation to cold space. The heat exchanges are in balance: the heat gained by the Earth through solar radiation equals the heat lost through thermal radiation. When the balance is perturbed, a temperature change and hence a climate change of the Earth will occur. One possible perturbation of the balance is the CO2 greenhouse effect: when the amount of CO2 in the atmosphere increases, this will reduce the loss of thermal infrared radiation to cold space. Earth will gain more heat and hence the temperature will rise. Another perturbation of the balance can occur through variation of the amount of energy emitted by the sun. When the sun emits more energy, this will directly cause a rise of temperature on Earth. For a long time scientists believed that the energy emitted by the sun was constant. The 'solar constant' is defined as the amount of solar energy received per unit surface at a distance of one astronomical unit (the average distance of Earth's orbit) from the sun. Accurate measurements of the variations of the solar constant have been made since 1978. From these we know that the solar constant varies approximately with the 11-year solar cycle observed in other solar phenomena, such as the occurrence of sunspots, dark spots that are sometimes visible on the solar surface. When a sunspot occurs on the sun, since the spot is dark, the radiation (light) emitted by the sun drops instantaneously. Oddly, periods of high solar activity, when a lot of sunspot numbers increase, correspond to periods when the average solar constant is high. This indicates that

  19. Solar Adoption and Energy Consumption in the Residential Sector

    NASA Astrophysics Data System (ADS)

    McAllister, Joseph Andrew

    This dissertation analyzes the energy consumption behavior of residential adopters of solar photovoltaic systems (solar-PV). Based on large data sets from the San Diego region that have been assembled or otherwise acquired by the author, the dissertation quantifies changes in energy consumption after solar-PV installation and determines whether certain household characteristics are correlated with such changes. In doing so, it seeks to answer two related questions: First, "Do residential solar adopters increase or decrease their electricity consumption after they install a solar-PV system?" Assuming that certain categories of residential adopters increase and others decrease, the second question is "Which residential adopters increase and which decrease their consumption and why?" The database that was used to conduct this analysis includes information about 5,243 residential systems in San Diego Gas & Electric's (SDG&E) service territory installed between January 2007 and December 2010. San Diego is a national leader in the installation of small-scale solar-electric systems, with over 12,000 systems in the region installed as of January 2012, or around 14% of the total number installed in California. The author performed detailed characterization of a significant subset of the solar installations in the San Diego region. Assembled data included technical and economic characteristics of the systems themselves; the solar companies that sold and installed them; individual customer electric utility billing data; metered PV production data for a subgroup of these solar systems; and data about the properties where the systems are located. Primarily, the author was able to conduct an electricity consumption analysis at the individual household level for 2,410 PV systems installed in SDG&E service territory between January 2007 and December 2010. This analysis was designed to detect changes in electricity consumption from the pre-solar to the post-installation period. To

  20. Optimized Latching Control of Floating Point Absorber Wave Energy Converter

    NASA Astrophysics Data System (ADS)

    Gadodia, Chaitanya; Shandilya, Shubham; Bansal, Hari Om

    2018-03-01

    There is an increasing demand for energy in today’s world. Currently main energy resources are fossil fuels, which will eventually drain out, also the emissions produced from them contribute to global warming. For a sustainable future, these fossil fuels should be replaced with renewable and green energy sources. Sea waves are a gigantic and undiscovered vitality asset. The potential for extricating energy from waves is extensive. To trap this energy, wave energy converters (WEC) are needed. There is a need for increasing the energy output and decreasing the cost requirement of these existing WECs. This paper presents a method which uses prediction as a part of the control scheme to increase the energy efficiency of the floating-point absorber WECs. Kalman Filter is used for estimation, coupled with latching control in regular as well as irregular sea waves. Modelling and Simulation results for the same are also included.