Science.gov

Sample records for passive solar commercial

  1. Passive Solar Commercial Demonstration Program: Phase I. Final report

    SciTech Connect

    1981-02-10

    The passive solar retrofit of a small existing commercial/residential building is described. An add on gallery/sunspace is integrated into the existing structure both in terms of energy and architectural functioning. The sunspace solution maximizes the amount of south facing glass for solar heat gain, while still allowing a deep penetration of daylight into the existing buildings. (MHR)

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

    NASA Astrophysics Data System (ADS)

    Powell, J. W.

    1980-06-01

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

  3. Passive solar renovation of an existing commercial greenhouse

    SciTech Connect

    McGinnis, J.W.; Whitehead, N.

    1980-01-01

    The renovation of an existing 1800 square foot commercial greenhouse to incorporate passive solar reliant and energy conserving features is detailed. The Aquatic-Agriculture Institute for Research, a non-profit group, sponsored the project to develop efficient production methods to raise vegetables and fish at the community level. The performance of the remodeled greenhouse will be compared to the performance of the same greenhouse as it was originally designed. The restored greenhouse began operation in September 1979. Accurate fuel and temperature records maintained through-out the past winter, show the cost of back-up heating under operating conditions to be approximately $150.00. Old fuel receipts dating back into the 1940's show an average use of 2000 gallons of heating fuel each winter prior to remodeling. This would indicate a yearly fuel savings of better than 90% through the use of passive solar techniques.

  4. Passive solar technology

    SciTech Connect

    Watson, D

    1981-04-01

    The present status of passive solar technology is summarized, including passive solar heating, cooling and daylighting. The key roles of the passive solar system designer and of innovation in the building industry are described. After definitions of passive design and a summary of passive design principles are given, performance and costs of passive solar technology are discussed. Passive energy design concepts or methods are then considered in the context of the overall process by which building decisions are made to achieve the integration of new techniques into conventional design. (LEW).

  5. Cooperative passive-solar commercial retrofit. Final report, September 1, 1980-December 31, 1982

    SciTech Connect

    Brown, W.T.

    1982-12-01

    The primary objectives of this project were: the conversion of an existing south-facing storefront into a trombe'-wall passive solar collector, the sharing of information on simple low-cost energy alternatives with the local community, and the reduction of the store building's dependence on non-renewable fossil fuel for space heating. Six 6' wide pre-assembled collector glazing panels were mounted on a 12' high by 36' long portion of the south-facing masonry wall. Vent-holes were cut through the wall at each panel to provide air inlets and outlets for the collector and monitoring equipment was installed to record performance. A series of hands-on construction workshops were attended by Co-op and community members. During these sessions, collector components were assembled. The panels were installed on April 22, 1981 in celebration of Earth Day. Additional sessions were held to complete the project, make necessary modifications and install sensors. Project personnel participated in several energy-education activities, including workshops, seminars and alternative energy home tours. A community-based energy resource council was founded with the assistance of several key Co-op project members and a fully-illustrated How-To manual, entitled Passive Solar Collector: A Trombe'-Wall Retrofit Guide was published. Finally, a variety of energy conservation measures were undertaken. These included a new airlock store entry, insulated store ceiling, destratification ceiling fans and wood-burning furnaces have combined with the passive solar collector to substantially reduce the use of fuel oil for heat.

  6. Passive solar energy: the genesis for architectural innovations in commercial buildings

    SciTech Connect

    Kroner, W.M.; Smith, P.N.

    1981-01-01

    The Campus Information Center (CIC) at Rensselaer Polytechnic Institute, Troy, New York, integrates environmental controls, energy conservation measures, and passive solar design. It demonstrates what can be done when the client, architect, and engineer work together to create a building that synthesizes energy-related technologies with architectural excellence in a cost effective manner. This paper discusses the unique process that led to the timely design of the CIC. It also provides specific information about three of the CIC's innovative systems: the multipath energy flow system, the individualized comfort system, and the building instrumentation system.

  7. User evaluation study of passive solar residences

    SciTech Connect

    Towle, S.

    1980-03-01

    Speculation exists regarding the readiness of various passive techniques for commercialization and the market potential for residential applications. This paper discusses the preliminary findings of a market assessment study designed to document user experiences with passive solar energy. Owners and builders of passive solar homes were interviewed and asked to comment on personal experiences with their homes.

  8. Passive solar construction handbook

    SciTech Connect

    Levy, E.; Evans, D.; Gardstein, C.

    1981-08-01

    Many of the basic elements of passive solar design are reviewed. The unique design constraints presented in passive homes are introduced and many of the salient issues influencing design decisions are described briefly. Passive solar construction is described for each passive system type: direct gain, thermal storage wall, attached sunspace, thermal storage roof, and convective loop. For each system type, important design and construction issues are discussed and case studies illustrating designed and built examples of the system type are presented. Construction details are given and construction and thermal performance information is given for the materials used in collector components, storage components, and control components. Included are glazing materials, framing systems, caulking and sealants, concrete masonry, concrete, brick, shading, reflectors, and insulators. The Load Collector Ratio method for estimating passive system performance is appended, and other analysis methods are briefly summarized. (LEW)

  9. Passive solar commercial buildings: design assistance and demonstration program. Phase 1. Final report

    SciTech Connect

    1981-01-26

    The final design of the Mount Airy Public Library is given. Incremental passive design costs are discussed. Performance and economic analyses are made and the results reported. The design process is thoroughly documented. Considerations discussed are: (1) building energy needs; (2) site energy potentials, (3) matching energy needs with site energy potentials, (4) design indicators for best strategies and concepts, (5) schematic design alternatives, (6) performance testing of the alternatives, (7) design selection, and (8) design development. Weather data and Duke Power electric rates are included. (LEW)

  10. Passive-solar greenhouse

    SciTech Connect

    Not Available

    1982-01-01

    Our project objective was to design, construct, and operate a commercialized (16' x 50') passive, solar greenhouse. The structure was originally intended as a vegetable forcing facility to produce vegetable crops in the off-season. Building and size constraints and economic considerations convinced us to use the greenhouse for producing bedding plants and vegetable starts in the spring, high value vegetables (tomatoes, cucumbers) in the fall and forced bulbs in the winter. This crop sequence allows us to use the greenhouse all year without additional heat as the crops are adopted to the temperature regime of the greenhouse during each particular season. In our first season, the greenhouse performed beautifully. The lowest temperature recorded was 38/sup 0/F after 4 cold, cloudy days in February. The production of bedding plants has allowed us to diversify our products and the early transplants we produced were a great asset to our vegetable farming operation. Although construction cost (4.57 sq. ft.) is higher than that of a conventional polyethylene-covered, quonset-type greenhouse (approx. $1.92 sq. ft.), our annual operating cost is cheaper than that of a conventional greenhouse (0.49 cents sq. ft. versus 0.67 cents sq. ft.) due to a longer usable lifetime of the structure and the elimination of heating costs. Our structure has been toured by interested individuals, school and farm groups. We plan to publicize the structure and its advantages by promoting more visits to the site.

  11. Passive-solar construction handbook

    SciTech Connect

    Levy, E.; Evans, D.; Gardstein, C.

    1981-02-01

    Many of the basic elements of passive solar design are reviewed. Passive solar construction is covered according to system type, each system type discussion including a general discussion of the important design and construction issues which apply to the particular system and case studies illustrating designed and built examples of the system type. The three basic types of passive solar systems discussed are direct gain, thermal storage wall, and attached sunspace. Thermal performance and construction information is presented for typical materials used in passive solar collector components, storage components, and control components. Appended are an overview of analysis methods and a technique for estimating performance. (LEW)

  12. Passive Solar Is Common Sense.

    ERIC Educational Resources Information Center

    Robison, Rita

    1979-01-01

    A checklist of concepts concerning passive solar energy techniques. Many can be applied immediately to existing buildings, while others should be brought into the initial planning of buildings. (Author/MLF)

  13. Passive solar hen house--Second year

    SciTech Connect

    MacDougall, E.A.

    1980-12-01

    This paper describes the second year's study of a passive solar hen house. The first year's study demonstrated that a small flock of hens living in a solar heated environment can produce more eggs at a better feed efficiency than that predicted by the U.S. Department of Agriculture (USDA) for hens housed in standard hen housing. For this second year's work a new flock of Rhode Island Reds was raised and then divided in two groups - one housed in the solar hen house; the other in a barn. The solar housed group showed slightly better feed efficiency, but the barn housed group had better egg production. Both groups produced consistently heavier eggs than comparative commercial hens. However, the commercial hens showed higher feed efficiency than either the barn housed or the solar housed group for the 15 week test.

  14. Neglect mars passive solar progress

    SciTech Connect

    Holzman, D.

    1984-02-01

    The development of solar technology in the United States was reviewed at the annual Passive Solar Update Conference held in Washington D.C. in Sept. 1983. Though it lacked the technological breakthroughs of some past conferences, this conference was notable because the mood was definitely upbeat. The promise of many solar approaches is as great as ever and they now seem to be reliazable.

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

    NASA Astrophysics Data System (ADS)

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

    1982-07-01

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

  16. Interior design for passive solar homes

    SciTech Connect

    Breen, J. C.

    1981-07-01

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

  17. Passive solar energy information user study

    SciTech Connect

    Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.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. Results 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.

  18. New England style passive solar

    SciTech Connect

    Kriescher, P.

    2000-06-01

    There are homeowners throughout New England who planned for and built homes that allow them to avoid the sting of winter's high heating bills. These climate-responsive homes rely on passive solar heating, cooling and lighting. An example of such a climate-responsive/passive solar house is the home that Arthur and Terry Becker build on 6 beautiful acres (2.4 hectares) of rolling farm and woodland southeast of Andover, Connecticut, in 1981. They worked very closely with their designer, Al Eggan of K.T. Lear and Associates, to ensure that they would never have to pay for home heating oil, and that they would enjoy a level of year-round comfort that they had not experienced in conventionally built homes.

  19. Passive solar in China: traditional and new

    SciTech Connect

    Balcomb, J D; Balcomb, S A

    1986-04-01

    The authors' observations of a tradition of passive solar architecture in northern China are described. Tendencies for modern buildings to depart from this tradition are noted. Major passive solar research programs are discussed and experimental buildings are illustrated. It is concluded that the Chinese could realize a major advantage by combining their strong tradition of passive solar architecture with modern insulation methods and improved glazing systems.

  20. Passive solar in the United States: 1976-1986

    SciTech Connect

    Balcomb, J D

    1987-01-01

    A decade of experience in passive solar development in the United States is reviewed. More than 200,000 residential and 15,000 institutional and commercial passive solar buildings have been constructed since 1976. The evolution of the program through its peak in 1980 to the present is described. Methods of performance prediction and evaluation are discussed including analysis methods, design tools, test modules and monitored buildings. Results of the monitoring show excellent performance, generally in agreement with the analysis, for both residences and larger buildings. Passive practice is analyzed and problems are discussed. The current research program is described. Potential savings are estimated.

  1. Gap between active and passive solar heating

    SciTech Connect

    Balcomb, J.D.

    1985-01-01

    The gap between active and passive solar could hardly be wider. The reasons for this are discussed and advantages to narrowing the gap are analyzed. Ten years of experience in both active and passive systems are reviewed, including costs, frequent problems, performance prediction, performance modeling, monitoring, and cooling concerns. Trends are analyzed, both for solar space heating and for service water heating. A tendency for the active and passive technologies to be converging is observed. Several recommendations for narrowing the gap are presented.

  2. Heterojunction solar cell with passivated emitter surface

    DOEpatents

    Olson, J.M.; Kurtz, S.R.

    1994-05-31

    A high-efficiency 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. A passivating window layer of defined composition is disposed over the emitter 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 window layer. 1 fig.

  3. Heterojunction solar cell with passivated emitter surface

    DOEpatents

    Olson, Jerry M.; Kurtz, Sarah R.

    1994-01-01

    A high-efficiency 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. A passivating window layer of defined composition is disposed over the emitter 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 window layer.

  4. Tierra Nueva -- A passive solar cohousing project

    SciTech Connect

    Haggard, K.; Cooper, P.

    1999-10-01

    California architects take on the formidable challenges of designing a cohousing project, and discover that the end result is well worth the effort. The Tierra Nueva Cohousing Project consists of living units, a common house, community orchard, community gardens, community play space, space for a future shop and at the periphery of the site, parking, carports and garages. The units use thermal mass, solar heating, passive solar cooling, perimeter insulation on slabs. Design was agreed to by the community as a whole.

  5. Mennonite Nursing Home passive solar demonstration

    SciTech Connect

    Not Available

    1984-03-01

    A long-term nursing care facility and retirement center was designed for passive solar heating. The system comprises thermal mass, thermal insulation, Trombe walls, and direct gain clerestories. Included here is a topical report, analysis of building performance, owner's perspective, designer's perspective, and summary of information dissemination activities. (MHR)

  6. Camp Sacajawea Passive Solar Demonstration Project

    SciTech Connect

    Not Available

    1983-08-31

    The intent of the Passive Solar Demonstration Project was to have: an actual demonstration of the effectiveness of a passive solar design and working automatic shading devices; accurate data of energy saved by the passive design and shading devices; a brochure distributed to architects, builders, and consumers, with the monitoring data and information about the project; and the continued monitoring of the building to help explain to those who are using the building the value of the system; this would not only include the 7000 members, bu visitors and other users of the facility. To accomplish these goals, a monitoring system was installed in the recently build Passive Solar Lodge at Camp Sacajawea on Casper Mountain south of Casper, Wyoming. The building was monitored continously for the remainder of the project. The installation of the automatic shading device, a curtain wall was accomplished but had some difficulty. The results indicate there is some effectiveness of the Curtain Wall, but a quantitative value would be impossible at this time.

  7. Passive solar in tornado alley

    SciTech Connect

    Kriescher, P.

    2000-02-01

    The renewable energy and energy efficiency industries have long relied on entrepreneurial individuals with a passion for integrating clean energy alternatives into residential and commercial construction. Most of these individuals were drawn into sustainable energy design during time of inflationary energy prices (e.g., the 1973 oil crisis), when government and industry were investing in clean energy technologies. Some of the best and brightest maintained their enthusiasm for high quality, low energy building design--even as government and industry support slowed--and worked tirelessly toward making sustainable design viable in the marketplace.

  8. Commercialization of solar space power

    NASA Astrophysics Data System (ADS)

    Pant, Alok; Sera, Gary

    1995-01-01

    The objective of this research is to help U.S. companies commercialize renewable energy in India, with a special focus on solar energy. The National Aeronautics and Space Administration (NASA) Mid-Continent Technology Transfer Center (MCTTC) is working with ENTECH, Inc., a solar photovoltaic (SPV) systems manufacturer to form partnerships with Indian companies. MCTTC has conducted both secondary and primary market research and obtained travel funding to meet potential Indian partners face to face. MCTTC and ENTECH traveled to India during June 2-20, 1994, and visited New Delhi, Bombay, Pune and Calcutta. Meetings were held with several key government officials and premier Indian business houses and entrepreneurs in the area of solar energy. A firsthand knowledge of India's renewable energy industry was gained, and companies were qualified in terms of capabilities and commitment to the SPV business. The World Bank has awarded India with 280 million to commercialize renewable energies, including 55 million for SPV. There is a market in India for both small-scale (kW) and large SPV (MW) applications. Each U.S. company needs to form a joint venture with an Indian firm and let the latter identify the states and projects with the greatest business potential. Several big Indian companies and entrepreneurs are planning to enter the SPV business, and they currently are seeking foreign technology partners. Since the lager companies have adopted a more conservative approach, however, partnerships with entrepreneurs might offer the quickest route to market entry in India.

  9. PASSIVE SMOKING ON COMMERCIAL AIRLINE FLIGHTS

    EPA Science Inventory

    Inflight exposure to nicotine, urinary cotinine and symptom self reports were assessed in a study of 9 subjects (5 passengers and 4 attendants) on four routine commercial flights each of approximately 4 hours duration. rine samples were collected for 72 hours following each fligh...

  10. Passive and Hybrid Solar Energy Program

    SciTech Connect

    Not Available

    1980-11-01

    The background and scope of the program is presented in general terms. The Program Plan is summarized describing how individual projects are categorized into mission-oriented tasks according to market sector categories. The individual projects funded by DOE are presented as follows: residential buildings, commercial buildings, solar products, solar cities and towns, and agricultural buildings. A summary list of projects by institution (contractors) and indexed by market application area is included. (MHR)

  11. User participation in passive solar housing design

    SciTech Connect

    McLain-Kark, J.H.

    1985-01-01

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

  12. Passive solar progress: a simplified guide to the 3rd national passive solar conference

    SciTech Connect

    Miller, H.; Howell, Y.; Richards, D.

    1980-10-01

    Some of the concepts and practices that have come to be known as passive solar heating and cooling are introduced, and a current picture of the field is presented. Much of the material presented is derived from papers given at the 3rd National Passive Solar Conference held in San Jose, California in January 1979 and sponsored by the US Department of Energy. Extracts and data from these papers have been integrated in the text with explanatory and descriptive material. In this way, it is attempted to present technical information in an introductory context. Topics include design considerations, passive and hybrid systems and applications, sizing methods and performance prediction, and implementation issues. A glossary is included. (WHK)

  13. SOLCOST-PASSIVE solar energy design program: User's Guide

    SciTech Connect

    Not Available

    1980-09-01

    The SOLCOST-PASSIVE solar energy design program is a public domain interactive computer design tool intended for use by non-thermal specialists to size passive solar systems with a methodology based on the Los Alamos Solar Load Ratio method. A life cycle savings analysis is included in the program. An overview of SOLCOST-PASSIVE capabilities and the Solar Load Ratio method which it is based on is presented. A detailed guide to the SOLCOST-PASSIVE input parameters is given. Sample problems showing typical execution sessions and the resulting SOLCOST-PASSIVE output are included. Appendices A thru D provide details on the SLR method and the life cycle savings methodology of SOLCOST-PASSIVE. (MHR)

  14. Passive solar sunset: Predicting our own demise

    SciTech Connect

    Milne, M.

    1986-01-01

    Phrases like solar heating, passive cooling, or energy-conserving design should be eliminated as quickly as possible from the vocabularies of all practicing architects. Such phrases should be replaced by the phrase ''competent design'' and simply taken for granted. Every client has a right to expect these features from a qualified professional just as they expect a structurally sound, fire-safe, and weather-tight building. In times past, indigenous builders knew very well how to design thermally efficient and energy-conserving buildings. They may not have understood the theory behind their designs, but the rituals, traditions, and cultural taboos governing their work embodied wisdom gained over the centuries. The elegance and thermal ingenuity of these buildings are still admired by even the most high-tech, post-modern architects of today.

  15. Solar air-conditioning-active, hybrid and passive

    SciTech Connect

    Yellott, J. I.

    1981-04-01

    After a discussion of summer air conditioning requirements in the United States, active, hybrid, and passive cooling systems are defined. Active processes and systems include absorption, Rankine cycle, and a small variety of miscellaneous systems. The hybrid solar cooling and dehumidification technology of desiccation is covered as well as evaporative cooling. The passive solar cooling processes covered include convective, radiative and evaporative cooling. Federal and state involvement in solar cooling is then discussed. (LEW)

  16. Passive solar technology aids biogas digesters

    SciTech Connect

    Not Available

    1988-07-01

    Farming communities throughout China rely on biogas generators as a primary source of light and heat, as well as using the sludge as a nitrogen-rich fertilizer. Now researchers at Beijing's Solar Energy Laboratory have improved efficiency by building a rectangular tank out of concrete slabs, with one slanted surface painted black and covered with glass. According to a report in New Scientist, this passive solar panel generates heat in the same way as a greenhouse, raising inside temperatures by 10{degree}C and increasing biogas production by 50%. Another advantage of the new tanks is easy access, since the tank's lid sites in wells of water which form a seal against oxygen. (Old biogas tanks were made of soil, sand and a little concrete, prone to developing severe cracks which would allow oxygen to enter thus slowing down anaerobic reaction). Explains Debora MacKenzie of New Scientist: with the new tank, the farmer can simply remove the lid and attack the contents with a spade. This means that the mixture can comprise more than 10% solids. Greater density allows smaller tanks. Rural families need one cubic meter of biogas daily for light and heat; instead of the former 8 cm biogas generator, the new tanks need only be 1 cm. The prediction is that the smaller size could make biogas more popular in China's crowded towns. The biogas department is headed by He Shao Qi, who is also investigating ways to reduce production costs for the tanks.

  17. Solar technology assessment project. Volume 4: Solar air conditioning: Active, hybrid and passive

    NASA Astrophysics Data System (ADS)

    Yellott, J. I.

    1981-04-01

    The status of absorption cycle solar air conditioning and the Rankine cycle solar cooling system is reviewed. Vapor jet ejector chillers, solar pond based cooling, and photovoltaic compression air conditioning are also briefly discussed. Hybrid solar cooling by direct and indirect evaporative cooling, and dehumidification by desiccation are described and discussed. Passive solar cooling by convective and radiative processes, evaporative cooling by passive processes, and cooling with roof ponds and movable insulation are reviewed. Federal and state involvement in solar cooling is discussed.

  18. Passive solar design: final evaluation, the Passive Studio

    SciTech Connect

    Bremer, Duncan S.; Rose, Stuart

    1980-08-01

    The further evaluation of the workshops in passive design for practicing architects and engineers through delayed interviews with a sample of the participants is reported with particular emphasis on the extent to which the participants have practiced passive design in the three-four months since attending. Also discussed is an unsuccessful attempt to conduct a lower-cost version of the program outside of normal office hours. Finally, the follow-on programs and improvements that the interviews indicated are needed are identified. (MHR)

  19. Window structure for passivating solar cells based on gallium arsenide

    NASA Technical Reports Server (NTRS)

    Barnett, Allen M. (Inventor)

    1985-01-01

    Passivated gallium arsenide solar photovoltaic cells with high resistance to moisture and oxygen are provided by means of a gallium arsenide phosphide window graded through its thickness from arsenic rich to phosphorus rich.

  20. Enhanced Charge Collection with Passivation Layers in Perovskite Solar Cells.

    PubMed

    Lee, Yong Hui; Luo, Jingshan; Son, Min-Kyu; Gao, Peng; Cho, Kyung Taek; Seo, Jiyoun; Zakeeruddin, Shaik M; Grätzel, Michael; Nazeeruddin, Mohammad Khaja

    2016-05-01

    The Al2 O3 passivation layer is beneficial for mesoporous TiO2 -based perovskite solar cells when it is deposited selectively on the compact TiO2 surface. Such a passivation layer suppressing surface recombination can be formed by thermal decomposition of the perovskite layer during post-annealing. PMID:26928481

  1. Commercializing solar for industry in California

    NASA Astrophysics Data System (ADS)

    Yudelson, J.

    1980-10-01

    The State of California has begun a commercialization program for increasing the rate of solar applications in industry. The components of this program include low interest loans, tax credits, revenue bonds and educational efforts. Many California industries appear to be likely candidates for solar systems, but as yet only a few companies have elected to install them. The various barriers to solar use by industry are primarily perceptual and financial. The emphasis of the state program for commercialization is turning increasingly towards educational seminars for industry groups and development of creative financial tools and arrangements. There are a few remaining legislative changes at state and federal levels, primarily involving leasing and tax laws which, if enacted, would overcome all of the remaining financial barriers to widespread adoption of solar applications by industry.

  2. NASA Solar Array Demonstrates Commercial Potential

    NASA Technical Reports Server (NTRS)

    Creech, Gray

    2006-01-01

    A state-of-the-art solar-panel array demonstration site at NASA's Dryden Flight Research Center provides a unique opportunity for studying the latest in high-efficiency solar photovoltaic cells. This five-kilowatt solar-array site (see Figure 1) is a technology-transfer and commercialization success for NASA. Among the solar cells at this site are cells of a type that was developed in Dryden Flight Research Center s Environmental Research Aircraft and Sensor Technology (ERAST) program for use in NASA s Helios solar-powered airplane. This cell type, now denoted as A-300, has since been transferred to SunPower Corporation of Sunnyvale, California, enabling mass production of the cells for the commercial market. High efficiency separates these advanced cells from typical previously commercially available solar cells: Whereas typical previously commercially available cells are 12 to 15 percent efficient at converting sunlight to electricity, these advanced cells exhibit efficiencies approaching 23 percent. The increase in efficiency is due largely to the routing of electrical connections behind the cells (see Figure 2). This approach to increasing efficiency originated as a solution to the problem of maximizing the degree of utilization of the limited space available atop the wing of the Helios airplane. In retrospect, the solar cells in use at this site could be used on Helios, but the best cells otherwise commercially available could not be so used, because of their lower efficiencies. Historically, solar cells have been fabricated by use of methods that are common in the semiconductor industry. One of these methods includes the use of photolithography to define the rear electrical-contact features - diffusions, contact openings, and fingers. SunPower uses these methods to produce the advanced cells. To reduce fabrication costs, SunPower continues to explore new methods to define the rear electrical-contact features. The equipment at the demonstration site includes

  3. Passive-solar design manual for the United States Navy

    SciTech Connect

    Wray, W.O.; Biehl, F.A.; Kosiewicz, C.R.; Miles, C.R. Durlak, E.R.

    1982-01-01

    A passive solar design manual for single-family detached residences and dormitory-type buildings is being developed. The design procedure employed in the manual is a simplification of the original monthly solar load ratio (SLR) method. The new SLR correlations involve a single constant for each system. The correlation constant appears as a scale factor permitting the use of a universal performance curve for all passive systems. Furthermore, by providing location-dependent correlations between the annual solar heating fraction (SHF)* and the minimum monthly SHF, we have eliminated the need to perform an SLR calculation for each month of the heating season.

  4. Illinois solar '80: how to build 18 passive solar homes for less than $30,000

    SciTech Connect

    Donahue, P.; Dean, K.

    1981-01-01

    Illinois Solar '80, a residential passive solar construction program targeted at Illinois vocational schools traditionally involved in home building projects, is discussed. Conducted by the Illinois Institute of Natural Resources (INR), the first round of this program has resulted in the construction of 18 energy efficient passive solar homes by 17 vocational schools throughout the state. The major program components of Illinois Solar '80 are: (1) an open solicitation process, (2) professional training in passive design and construction, (3) $1000 grant award to each school, (4) technical assistance, (5) promotional support, and (6) site visits. A total agency investment of $29,000 in direct costs has resulted in training over 650 building trades students in passive solar design through construction of 18 solar homes.

  5. Locally contacted rear surface passivated solar cells by inkjet printing

    NASA Astrophysics Data System (ADS)

    Phiwpha, N.; Fangsuwannarak, T.; Sopitpan, S.

    2014-06-01

    Inkjet printing of photoresist material may provide a new route for low-cost fabrication of patterned oxide passivation layer of solar cells that require fine patterning and simple process. However, printing by liquid-based, environmentally friendly ink and printing device required development efforts aimed at achieving a fine patterning and long used inkjet nozzles under corrosive influence. This work was demonstrated a concept for grooved silicon oxide patterning for rear localized contact of p-n junction solar cells by chemical etching after photoresist patterning obtained. This article reviews the silicon dioxide fabrication on p-Si substrate from sol-gel technique for oxide passivation layer of solar cells. The aluminium was deposited on the patterned oxide layer and then heated at its Al-Si eutectic temperature. Finally, an aluminium-induced solid-phase epitaxial growth of p+ forming into the openings of the oxide passivation layer was presented. The sheet resistance of n-emitter layer, carrier life-time and surface recombination velocity values are investigated. Photoconductive measurements were performed on the prepared samples after each thermal process to measure the effective lifetime of the minority carriers. Carrier lifetime up to 60 microseconds has been measured on c-Si wafer passivated by the opened SiO2 layer. It was shown that the patterned SiO2 passivation has obtained high passivation quality making by the proposed inkjet printing method.

  6. Front surface passivation of silicon solar cells with antireflection coating

    NASA Technical Reports Server (NTRS)

    Crotty, G.; Daud, T.; Kachare, R.

    1987-01-01

    It is demonstrated that the deposition and postdeposition sintering of an antireflection (AR) coating in hydrogen acts to passivate silicon solar cells. Cells with and without an SiO2 passivating layer, coated with a TiO(x)/Al2O3 AR coating, showed comparable enhancements in short-wavelength spectral response and in open-circuit voltage Voc after sintering at 400 C for 5 min in a hydrogen ambient. The improvement in Voc of cells without SiO2 is attributed to front-surface passivation by the AR coating during processing.

  7. Passive-solar retrofit study for the United States Navy

    SciTech Connect

    Wray, W.O.; Miles, C.R.

    1981-01-01

    A passive solar retrofit study has been conducted for the United States Navy at the Los Alamos National Laboratory. The purpose of the study was to determine the energy savings obtainable in concrete block buildings from several passive solar heating strategies. A procedure involving the use of test cell data and computer simulation was employed to assess the merits of six retrofit options. The six strategies selected were chosen on the basis of providing a series of options that will deliver increasing energy savings at the cost of correspondingly increased levels of commitment.

  8. Passive-solar-retrofit study for the United States Navy

    SciTech Connect

    Wray, W.O.; Miles, C.R.

    1981-01-01

    A passive solar retrofit study has been conducted for the United States Navy at the Los Alamos National Laboratory. The purpose of the study was to determine the energy savings obtainable in concrete block buildings from several passive solar heating strategies. A procedure involving the use of test cell data and computer simulation was employed to assess the merits of six retrofit options. The six strategies selected were chosen on the basis of providing a series of options that will deliver increasing energy savings at the cost of correspondingly increased levels of commitment.

  9. Progress in passive solar energy systems. Volume 8. Part 1

    SciTech Connect

    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 photovoltaic system for a shopping center, photovoltaic power generation for the utility industry, spectral solar radiation, and the analysis of insolation data.

  10. Passive solar array orientation devices for terrestrial application.

    NASA Technical Reports Server (NTRS)

    Fairbanks, J. W.; Morse, F. H.

    1972-01-01

    A passive solar array orientation device, called a thermal heliotrope, is described, and several terrestrial applications are illustrated. The thermal heliotrope consists of a bimetallic helical coil that serves as the motor element, producing torque and angular displacement. A control mechanism in the form of one or more shades completes the basic device. In comparison with electromechanical tracking systems, the thermal heliotrope is electrically passive, has relatively few parts, and is low cost. After describing the principle of operation and several models built for space applications, the design considerations for several terrestrial thermal heliotrope units are presented. It is suggested that the use of the thermal heliotrope for solar array orientation could significantly reduce array cost, thereby increasing the competitive economic posture of solar arrays for terrestrial applications. The thermal heliotrope modified for terrestrial use is readily adaptable to orient solar energy concentrators, such as furnaces and stills.

  11. Commercial dissemination approaches for solar home systems

    SciTech Connect

    Terrado, E.

    1997-12-01

    The author discusses the issue of providing solar home systems to primarily rural areas from the perspective of how to commercialize the process. He considers two different approaches, one an open market approach and the other an exclusive market approach. He describes examples of the exclusive market approach which are in process in Argentina and Brazil. Coming from a banking background, the business aspects are discussed in detail. He points out the strengths and weaknesses of both approaches toward developing such systems.

  12. Passive Solar Design: Technology Fact Sheet; Office of Building Technology, State and Community Programs (BTS)

    SciTech Connect

    Southern Energy Institute

    2000-12-14

    Fact sheet for homeowners and contractors on using passive solar design features in homes can increase energy efficiency and comfort. Topics include design techniques, cost, and passive solar design tools.

  13. Simple procedure for schematic design of passive solar buildings

    SciTech Connect

    Wray, W.O.; Kosiewicz, C.E.

    1984-01-01

    A simple procedure for use during the schematic phase of passive solar building design is presented in this article. The procedure is quantitative and accurate enough to insure that designs based on the provided starting point values of the primary building parameters will be cost effective.

  14. Passive cooling with solar updraft and evaporative downdraft chimneys

    SciTech Connect

    Mignon, G.V.; Cunningham, W.A.; Thompson, T.L.

    1985-01-01

    Computer models have been developed to describe the operation of both solar updraft and evaporative downdraft chimneys. Design studies are being conducted at the present time to use the towers for cooling an experimental, well instrumented, structure to study passive cooling in residential buildings. (MHR)

  15. Vocational-Technical Instructors Passive-Solar Training Workshop

    NASA Astrophysics Data System (ADS)

    1981-07-01

    The successful efforts to provide training to instructors who teach residential design and construction at vocational-technical (vo-tech) schools are described. The training was directed toward those techniques one must consider when designing and/or constructing an energy efficient passive solar home.

  16. Vocational-technical instructors passive-solar training workshop

    SciTech Connect

    Not Available

    1981-07-01

    The successful efforts to provide training to instructors who teach residential design and construction at vocational-technical (vo-tech) schools are described. The training was directed toward those techniques one must consider when designing and/or constructing an energy efficient passive solar home.

  17. Passive solar house in Skillman, NJ: Case study

    SciTech Connect

    Kendig, J.

    1999-07-01

    This study traces the history of a single family residence in Skillman, NJ designed by Harrison Fraker. The house, built in 1978, was conceived as primarily passive solar house intended to rely on solar energy for most of its heating needs. Solar features include direct gain windows, water walls and sunspace. The study documents original solar features, identifies changes over time and evaluates performance of the house. The owners have removed movable insulation and significantly reduced the amount of thermal mass over the life of the building. The owner reported comfort level changes intuitively consistent with those modifications. The owner is contemplating further changes to make the house more marketable, changes likely to further alter the remaining passive solar features. Builders Guide software was used to calculate changes in solar performance of the house related to building modifications. Calculations of solar performance generally correspond to anecdotal information from the owner. The author's attempts with Energy 10 program showed some promise, but are as yet inconclusive. At this time BG appears to be more useful and user friendly to the average practitioner with limited time and design resources. As a practicing architect the author is most interested in lessons to be learned from the past as they might contribute to future projects. Information gleaned from this study did confirm intuitively expected and currently disseminated thinking regarding passive solar design. The thermal mass proved to be vulnerable to change. Features which required daily manual adjustment were quickly discarded. Desire for comfort was driving force in changing the house and took precedence over the need to save energy or money.

  18. Efficient passivated phthalocyanine-quantum dot solar cells.

    PubMed

    Blas-Ferrando, Vicente M; Ortiz, Javier; González-Pedro, Victoria; Sánchez, Rafael S; Mora-Seró, Iván; Fernández-Lázaro, Fernando; Sastre-Santos, Ángela

    2015-01-31

    The power conversion efficiency of CdSe and CdS quantum dot sensitized solar cells is enhanced by passivation with asymmetrically substituted phthalocyanines. The introduction of the phthalocyanine dye increases the efficiency up to 45% for CdSe and 104% for CdS. The main mechanism causing this improvement is the quantum dot passivation. This study highlights the possibilities of a new generation of dyes designed to be directly linked to QDs instead of the TiO2 electrodes. PMID:25519050

  19. Analysis of thermal comfort in a passive solar heated residence

    NASA Astrophysics Data System (ADS)

    Liu, S. T.

    1981-11-01

    The thermal comfort conditions in a passive solar heated residence of the popular Trombe Wall configuration were investigated. The indoor thermal environment of an actual passive solar residence, using the typical meteorological year (TMY) weather data tape as input as three locations of different climatic conditions was simulated. The relevant thermal comfort parameters such as the space air temperature, mean radiant temperatures, operative temperatures, radiant temperature asymmetry, and temperature drifts of the occupied zone, were computed for a prime heating month, a transition month and a prime cooling month of a typical weather year at the three locations. It is found that for the specific passive solar residence analyzed, the upper boundary of the comfort envelope can be exceeded (overheating) during a typical clear day in the transition month of April unless a change of clothing to summer wear is made during the daytime high solar radiation house. The upper boundary will be exceeded during a typical clear day in the prime cooling month of August for a person in typical summer clothing at all three locations unless the average air movement in the occupied zone is increased above the level of natural circulation, or the thermostat setting is reduced to a lower level, or both.

  20. Passive-solar-cooling system concepts for small office buildings. Final report

    SciTech Connect

    Whiddon, W.I.; Hart, G.K.

    1983-02-01

    This report summarizes the efforts of a small group of building design professionals and energy analysis experts to develop passive solar cooling concepts including first cost estimates for small office buildings. Two design teams were brought together at each of two workshops held in the fall of 1982. Each team included an architect, mechanical engineer, structural engineer, and energy analysis expert. This report presents the passive cooling system concepts resulting from the workshops. It summarizes the design problems, solutions and first-cost estimates relating to each technology considered, and documents the research needs identified by the participants in attempting to implement the various technologies in an actual building design. Each design problem presented at the workshops was based on the reference (base case) small office building analyzed as part of LBL's Cooling Assessment. Chapter II summarizes the thermal performance, physical specifications and estimated first-costs of the base case design developed for this work. Chapters III - VI describe the passive cooling system concepts developed for each technology: beam daylighting; mass with night ventilation; evaporative cooling; and integrated passive cooling systems. The final Chapters, VII and VIII present the preliminary implications for economics of passive cooling technologies (based on review of the design concepts) and recommendations of workshop participants for future research in passive cooling for commercial buildings. Appendices provide backup information on each chapter as indicated.

  1. Surface passivation of high efficiency silicon solar cells

    NASA Astrophysics Data System (ADS)

    Aberle, A.; Warta, W.; Knobloch, J.; Voss, B.

    Theoretically and experimentally determined design guides for significantly reducing recombination at the emitter and rear surfaces of full-area Al-BSF (back-surface region) and oxide-passivated bifacial cells are given. The impact of emitter thickness and surface dopant concentration on emitter saturation current and solar cell efficiency is outlined. A modified emitter structure (locally deep diffused below the metal contacts) is predicted to have superior performance. Measured Voc values reveal the potential of deep emitter cells to achieve efficiencies above 20 percent in spite of high metallization factors. Experimentally, a strong dependence of passivation quality on oxide thickness and base doping concentration is found. The BSF quality of a diffused aluminum layer decreases strongly with increasing drive-in time. For SiO2-passivated rear surfaces of bifacial cells, measurements of the dependence of the surface recombination velocity on the excess carrier concentration are presented.

  2. Environmentally friendly education: A passive solar, straw-bale school

    SciTech Connect

    Stone, L.; Dickinson, J.

    1999-07-01

    The Waldorf students in the Roaring Fork Valley of western Colorado are learning their reading, writing and arithmetic in the cozy confines of a solar heated, naturally lit, straw-bale school. The Waldorf education system, founded in 1919 by Austrian Rudolph Steiner, stresses what's appropriate for the kids, not what's easiest to teach. In constructing a new school, the Waldorf community wanted a building that would reflect their philosophy. There was a long list of requirements: natural, energy efficient, light, warm, alive, and earthy. Passive solar straw-bale construction brought together all those qualities.

  3. Novel Passivating/Antireflective Coatings for Space Solar Cells

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  4. National Passive Solar Conference, 4th, Kansas City, MO, October 3-5, 1979, Proceedings. Volume 4

    NASA Astrophysics Data System (ADS)

    Franta, G.

    1981-10-01

    Papers concern recent experience in the research, development and application of passive solar technology. Specific topics include the legislative barriers and incentives to passive solar systems, coupled thermal and lighting simulations for evaluating daylighting design effectiveness, passive solar applications in inner city housing, radiative cooling in a desert climate, salinity gradient solar ponds, the retrofit of a masonry home for passive space heating, the performances of active and passive solar domestic hot water systems, builder experience with passive solar home construction, the use of solar energy installations on farm buildings, and a method of determining the thermal performance of passive storage walls.

  5. Advanced phase change materials and systems for solar passive heating and cooling of residential buildings

    SciTech Connect

    Salyer, I.O.; Sircar, A.K.; Dantiki, S.

    1988-01-01

    During the last three years under the sponsorship of the DOE Solar Passive Division, the University of Dayton Research Institute (UDRI) has investigated four phase change material (PCM) systems for utility in thermal energy storage for solar passive heating and cooling applications. From this research on the basis of cost, performance, containment, and environmental acceptability, we have selected as our current and most promising series of candidate phase change materials, C-15 to C-24 linear crystalline alkyl hydrocarbons. The major part of the research during this contract period was directed toward the following three objectives. Find, test, and develop low-cost effective phase change materials (PCM) that melt and freeze sharply in the comfort temperature range of 73--77{degree}F for use in solar passive heating and cooling of buildings. Define practical materials and processes for fire retarding plasterboard/PCM building products. Develop cost-effective methods for incorporating PCM into building construction materials (concrete, plasterboard, etc.) which will lead to the commercial manufacture and sale of PCM-containing products resulting in significant energy conservation.

  6. Ion Implanted Passivated Contacts for Interdigitated Back Contacted Solar Cells

    SciTech Connect

    Young, David L.; Nemeth, William; LaSalvia, Vincenzo; Reedy, Robert; Bateman, Nicholas; Stradins, Pauls

    2015-06-14

    We describe work towards an interdigitated back contacted (IBC) solar cell utilizing ion implanted, passivated contacts. Formation of electron and hole passivated contacts to n-type CZ wafers using tunneling SiO2 and ion implanted amorphous silicon (a-Si) are described. P and B were ion implanted into intrinsic amorphous Si films at several doses and energies. A series of post-implant anneals showed that the passivation quality improved with increasing annealing temperatures up to 900 degrees C. The recombination parameter, Jo, as measured by a Sinton lifetime tester, was Jo ~ 14 fA/cm2 for Si:P, and Jo ~ 56 fA/cm2 for Si:B contacts. The contact resistivity for the passivated contacts, as measured by TLM patterns, was 14 milliohm-cm2 for the n-type contact and 0.6 milliohm-cm2 for the p-type contact. These Jo and pcontact values are encouraging for forming IBC cells using ion implantation to spatially define dopants.

  7. Simulation of a passive solar energy system. Master's thesis

    SciTech Connect

    Slate, M.P.

    1982-12-01

    A simple lumped capacitance-resistance model is used to simulate heat flow in a residential size structure heated passively by the sun. The model takes the form of an analogous electrical circuit. A computer program was written to analyse the circuit. By altering the input parameters of the program, the thermal performance of a wide variety of passive solar designs can be investigated for any geographical location. By comparing program generated data to data taken from experimental test cells in Los Alamos, New Mexico, it was found that the simulation program predicted energy use to within 4 percent of measured values. Also, the computer program predicted temperature swings to within 16 percent of measured swings. Correlation with empirical methods of calculating monthly and annual savings in fuel use for heating was poor. Using the simulation calculations as a base, the predictions of anual savings differed by as much as 76 percent.

  8. The role of surface passivation for efficient and photostable PbS quantum dot solar cells

    NASA Astrophysics Data System (ADS)

    Cao, Yiming; Stavrinadis, Alexandros; Lasanta, Tania; So, David; Konstantatos, Gerasimos

    2016-04-01

    For any emerging photovoltaic technology to become commercially relevant, both its power conversion efficiency and photostability are key parameters to be fulfilled. Colloidal quantum dot solar cells are a solution-processed, low-cost technology that has reached an efficiency of about 9% by judiciously controlling the surface of the quantum dots to enable surface passivation and tune energy levels. However, the role of the quantum dot surface on the stability of these solar cells has remained elusive. Here we report on highly efficient and photostable quantum dot solar cells with efficiencies of 9.6% (and independently certificated values of 8.7%). As a result of optimized surface passivation and the suppression of hydroxyl ligands—which are found to be detrimental for both efficiency and photostability—the efficiency remains within 80% of its initial value after 1,000 h of continuous illumination at AM1.5G. Our findings provide insights into the role of the quantum dot surface in both the stability and efficiency of quantum dot solar cells.

  9. Optimization of storage in passive solar heating systems. Final report

    SciTech Connect

    Bahm, R.J.

    1980-05-01

    The search for a simple method of estimating the optimum amount of storage for passive solar space heating system designs and the results of that search are described. The project goals, and why the project is important are described. The major project results are presented in the order of their importance with respect to meeting the project goal. A narrative description of the project is given. Here the various approaches attempted are described, giving the reasons for failure in those areas that were not successful. The Appendices contain the bulk of data generated by this project. Most of the data is presented in graphical form. (MHR)

  10. Thermal and cost goal analysis for passive solar heating designs

    SciTech Connect

    Noll, S.A.; Kirschner, C.

    1980-01-01

    Economic methodologies developed over the past several years for the design of residential solar systems have been based on life cycle cost (LCC) minimization. Because of uncertainties involving future economic conditions and the varied decision making processes of home designers, builders, and owners, LCC design approaches are not always appropriate. To deal with some of the constraints that enter the design process, and to narrow the number of variables to those that do not depend on future economic conditions, a simplified thermal and cost goal approach for passive designs is presented. Arithmetic and graphical approaches are presented with examples given for each. Goals discussed include simple payback, solar savings fraction, collection area, maximum allowable construction budget, variable cost goals, and Btu savings.

  11. Nanoporous Anodic Edge Passivation of Si Solar Cells.

    PubMed

    Choi, Jaeho; Palei, Srikanta; Parida, Bhaskar; Ko, Seuk Yong; Kim, Keunjoo

    2015-11-01

    We investigated the anodization effect on edge passivation of Si solar cells. The Si anodization allowed SiO2 formation on the edges of the cell for electrical passivation. The edge passivated cell showed enhanced conversion efficiency with reduced carrier recombination which was observed from photoluminescence and electroluminescence images. The luminescences were reduced at the edges indicating prevention of edge current leakage. However, when the rear Al paste layer of a sample was contacted to the solution during the anodization process, the conversion efficiency of the cell was reduced. We characterized oxide thin films by performing the anodization process for front Al thin film layer deposited by evaporation and rear Al paste layer. The front anodic aluminum oxide covering the Si emitter layer showed the excellent phototransmission with small photoreflectance lower than 5% and the anodization of Al paste showed the formation of a thin SiO2 film as well as nanoporous Al2O3 layer originating from the microspherical Al paste. The rear Al paste anodization allowed the Al microspheres to be filled with the nanopores in the inner empty space. PMID:26726608

  12. A passive solar system for downward heat transport

    SciTech Connect

    Stacy, W.D.

    1982-01-01

    This paper discusses the development and testing of a unique passive solar DHW system employing roof mounted conventional flat plate collectors and a conventional coil-in-tank hot water heater located 20 feet below the collectors. The system operates as an intermittent heat pipe in a two stroke cycle involving day time boil down/night time condensate return. System concept, construction details, and test results are presented for the 40 ft/sup 2/, 40 gpd workhorse prototype DHW system. Passive system cycling was experimentally confirmed to be completely reliable under both design and off-design conditions of usage, isolation, and weather. Day long system efficiency averaged 35% to 40% between July and December in northern New England and reached 45% under favorable ambient conditions. System attributes regarding performance, reliability, and site/installation flexibility are described and discussed. Key advantages of boiling/condensing fluid systems in solar applications are noted, and the need for further development of appropriate working fluids is discussed in the context of evolving codes.

  13. Economic analysis of commercial solar water-heating systems

    SciTech Connect

    1980-09-23

    A brief description is given of a typical commercial solar water heating system, outlining typical cost and performance levels. The economic performance of solar energy systems is described through the use of Cash Flow Diagrams. The economic performance of solar energy systems is described through the calculation of equivalent Return-On-Investment (ROI). Appendices are included that enable one to calculate the ROI for any particular solar hot water system investment. (MHR)

  14. Alternative Architecture for Commercial Space Solar Power

    NASA Technical Reports Server (NTRS)

    Potter, Seth

    2000-01-01

    This presentation discuss the space solar power (SSP) concept. It takes us step by step through the process: the use of sunlight and solar cells to create power, the conversion of the sunlight into electricity, the conversion of electricity to microwaves, and finally the from microwaves back to electricity by the Rectennas on Earth.

  15. NATURAL CONVECTION IN PASSIVE SOLAR BUILDINGS: EXPERIMENTS, ANALYSIS AND RESULTS

    SciTech Connect

    Gadgil, A.; Bauman, F.; Kammerud, R.

    1981-04-01

    Computer programs have been developed to numerically simulate natural convection in two- and three-dimensional room geometries. The programs have been validated using published data from the literature, results from a full-scale experiment performed at the Massachusetts Institute of Technology, and results from a small-scale experiment performed at LBL. One of the computer programs has been used to study the influence of natural convection on the thermal performance of a single zone in a direct-gain passive solar building. It is found that the convective heat transfer coefficients between the air and the enclosure surfaces can be substantially different from the values assumed in the standard building energy analysis methods, and can exhibit significant variations across a given surface. This study implies that the building heating loads calculated by standard building energy analysis methods may have substantial errors as a result of their use of common assumptions regarding the convection processes which occur in an enclosure.

  16. Wallboard with Latent Heat Storage for Passive Solar Applications

    SciTech Connect

    Kedl, R.J.

    2001-05-31

    Conventional wallboard impregnated with octadecane paraffin [melting point-23 C (73.5 F)] is being developed as a building material with latent heat storage for passive solar and other applications. Impregnation was accomplished simply by soaking the wallboard in molten wax. Concentrations of wax in the combined product as high as 35% by weight can be achieved. Scale-up of the soaking process, from small laboratory samples to full-sized 4- by 8-ft sheets, has been successfully accomplished. The required construction properties of wallboard are maintained after impregnation, that is, it can be painted and spackled. Long-term, high-temperature exposure tests and thermal cycling tests showed no tendency of the paraffin to migrate within the wallboard, and there was no deterioration of thermal energy storage capacity. In support of this concept, a computer model was developed to handle thermal transport and storage by a phase change material (PCM) dispersed in a porous media. The computer model was confirmed by comparison with known analytical solutions and also by comparison with temperatures measured in wallboard during an experimentally generated thermal transient. Agreement between the model and known solution was excellent. Agreement between the model and thermal transient was good, only after the model was modified to allow the PCM to melt over a temperature range, rather than at a specific melting point. When the melting characteristics of the PCM (melting point, melting range, and heat of fusion), as determined from a differential scanning calorimeter plot, were used in the model, agreement between the model and transient data was very good. The confirmed computer model may now be used in conjunction with a building heating and cooling code to evaluate design parameters and operational characteristics of latent heat storage wallboard for passive solar applications.

  17. A passive, sun-pointing, millimeter-scale solar sail

    NASA Astrophysics Data System (ADS)

    Atchison, Justin A.; Peck, Mason A.

    2010-07-01

    Taking inspiration from the orbital dynamics of dust, we find that spacecraft length scaling is a means of enabling infinite-impulse orbits that require no feedback control. Our candidate spacecraft is a 25 μm thick, 1 cm square silicon chip equipped with signal transmitting circuitry. This design reduces the total mass to less than 7.5 mg and enables the spacecraft bus itself to serve as a solar sail with characteristic acceleration on the order of 0.1 mm/s 2. It is passive in that it maneuvers with no closed-loop actuation of orbital or attitude states. The unforced dynamics that result from an insertion orbit and a launch-vehicle separation determine its subsequent state evolution. We have developed a system architecture that uses solar radiation torques to maintain a sun-pointing heading and can be fabricated with standard microfabrication processes. This architecture has potential applications in heliocentric, geocentric, and three-body orbits.

  18. Solar passive ceiling system. Final report. [Passive solar heating system with venetian blind reflectors and latent heat storage in ceiling

    SciTech Connect

    Schneider, A.R.

    1980-01-01

    The construction of a 1200 square foot building, with full basement, built to be used as a branch library in a rural area is described. The primary heating source is a passive solar system consisting of a south facing window system. The system consists of: a set of windows located in the south facing wall only, composed of double glazed units; a set of reflectors mounted in each window which reflects sunlight up to the ceiling (the reflectors are similar to venetian blinds); a storage area in the ceiling which absorbs the heat from the reflected sunlight and stores it in foil salt pouches laid in the ceiling; and an automated curtain which automatically covers and uncovers the south facing window system. The system is totally passive and uses no blowers, pumps or other active types of heat distribution equipment. The building contains a basement which is normally not heated, and the north facing wall is bermed four feet high around the north side.

  19. Passive solar design strategies: Remodeling guidelines for conserving energy at home. [Final report

    SciTech Connect

    Not Available

    1991-12-31

    The idea of passive solar is simple, but applying it effectively does require information and attention to the details of design and construction. Some passive solar techniques are modest and low-cost, and require only small changes in remodeler`s typical practice. At the other end of the spectrum, some passive solar systems can almost eliminate a house`s need for purchased heating (and in some cases, cooling) energy -- but probably at a relatively high first cost. In between are a broad range of energy-conserving passive solar techniques. Whether or not they are cost-effective, practical and attractive enough to offer a market advantage to any individual remodeler depends on very specific factors such as local costs, climate, and market characteristics. Passive solar design strategies: Remodeling Guidelines For Conserving Energy At Homes is written to help give remodelers the information they need to make these decisions. Passive Solar Design Strategies is a package in three basic parts: The Guidelines contain information about passive solar techniques and how they work, and provides specific examples of systems which will save various percentages of energy; The Worksheets offer a simple, fill-in-the-blank method to pre-evaluate the performance of a specific design; The Worked Example demonstrates how to complete the worksheets for a typical residence.

  20. Passive solar design strategies: Remodeling guidelines for conserving energy at home

    SciTech Connect

    Not Available

    1991-01-01

    The idea of passive solar is simple, but applying it effectively does require information and attention to the details of design and construction. Some passive solar techniques are modest and low-cost, and require only small changes in remodeler's typical practice. At the other end of the spectrum, some passive solar systems can almost eliminate a house's need for purchased heating (and in some cases, cooling) energy -- but probably at a relatively high first cost. In between are a broad range of energy-conserving passive solar techniques. Whether or not they are cost-effective, practical and attractive enough to offer a market advantage to any individual remodeler depends on very specific factors such as local costs, climate, and market characteristics. Passive solar design strategies: Remodeling Guidelines For Conserving Energy At Homes is written to help give remodelers the information they need to make these decisions. Passive Solar Design Strategies is a package in three basic parts: The Guidelines contain information about passive solar techniques and how they work, and provides specific examples of systems which will save various percentages of energy; The Worksheets offer a simple, fill-in-the-blank method to pre-evaluate the performance of a specific design; The Worked Example demonstrates how to complete the worksheets for a typical residence.

  1. Energy-conserving passive solar multi-family retrofit projects. Cycle 5, category 1: HUD Solar Heating and Cooling Demonstration Program

    NASA Astrophysics Data System (ADS)

    1981-10-01

    A total of 14 passive solar retrofit buildings are described. The concept of passive solar energy and the various types of passive systems found in the Cycle 5 projects are discussed. Each of the 14 solar designs is described, and some of the key points raised in the discussion of passive concepts are illustrated. Each project description cites the location of the passive solar home and presents the following information: grantee/builder, designer, solar designer, price, number of units, net heated area, heat load, degree days, solar fraction of the total heat load, and auxiliary heat required. Project descriptions also include data on recognition factors (the five passive elements necessary for a complete passive system), the type of auxiliary heating system used in the building, the solar water heating system (if any), and the passive cooling techniques used (if any).

  2. DOE passive solar commercial buildings program: project summaries

    SciTech Connect

    Not Available

    1982-01-01

    The 23 projects participating in this program comprise a wide range of building types including offices, retail establishments, educational facilities, public service facilities, community and visitor centers, and private specialized-use facilities, located throughout the United States. Summary data and drawings are presented for each project. (MHR)

  3. Concentrating Solar Power Commercial Application Study

    SciTech Connect

    none,

    2009-10-01

    This report has been prepared in response to section 603(b) of the Energy Independence and Security Act of 2007, (Pub. L. No. 110-140), which states that “…the Secretary of Energy shall transmit to Congress a report on the results of a study on methods to reduce the amount of water consumed by concentrating solar power systems.”

  4. Solar heating for a commercial broiler house

    SciTech Connect

    Rokeby, T.R.C.; Pitts, D.J.; Redfern, J.M.

    1981-01-01

    A solar air heater with rock storage has been used to provide heated ventilating air to an 8000-bird broiler chicken house. The system has operated successfully for four years. Fuel savings of 71% were recorded. Feed conversion and live weight were better than average. Overall system efficiency was 28.5% for a two week period in January 1981.

  5. Solar heating for a commercial broiler house

    SciTech Connect

    Rokeby, T.R.C.; Pitts, D.J.; Redfern, J.M.

    1981-01-01

    A solar air heater with rock storage has been used to provide heated ventilating air to an 8000-bird broiler chicken house. The system has operated successfully for four years. Fuel savings of 71% were recorded. Feed conversion and live weight were better than average. Overall system efficiency was 28.5% for a two week period in January, 1981. 7 refs.

  6. Low-cost passive solar-retrofit options for mobile homes

    SciTech Connect

    Brant, S.; Holtz, M.; Tasker, M.

    1981-03-01

    Passive solar heating and cooling retrofit options can significantly reduce the energy consumption of new and existing mobile homes. The initial efforts of the Solar Energy Research Institute to explore the solar potential for the existing stock of mobile homes and those in the production stage are described.

  7. Combined Active and Passive Solar Space Heating and Solar Hot Water Systems for an Elementary School in Boise, Idaho.

    ERIC Educational Resources Information Center

    Smull, Neil A.; Armstrong, Gerald L.

    1979-01-01

    Amity Elementary School in Boise, Idaho, features a solar space heating and domestic hot water system along with an earth covering to accommodate the passive aspects of energy conservation. (Author/MLF)

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

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  9. Effect of Organic and Inorganic Passivation in Quantum-Dot-Sensitized Solar Cells.

    PubMed

    de la Fuente, Mauricio Solis; Sánchez, Rafael S; González-Pedro, Victoria; Boix, Pablo P; Mhaisalkar, S G; Rincón, Marina E; Bisquert, Juan; Mora-Seró, Iván

    2013-05-01

    The effect of semiconductor passivation on quantum-dot-sensitized solar cells (QDSCs) has been systematically characterized for CdS and CdS/ZnS. We have found that passivation strongly depends on the passivation agent, obtaining an enhancement of the solar cell efficiency for compounds containing amine and thiol groups and, in contrast, a decrease in performance for passivating agents with acid groups. Passivation can induce a change in the position of TiO2 conduction band and also in the recombination rate and nature, reflected in a change in the β parameter. Especially interesting is the finding that β, and consequently the fill factor can be increased with the passivation treatment. Applying this strategy, record cells of 4.65% efficiency for PbS-based QDSCs have been produced. PMID:26282308

  10. Light-induced anodisation of silicon for solar cell passivation

    NASA Astrophysics Data System (ADS)

    Cui, J.; Wang, X.; Opila, R.; Lennon, A.

    2013-11-01

    This paper reports a new method for forming anodic oxides on silicon surfaces using the light-induced current of pn-junction solar cells to make p-type silicon surfaces anodic. The light-induced anodisation process enables anodic oxide layers as thick as 79 nm to be formed at room temperature in a faster, more uniform, and controllable manner compared to previously reported clip-based anodisation methods. Although the effective minority carrier lifetime decreased immediately after light-induced anodisation from initial values measured with an 17 nm thermally grown oxide on both wafer surfaces, the 1-sun implied open circuit voltage of wafers on which the thermally grown oxide on the p-type surface was replaced by an anodic oxide of the same thickness could be returned to its initial value of ˜635 mV (for 3-5 Ω-cm Cz silicon wafers) after a 400 °C anneal in oxygen and then forming gas. The passivation of the formed anodic oxide layers was stable for a period of 50 days providing the oxide was protected by a 75 nm thick silicon nitride capping layer.

  11. Conventional wallboard with latent heat storage for passive solar applications

    SciTech Connect

    Kedl, R.J.

    1990-01-01

    Conventional wallboard impregnated with octadecane paraffin (Melting Point -- 73.5{degree}F) is being developed as a building material with latent heat storage for passive solar applications. Impregnation was accomplished simply by soaking the wallboard in molten paraffin. Concentrations of paraffin in the combined product as high as 35{percent} by weight were achieved. In support of this concept, a computer model was developed to describe thermal transport and storage by a phase change material (PCM) dispersed in a porous media. The computer model was confirmed by comparison with known analytical solutions where the PCM melts at a specific melting point. However, agreement between the model and an experimentally produced thermal transient involving impregnated wallboard was only good after the model was modified to allow the paraffin to melt over a temperature range. This was accomplished by replacing the heat of fusion with a triangular heat capacity relationship that mimics the triangular melt curve found through differential scanning calorimetry. When this change was made, agreement between the model and the experimental transient was very good. 4 refs., 8 figs.

  12. Wallboard with latent heat storage for passive solar applications

    SciTech Connect

    Kedl, R.J.

    1991-05-01

    Conventional wallboard impregnated with octadecane paraffin is being developed as a building material with latent heat storage for passive solar and other applications. Impregnation was accomplished simply by soaking the wallboard in molten wax. Concentrations of wax in the combined product as high as 35% by weight can be achieved. Scale-up of the soaking process, from small laboratory samples to full-sized 4- by 8-ft sheets, has been successfully accomplished. The required construction properties of wallboard are maintained after impregnation, that is, it can be painted and spackled. Long-term, high-temperature exposure tests and thermal cycling tests showed no tendency of the paraffin to migrate within the wallboard, and there was no deterioration of thermal energy storage capacity. In support of this concept, a computer model was developed to handle thermal transport and storage by a phase change material (PCM) dispersed in a porous media. The computer model was confirmed by comparison with known analytical solutions and also by comparison with temperatures measured in wallboard during an experimentally generated thermal transient. Agreement between the model and known solution was excellent. Agreement between the model and thermal transient was good, only after the model was modified to allow the PCM to melt over a temperature range, rather than at a specific melting point. When the melting characteristics of the PCM, as determined from a differential scanning calorimeter plot, were used in the model, agreement between the model and transient data was very good. 11 refs., 25 figs., 2 tabs.

  13. Economic analysis of a passive solar multiple-family dwelling for upstate New York

    SciTech Connect

    Laquatra, J. Jr.

    1982-02-01

    The objective of this study was to examine the economic feasibility of passive solar energy as applied to a multiple-family dwelling in three upstate New York cities: Buffalo, Rochester, and Syracuse. Specifically, two passive solar applications - a Trombe wall and a direct-gain system - for a nine-unit structure designed by Total Environmental Action, Inc. were analyzed through the use of a solar economic performance code. City-specific data, including climatological information, building construction costs, utility rates, and property taxes were used, as were various economic parameters to reflect economic conditions in general and specifically those of the solar systems' owners.

  14. Daily radiation model for use in the simulation of passive solar buildings

    SciTech Connect

    Sillman, S.; Wortman, D.

    1981-04-01

    A model is presented to characterize solar radiation with just three input parameters for each day. This compressed daily radiation data may be used in place of hourly data in simulations of passive solar buildings. This method is tested with the SUNCAT passive simulation. Global horizontal and direct normal radiation data are input using the compressed daily form instead of by hour. Simulation results are found to be comparable to results based on hourly radiation data.

  15. Solar photocatalytic mineralization of commercial pesticides: acrinathrin.

    PubMed

    Malato, S; Blanco, J; Fernández-Alba, A R; Agüera, A

    2000-02-01

    A comparative study of the degradation of commercial acrinathrin spiked in water using TiO2 photocatalysis and photolysis under sunlight was performed. Samples were analysed by liquid chromatography-diode array detector (HPLC-DAD) and gas chromatography-ion trap-mass spectrometric detector (GC-ITMS). Additional total organic carbon (TOC) analyses were carried out to evaluate the mineralisation rates. One photoproduct, 2-phenoxy benzaldehyde, was unequivocally identified and evaluated by GC-ITMS during the processes. Although acrinathrin is almost destroyed when exposed to irradiation for more than 400 h, photocatalysis with TiO2 noticeably reduced degradation to a few hours. In this case, with the additional presence of peroxydisulphate, in less than 2 h acrinathrin is completely destroyed. Mineralisation of acrinathrin, without catalyst, was only around 50% after 400 h of irradiation. PMID:10665406

  16. Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells

    NASA Astrophysics Data System (ADS)

    Reichel, Christian; Feldmann, Frank; Müller, Ralph; Reedy, Robert C.; Lee, Benjamin G.; Young, David L.; Stradins, Paul; Hermle, Martin; Glunz, Stefan W.

    2015-11-01

    Passivated contacts (poly-Si/SiOx/c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF2), the ion implantation dose (5 × 1014 cm-2 to 1 × 1016 cm-2), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells. Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iVoc) of 725 and 720 mV, respectively. For p-type passivated contacts, BF2 implantations into intrinsic a-Si yield well passivated contacts and allow for iVoc of 690 mV, whereas implanted B gives poor passivation with iVoc of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved Voc of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF2 implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with Voc of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts.

  17. Demonstration of a commercial solar greenhouse. Final report

    SciTech Connect

    Figueras, A.

    1982-03-31

    The greenhouse is located in the town of Russell, in St. Lawrence County, New York. It was built to demonstrate the economics of using the solar greenhouse design as a commercial greenhouse growing vegetables for local sale. The design and construction of the greenhouse are briefly described. Records of temperatures monitored and produce grown and sold are included. (BCS)

  18. Small solar thermal electric power plants with early commercial potential

    NASA Technical Reports Server (NTRS)

    Jones, H. E.; Bisantz, D. J.; Clayton, R. N.; Heiges, H. H.; Ku, A. C.

    1979-01-01

    Cost-effective small solar thermal electric power plants (1- to 10-MW nominal size) offer an attractive way of helping the world meet its future energy needs. The paper describes the characteristics of a conceptual near-term plant (about 1 MW) and a potential 1990 commercial version. The basic system concept is one in which steam is generated using two-axis tracking, parabolic dish, and point-focusing collectors. The steam is transported through low-loss piping to a central steam turbine generator unit where it is converted to electricity. The plants have no energy storage and their output power level varies with the solar insolation level. This system concept, which is firmly based on state-of-the-art technology, is projected to offer one of the fastest paths for U.S. commercialization of solar thermal electric power plants through moderate technology advances and mass production.

  19. Financial study of commercialization of solar central receiver power systems

    NASA Astrophysics Data System (ADS)

    1981-03-01

    Commercialization requires that central receiver (CR) systems meet the economic criteria used by industry to select systems for capital ventures. Quantitative estimates are given of the investment required by government, utilities, and the manufacturing sector to meet the energy displacement goals for central receiver technology. Initial solar repowering and stand-alone electric utility plants will not have economic comparability with competitive energy sources. A major factor for this is that initial (first of a kind) heliostat costs will be high. As heliostat costs are reduced due to automated manufacturing economies, learning, and high volume production, central receiver technology will become more competitive. Under this task, several scenarios (0.1, 0.5, and 1.0 quad/y) were evaluated to determine the effect on commercial attractiveness and to determine the cost to government to bring about commercialization of solar central receivers.

  20. Passive solar addition to therapeutic pre-school. Final technical report

    SciTech Connect

    Not Available

    1983-10-01

    This project consisted of designing and constructing a passive solar system on a new classroom addition to the Peanut Butter and Jelly Therapeutic Pre-School in Albuquerque, NM. The purpose of this project was to demonstrate the applicability of solar space heating systems to large institutional buildings, and to demonstrate the energy and cost savings available through the use of such systems. Preliminary estimates indicated that the passive solar systems will provide about 90 percent of the heating and cooling needs for the new classroom addition to the school.

  1. Amorphous/crystalline silicon interface passivation: Ambient-temperature dependence and implications for solar cell performance

    DOE PAGESBeta

    Seif, Johannes P.; Krishnamani, Gopal; Demaurex, Benedicte; Ballif, Christophe; Wolf, Stefaan De

    2015-03-02

    Silicon heterojunction (SHJ) solar cells feature amorphous silicon passivation films, which enable very high voltages. We report how such passivation increases with operating temperature for amorphous silicon stacks involving doped layers and decreases for intrinsic-layer-only passivation. We discuss the implications of this phenomenon on the solar cell's temperature coefficient, which represents an important figure-of-merit for the energy yield of devices deployed in the field. We show evidence that both open-circuit voltage (Voc) and fill factor (FF) are affected by these variations in passivation and quantify these temperature-mediated effects, compared with those expected from standard diode equations. We confirm that devicesmore » with high Voc values at 25°C show better high-temperature performance. Thus, we also argue that the precise device architecture, such as the presence of charge-transport barriers, may affect the temperature-dependent device performance as well.« less

  2. Amorphous/crystalline silicon interface passivation: Ambient-temperature dependence and implications for solar cell performance

    SciTech Connect

    Seif, Johannes P.; Krishnamani, Gopal; Demaurex, Benedicte; Ballif, Christophe; Wolf, Stefaan De

    2015-03-02

    Silicon heterojunction (SHJ) solar cells feature amorphous silicon passivation films, which enable very high voltages. We report how such passivation increases with operating temperature for amorphous silicon stacks involving doped layers and decreases for intrinsic-layer-only passivation. We discuss the implications of this phenomenon on the solar cell's temperature coefficient, which represents an important figure-of-merit for the energy yield of devices deployed in the field. We show evidence that both open-circuit voltage (Voc) and fill factor (FF) are affected by these variations in passivation and quantify these temperature-mediated effects, compared with those expected from standard diode equations. We confirm that devices with high Voc values at 25°C show better high-temperature performance. Thus, we also argue that the precise device architecture, such as the presence of charge-transport barriers, may affect the temperature-dependent device performance as well.

  3. Terrestrial Solar Thermal Power Plants: On the Verge of Commercialization

    NASA Astrophysics Data System (ADS)

    Romero, M.; Martinez, D.; Zarza, E.

    2004-12-01

    Solar Thermal Power Plants (STPP) with optical concentration technologies are important candidates for providing the bulk solar electricity needed within the next few decades, even though they still suffer from lack of dissemination and confidence among citizens, scientists and decision makers. Concentrating solar power is represented nowadays at pilot-scale and demonstration-scale by four technologies, parabolic troughs, linear Fresnel reflector systems, power towers or central receiver systems, and dish/engine systems, which are ready to start up in early commercial/demonstration plants. Even though, at present those technologies are still three times more expensive than intermediate-load fossil thermal power plants, in ten years from now, STPP may already have reduced production costs to ranges competitive. An important portion of this reduction (up to 42%) will be obtained by R&D and technology advances in materials and components, efficient integration schemes with thermodynamic cycles, highly automated control and low-cost heat storage systems.

  4. Application of PECVD for bulk and surface passivation of high efficiency silicon solar cells

    SciTech Connect

    Krygowski, T.; Doshi, P.; Cai, L.; Doolittle, A.; Rohatgi, A.

    1995-08-01

    Plasma enhanced chemical vapor deposition (PECVD) passivation of bulk and surface defects has been shown to be an important technique to improve the performance of multicrystalline silicon (mc-Si) and single crystalline silicon solar cells. In this paper, we report the status of our on-going investigation into the bulk and surface passivation properties of PECVD insulators for photovoltaic applications. The objective of this paper is to demonstrate the ability of PECVD films to passivate the front (emitter) surface, bulk, and back surface by proper tailoring of deposition and post-PECVD annealing conditions.

  5. Positioning Your Library for Solar (and Financial) Gain. Improving Energy Efficiency, Lighting, and Ventilation with Primarily Passive Techniques

    ERIC Educational Resources Information Center

    Shane, Jackie

    2012-01-01

    This article stresses the importance of building design above technology as a relatively inexpensive way to reduce energy costs for a library. Emphasis is placed on passive solar design for heat and daylighting, but also examines passive ventilation and cooling, green roofs, and building materials. Passive design is weighed against technologies…

  6. Tunnel oxide passivated contacts formed by ion implantation for applications in silicon solar cells

    SciTech Connect

    Reichel, Christian; Feldmann, Frank; Müller, Ralph; Hermle, Martin; Glunz, Stefan W.; Reedy, Robert C.; Lee, Benjamin G.; Young, David L.; Stradins, Paul

    2015-11-28

    Passivated contacts (poly-Si/SiO{sub x}/c-Si) doped by shallow ion implantation are an appealing technology for high efficiency silicon solar cells, especially for interdigitated back contact (IBC) solar cells where a masked ion implantation facilitates their fabrication. This paper presents a study on tunnel oxide passivated contacts formed by low-energy ion implantation into amorphous silicon (a-Si) layers and examines the influence of the ion species (P, B, or BF{sub 2}), the ion implantation dose (5 × 10{sup 14 }cm{sup −2} to 1 × 10{sup 16 }cm{sup −2}), and the subsequent high-temperature anneal (800 °C or 900 °C) on the passivation quality and junction characteristics using double-sided contacted silicon solar cells. Excellent passivation quality is achieved for n-type passivated contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iV{sub oc}) of 725 and 720 mV, respectively. For p-type passivated contacts, BF{sub 2} implantations into intrinsic a-Si yield well passivated contacts and allow for iV{sub oc} of 690 mV, whereas implanted B gives poor passivation with iV{sub oc} of only 640 mV. While solar cells featuring in-situ B-doped selective hole contacts and selective electron contacts with P implanted into intrinsic a-Si layers achieved V{sub oc} of 690 mV and fill factor (FF) of 79.1%, selective hole contacts realized by BF{sub 2} implantation into intrinsic a-Si suffer from drastically reduced FF which is caused by a non-Ohmic Schottky contact. Finally, implanting P into in-situ B-doped a-Si layers for the purpose of overcompensation (counterdoping) allowed for solar cells with V{sub oc} of 680 mV and FF of 80.4%, providing a simplified and promising fabrication process for IBC solar cells featuring passivated contacts.

  7. A commercially viable solar wood drying kiln system

    SciTech Connect

    Vore, J.B. de; Denny, G.S.; Harper, T.S.

    1999-01-01

    The purpose of the study was to create a totally passive solar wood drying kiln that would dry lumber to 9% moisture content in a reasonable amount of time. A series of modifications led to a kiln design that dried freshly-cut lumber to 8% in a 29-day period with no case hardening or cracking. Air speed, internal and external temperatures and relative humidity levels were measured at 5-minute intervals. The average temperature inside the kiln was 12% higher with relative humidity levels 19% lower than outside the kiln. It is hypothesized that the daily cycles of heating and cooling permitted the interior moisture of the wood to reach the surface through diffusion, thus lessening stress and speeding drying of the lumber.

  8. A passive cooling system of residential and commercial buildings in summer or hot season

    NASA Astrophysics Data System (ADS)

    Rahman, M. M.; Mashud, M.; Chu, C. M.; Misaran, M. S. bin; Sarker, M.; Kumaresen, S.

    2015-12-01

    The increasing number of high rise buildings may contribute to lack of natural ventilation in modern buildings. Generally, fans and air conditioning are used in the modern building for cooling and air ventilation. Most of the energy in tropical regions are consumed by heating, cooling and ventilation appliances. Therefore, solar power appliances for cooling, heating and ventilation will be a suitable option for saving energy from the household sector. A modified-structure building is designed and constructed with solar chimney to enhance ventilation rate that increases cooling performance and ensure thermal comfort. An evaporative cooler is introduced with a newly designed room to enhance the temperature reduction capacity. The room temperature is compared with a non-modified room as well as with ambient temperature. The results show that passive cooling system with evaporative cooler was able to reduce temperature by 5°C compared to the ambient temperature and about 2°C to 3°C below the reference room temperature.

  9. Passive solar space heating and cooling. (Latest citations from the NTIS Bibliographic database). NewSearch

    SciTech Connect

    Not Available

    1994-10-01

    The bibliography contains citations concerning the passive use of solar energy for space heating and cooling in buildings, houses, and homes. Citations discuss the design, performance, models, and economic analysis of heating and cooling systems. Topics include solar architecture, energy consumption analysis, energy conservation, and heat recovery. Also included are thermal comfort, quality of life, and housing for the elderly. (Contains a minimum of 209 citations and includes a subject term index and title list.)

  10. Low temperature front surface passivation of interdigitated back contact silicon heterojunction solar cell

    SciTech Connect

    Shu, Brent; Das, Ujjwal; Jani, Omkar; Hegedus, Steve; Birkmire, Robert

    2009-06-08

    The interdigitated back contact silicon heterojunction (IBC-SHJ) solar cell requires a low temperature front surface passivation/anti-reflection structure. Conventional silicon surface passivation using SiO2 or a-SiNx is performed at temperature higher than 400°C, which is not suitable for the IBC-SHJ cell. In this paper, we propose a PECVD a-Si:H/a-SiNx:H/a-SiC:H stack structure to passivate the front surface of crystalline silicon at low temperature. The optical properties and passivation quality of this structure are characterized and solar cells using this structure are fabricated. With 2 nm a-Si:H layer, the stack structure exhibits stable passivation with effective minority carrier lifetime higher than 2 ms, and compatible with IBC-SHJ solar cell processing. A critical advantage of this structure is that the SiC allows it to be HF resistant, thus it can be deposited as the first step in the process. This protects the a-Si/c-Si interface and maintains a low surface recombination velocity.

  11. Commercialization of dish-Stirling solar terrestrial systems

    NASA Astrophysics Data System (ADS)

    Ross, Brad; Penswick, Barry; White, Maury; Cooper, Martin; Farbman, Gerald

    The requirements for dish-Stirling commercialization are described. The requirements for practical terrestrial power systems, both technical and economic, are described. Solar energy availability, with seasonal and regional variations, is discussed. The advantages and disadvantages of hybrid operation are listed. The two systems described use either a 25-kW free-piston Stirling hydraulic engine or a 5-kW kinematic Stirling engine. Both engines feature long-life characteristics that result from the use of welded metal bellows as hermetic seals between the working gas and the crankcase fluid. The advantages of the systems, the state of the technology, and the challenges that remain are discussed. Technology transfer between solar terrestrial Stirling applications and other Stirling applications is predicted to be important and synergistic.

  12. Commercialization of dish-Stirling solar terrestrial systems

    NASA Technical Reports Server (NTRS)

    Ross, Brad; Penswick, Barry; White, Maury; Cooper, Martin; Farbman, Gerald

    1990-01-01

    The requirements for dish-Stirling commercialization are described. The requirements for practical terrestrial power systems, both technical and economic, are described. Solar energy availability, with seasonal and regional variations, is discussed. The advantages and disadvantages of hybrid operation are listed. The two systems described use either a 25-kW free-piston Stirling hydraulic engine or a 5-kW kinematic Stirling engine. Both engines feature long-life characteristics that result from the use of welded metal bellows as hermetic seals between the working gas and the crankcase fluid. The advantages of the systems, the state of the technology, and the challenges that remain are discussed. Technology transfer between solar terrestrial Stirling applications and other Stirling applications is predicted to be important and synergistic.

  13. CVD-Based Valence-Mending Passivation for Crystalline-Si Solar Cells

    SciTech Connect

    Tao, Meng

    2015-03-01

    The objective of this project is to investigate a new surface passivation technique, valence-mending passivation, for its applications in crystalline-Si solar cells to achieve significant efficiency improvement and cost reduction. As the enabling technique, the project includes the development of chemical vapor deposition recipes to passivate textured Si(100) and multicrystalline-Si surfaces by sulfur and the characterization of the passivated Si surfaces, including thermal stability, Schottky barrier height, contact resistance and surface recombination. One important application is to replace the Ag finger electrode in Si cells with Al to reduce cost, by ~$0.1/Wp, and allow terawatt-scale deployment of crystalline-Si solar cells. These all-Al Si cells require a low-temperature metallization process for the Al electrode, to be compatible with valence-mending passivation and to prevent Al diffusion into n-type Si. Another application is to explore valence-mending passivation of grain boundaries in multicrystalline Si by diffusing sulfur into grain boundaries, to reduce the efficiency gas between monocrystalline-Si solar cells and multicrystalline-Si cells. The major accomplishments of this project include: 1) Demonstration of chemical vapor deposition processes for valence-mending passivation of both monocrystalline Si(100) and multicrystalline Si surfaces. Record Schottky barriers have been demonstrated, with the new record-low barrier of less than 0.08 eV between Al and sulfur-passivated n-type Si(100) and the new record-high barrier of 1.14 eV between Al and sulfur-passivated p-type Si(100). On the textured p-type monocrystalline Si(100) surface, the highest barrier with Al is 0.85 eV by valence-mending passivation. 2) Demonstration of a low-temperature metallization process for Al in crystalline-Si solar cells. The new metallization process is based on electroplating of Al in a room-temperature ionic liquid. The resistivity of the electroplated Al is ~7×10–6

  14. Study of novel chemical surface passivation techniques on GaAs pn junction solar cells

    SciTech Connect

    Mauk, M.G.; Xu, S.; Arent, D.J.; Mertens, R.P.; Borghs, G.

    1989-01-16

    Novel methods of GaAs surface passivation are investigated. Passivation is acheived by simple chemical treatments using aqueous solutions of Na/sub 2/S, KOH, RuCl/sub 3/, and K/sub 2/Se. GaAs pn homojunction solar cells are used to evaluate the effectiveness of these passivation techniques. A significant reduction in minority-carrier surface recombination velocity is demonstrated. In the best case, the surface recombination velocity decreased from 5 x 10/sup 6/ cm/s (untreated surface) to 10/sup 3/ cm/s. In addition, we observe improvements in solar cell photogenerated current, short wavelength spectral response, open-circuit voltage, and junction ''dark'' current.

  15. 10.6% Certified Colloidal Quantum Dot Solar Cells via Solvent-Polarity-Engineered Halide Passivation.

    PubMed

    Lan, Xinzheng; Voznyy, Oleksandr; García de Arquer, F Pelayo; Liu, Mengxia; Xu, Jixian; Proppe, Andrew H; Walters, Grant; Fan, Fengjia; Tan, Hairen; Liu, Min; Yang, Zhenyu; Hoogland, Sjoerd; Sargent, Edward H

    2016-07-13

    Colloidal quantum dot (CQD) solar cells are solution-processed photovoltaics with broad spectral absorption tunability. Major advances in their efficiency have been made via improved CQD surface passivation and device architectures with enhanced charge carrier collection. Herein, we demonstrate a new strategy to improve further the passivation of CQDs starting from the solution phase. A cosolvent system is employed to tune the solvent polarity in order to achieve the solvation of methylammonium iodide (MAI) and the dispersion of hydrophobic PbS CQDs simultaneously in a homogeneous phase, otherwise not achieved in a single solvent. This process enables MAI to access the CQDs to confer improved passivation. This, in turn, allows for efficient charge extraction from a thicker photoactive layer device, leading to a certified solar cell power conversion efficiency of 10.6%, a new certified record in CQD photovoltaics. PMID:27351104

  16. The effect of microscopic texture on the direct plasma surface passivation of Si solar cells

    NASA Astrophysics Data System (ADS)

    Mehrabian, S.; Xu, S.; Qaemi, A. A.; Shokri, B.; Chan, C. S.; Ostrikov, K.

    2013-04-01

    Textured silicon surfaces are widely used in manufacturing of solar cells due to increasing the light absorption probability and also the antireflection properties. However, these Si surfaces have a high density of surface defects that need to be passivated. In this study, the effect of the microscopic surface texture on the plasma surface passivation of solar cells is investigated. The movement of 105 H+ ions in the texture-modified plasma sheath is studied by Monte Carlo numerical simulation. The hydrogen ions are driven by the combined electric field of the plasma sheath and the textured surface. The ion dynamics is simulated, and the relative ion distribution over the textured substrate is presented. This distribution can be used to interpret the quality of the Si dangling bonds saturation and consequently, the direct plasma surface passivation.

  17. The effect of microscopic texture on the direct plasma surface passivation of Si solar cells

    SciTech Connect

    Mehrabian, S.; Xu, S.; Qaemi, A. A.; Shokri, B.; Chan, C. S.; Ostrikov, K.

    2013-04-15

    Textured silicon surfaces are widely used in manufacturing of solar cells due to increasing the light absorption probability and also the antireflection properties. However, these Si surfaces have a high density of surface defects that need to be passivated. In this study, the effect of the microscopic surface texture on the plasma surface passivation of solar cells is investigated. The movement of 10{sup 5} H{sup +} ions in the texture-modified plasma sheath is studied by Monte Carlo numerical simulation. The hydrogen ions are driven by the combined electric field of the plasma sheath and the textured surface. The ion dynamics is simulated, and the relative ion distribution over the textured substrate is presented. This distribution can be used to interpret the quality of the Si dangling bonds saturation and consequently, the direct plasma surface passivation.

  18. Solar Energy: Energy Conservation and Passive Design Concepts: Student Material. First Edition.

    ERIC Educational Resources Information Center

    Younger, Charles; Orsak, Charles G., Jr.

    Designed for student use in "Energy Conservation and Passive Design Concepts," one of 11 courses in a 2-year associate degree program in solar technology, this manual provides readings, bibliographies, and illustrations for seven course modules. The manual, which corresponds to an instructor guide for the same course, covers the following topics:…

  19. Past, present and future of passive homes in solar village 3, Athens

    NASA Astrophysics Data System (ADS)

    Kalogridis, Achilles

    Solar village 3 in Pefki, Athens, was part of an ambitious program for the promotion of solar technology, applied to a large scale social housing scheme, designed in mid 80's and firstly inhabited in the early 1990's. Among the aims of the project was the demonstration of the latest of technology in active solar systems and passive techniques, incorporated in a new settlement's layout and houses' building envelop, in order to create an energy saving, comfortable environment. More than fifteen years later, the housing complex remains the largest residential development of bioclimatic "solar" architecture in Athens, with the active and passive solar systems providing space and water heating for about 1750 inhabitants. The study focuses in the passive solar systems that have been applied to a number of the buildings of the settlement. The systems provide space heating with no need of any active mechanism, however with demand of the participation of the end users for their proper operation. The essay reviews various previous studies, monitoring reports and criticisms that have appeared throughout the past years, and identifies how the houses perform today, through a recent survey, sample monitoring and thermal comfort simulation. The report records things that have changed, features which worked well or others that did not and comments on the residents' behaviour. Interesting findings come into question, regarding the passive solar systems, their integration into the building's design, their current condition and their contribution to energy savings and thermal comfort conditions. Finally, current plans concerning the future of the settlement are highlighted, and considerations about the houses sustainability are suggested.

  20. Passivating boron silicate glasses for co-diffused high-efficiency n-type silicon solar cell application

    SciTech Connect

    Engelhardt, Josh Frey, Alexander; Gloger, Sebastian; Hahn, Giso; Terheiden, Barbara

    2015-07-27

    Doping layers commonly have but one function: supplying the dopants to form a doped region within a substrate. This work presents B doping layers/stacks, which at the same time supply dopant atoms, passivate the B-doped crystalline Si surface sufficiently well (j{sub 0E} < 50 fA/cm{sup 2}), and show optical properties suitable for anti-reflective coating. Furthermore, these boron silicate glasses can act as a barrier against parasitic P in-diffusion during a co-diffusion step. The boron emitters diffused from the inductively coupled plasma plasma-enhanced chemical vapor-deposited B containing SiO{sub x} layers are investigated and optimized concerning passivation quality and contact properties for high-efficiency n-type solar Si cell designs. It is shown that even 10 nm thin SiO{sub x}:B films already allow for suitable emitter sheet resistance for screen-printed contacts. Furthermore, SiO{sub x}:B layers presented here allow for iV{sub OC} values of 675 mV and contact resistivity of 1 mΩcm{sup 2} for commercial Ag instead of Ag/Al pastes on the diffused boron emitter passivated with the SiO{sub x}:B layer supporting the contact formation. All of these properties can be achieved within one single B doping layer/stack.

  1. Passivating boron silicate glasses for co-diffused high-efficiency n-type silicon solar cell application

    NASA Astrophysics Data System (ADS)

    Engelhardt, Josh; Frey, Alexander; Gloger, Sebastian; Hahn, Giso; Terheiden, Barbara

    2015-07-01

    Doping layers commonly have but one function: supplying the dopants to form a doped region within a substrate. This work presents B doping layers/stacks, which at the same time supply dopant atoms, passivate the B-doped crystalline Si surface sufficiently well (j0E < 50 fA/cm2), and show optical properties suitable for anti-reflective coating. Furthermore, these boron silicate glasses can act as a barrier against parasitic P in-diffusion during a co-diffusion step. The boron emitters diffused from the inductively coupled plasma plasma-enhanced chemical vapor-deposited B containing SiOx layers are investigated and optimized concerning passivation quality and contact properties for high-efficiency n-type solar Si cell designs. It is shown that even 10 nm thin SiOx:B films already allow for suitable emitter sheet resistance for screen-printed contacts. Furthermore, SiOx:B layers presented here allow for iVOC values of 675 mV and contact resistivity of 1 mΩcm2 for commercial Ag instead of Ag/Al pastes on the diffused boron emitter passivated with the SiOx:B layer supporting the contact formation. All of these properties can be achieved within one single B doping layer/stack.

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

    SciTech Connect

    1980-01-01

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

  3. Passive solar system for maintaining and rearing marine organisms

    SciTech Connect

    Yuschak, P.; Richards, F.M.

    1987-04-01

    A solar-heated facility for maintaining and rearing marine organisms is described. Water from a shallow tidal bay is moved by a tide-regulated pumping system into settling tanks for removal of suspended silt and clay, from which the water drains by gravity flow to circular rearing tanks.

  4. Passive thermosyphon solar heating and cooling module with supplementary heating

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A collection of three quarterly reports from Sigma Research, Inc., covering progress and status from January through September 1977 are presented. Three heat exchangers are developed for use in a solar heating and cooling system for installation into single-family dwellings. Each exchanger consists of one heating and cooling module and one submerged electric water heating element.

  5. Active charge/passive discharge solar heating systems: Thermal analysis and performance comparisons and performance comparisons

    NASA Astrophysics Data System (ADS)

    Swisher, J.

    1981-06-01

    This type of system combines liquid-cooled solar collector panels with a massive integral storage component that passively heats the building interior by radiation and free convection. The TRNSYS simulation program is used to evaluate system performance and to provide input for the development of a simplified analysis method. This method, which provides monthly calculations of delivered solar energy, is based on Klein's Phi-bar procedure and data from hourly TRNSYS simulations. The method can be applied to systems using a floor slab, a structural wall, or a water tank as the storage component. Important design parameters include collector area and orientation, building heat loss, collector and heat exchanger efficiencies, storage capacity, and storage to room coupling. Performance simulation results are used for comparisons with active and passive solar designs.

  6. Amorphous silicon carbide passivating layers for crystalline-silicon-based heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Boccard, Mathieu; Holman, Zachary C.

    2015-08-01

    Amorphous silicon enables the fabrication of very high-efficiency crystalline-silicon-based solar cells due to its combination of excellent passivation of the crystalline silicon surface and permeability to electrical charges. Yet, amongst other limitations, the passivation it provides degrades upon high-temperature processes, limiting possible post-deposition fabrication possibilities (e.g., forcing the use of low-temperature silver pastes). We investigate the potential use of intrinsic amorphous silicon carbide passivating layers to sidestep this issue. The passivation obtained using device-relevant stacks of intrinsic amorphous silicon carbide with various carbon contents and doped amorphous silicon are evaluated, and their stability upon annealing assessed, amorphous silicon carbide being shown to surpass amorphous silicon for temperatures above 300 °C. We demonstrate open-circuit voltage values over 700 mV for complete cells, and an improved temperature stability for the open-circuit voltage. Transport of electrons and holes across the hetero-interface is studied with complete cells having amorphous silicon carbide either on the hole-extracting side or on the electron-extracting side, and a better transport of holes than of electrons is shown. Also, due to slightly improved transparency, complete solar cells using an amorphous silicon carbide passivation layer on the hole-collecting side are demonstrated to show slightly better performances even prior to annealing than obtained with a standard amorphous silicon layer.

  7. Amorphous silicon carbide passivating layers for crystalline-silicon-based heterojunction solar cells

    DOE PAGESBeta

    Boccard, Mathieu; Holman, Zachary C.

    2015-08-14

    With this study, amorphous silicon enables the fabrication of very high-efficiency crystalline-silicon-based solar cells due to its combination of excellent passivation of the crystalline silicon surface and permeability to electrical charges. Yet, amongst other limitations, the passivation it provides degrades upon high-temperature processes, limiting possible post-deposition fabrication possibilities (e.g., forcing the use of low-temperature silver pastes). We investigate the potential use of intrinsic amorphous silicon carbide passivating layers to sidestep this issue. The passivation obtained using device-relevant stacks of intrinsic amorphous silicon carbide with various carbon contents and doped amorphous silicon are evaluated, and their stability upon annealing assessed, amorphousmore » silicon carbide being shown to surpass amorphous silicon for temperatures above 300°C. We demonstrate open-circuit voltage values over 700 mV for complete cells, and an improved temperature stability for the open-circuit voltage. Transport of electrons and holes across the hetero-interface is studied with complete cells having amorphous silicon carbide either on the hole-extracting side or on the electron-extracting side, and a better transport of holes than of electrons is shown. Also, due to slightly improved transparency, complete solar cells using an amorphous silicon carbide passivation layer on the hole-collecting side are demonstrated to show slightly better performances even prior to annealing than obtained with a standard amorphous silicon layer.« less

  8. Amorphous silicon carbide passivating layers for crystalline-silicon-based heterojunction solar cells

    SciTech Connect

    Boccard, Mathieu; Holman, Zachary C.

    2015-08-14

    With this study, amorphous silicon enables the fabrication of very high-efficiency crystalline-silicon-based solar cells due to its combination of excellent passivation of the crystalline silicon surface and permeability to electrical charges. Yet, amongst other limitations, the passivation it provides degrades upon high-temperature processes, limiting possible post-deposition fabrication possibilities (e.g., forcing the use of low-temperature silver pastes). We investigate the potential use of intrinsic amorphous silicon carbide passivating layers to sidestep this issue. The passivation obtained using device-relevant stacks of intrinsic amorphous silicon carbide with various carbon contents and doped amorphous silicon are evaluated, and their stability upon annealing assessed, amorphous silicon carbide being shown to surpass amorphous silicon for temperatures above 300°C. We demonstrate open-circuit voltage values over 700 mV for complete cells, and an improved temperature stability for the open-circuit voltage. Transport of electrons and holes across the hetero-interface is studied with complete cells having amorphous silicon carbide either on the hole-extracting side or on the electron-extracting side, and a better transport of holes than of electrons is shown. Also, due to slightly improved transparency, complete solar cells using an amorphous silicon carbide passivation layer on the hole-collecting side are demonstrated to show slightly better performances even prior to annealing than obtained with a standard amorphous silicon layer.

  9. Amorphous silicon carbide passivating layers for crystalline-silicon-based heterojunction solar cells

    SciTech Connect

    Boccard, Mathieu; Holman, Zachary C.

    2015-08-14

    Amorphous silicon enables the fabrication of very high-efficiency crystalline-silicon-based solar cells due to its combination of excellent passivation of the crystalline silicon surface and permeability to electrical charges. Yet, amongst other limitations, the passivation it provides degrades upon high-temperature processes, limiting possible post-deposition fabrication possibilities (e.g., forcing the use of low-temperature silver pastes). We investigate the potential use of intrinsic amorphous silicon carbide passivating layers to sidestep this issue. The passivation obtained using device-relevant stacks of intrinsic amorphous silicon carbide with various carbon contents and doped amorphous silicon are evaluated, and their stability upon annealing assessed, amorphous silicon carbide being shown to surpass amorphous silicon for temperatures above 300 °C. We demonstrate open-circuit voltage values over 700 mV for complete cells, and an improved temperature stability for the open-circuit voltage. Transport of electrons and holes across the hetero-interface is studied with complete cells having amorphous silicon carbide either on the hole-extracting side or on the electron-extracting side, and a better transport of holes than of electrons is shown. Also, due to slightly improved transparency, complete solar cells using an amorphous silicon carbide passivation layer on the hole-collecting side are demonstrated to show slightly better performances even prior to annealing than obtained with a standard amorphous silicon layer.

  10. A new structure for comparing surface passivation materials of GaAs solar cells

    NASA Technical Reports Server (NTRS)

    Desalvo, Gregory C.; Barnett, Allen M.

    1989-01-01

    The surface recombination velocity (S sub rec) for bare GaAs is typically as high as 10 to the 6th power to 10 to the 7th power cm/sec, which dramatically lowers the efficiency of GaAs solar cells. Early attempts to circumvent this problem by making an ultra thin junction (xj less than .1 micron) proved unsuccessful when compared to lowering S sub rec by surface passivation. Present day GaAs solar cells use an GaAlAs window layer to passivate the top surface. The advantages of GaAlAs in surface passivation are its high bandgap energy and lattice matching to GaAs. Although GaAlAs is successful in reducing the surface recombination velocity, it has other inherent problems of chemical instability (Al readily oxidizes) and ohmic contact formation. The search for new, more stable window layer materials requires a means to compare their surface passivation ability. Therefore, a device structure is needed to easily test the performance of different passivating candidates. Such a test device is described.

  11. Advanced Passivation Technology and Loss Factor Minimization for High Efficiency Solar Cells.

    PubMed

    Park, Cheolmin; Balaji, Nagarajan; Jung, Sungwook; Choi, Jaewoo; Ju, Minkyu; Lee, Seunghwan; Kim, Jungmo; Bong, Sungjae; Chung, Sungyoun; Lee, Youn-Jung; Yi, Junsin

    2015-10-01

    High-efficiency Si solar cells have attracted great attention from researchers, scientists, photovoltaic (PV) industry engineers for the past few decades. With thin wafers, surface passivation becomes necessary to increase the solar cells efficiency by overcoming several induced effects due to associated crystal defects and impurities of c-Si. This paper discusses suitable passivation schemes and optimization techniques to achieve high efficiency at low cost. SiNx film was optimized with higher transmittance and reduced recombination for using as an effective antireflection and passivation layer to attain higher solar cell efficiencies. The higher band gap increased the transmittance with reduced defect states that persisted at 1.68 and 1.80 eV in SiNx films. The thermal stability of SiN (Si-rich)/SiN (N-rich) stacks was also studied. Si-rich SiN with a refractive index of 2.7 was used as a passivation layer and N-rich SiN with a refractive index of 2.1 was used for thermal stability. An implied Voc of 720 mV with a stable lifetime of 1.5 ms was obtained for the stack layer after firing. Si-N and Si-H bonding concentration was analyzed by FTIR for the correlation of thermally stable passivation mechanism. The passivation property of spin coated Al2O3 films was also investigated. An effective surface recombination velocity of 55 cm/s with a high density of negative fixed charges (Qf) on the order of 9 x 10(11) cm(-2) was detected in Al2O3 films. PMID:26726397

  12. Solar-heated commercial-greenhouse demonstration. Final performance report

    SciTech Connect

    1983-01-01

    Poly Solar Company was formed to design and fabricate a demonstration of a solar heating system for commercial greenhouses in moderate climates. This system is built of readily available materials, and can be constructed using conventional techniques available to most builders and farmers. Construction began on the demonstration project in August 1981 and the system was placed into operation that winter. Energy savings were calculated by monitoring the running time on an oil furnace in a duplicate greenhouse with the same crop as the solar heated greenhouse with an oil backup furnace. The first monitoring period was before the Christmas season with poinsettias used as the comparison crop with 60/sup 0/ to 64/sup 0/F. During this period the 126 ton mass storage and waste heat recovery sections of the system were used. These trials showed energy savings over the 100% oil heated structure to be 23.4%. After the crops were removed from the greenhouse trials were ran which showed this portion of the system could maintain night time temperatures as high as 56/sup 0/F with no other heat source and an outside temperature of 26/sup 0/F. The 1860 sq ft solar collector/storage system was monitored with a winter-spring crop of geraniums at a night time temperature of 60/sup 0/ to 64/sup 0/F. In April 1982 a severe storm with wind gusts in excess of 50 mph destroyed a section of duct that feeds heated air from the collector to the rock storage bed and caused light damage to the collector itself.

  13. Silicon diffusion in aluminum for rear passivated solar cells

    SciTech Connect

    Urrejola, Elias; Peter, Kristian; Plagwitz, Heiko; Schubert, Gunnar

    2011-04-11

    We show that the lateral spread of silicon in a screen-printed aluminum layer increases by (1.50{+-}0.06) {mu}m/ deg. C, when increasing the peak firing temperature within an industrially applicable range. In this way, the maximum spread limit of diffused silicon in aluminum is predictable and does not depend on the contact area size but on the firing temperature. Therefore, the geometry of the rear side pattern can influence not only series resistance losses within the solar cell but the process of contact formation itself. In addition, too fast cooling lead to Kirkendall void formations instead of an eutectic layer.

  14. Effect of plants on sunspace passive solar heating

    SciTech Connect

    Best, E.D.; McFarland, R.D.

    1985-01-01

    The effect of plants on sunspace thermal performance is investigated, based on experiments done in Los Alamos using two test rooms with attached sunspaces, which were essentially identical except for the presence of plants in one. Performance is related to plant transpiration, evaporation from the soil, condensation on the glazing and the absorbtance of solar energy by the lightweight leaves. Performance effects have been quantified by measurements of auxiliary heat consumption in the test rooms and analyzed by means of energy balance calculations. A method for estimating the transpiration rate is presented.

  15. Sulfur passivation and contact methods for GaAs nanowire solar cells

    NASA Astrophysics Data System (ADS)

    Tajik, N.; Peng, Z.; Kuyanov, P.; LaPierre, R. R.

    2011-06-01

    The effect of sulfur passivation on core-shell p-n junction GaAs nanowire (NW) solar cells has been investigated. Devices of two types were investigated, consisting of indium tin oxide contact dots or opaque Au finger electrodes. Lateral carrier transport from the NWs to the contact fingers was achieved via a p-doped GaAs surface conduction layer. NWs between the opaque contact fingers had sidewall surfaces exposed for passivation by sulfur. The relative cell efficiency increased by 19% upon passivation. The contribution of the thin film grown between the NWs to the total cell efficiency was estimated by removing the NWs using a sonication procedure. Mechanisms of carrier transport and photovoltaic effects are discussed on the basis of spatially resolved laser scanning measurements.

  16. Sulfur passivation and contact methods for GaAs nanowire solar cells.

    PubMed

    Tajik, N; Peng, Z; Kuyanov, P; LaPierre, R R

    2011-06-01

    The effect of sulfur passivation on core-shell p-n junction GaAs nanowire (NW) solar cells has been investigated. Devices of two types were investigated, consisting of indium tin oxide contact dots or opaque Au finger electrodes. Lateral carrier transport from the NWs to the contact fingers was achieved via a p-doped GaAs surface conduction layer. NWs between the opaque contact fingers had sidewall surfaces exposed for passivation by sulfur. The relative cell efficiency increased by 19% upon passivation. The contribution of the thin film grown between the NWs to the total cell efficiency was estimated by removing the NWs using a sonication procedure. Mechanisms of carrier transport and photovoltaic effects are discussed on the basis of spatially resolved laser scanning measurements. PMID:21454946

  17. Development and Commercialization of the Lunar Solar Power System

    NASA Astrophysics Data System (ADS)

    Criswell, D. R.

    2002-01-01

    The proposed Lunar Solar Power (LSP) System consists of pairs of power bases located on opposite limbs of the Moon as seen from Earth. The power bases collect the solar energy and convert it to beams of microwaves. The microwaves are delivered directly to moonward-facing receivers on Earth or indirectly through relay satellites in orbit about Earth (1, 2, 3, 4). The LSP System may be the only reasonable method for establishing sustainable global energy prosperity within two generations. Commercial power prosperity requires at least 2 kWe/person. For ten billion people this implies 20 TWe and 2,000 TWe-y of electric energy or ~6,000 TWt-y of thermal energy per century (5, 6, 7, 8). A brief overview is presented of a reference LSP System that supplies 20 TWe by 2050. The engineering scales and the cost and benefits of this system are described. In order to provide low cost commercial electric energy, the power bases are made primarily of local lunar materials by machines, facilities, and people deployed from Earth (1, 2, 3). In addition, lunar production machinery can be made primarily from lunar materials. Advantages of this approach, versus the reference LSP System, are discussed. Full-scale production of a LSP System will certainly be proceeded by terrestrial and lunar operation of the production machinery and a small-scale demonstration of the operational system (1). Using government funds to establishing a permanent lunar base and the associated transportation system would significantly reduce the upfront cost for the demonstration of a commercial LSP System (2). The government program would provide a legal framework for commercial development of the LSP System (3, 9). The LSP System offers the opportunity to establish a materials industry on the Moon that can produce a growing mass and variety of goods and enable new services of benefit on the Earth and the Moon (10). New priorities are suggested for civilian space programs that can accelerate the establishment

  18. Silicon Heterojunction Solar Cells: Temperature Impact on Passivation and Performance

    SciTech Connect

    Seif, J.; Krishnamani, G.; Demaurex, B.; Martin de Nicholas, S.; Holm, N.; Ballif, C.; De Wolf, S.

    2015-03-23

    Photovoltaic devices deployed in the field can reach operation temperatures (T) as high as 90 °C [1]. Hence, their temperature coefficients (TC1) are of great practical importance as they determine their energy yield. In this study we concentrate on T-related lifetime variations of amorphous/crystalline interfaces and study their influence on the TCs of the individual solar cell parameters. We find that both the open-circuit voltage (Voc) and fill factor (FF) are influenced by these lifetime variations. However, this is only a minor effect compared to the dominant increase of the intrinsic carrier density and the related increase in dark saturation current density. Additionally, in this paper we will show that the TCVoc does not depend solely on the initial value of the Voc [2, 3], but that the structure of the device has to be considered as well.

  19. Commercial Development Of Ovonic Thin Film Solar Cells

    NASA Astrophysics Data System (ADS)

    Ovshinsky, Stanford R.

    1983-09-01

    One square foot Ovonic amorphous photovoltaic devices are already in commercial production and are manufactured through a continuous web process. The next levels of commercialization required to achieve a large-volume power market will be discussed, and the device specifications correlated with the chemical and electronic properties of the materials that we are developing to achieve even higher efficiencies. It has been long considered a utopian dream to harness the energy of the sun to create electricity that would be competitive in cost to that produced from the conventional sources of energy such as oil, gas, and uranium. The impact on our society of stand-alone power generators without moving parts using the continually available, ubiquitous energy of the sun could certainly lead to a new age with consequences comparable to the first introduction of electricity which greatly accelerated the Industrial Revolution. Low cost, nonpolluting energy not dependent upon or limited by transmission costs could again make DC electricity a realistic option. The relatively young field of photovoltaics suffers from certain dogmas that are just now being questioned. For example, it is thought by many that solar cells utilizing crys-talline materials have inherently higher efficiencies than those using amorphous materials, and that somehow crystalline solar cells, whether fabricated from single crystals or polycrystalline material, in round or rectangular geometries, grown from the melt or by a rib-bon process, can be reduced in cost sufficiently that the economics become attractive enough for large-scale terrestrial generation of power. In this paper, we shall show that amorphous materials can have much higher efficiencies than do crystalline and that the answer to our power generation needs lies not in crystalline but in amorphous technology. At Energy Conversion Devices, Inc. (ECD), we have designed and built a production machine (described by my colleague, Dr. Izu, in a

  20. Performance of passive Q-switched solar-pumped high-power Nd:YAG lasers

    NASA Astrophysics Data System (ADS)

    Noter, Yoram; Naftali, Nir; Pe'er, Idit L.; Yogev, Amnon; Lando, Mordechai; Shimony, Yehoshua

    1997-09-01

    Q-switched, solar-pumped, high power Nd:YAG lasers are attractive for a variety of applications requiring high instantaneous peak power density. The Q-switching can be obtained by an acousto-optic, electro-optic or passive device. Passive Q-switching seems an excellent choice for space as well as for other applications since it neither requires an external driver nor an electrical power supply. In recent years Cr+4:YAG single crystals were extensively used as passive Q-switches for flashlamp-pumped high power Nd:YAG lasers, demonstrating their superior thermal superior thermal characteristics and durability. In this work we report the first operation of passive Q- switched, solar-pumped, high power Nd:YAG lasers. The concentrated solar energy for he optical pumping of the laser was obtained by a 3-stage combination of imaging and non-imaging optics. It included: i) Weizmann Institute solar tower heliostats, ii) 3D compound parabolic concentrator, and iii) 2D compound parabolic concentrator in which the laser rod was placed. 72 mm long laser rods with either 3 mm or 4 mm diameter were used. The passive Q-switch was made from a Cr$=+4):YAG single crystal having a low- intensity transmission of 72 percent at 1.06 (mu) . Its rear surface was coated by a high reflectivity coating, serving as the rear mirror of the cavity. Output coupling mirrors with various reflectivities were used. The passive Q-switch demonstrated excellent durability and reliability during all the experiments. Repetition rates of 6-39 kHz were measured, showing higher repetition rates at higher laser power levels. The pulses demonstrated shorter full width at half maximum (FWHM) time for higher laser power elves, and the FWHM time range was 190-310 nsec. The maximal measured average power was 14 W. Thermal lensing was measured as a function of the absorbed solar power in the laser rod. It is estimated that laser peak power densities of approximately 100 kW/cm2 were achieved in the experiments. It is

  1. Enhanced Conversion Efficiency of Cu(In,Ga)Se2 Solar Cells via Electrochemical Passivation Treatment.

    PubMed

    Tsai, Hung-Wei; Thomas, Stuart R; Chen, Chia-Wei; Wang, Yi-Chung; Tsai, Hsu-Sheng; Yen, Yu-Ting; Hsu, Cheng-Hung; Tsai, Wen-Chi; Wang, Zhiming M; Chueh, Yu-Lun

    2016-03-30

    Defect control in Cu(In,Ga)Se2 (CIGS) materials, no matter what the defect type or density, is a significant issue, correlating directly to PV performance. These defects act as recombination centers and can be briefly categorized into interface recombination and Shockley-Read-Hall (SRH) recombination, both of which can lead to reduced PV performance. Here, we introduce an electrochemical passivation treatment for CIGS films that can lower the oxygen concentration at the CIGS surface as observed by X-ray photoelectron spectrometer analysis. Temperature-dependent J-V characteristics of CIGS solar cells reveal that interface recombination is suppressed and an improved rollover condition can be achieved following our electrochemical treatment. As a result, the surface defects are passivated, and the power conversion efficiency performance of the solar cell devices can be enhanced from 4.73 to 7.75%. PMID:26815164

  2. Cooling-load implications for residential passive-solar-heating systems

    SciTech Connect

    Jones, R.W.; McFarland, R.D.

    1983-01-01

    Ongoing research on quantifying the cooling loads in residential buildings, particularly buildings with passive solar heating systems, is described, along with the computer simulation model used for calculating cooling loads. A sample of interim results is also presented. The objective of the research is to develop a simple analysis method, useful early in design, to estimate the annual cooling energy requirement of a given building.

  3. Passive and hybrid solar manufactured housing and buildings. [Includes architectural drawings

    SciTech Connect

    Scholz, D; Bowling, C; Winter, S; Levy, E; Marks, R; Zgolinski, A

    1980-01-01

    The final design work on a passive solar two story modular home to be built by Unibilt Industries is summarized. After reviewing alternative insulation, glazing, and water wall schemes, five options were identified for detailed energy use and life cycle cost analysis. Using the PASCALC/SLR analysis procedure, the performance of the base case home and each of the energy conservation options was calculated. (MHR)

  4. Large resource development projects as markets for passive solar technologies. Final report

    SciTech Connect

    Roze-Benson, R V

    1980-12-01

    A basic premise of this study is that large resource development projects provide a major market opportunity for passive solar manufactured buildings. The primary objectives of the work are to document selected resource development projects and identify their potential housing needs and development schedules, to contact resource industry representatives and assess some of the processes and motivations behind their involvement in housing decisions, and to provide passive solar manufactured buildings producers with results of these steps as early initial market intelligence. The intent is to identify not only the industries, location of their planned projects, and their likely worker housing needs, but also the individuals involved in making housing-related decisions. The 56 identified projects are located within 18 states and cover 11 types of resources. The report documents individual projects, provides protections of total worker-related housing needs, and presents overviews of resource development company involvement in the new construction market. In addition, the report profiles three organizations that expressed a strong interest in implementing the use of low-cost passive solar manufactured buildings in resource-development-related activities.

  5. Economic analysis of commercial solar combined space-heating and hot-water systems

    SciTech Connect

    1980-09-23

    Typical commercial solar energy systems are described, outlining typical cost and performance lvels. The economic performance of solar energy systems are described through the use of Cash Flow Diagrams. These diagrams indicate the cumulative cash situation of a solar investment over the life of the investment. The economic performance of solar energy systems is described through the calculation of equivalent Return-on-Investment (ROI). Appendices are included that enable one to calculate the ROI for any particular solar energy system investment. (MHR)

  6. Diffusion-free back contact solar cells on sulfur-passivated silicon(100) substrates

    NASA Astrophysics Data System (ADS)

    Song, Guanghua

    A diffusion-free back contact solar cell is proposed in this work. The textured front-side of this cell is coated with ˜100 nm thermal SiO2 to enhance the light trapping meanwhile reduce the surface recombination velocity (SRV). The back-side of this cell is finger-patterned, using a diffusion-free junction as its emitter region and Al-Si alloy as its base contact. The diffusion-free junction is made by a Schottky contact between low work-function metal aluminum (Al) and sulfur (S)-passivated p-type Si(100) surface. Solution-based S passivation is one of the experimental realizations of the "valence-mending concept". Previously developed MBE (molecular bean epitaxy) selenium (Se) passivation is not used due to its time-consuming process and high energy input. Following the concept, passivation of Si(100) surface by Group VI elements such as S and Se terminates the dangling bonds and releases the strained bonds and dimer bonds, thus significantly reduces the surface states. Quantification of surface states or interface states is introduced through the nano-CMOS devices. Removal of surface states enables an almost ideal barrier height after metal contact. This is one of the methods achieving the high Schottky barrier. Al on S-passivated p-type Si(100) surface yields an extremely high Schottky barrier of 1.1 eV, about 0.2 eV higher than the corresponding ideal barrier height. This discrepancy is accounted by S-Si dipole moment on the surface. Calculations using Fermi statistics discloses that the barrier height of 1.1 eV causes the degenerate inversion on Si surface, making this Schottky junction electrically behave like a diffused p-n junction. Eventually this junction as a field-induced junction free of any diffusion is integrated in the fabrication of the proposed back contact solar cells. High work-function metal Platinum (Pt) and nickel (Ni) on S-passivated n-type Si(100) are also investigated, but the yielding barrier heights are not high enough to create

  7. Solar thermal central receiver integrated commercialization analysis. Volume 2. Appendices. Final report

    SciTech Connect

    Doyle, J.F.; Bos, P.B.; Weingart, J.M.

    1986-03-01

    The report presents brief discussions on the following topics: (1) value analysis computer program; (2) levelized busbar energy cost computation; (3) electric utility avoided cost; and (4) commercial solar tax credits. Each topic is in reference to the integrated commercialization of solar thermal central receivers. (BCS)

  8. Aluminum oxide passivated radial junction sub-micrometre pillar array textured silicon solar cells

    NASA Astrophysics Data System (ADS)

    Pudasaini, Pushpa Raj; Elam, David; Ayon, Arturo A.

    2013-06-01

    We report radial, p-n junction, sub-micrometre, pillar array textured solar cells, fabricated on an n-type Czochralski silicon wafer. Relatively simple processing schemes such as metal-assisted chemical etching and spin on dopant techniques were employed for the fabrication of the proposed solar cells. Atomic layer deposition (ALD) grown aluminum oxide (Al2O3) was employed as a surface passivation layer on the B-doped emitter surface. In spite of the fact that the sub-micrometre pillar array textured surface has a relatively high surface-to-volume ratio, we observed an open circuit voltage (VOC) and a short circuit current density (JSC) as high as 572 mV and 29.9 mA cm-2, respectively, which leads to a power conversion efficiency in excess of 11.30%, for the optimized structure of the solar cell described herein. Broadband omnidirectional antireflection effects along with the light trapping property of the sub-micrometre, pillar array textured surface and the excellent passivation quality of the ALD-grown Al2O3 on the B-doped emitter surface were responsible for the enhanced electrical performance of the proposed solar cells.

  9. Improved performance in GaInNAs solar cells by hydrogen passivation

    SciTech Connect

    Fukuda, M.; Whiteside, V. R.; Keay, J. C.; Meleco, A.; Sellers, I. R.; Hossain, K.; Golding, T. D.; Leroux, M.; Al Khalfioui, M.

    2015-04-06

    The effect of UV-activated hydrogenation on the performance of GaInNAs solar cells is presented. A proof-of-principle investigation was performed on non-optimum GaInNAs cells, which allowed a clearer investigation of the role of passivation on the intrinsic nitrogen-related defects in these materials. Upon optimized hydrogenation of GaInNAs, a significant reduction in the presence of defect and impurity based luminescence is observed as compared to that of unpassivated reference material. This improvement in the optical properties is directly transferred to an improved performance in solar cell operation, with a more than two-fold improvement in the external quantum efficiency and short circuit current density upon hydrogenation. Temperature dependent photovoltaic measurements indicate a strong contribution of carrier localization and detrapping processes, with non-radiative processes dominating in the reference materials, and evidence for additional strong radiative losses in the hydrogenated solar cells.

  10. Transparent electrodes in silicon heterojunction solar cells: Influence on contact passivation

    SciTech Connect

    Tomasi, Andrea; Sahli, Florent; Seif, Johannes Peter; Fanni, Lorenzo; de Nicolas Agut, Silvia Martin; Geissbuhler, Jonas; Paviet-Salomon, Bertrand; Nicolay, Sylvain; Barraud, Loris; Niesen, Bjoern; De Wolf, Stefaan; Ballif, Christophe

    2015-10-26

    Charge carrier collection in silicon heterojunction solar cells occurs via intrinsic/doped hydrogenated amorphous silicon layer stacks deposited on the crystalline silicon wafer surfaces. Usually, both the electron and hole collecting stacks are externally capped by an n-type transparent conductive oxide, which is primarily needed for carrier extraction. Earlier, it has been demonstrated that the mere presence of such oxides can affect the carrier recombination in the crystalline silicon absorber. Here, we present a detailed investigation of the impact of this phenomenon on both the electron and hole collecting sides, including its consequences for the operating voltages of silicon heterojunction solar cells. As a result, we define guiding principles for improved passivating contact design for high-efficiency silicon solar cells.

  11. Bifacial MIS inversion layer solar cells based on low temperature silicon surface passivation

    NASA Astrophysics Data System (ADS)

    Jaeger, K.; Hezel, R.

    A novel bifacial silicon solar cell fabricated by a simple low-temperature process is introduced. The front side is characterized by an MIS contact grid and a charged plasma silicon nitride layer. The rear side is made up of ohmic grid lines in combination with silicon nitride for surface passivation. This appears to be the first bifacial solar cell without any highly doped region and completely processed at temperatures below 500 C. An AM1 efficiency of 15 and 13.2 percent was achieved for front and back illumination, respectively. The dependence of the solar cell data on cell thickness was experimentally investigated in the range from 80 microns to 330 microns. This thickness dependence was confirmed by theoretical one-dimensional calculations.

  12. The Role of Education and Training Programs in the Commercialization and Diffusion of Solar Energy Technologies.

    ERIC Educational Resources Information Center

    Burns, Barbara; And Others

    The solar energy labor force is analyzed by identifying the importance of education and training in the commercialization and diffusion of solar technologies, discussing issues for planning and analysis of solar education and training efforts, and illustrating the range of programs and courses presently available. Four general perspectives are…

  13. Layered insulator hexagonal boron nitride for surface passivation in quantum dot solar cell

    SciTech Connect

    Shanmugam, Mariyappan; Jain, Nikhil; Jacobs-Gedrim, Robin; Yu, Bin; Xu, Yang

    2013-12-09

    Single crystalline, two dimensional (2D) layered insulator hexagonal boron nitride (h-BN), is demonstrated as an emerging material candidate for surface passivation on mesoporous TiO{sub 2}. Cadmium selenide (CdSe) quantum dot based bulk heterojunction (BHJ) solar cell employed h-BN passivated TiO{sub 2} as an electron acceptor exhibits photoconversion efficiency ∼46% more than BHJ employed unpassivated TiO{sub 2}. Dominant interfacial recombination pathways such as electron capture by TiO{sub 2} surface states and recombination with hole at valence band of CdSe are efficiently controlled by h-BN enabled surface passivation, leading to improved photovoltaic performance. Highly crystalline, confirmed by transmission electron microscopy, dangling bond-free 2D layered h-BN with self-terminated atomic planes, achieved by chemical exfoliation, enables efficient passivation on TiO{sub 2}, allowing electronic transport at TiO{sub 2}/h-BN/CdSe interface with much lower recombination rate compared to an unpassivated TiO{sub 2}/CdSe interface.

  14. Control system analysis for off-peak auxiliary heating of passive solar systems

    SciTech Connect

    Murray, H.S.; Melsa, J.L.; Balcomb, J.D.

    1980-01-01

    A computer simulation method is presented for the design of an electrical auxiliary energy system for passive solar heated structures. The system consists of electrical mats buried in the ground underneath the structure. Energy is stored in the ground during utility off-peak hours and released passively to the heated enclosure. An optimal control strategy is used to determine the system design parameters of depth of mat placement and minimum instaled electrical heating capacity. The optimal control applies combinations of fixed duration energy pulses to the heater, which minimize the room temperature error-squared for each day, assuming advance knowledge of the day's weather. Various realizable control schemes are investigated in an attempt to find a system that approaches the performance of the optimal control system.

  15. Proposal of leak path passivation for InGaN solar cells to reduce the leakage current

    NASA Astrophysics Data System (ADS)

    Wang, Ke; Imai, Daichi; Kusakabe, Kazuhide; Yoshikawa, Akihiko

    2016-01-01

    We propose some general ways to passivate the leak paths in InGaN solar cells and report some experimental evidences of its effectiveness. By adopting an AlOx passivation process, the photovoltaic performances of GaN pn-junctions and InGaN solar cells, grown by molecular beam epitaxy, have been significantly improved. The open circuit voltage under 1 sun illumination increases from 1.46 to 2.26 V for a GaN pn junction, and from 0.95 to 1.27 V for an InGaN solar cell, demonstrating evidence of leak path passivation (LPP) by AlOx. The proposed LPP is expected to be a realistic way to exploit the potential of thick and relaxed but defective InGaN for solar cell applications.

  16. Antireflection and SiO2 Surface Passivation by Liquid-Phase Chemistry for Efficient Black Silicon Solar Cells: Preprint

    SciTech Connect

    Yuan, H. C.; Oh, J.; Zhang, Y.; Kuznetsov, O. A.; Flood, D. J.; Branz, H. M.

    2012-06-01

    We report solar cells with both black Si antireflection and SiO2 surface passivation provided by inexpensive liquid-phase chemistry, rather than by conventional vacuum-based techniques. Preliminary cell efficiency has reached 16.4%. Nanoporous black Si antireflection on crystalline Si by aqueous etching promises low surface reflection for high photon utilization, together with lower manufacturing cost compared to vacuum-based antireflection coating. Ag-nanoparticle-assisted black Si etching and post-etching chemical treatment recently developed at NREL enables excellent control over the pore diameter and pore separation. Performance of black Si solar cells, including open-circuit voltage, short-circuit current density, and blue response, has benefited from these improvements. Prior to this study, our black Si solar cells were all passivated by thermal SiO2 produced in tube furnaces. Although this passivation is effective, it is not yet ideal for ultra-low-cost manufacturing. In this study, we report, for the first time, the integration of black Si with a proprietary liquid-phase deposition (LPD) passivation from Natcore Technology. The Natcore LPD forms a layer of <10-nm SiO2 on top of the black Si surface in a relatively mild chemical bath at room temperature. We demonstrate black Si solar cells with LPD SiO2 with a spectrum-weighted average reflection lower than 5%, similar to the more costly thermally grown SiO2 approach. However, LPD SiO2 provides somewhat better surface-passivation quality according to the lifetime analysis by the photo-conductivity decay measurement. Moreover, black Si solar cells with LPD SiO2 passivation exhibit higher spectral response at short wavelength compared to those passivated by thermally grown SiO2. With further optimization, the combination of aqueous black Si etching and LPD could provide a pathway for low-cost, high-efficiency crystalline Si solar cells.

  17. The Pyramid House: A ten-day thermal time constant passive solar home

    SciTech Connect

    Ellison, T.

    1999-07-01

    The Pyramid House is a passive solar home being designed and built to operate without back-up heating. Having told people this, the fear that someday the author might have to swallow his pride and seek the warmth of a neighbor's cozy wood-heated cabin has encouraged him to analyze the Pyramid House's projected winter performance. This performance is easy to visualize when described in terms of the home's thermal time constant, {tau}--an easily calculated measure of the time it takes the house to reach equilibrium with the ambient temperature. The Pyramid House obtains its long time constant using conventional insulation, and a very high degree of thermal mass via a radiant heat flooring system and water storage. After presenting the time constant concept, it is employed to analyze building materials and then the Pyramid House. The analyses show the ineffectuality of adding solar gain to homes with low time constants, such as typical US homes.

  18. Passive solar-heating retrofit of a maintenance facility: First-year performance

    NASA Astrophysics Data System (ADS)

    Jackson, D. R.; Callahan, J. M.

    1982-09-01

    A 12,000 sf maintenance facility in Connecticut was retrofitted with a 1,500 sf passive solar Trombe wall, 2 in. of foam roof insulation and a new control system that allows night/weekend temperature setback. A new separate boiler was installed to heat an office/locker wing of the facility. An energy-consumption monitoring system was installed and collected data for 11/2 years before the retrofit and one complete year after the retrofit. Actual energy consumption for the facility was very close to that predicted using simple analytic methods. After the solar wall was installed and other energy-conservation measures implemented the yearly oil consumption was reduced to 2744 gallons/year.

  19. Transparent electrodes in silicon heterojunction solar cells: Influence on contact passivation

    DOE PAGESBeta

    Tomasi, Andrea; Sahli, Florent; Seif, Johannes Peter; Fanni, Lorenzo; de Nicolas Agut, Silvia Martin; Geissbuhler, Jonas; Paviet-Salomon, Bertrand; Nicolay, Sylvain; Barraud, Loris; Niesen, Bjoern; et al

    2015-10-26

    Charge carrier collection in silicon heterojunction solar cells occurs via intrinsic/doped hydrogenated amorphous silicon layer stacks deposited on the crystalline silicon wafer surfaces. Usually, both the electron and hole collecting stacks are externally capped by an n-type transparent conductive oxide, which is primarily needed for carrier extraction. Earlier, it has been demonstrated that the mere presence of such oxides can affect the carrier recombination in the crystalline silicon absorber. Here, we present a detailed investigation of the impact of this phenomenon on both the electron and hole collecting sides, including its consequences for the operating voltages of silicon heterojunction solarmore » cells. As a result, we define guiding principles for improved passivating contact design for high-efficiency silicon solar cells.« less

  20. Amorphous Silicon Carbide Passivating Layers to Enable Higher Processing Temperature in Crystalline Silicon Heterojunction Solar Cells

    SciTech Connect

    Boccard, Mathieu; Holman, Zachary

    2015-04-06

    "Very efficient crystalline silicon (c-Si) solar cells have been demonstrated when thin layers of intrinsic and doped hydrogenated amorphous silicon (a-Si:H) are used for passivation and carrier selectivity in a heterojunction device. One limitation of this device structure is the (parasitic) absorption in the front passivation/collection a-Si:H layers; another is the degradation of the a-Si:H-based passivation upon temperature, limiting the post-processes to approximately 200°C thus restricting the contacting possibilities and potential tandem device fabrication. To alleviate these two limitations, we explore the potential of amorphous silicon carbide (a-SiC:H), a widely studied material in use in standard a-Si:H thin-film solar cells, which is known for its wider bandgap, increased hydrogen content and stronger hydrogen bonding compared to a-Si:H. We study the surface passivation of solar-grade textured n-type c-Si wafers for symmetrical stacks of 10-nm-thick intrinsic a-SiC:H with various carbon content followed by either p-doped or n-doped a-Si:H (referred to as i/p or i/n stacks). For both doping types, passivation (assessed through carrier lifetime measurements) is degraded by increasing the carbon content in the intrinsic a-SiC:H layer. Yet, this hierarchy is reversed after annealing at 350°C or more due to drastic passivation improvements upon annealing when an a-SiC:H layer is used. After annealing at 350°C, lifetimes of 0.4 ms and 2.0 ms are reported for i/p and i/n stacks, respectively, when using an intrinsic a-SiC:H layer with approximately 10% of carbon (initial lifetimes of 0.3 ms and 0.1 ms, respectively, corresponding to a 30% and 20-fold increase, respectively). For stacks of pure a-Si:H material the lifetimes degrade from 1.2 ms and 2.0 ms for i/p and i/n stacks, respectively, to less than 0.1 ms and 1.1 ms (12-fold and 2-fold decrease, respectively). For complete solar cells using pure a-Si:H i/p and i/n stacks, the open-circuit voltage (Voc

  1. Site-Selective Passivation of Defects in NiO Solar Photocathodes by Targeted Atomic Deposition.

    PubMed

    Flynn, Cory J; McCullough, Shannon M; Oh, EunBi; Li, Lesheng; Mercado, Candy C; Farnum, Byron H; Li, Wentao; Donley, Carrie L; You, Wei; Nozik, Arthur J; McBride, James R; Meyer, Thomas J; Kanai, Yosuke; Cahoon, James F

    2016-02-01

    For nanomaterials, surface chemistry can dictate fundamental material properties, including charge-carrier lifetimes, doping levels, and electrical mobilities. In devices, surface defects are usually the key limiting factor for performance, particularly in solar-energy applications. Here, we develop a strategy to uniformly and selectively passivate defect sites in semiconductor nanomaterials using a vapor-phase process termed targeted atomic deposition (TAD). Because defects often consist of atomic vacancies and dangling bonds with heightened reactivity, we observe-for the widely used p-type cathode nickel oxide-that a volatile precursor such as trimethylaluminum can undergo a kinetically limited selective reaction with these sites. The TAD process eliminates all measurable defects in NiO, leading to a nearly 3-fold improvement in the performance of dye-sensitized solar cells. Our results suggest that TAD could be implemented with a range of vapor-phase precursors and be developed into a general strategy to passivate defects in zero-, one-, and two-dimensional nanomaterials. PMID:26821265

  2. Role of hydrogen plasma pretreatment in improving passivation of the silicon surface for solar cells applications.

    PubMed

    Wang, Fengyou; Zhang, Xiaodan; Wang, Liguo; Jiang, Yanjian; Wei, Changchun; Sun, Jian; Zhao, Ying

    2014-09-10

    We have investigated the role of hydrogen plasma pretreatment in promoting silicon surface passivation, in particular examining its effects on modifying the microstructure of the subsequently deposited thin hydrogenated amorphous silicon (a-Si:H) passivation film. We demonstrate that pretreating the silicon surface with hydrogen plasma for 40 s improves the homogeneity and compactness of the a-Si:H film by enhancing precursor diffusion and thus increasing the minority carrier lifetime (τ(eff)). However, excessive pretreatment also increases the density of dangling bond defects on the surface due to etching effects of the hydrogen plasma. By varying the duration of hydrogen plasma pretreatment in fabricating silicon heterojunction solar cells based on textured substrates, we also demonstrate that, although the performance of the solar cells shows a similar tendency to that of the τ(eff) on polished wafers, the optimal duration is prolonged owing to the differences in the surface morphology of the substrates. These results suggest that the hydrogen plasma condition must be carefully regulated to achieve the optimal level of surface atomic hydrogen coverage and avoid the generation of defects on the silicon wafer. PMID:25141300

  3. Comal County MHMR Center passive solar demonstration program. Operation and evaluation final report

    SciTech Connect

    Svedeman, S.J.; Stubblefield, J.; Wyatt, R.

    1983-10-01

    A stone school building, built in New Braunfels, Texas in 1934, was renovated for use as a mental health facility. Included in the renovation of the 4805 ft/sup 2/ building were cost effective passive solar and conservation options. The total cost for building renovation was $125,000 with the cost of the energy related options totaling $14,000. The passive solar and conservation options included in building construction were ceiling insulation, weather proofing, fluorescent lighting, roof evaporative spray cooling systems, awnings, and ceiling fans. Natural ventilation and night cooling are used to reduce the cooling load. Natural daylighting is utilized to replace the dependence on artificial lighting. The yearly space heating energy consumption at the MHMR Center was 16,000 Btu/ft/sup 2//year. The energy usage for lighting (including ceiling fans), water heating, and air conditioning was 7380 Btu/ft/sup 2//year, 2070 Btu/ft/sup 2//year, and 3700 Btu/ft/sup 2//year, respectively. Approximately 23% of the lighting load was for external night lighting. The average monthly utility bill, including natural gas and electric, for the 4805 ft/sup 2/ building was $171.

  4. Materials research for passive solar systems: solid-state phase-change materials

    SciTech Connect

    Benson, D.K.; Webb, J.D.; Burrows, R.W.; McFadden, J.D.O.; Christensen, C.

    1985-03-01

    A set of solid-state phase-change materials is being evaluated for possible use in passive solar thermal energy storage systems. The most promising materials are organic solid solutions of pentaerythritol (C/sub 5/H/sub 12/O/sub 4/), pentaglycerinve (C/sub 5/H/sub 12/O/sub 3/), and neopentyl glycol (C/sub 5/H/sub 12/O/sub 2/). Solid solution mixtures of these compounds can be tailored so that they exhibit solid-to-solid phase transformations at any desired temperature betweeen 25/sup 0/C and 188/sup 0/C, and have latent heats of transformation between 20 and 70 cal/g. Transformation temperatures, specific heats, and latent heats of transformation have been measured for a number of these materials. Limited cyclic experiments suggest that the solid solutions are stable. These phase-change materials exhibit large amounts of undercooling; however, the addition of certain nucleating agents as particulate dispersions in the solid phase-change material greatly reduces this effect. Computer simulations suggest that the use of an optimized solid-state phase-change material in a Trombe wall could provide better performance than a concrete Trombe wall four times thicker and nine times heavier. Nevertheless, a higher cost of the phase-change materials (approx. =$0.70 per pound) is likely to limit their applicability in passive solar systems unless their performance can be significantly improved through further research.

  5. Temperature resolution enhancing of commercially available THz passive cameras due to computer processing of images

    NASA Astrophysics Data System (ADS)

    Trofimov, Vyacheslav A.; Trofimov, Vladislav V.; Kuchik, Igor E.

    2014-06-01

    As it is well-known, application of the passive THz camera for the security problems is very promising way. It allows seeing concealed object without contact with a person and this camera is non-dangerous for a person. Efficiency of using the passive THz camera depends on its temperature resolution. This characteristic specifies possibilities of the detection of concealed object: minimal size of the object, maximal distance of the detection, image detail. One of probable ways for a quality image enhancing consists in computer processing of image. Using computer processing of the THz image of objects concealed on the human body, one may improve it many times. Consequently, the instrumental resolution of such device may be increased without any additional engineering efforts. We demonstrate new possibilities for seeing the clothes details, which raw images, produced by the THz cameras, do not allow to see. We achieve good quality of the image due to applying various spatial filters with the aim to demonstrate independence of processed images on math operations. This result demonstrates a feasibility of objects seeing. We consider images produced by THz passive cameras manufactured by Microsemi Corp., and ThruVision Corp., and Capital Normal University (Beijing, China).

  6. Ultrathin flexible planar crystalline-silicon/polymer hybrid solar cell with 5.68% efficiency by effective passivation

    NASA Astrophysics Data System (ADS)

    Li, Yingfeng; Fu, Pengfei; Li, Ruike; Li, Meicheng; Luo, Younan; Song, Dandan

    2016-03-01

    Ultrathin silicon based solar cells provide a viable way to reduce the material usage and diversify their applications. However, complex light-trapping structures are always needed to be fabricated to enhance light absorption, which will lead to exacerbation of carrier collection and expensive fabrication cost. Here, we report very simple planar flexible crystalline silicon-polymer hybrid solar cell with thickness about 18 μm, whose power conversion efficiency (PCE) reaches 5.68%. By introducing the amorphous silicon layer to passivate the Silicon/Polymer interface in our device, with accuracy control of the thickness of 2 nm to balance the passivation effect and the deterioration of internal electric field, the short current density reaches 83.0% of the theoretical limit. Additionally, we found that the average PCE of solar cells passivated by such technology is 5.8% and 7.1% enhanced compared with those without passivation (H-terminated) and passivated by native oxide approaches. The simple device structure provided in this study has great practicability, and the passivation processes can be duplicated for other silicon based photovoltaic devices.

  7. High-Efficiency, Commercial Ready CdTe Solar Cells

    SciTech Connect

    Sites, James R.

    2015-11-19

    Colorado State’s F-PACE project explored several ways to increase the efficiency of CdTe solar cells and to better understand the device physics of those cells under study. Increases in voltage, current, and fill factor resulted in efficiencies above 17%. The three project tasks and additional studies are described in detail in the final report. Most cells studied were fabricated at Colorado State using an industry-compatible single-vacuum closed-space-sublimation (CSS) chamber for deposition of the key semiconductor layers. Additionally, some cells were supplied by First Solar for comparison purposes, and a small number of modules were supplied by Abound Solar.

  8. Commercially available black chrome is an effective solar collector coating

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. E.

    1974-01-01

    Black chrome, electroplated decorative finish, which absorbs and retains solar energy is readily available, easily applied, and low cost. It is indistinguishable from black nickel and is equally feasible on aluminum or steel.

  9. Properties of dye-sensitized solar cells with TiO2 passivating layers prepared by electron-beam evaporation.

    PubMed

    Jin, Young Sam; Choi, Hyung Wook

    2012-01-01

    The aim of this work is to prevent back transfer of electrons due to direct contact between the electrolyte and the FTO glass substrate using a TiO2 passivating layer. The TiO2 passivating layer was deposited on FTO glass by e-beam evaporation. The TiO2 film was prepared with different deposition rates. The specific surface area was reduced with increasing deposition rate. The nanoporous TiO2 upper layer was coated by screen-printing on the TiO2 passivating layer prepared by e-beam evaporation. The optical transmittance and absorbance of the TiO2 films depend on the morphology of the TiO2 passivating layer. The dye-sensitized solar cells influenced the surface morphology of the TiO2 passivating layer. The dye-sensitized solar cell using the TiO2 passivating layer recorded a maximum conversion efficiency of 4.93% due to effective prevention of the electron recombination to the electrolyte. PMID:22524036

  10. Hodges residence: performance of a direct gain passive solar home in Iowa

    SciTech Connect

    Hodges, L.

    1980-01-01

    Results are presented for the performance of the Hodges Residence, a 2200-square-foot earth-sheltered direct gain passive solar home in Ames, Iowa, during the 1979-80 heating season, its first occupied season. No night insulation was used on its 500 square feet of double-pane glass. Total auxiliary heat required was 43 GJ (41 MBTU) gross and 26 GJ (25 MBTU) net, amounting, respectively, to 60 and 36 kJ/C/sup 0/-day-m/sup 2/ (2.9 and 1.8 BTU/F/sup 0/-day-ft/sup 2/). The heating season was unusually cloudy and included the cloudiest January in the 21 years of Ames insolation measurements. Results are also presented for the performance of the hollow-core floor which serves as the main storage mass and for the comfort range in the house.

  11. Hydrogen passivation of electrically active defects in crystalline silicon solar cells

    SciTech Connect

    Milstein, J B; Tsuo, Y S; Osterwald, C R; White, C W

    1984-06-01

    We have observed significant improvements in the efficiencies of dendritic web and edge-supported-pulling (ESP) silicon sheet solar cells after hydrogen ion beam passivation for a period of ten minutes or less. We have studied the effects of the hydrogen ion beam treatment with respect to silicon material damage, silicon sputter rate, introduction of impurities, and changes in reflectance. We have determined that the silicon sputter rate for a constant ion beam flux of 0.60 +- 0.05 mA/cm/sup 2/ exhibits a maximum at approximately 1400 eV ion beam energy. We have observed that hydrogen ion beam treatment can result in a reduced fill factor, which is caused by damage to the front metallization of the cell rather than by damage to the p-n junction.

  12. Development of an exterior insulating mechanism for passive solar walls. Final report

    SciTech Connect

    Christianson, L.

    1984-01-01

    A movable, mechanically operated, insulated cover for insulating and protecting the exterior side of south-facing window walls typical of passive solar homes was designed, built and tested. The shutter, which covers an 8 ft by 32 ft glass wall on a house near Brookings, South Dakota, is constructed of 4 in. of styrofoam insulation sandwiched between 3/8 in. plywood. The shutter consists of two 4-1/3 ft by 33 ft sections which are raised or lowered by cables. Each section is attached to a mechanical drive operated by a 1/2 HP electric motor coupled to a worm gear box which automatically locks in position whenever re-energized. Major problems encountered were (1) selection of a motor and gear box combination which locked in position when de-energized to avoid problems which could occur during a power outage, (2) design of the door guide system to minimize possibilities of the door sections binding or catching while moving up or down, and (3) minimizing the door system cost to enhance the economic feasibility of insulating passive window walls at night. Energy consumption can be reduced by approximately 80,000 to 90,000 Btu/ft/sup 2/-y by using this window cover device. Material costs for the cover are approximately $8.00/ft/sup 2/.

  13. Hydrogen passivation of defects and rapid thermal processing for high-efficiency silicon ribbon solar cells

    NASA Astrophysics Data System (ADS)

    Jeong, Ji-Weon

    2002-01-01

    The use of photovoltaic (PV) system offers a unique opportunity to solve the energy and the environmental problems simultaneously because solar energy is free and can be directly converted into electrical energy by solar cells without any undesirable impact on the environment. In spite of the many advantages, PV still accounts for less than 0.05% of the current U.S. energy portfolio. This is mainly because PV is 2-4 times more expensive than traditional energy sources. PV modules should cost about $1/W to produce electricity at a rate of 6¢/kWh and to compete with fossil fuels. Since Si material accounts for ˜40% of the cost of current Si PV modules, the use of low-cost Si substrate is critical for cost reduction. Edge-defined film-fed grown (EFG) Si ribbon is the focus as substrate materials for this research because it is one of the most promising for low-cost PV. However, as-grown EFG Si has a lot of impurities and crystal defects resulted from the Si feedstock and its growth system, which reduce the bulk lifetime of less than 3 ms. In this research, first, the requirements for achieving 16% efficiency have been established using computer model simulations. To improve the bulk lifetime, manufacturable P and Al gettering techniques are developed to remove the lifetime-killing impurities from the active to inactive device regions. PECVD SiN-induced hydrogen defect passivation is investigated and maximized through the fundamental understanding of the role of Al, the impact of RTP firing, and the difference between two PECVD SiN films. For low-cost contact formation, a novel RTP firing process is developed for high-quality screen-printed contacts and Al-BSF. Finally, a complete process sequence that involves the optimal conditions for defect passivation and contacts is developed to produce ˜16% efficiency on screen-printed EFG Si solar cells, which is the highest efficiency for any screen-printed Si ribbon solar cells to date.

  14. Passive cooling with solar updraft and evaporative downdraft chimneys. Interim report, June 15, 1984--March 1, 1985

    SciTech Connect

    Mignon, G.V.; Cunningham, W.A.; Thompson, T.L.

    1985-12-31

    Computer models have been developed to describe the operation of both solar updraft and evaporative downdraft chimneys. Design studies are being conducted at the present time to use the towers for cooling an experimental, well instrumented, structure to study passive cooling in residential buildings. (MHR)

  15. New three-layer antireflection/surface passivating coating for high efficiency III-V compound solar cells

    SciTech Connect

    Moulot, J.; Faur, M.; Goradia, C.; Goradia, M.; Faur, M.; Alterovitz, S.; Bailey, S.

    1996-12-31

    By using a chemically grown In(PO{sub 3}){sub 3}-rich oxide layer as the first layer of a 3-layer AR coating, with Al{sub 2}O{sub 3} and MgF{sub 2} as the second and third layers, the authors have addressed the problem of surface passivation and AR coating on InP solar cells. They have designed a 3-layer optimized AR coating for p{sup +}n InP solar cell, which reduces the average reflectance on the surface of cell from about 40% (bare) to less than 2%. At the same time the AR coating significantly improves the J{sub SC} and V{sub OC} by passivating the top surface of the emitter. The authors believe that the significant front surface passivation is to a large extent responsible for their achieving the record high AM0, 25 C, open-circuit voltage of 890.3 mV on a thermally diffused p{sup +}n InP(Cd,S) solar cell. This concept of using a passivating chemically grown oxide as the first layer of a multilayer AR coating can be beneficial to other III-V compound solar cells as well.

  16. Development of high-efficiency solar cells on thin silicon through design optimization and defect passivation

    NASA Astrophysics Data System (ADS)

    Sheoran, Manav

    The focus of this research is to investigate the potential of lower quality cast multicrystalline Si (mc-Si) as well as thin single and mc-Si cells. The overall goal of this research is to improve fundamental understanding of the hydrogen passivation of defects in low-cost Si and the fabrication of high-efficiency solar cells on thin crystalline silicon through low-cost technology development. This is addressed by a combination of five research tasks. The key results of these tasks are summarized below. A novel method was developed to determine the concentration and flux of H diffusing into the Si. The understanding of defect passivation acquired in task 1 was used to fabricate high-efficiency solar cells on cast mc-Si wafers. An optimized co-firing process was developed, which resulted in ˜17% efficient 4 cm2 screen-printed solar cells with single-layer AR coating, and no surface texturing or selective emitter. The HEM mc-Si wafer gave an average efficiency of 16.5%, with a maximum of 16.9%. The identical process applied to the un-textured Float zone (FZ) wafers gave an efficiency of 17.2%. These cells were fabricated using the same simple, manufacturable process involving POCl3 diffusion for a 45 O/sq emitter, PECVD SiNx:H deposition for single-layer antireflection coating and rapid co-firing of a Ag grid, an Al back contact, and Al-BSF formation in a belt furnace. A high-efficiency of 17.1% was achieved on high sheet-resistance HEM mc-Si with good quality contacts. The effects of changing several device parameters on the efficiency of the solar cells was modeled with PC1D and guidelines were established to improve the efficiency from ˜17% to over 20% cells on low lifetime (100 mus), thin (140 mum) silicon wafers. The understanding of enhanced defect hydrogenation and the optimized fabrication sequence was applied to fabricate high-efficiency solar cells on top, middle, and bottom regions of several mc-Si ingots. Screen-printed solar cells were fabricated on

  17. Commercial solar/load management experiment: New mechanical engineering building

    NASA Astrophysics Data System (ADS)

    Noble, J. M.

    1981-01-01

    The effects of load management heat recovery, thermal storage, and solar systems on energy usage and power demand profiles in the University of New Mexico's Mechanical Engineering Building are presented. Results were obtained from a year monitoring of the building's heating and cooling systems and recording of sensor signals by a computer based data acquisition system. A modified AXCESS Energy Analysis Program to simulate energy usage is detailed, and the development of perferred strategies for maximizing the building's load management capabilities is outlined.

  18. Passive-solar-heating project for a single-family residence. Final report

    SciTech Connect

    Starkey, V.J.

    1982-05-01

    This project was a passive home heating system utilizing solar collectors that are part of the roof structure of a 15' x 30' greenhouse. The design utilized solar air collectors constructed on site that are actually part of the roof of the greenhouse. The flow of air is from the storage to the collectors then back to the storage. The storage bin consists of a 5' x 19' concrete insulated bin built into the floor of the greenhouse. The storage mass was gallon plastic jugs. The plastic jugs did not work properly, so they are being replaced by salt rods. This replacement will be an after the fact project by the owner. The concrete storage bin was insulated with 2'' plastic foam insulation, applied to the 8'' concrete wall. The ducts entering and leaving the storage bin have low voltage (12 volt) electric dampers. A cross flow system was used. The heated air circulates from the collectors to storage via ducts in the walls of the lean-to design. The removal of heat from the storage bin was from end to end via the ducts to the central air system for the house. In addition, the greenhouse is connected to the house with a doorway that can be opened to circulate air into the house, a shuttled exhaust fan 1/3H.P. motor has aided in the circulation of air from the storage bin to the collectors and back.

  19. Tuning semiconductor band edge energies for solar photocatalysis via surface ligand passivation.

    PubMed

    Yang, Shenyuan; Prendergast, David; Neaton, Jeffrey B

    2012-01-11

    Semiconductor photocatalysts capable of broadband solar photon absorption may be nonetheless precluded from use in driving water splitting and other solar-to-fuel related reactions due to unfavorable band edge energy alignment. Using first-principles density functional theory and beyond, we calculate the electronic structure of passivated CdSe surfaces and explore the opportunity to tune band edge energies of this and related semiconductors via electrostatic dipoles associated with chemisorbed ligands. We predict substantial shifts in band edge energies originating from both the induced dipole at the ligand/CdSe interface and the intrinsic dipole of the ligand. Building on important induced dipole contributions, we further show that, by changing the size and orientation of the ligand's intrinsic dipole moment via functionalization, we can control the direction and magnitude of the shifts of CdSe electronic levels. Our calculations suggest a general strategy for enabling new active semiconductor photocatalysts with both optimal opto-electronic, and photo- and electrochemical properties. PMID:22192078

  20. Progress toward achieving a commercially viable solar reflective material

    SciTech Connect

    Kennedy, C.E.; Smilgys, R.V. |

    1998-06-01

    Solar thermal technologies use large mirrors to concentrate sunlight for renewable power generation. The development of advanced reflector materials is important to the viability of electricity production by solar thermal energy systems. The reflector materials must be low in cost and maintain high specular reflectance for extended lifetimes under severe outdoor environments. Production processes associated with candidate materials must be scalable to mass production techniques. A promising low-cost construction uses a stainless steel foil substrate with a silver reflective layer protected by an optically transparent oxide topcoat. Thick (2 to 4 micron), dense alumina coatings provide durable protective layers. The excellent performance of alumina-coated reflector materials in outdoor and accelerated testing suggests that a larger field trial of the material is warranted. The key to producing a greater quantity of material for field deployment and testing without incurring substantial capital is the use of a chilled drum coater. An existing chamber is being modified, and the deposition rate will be increased prior to the installation of a drum coater to produce 1-ft wide by 10-ft long strips of solar reflector material. The production and performance of these materials are discussed.

  1. High reduction of interfacial charge recombination in colloidal quantum dot solar cells by metal oxide surface passivation

    NASA Astrophysics Data System (ADS)

    Chang, Jin; Kuga, Yuki; Mora-Seró, Iván; Toyoda, Taro; Ogomi, Yuhei; Hayase, Shuzi; Bisquert, Juan; Shen, Qing

    2015-03-01

    Bulk heterojunction (BHJ) solar cells based on colloidal QDs and metal oxide nanowires (NWs) possess unique and outstanding advantages in enhancing light harvesting and charge collection in comparison to planar architectures. However, the high surface area of the NW structure often brings about a large amount of recombination (especially interfacial recombination) and limits the open-circuit voltage in BHJ solar cells. This problem is solved here by passivating the surface of the metal oxide component in PbS colloidal quantum dot solar cells (CQDSCs). By coating thin TiO2 layers onto ZnO-NW surfaces, the open-circuit voltage and power conversion efficiency have been improved by over 40% in PbS CQDSCs. Characterization by transient photovoltage decay and impedance spectroscopy indicated that the interfacial recombination was significantly reduced by the surface passivation strategy. An efficiency as high as 6.13% was achieved through the passivation approach and optimization for the length of the ZnO-NW arrays (device active area: 16 mm2). All solar cells were tested in air, and exhibited excellent air storage stability (without any performance decline over more than 130 days). This work highlights the significance of metal oxide passivation in achieving high performance BHJ solar cells. The charge recombination mechanism uncovered in this work could shed light on the further improvement of PbS CQDSCs and/or other types of solar cells.Bulk heterojunction (BHJ) solar cells based on colloidal QDs and metal oxide nanowires (NWs) possess unique and outstanding advantages in enhancing light harvesting and charge collection in comparison to planar architectures. However, the high surface area of the NW structure often brings about a large amount of recombination (especially interfacial recombination) and limits the open-circuit voltage in BHJ solar cells. This problem is solved here by passivating the surface of the metal oxide component in PbS colloidal quantum dot solar

  2. Long-lasting FR-4 surface hydrophilisation towards commercial PCB passive microfluidics

    NASA Astrophysics Data System (ADS)

    Vasilakis, Nikolaos; Moschou, Despina; Carta, Daniela; Morgan, Hywel; Prodromakis, Themistoklis

    2016-04-01

    Printed circuit boards (PCB) technologies are an attractive system for simple sensing and microfluidic systems. Controlling the surface properties of PCB material is an important part of this technology and to date there has been no study on long-term hydrophilisation stability of these materials. In this work, the effect of different oxygen plasma input power and treatment duration times on the wetting properties of FR-4 surfaces was investigated by sessile droplet contact angle measurements. Super and weakly hydrophilic behaviour was achieved and the retention time of these properties was studied, with the hydrophilic nature being retained for at least 26 days. To demonstrate the applicability of this treatment method, a commercially manufactured microfluidic structure made from a multilayer PCB (3-layer FR-4 stack) was exposed to oxygen plasma at the optimum conditions. The structures could be filled with deionised (DI) water under capillary flow unlike the virgin devices.

  3. Economic Recovery Act of 1981 and tax policies for commercial solar-energy applications

    SciTech Connect

    Ball, D. E.

    1981-12-01

    Key tax policies relevant to commercial solar energy applications are outlined. Included are certain changes in depreciation rules and small business federal income tax percentages that were part of the recently enacted Economic Recovery Tax Act of 1981. Also, the regulations for business investment and energy tax credits are explained. An example of the effects of the new depreciation schedule on a solar industrial process heat system is given.

  4. Black chrome on commercially electroplated tin as a solar selecting coating

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. E.

    1977-01-01

    The reflectance properties of black chrome electroplated on commercially electroplated tin were measured for various black chrome plating times for both the solar and infrared spectrum. The values of absorptance and emittance were calculated from the measured reflectance values. The results indicate that the optimum combination of the highest absorptance in the solar region and the lowest emittance in the infrared of the black chrome plated on commercially electroplated tin is obtained for a black chrome plating time of between one and two minutes.

  5. Commercialization of a thick-film solar cell

    NASA Astrophysics Data System (ADS)

    McDonald, G. D.

    1980-12-01

    The use of screen printing as a technique for producing large area solar cells was evaluated with emphasis on the preparation and improvement in performance of screen printed CdS cells. Thermal gravimetric analysis of the CdS inks used to print CdS films confirm that all the fugitive binders and flux are removed under firing conditions used to prepare the CdS films. Warpage of the Nesatron glass substrates makes their use questionable. Multiple layers of CdS appear to resolve a pin hole problem previously encountered.

  6. Tantalum oxide/silicon nitride: A negatively charged surface passivation stack for silicon solar cells

    SciTech Connect

    Wan, Yimao Bullock, James; Cuevas, Andres

    2015-05-18

    This letter reports effective passivation of crystalline silicon (c-Si) surfaces by thermal atomic layer deposited tantalum oxide (Ta{sub 2}O{sub 5}) underneath plasma enhanced chemical vapour deposited silicon nitride (SiN{sub x}). Cross-sectional transmission electron microscopy imaging shows an approximately 2 nm thick interfacial layer between Ta{sub 2}O{sub 5} and c-Si. Surface recombination velocities as low as 5.0 cm/s and 3.2 cm/s are attained on p-type 0.8 Ω·cm and n-type 1.0 Ω·cm c-Si wafers, respectively. Recombination current densities of 25 fA/cm{sup 2} and 68 fA/cm{sup 2} are measured on 150 Ω/sq boron-diffused p{sup +} and 120 Ω/sq phosphorus-diffused n{sup +} c-Si, respectively. Capacitance–voltage measurements reveal a negative fixed insulator charge density of −1.8 × 10{sup 12 }cm{sup −2} for the Ta{sub 2}O{sub 5} film and −1.0 × 10{sup 12 }cm{sup −2} for the Ta{sub 2}O{sub 5}/SiN{sub x} stack. The Ta{sub 2}O{sub 5}/SiN{sub x} stack is demonstrated to be an excellent candidate for surface passivation of high efficiency silicon solar cells.

  7. International solar commercialization study of the market potential of solar products in Latin America: Jamaica. Final report

    SciTech Connect

    Not Available

    1981-12-01

    The current and forecasted economic situations in Jamaica are reviewed. The logistics of doing business is reviewed, including finance, labor, investment and import policy. Market penetration strategy is presented, with emphasis on the Kingston free zone analysis. A Market Potential for US Renewable Energy Products in Jamaica included government, agricultural, tourism, manufacturing, and mining sectors. Conclusions and recommendations are given. The market readiness of the following renewable technologies was analyzed: photovoltaics; industrial process heat; active and passive solar; biomass; wind; small-scale hydro; ocean thermal; geothermal; and conservation. When appropriate, the foreign competition was also analyzed.

  8. Enhanced Lifetime of Polymer Solar Cells by Surface Passivation of Metal Oxide Buffer Layers.

    PubMed

    Venkatesan, Swaminathan; Ngo, Evan; Khatiwada, Devendra; Zhang, Cheng; Qiao, Qiquan

    2015-07-29

    The role of electron selective interfaces on the performance and lifetime of polymer solar cells were compared and analyzed. Bilayer interfaces consisting of metal oxide films with cationic polymer modification namely poly ethylenimine ethoxylated (PEIE) were found to enhance device lifetime compared to bare metal oxide films when used as an electron selective cathode interface. Devices utilizing surface-modified metal oxide layers showed enhanced lifetimes, retaining up to 85% of their original efficiency when stored in ambient atmosphere for 180 days without any encapsulation. The work function and surface potential of zinc oxide (ZnO) and ZnO/PEIE interlayers were evaluated using Kelvin probe and Kelvin probe force microscopy (KPFM) respectively. Kelvin probe measurements showed a smaller reduction in work function of ZnO/PEIE films compared to bare ZnO films when aged in atmospheric conditions. KPFM measurements showed that the surface potential of the ZnO surface drastically reduces when stored in ambient air for 7 days because of surface oxidation. Surface oxidation of the interface led to a substantial decrease in the performance in aged devices. The enhancement in the lifetime of devices with a bilayer interface was correlated to the suppressed surface oxidation of the metal oxide layers. The PEIE passivated surface retained a lower Fermi level when aged, which led to lower trap-assisted recombination at the polymer-cathode interface. Further photocharge extraction by linearly increasing voltage (Photo-CELIV) measurements were performed on fresh and aged samples to evaluate the field required to extract maximum charges. Fresh devices with a bare ZnO cathode interlayer required a lower field than devices with ZnO/PEIE cathode interface. However, aged devices with ZnO required a much higher field to extract charges while aged devices with ZnO/PEIE showed a minor increase compared to the fresh devices. Results indicate that surface modification can act as a

  9. Passivated Tunneling Contacts to N-Type Wafer Silicon and Their Implementation into High Performance Solar Cells: Preprint

    SciTech Connect

    Stradins, P.; Essig, S.; Nemeth, W.; Lee, B. G.; Young, D.; Norman, A.; Liu, Y.; Luo, J.-W.; Warren, E.; Dameron, A.; LaSalvia, V.; Page, M.; Rohatgi, A.; Upadhyaya, A.; Rounsaville, B.; Ok, Y.-W.; Glunz, S.; Benick, J.; Feldmann, F.; Hermle, M.

    2014-12-01

    We present a case that passivated contacts based on a thin tunneling oxide layer, combined with a transport layer with properly selected work function and band offsets, can lead to high efficiency c-Si solar cells. Passivated contacts contribute to cell efficiency as well as design flexibility, process robustness, and a simplified process flow. Material choices for the transport layer are examined, including transparent n-type oxides and n+-doped poly-Si. SiO2/n+-poly-Si full-area, induced-junction back surface field contacts to n-FZ and n-Cz Si are incorporated into high efficiency cells with deep, passivated boron emitters.

  10. Solar-Energy System for a Commercial Building--Topeka, Kansas

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Report describes a solar-energy system for space heating, cooling and domestic hot water at a 5,600 square-foot (520-square-meter) Topeka, Kansas, commercial building. System is expected to provide 74% of annual cooling load, 47% of heating load, and 95% of domestic hot-water load. System was included in building design to maximize energy conservation.

  11. Photovoltaic commercialization: an analysis of legal issues affecting a government-accelerated solar industry

    SciTech Connect

    Lamm, D.

    1980-06-01

    The Photovoltaics Research, Development, and Demonstration Act of 1978 is discussed. Legal issues, including solar access, the need for performance standards, the effects of building codes on photovoltaic system use and commercialization, and manufacturer and installer performance guarantees, are examined. Electric utility policies are examined, including interconnection, and rates and legal issues affecting them. (LEW)

  12. Interim Policy Options for Commercialization of Solar Heating and Cooling Systems.

    ERIC Educational Resources Information Center

    Bezdek, Roger

    This interim report reviews the major incentive policy options available to accelerate market penetration of solar heating and cooling (SHAC) systems. Feasible policy options designed to overcome existing barriers to commercial acceptance and market penetration are identified and evaluated. The report is divided into seven sections, each dealing…

  13. A numerical simulation study of gallium-phosphide/silicon heterojunction passivated emitter and rear solar cells

    SciTech Connect

    Wagner, Hannes; Ohrdes, Tobias; Dastgheib-Shirazi, Amir; Puthen-Veettil, Binesh; König, Dirk; Altermatt, Pietro P.

    2014-01-28

    The performance of passivated emitter and rear (PERC) solar cells made of p-type Si wafers is often limited by recombination in the phosphorus-doped emitter. To overcome this limitation, a realistic PERC solar cell is simulated, whereby the conventional phosphorus-doped emitter is replaced by a thin, crystalline gallium phosphide (GaP) layer. The resulting GaP/Si PERC cell is compared to Si PERC cells, which have (i) a standard POCl{sub 3} diffused emitter, (ii) a solid-state diffused emitter, or (iii) a high efficiency ion-implanted emitter. The maximum efficiencies for these realistic PERC cells are between 20.5% and 21.2% for the phosphorus-doped emitters (i)–(iii), and up to 21.6% for the GaP emitter. The major advantage of this GaP hetero-emitter is a significantly reduced recombination loss, resulting in a higher V{sub oc}. This is so because the high valence band offset between GaP and Si acts as a nearly ideal minority carrier blocker. This effect is comparable to amorphous Si. However, the GaP layer can be contacted with metal fingers like crystalline Si, so no conductive oxide is necessary. Compared to the conventional PERC structure, the GaP/Si PERC cell requires a lower Si base doping density, which reduces the impact of the boron-oxygen complexes. Despite the lower base doping, fewer rear local contacts are necessary. This is so because the GaP emitter shows reduced recombination, leading to a higher minority electron density in the base and, in turn, to a higher base conductivity.

  14. Starting a local conservation and passive solar retrofit program: an energy planning sourcebook

    SciTech Connect

    Barber, V; Mathews, R

    1982-02-01

    A city planner or a neighborhood activist may wish to initiate a local conservation and passive solar retrofit program but may not have previous experience in doing so. This sourcebook is designed to assist interested individuals with their energy planning efforts, from determining retrofit potential, to financing and implementing the program. An approach or methodology is provided which can be applied to determine retrofit potential in single-family residences, mobile homes, multifamily residences, and nonresidential buildings. Case studies in Albuquerque, New Mexico, are given as examples. Guidelines are provided for evaluating the economic benefits of a retrofit program through benefit-cost analysis and economic base studies at the city and neighborhood levels. Also included are approaches to community outreach, detailing how to get started, how to gain local support, and examples of successful programs throughout the US. The need for financing, the development of a local strategy, public and private financing techniques, and community energy service organizations are examined. In addition to the Albuquerque case studies, a brief technology characterization, heat-loss calculations, economic tools, and a list of resources are appended.

  15. Comal County Mental Health and Mental Retardation Center Passive Solar Demonstration Program. Final report

    SciTech Connect

    Risner, P. S.; Stubblefield, J.; Deffenbaugh, D. M.; Stevenson, J.

    1980-07-31

    An extensive energy analysis was performed on an existing schoolhouse built in New Braunfels, Texas, in the 1930's. The purpose of the analysis was to evaluate the potentials for passive solar retrofitting concepts and energy conservation techniques which could be applied to the structure on an economically justifiable basis. The energy analysis was performed by the Bin methodology, and a life cycle cost analysis was utilized in determining the economics of the alternatives under consideration. The alternatives which were considered were analyzed on an individual basis as to the percentage improvement in the existing structure's yearly energy loads which each option could be expected to provide. The life cycle cost analysis was based on the assumed useful life of the option; the estimated fuel savings the option provided; the initial investment required to incorporate the option into the retrofitted structure; and discount and fuel escalation rates of 10 and 12%, respectively. If the option provided a positive annual real savings over its assumed life, then the selection of the option was considered to be economically feasible. The selected options were subsequently combined into a revised construction package, and an energy/economic analysis was performed to estimate the annual savings which could be expected by the revisions. A conservative building temperature control strategy which consisted of turning off the mechanical equipment during unoccupied hours, and utilizing natural ventilation when applicable was also investigated. The options which were selected and the relative annual savings are given.

  16. Nationwide Analysis of U.S. Commercial Building Solar Photovoltaic (PV) Breakeven Conditions

    SciTech Connect

    Davidson, Carolyn; Gagnon, Pieter; Denholm, Paul; Margolis, Robert

    2015-10-01

    The commercial sector offers strong potential for solar photovoltaics (PV) owing to abundant available roof space suitable for PV and the opportunity to offset the sector's substantial retail electricity purchases. This report evaluated the breakeven price of PV for 15 different building types and various financing options by calculating electricity savings based on detailed rate structures for most U.S. utility territories (representing approximately two thirds of U.S. commercial customers). We find that at current capital costs, an estimated 1/3 of U.S. commercial customers break even in the cash scenario and approximately 2/3 break even in the loan scenario. Variation in retail rates is a stronger driver of breakeven prices than is variation in building load or solar generation profiles. At the building level, variation in the average breakeven price is largely driven by the ability for a PV system to reduce demand charges.

  17. Remote trap passivation in colloidal quantum dot bulk nano-heterojunctions and its effect in solution-processed solar cells.

    PubMed

    Rath, Arup K; Pelayo Garcia de Arquer, F; Stavrinadis, Alexandros; Lasanta, Tania; Bernechea, Maria; Diedenhofen, Silke L; Konstantatos, Gerasimos

    2014-07-16

    More-efficient charge collection and suppressed trap recombination in colloidal quantum dot (CQD) solar cells is achieved by means of a bulk nano-heterojunction (BNH) structure, in which p-type and n-type materials are blended on the nanometer scale. The improved performance of the BNH devices, compared with that of bilayer devices, is displayed in higher photocurrents and higher open-circuit voltages (resulting from a trap passivation mechanism). PMID:24895324

  18. Shellfish mariculture facility which employs passive solar heating and heat pump systems. Performance and cost analysis study. Final report

    SciTech Connect

    Zoto, G.A.; Krabach, M.H.

    1984-06-01

    This report incorporates operations data such as clam growth rates, clam biomass buildup, water volume, and algal food requirements compiled while developing a year-round production schedule for production of hard clam seed. The facility includes a passive solar hatchery and heat pump. Three major areas which affect development of energy-efficient mariculture are addressed: biological operation parameters, energy requirements, and system economics. (LEW)

  19. Early commercial demonstration of space solar power using ultra-lightweight arrays

    NASA Astrophysics Data System (ADS)

    Reed, Kevin; Willenberg, Harvey J.

    2009-11-01

    Space solar power shows great promise for future energy sources worldwide. Most central power stations operate with power capacity of 1000 MW or greater. Due to launch size limitations and specific power of current, rigid solar arrays, the largest solar arrays that have flown in space are around 50 kW. Thin-film arrays offer the promise of much higher specific power and deployment of array sizes up to several MW with current launch vehicles. An approach to early commercial applications for space solar power to distribute power to charge hand-held, mobile battery systems by wireless power transmission (WPT) from thin-film solar arrays in quasi-stationary orbits will be presented. Four key elements to this prototype will be discussed: (1) Space and near-space testing of prototype wireless power transmission by laser and microwave components including WPT space to space and WPT space to near-space HAA transmission demonstrations; (2) distributed power source for recharging hand-held batteries by wireless power transmission from MW space solar power systems; (3) use of quasi-geostationary satellites to generate electricity and distribute it to targeted areas; and (4) architecture and technology for ultra-lightweight thin-film solar arrays with specific energy exceeding 1 kW/kg. This approach would yield flight demonstration of space solar power and wireless power transmission of 1.2 MW. This prototype system will be described, and a roadmap will be presented that will lead to still higher power levels.

  20. Passive solar in Milton Keynes, England. A description of some of the more numerical aspects of the design of an estate of low energy houses

    NASA Astrophysics Data System (ADS)

    Everett, R.

    1980-07-01

    The numerical aspects of the design of low energy consumption houses using passive solar energy collection and high levels of insulation are described. Two housing energy conservation projects were begun, one involving the construction of 177 low energy houses on a cost-effective basis, and the other involving the detailed monitoring of eight highly insulated passive solar houses. Both experimental data and theoretical analysis are presented, and the relative effectiveness of the various design alternatives are discussed.

  1. Preliminary energy sector assessments of Jamaica. Volume III: renewable energy. Part I: solar energy - commercial and industrial

    SciTech Connect

    Not Available

    1980-01-01

    This study concerns commercial and industrial solar applications, specifically solar water heating and solar air cooling. The study finds that solar domestic water heating and boiler make-up water preheating are technically feasible and, depending on the displaced energy source (electrical or various fuel types), economically justified; and that solar hot water installations could displace the equivalent of 189,842 barrels of fuel oil per year. However, solar cooling requires high performance collectors not currently manufactured in Jamaica, and feasibility studies indicate that solar cooling in the near term is not economically justified.

  2. Passive solar commercial buildings project. Project status report, November 1-December 31, 1983

    SciTech Connect

    Not Available

    1983-01-01

    Additional work on the Security State BLAST input file has resulted in better agreement between measured and estimated conditions. Although agreement is not complete, additional sources of error have been identified and some original problems corrected. A third visit has been made to the Security State Bank and data on the modified building operation obtained. The planned continuous infiltration test using equipment supplied by Lawrence Berkeley Laboratories was cancelled. It was found that the complexity of the test was beyond the scope of this project. The data acquisition system installed by ESG in the Security State Bank has been turned over to representatives of Architectural Energy Corporation (AEC) for long term data retrieval. Further monitoring of this site by ESG is not expected. A data acquisition system has been installed in the Salt Lake City Johnson Controls building. The necessary one time measurements were made on the building. Hourly data from the building is to be provided to ESG by AEC over telecommunication lines. No data has been made available yet from this site. The final data from the building modifications is not expected before the end of January, 1984.

  3. Endurance testing of first generation (Block 1) commercial solar cell modules

    NASA Technical Reports Server (NTRS)

    Anagnostou, E.; Forestieri, A. F.

    1978-01-01

    To determine lifetimes of the first generation (Block 1) commercial solar cell modules used in solar cell arrays, a program was initiated to expose these modules to a range of environments. The conditions endured by these modules encompassed hot and dry, hot and humid, tropical rain forests, sea-air, urban industrial and urban clean. Exposures were for periods up to 1 year. The effect of outdoor exposure on the performance of the modules was determined using current-voltage curves. Short-circuit current (I sub sc) and maximum power (P sub max) were the parameters monitored. In all cases, there was a loss of performance of the modules with outdoor exposure.

  4. Endurance testing of first generation /Block I/ commercial solar cell modules

    NASA Technical Reports Server (NTRS)

    Anagnostou, E.; Forestieri, A. F.

    1978-01-01

    NASA-LeRC has conducted outdoor endurance tests on modules commercially produced as part of the 46-kW purchase of first generation (Block I) modules by the JPL Low Cost Silicon Solar Array Project. Block I modules from four manufacturers were installed at commercial testing sites in Florida, Puerto Rico, and Arizona and at noncommercial sites in Cleveland, Ohio. The conditions endured by these modules included hot and dry, hot and humid, tropical rain forest, sea-air, urban industrial and urban clean; exposures were for periods up to one year. Test results are presented and discussed.

  5. Dish/Stirling systems: Overview of an emerging commercial solar thermal electric technology

    SciTech Connect

    Strachan, J.W.; Diver, R.B.; Estrada, C.

    1995-11-01

    Dish/Stirling is a solar thermal electric technology which couples parabolic, point-focusing solar collectors and heat engines which employ the Stirling thermodynamic cycle. Since the late 1970s, the development of Dish/Stirling systems intended for commercial use has been in progress in Germany, Japan, and the US. In the next several years it is expected that one or more commercial systems will enter the market place. This paper provides a general overview of this emerging technology, including: a description of the fundamental principles of operation of Dish/Stirling systems; a presentation of the major components of the systems (concentrator, receiver, engine/alternator, and controls); an overview of the actual systems under development around the world, with a discussion of some of the technical issues and challenges facing the Dish/Stirling developers. A brief discussion is also presented of potential applications for small Dish/Stirling systems in northern Mexico.

  6. Investigation of positive roles of hydrogen plasma treatment for interface passivation based on silicon heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Zhang, Liping; Guo, Wanwu; Liu, Wenzhu; Bao, Jian; Liu, Jinning; Shi, Jianhua; Meng, Fanying; Liu, Zhengxin

    2016-04-01

    The positive roles of H2-plasma treatment (HPT) have been investigated by using different treatment procedures in view of the distinctly improved passivation performance of amorphous-crystalline silicon heterojunctions (SHJs). It has been found that a hydrogenated amorphous silicon thin film and crystalline silicon (a-Si:H/c-Si) interface with a high stretching mode (HSM) is detrimental to passivation. A moderate pre-HPT introduces atomic H, which plays an effective tuning role in decreasing the interfacial HSM; unfortunately, an epitaxial layer is formed. Further improvement in passivation can be achieved in terms of increasing the HSM of a-Si:H film treated by appropriate post-HPT based on the a-Si:H thickness. The minority carrier lifetime of crystalline wafers can be improved by treated films containing a certain quantity of crystallites. The microstructure factor R and the maximum intensity of the dielectric function ε 2max have been found to be critical microstructure parameters that describe high-quality a-Si:H passivation layers, which are associated with the amorphous-to-microcrystalline transition phase induced by multi-step HPT. Finally, the open circuit voltage and conversion efficiency of the SHJ solar cell can be improved by implementing an effective HPT process.

  7. Solar Design Workbook

    SciTech Connect

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

    1981-06-01

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

  8. Estimating the economic and demographic impacts of solar technology commercialization on US regions

    SciTech Connect

    Kort, J.R.

    1980-12-01

    The purpose of this study is to develop a framework through which these regional economic and demographic impacts of solar technology commercialization can be analyzed. Two models comprise the basis of this framework - a national input/output model and an interregional econometric model, the National-Regional Impact Evaluation System (NRIES). These models are used to convert projected sales of solar energy systems to gross output concepts, and to evaluate the impacts associated with these sales. Analysis is provided for the nine census regions and 50 states and the District of Columbia for the years 1980 through 1990. Impacts on major economic aggregates such as output, employment, income, and population are described. The methodology used in this study is described. The economic and demographic impacts of solar technology commercialization on US regions and states are presented. The major conclusions of the study are summarized, and direction is provided for further research. Detailed tables of regional and state solar energy expenditures and their impacts appear in the Appendix.

  9. SiC formation for a solar cell passivation layer using an RF magnetron co-sputtering system.

    PubMed

    Joung, Yeun-Ho; Kang, Hyun Il; Kim, Jung Hyun; Lee, Hae-Seok; Lee, Jaehyung; Choi, Won Seok

    2012-01-01

    In this paper, we describe a method of amorphous silicon carbide film formation for a solar cell passivation layer. The film was deposited on p-type silicon (100) and glass substrates by an RF magnetron co-sputtering system using a Si target and a C target at a room-temperature condition. Several different SiC [Si1-xCx] film compositions were achieved by controlling the Si target power with a fixed C target power at 150 W. Then, structural, optical, and electrical properties of the Si1-xCx films were studied. The structural properties were investigated by transmission electron microscopy and secondary ion mass spectrometry. The optical properties were achieved by UV-visible spectroscopy and ellipsometry. The performance of Si1-xCx passivation was explored by carrier lifetime measurement. PMID:22221730

  10. A correction factor to f-chart predictions of active solar fraction in active-passive heating systems

    NASA Astrophysics Data System (ADS)

    Evans, B. L.; Beckman, W. A.; Duffie, J. A.; Mitchell, J. W.; Klein, S. A.

    1983-11-01

    The extent to which a passive system degrades the performance of an active solar space heating system was investigated, and a correction factor to account for these interactions was developed. The transient system simulation program TRNSYS is used to simulate the hour-by-hour performance of combined active-passive (hybrid) space heating systems in order to compare the active system performance with simplified design method predictions. The TRNSYS simulations were compared to results obtained using the simplified design calculations of the f-Chart method. Comparisons of TRNSYS and f-Chart were used to establish the accuracy of the f-Charts for active systems. A correlation was then developed to correct the monthly loads input into the f-Chart method to account for controller deadbands in both hybrid and active only buildings. A general correction factor was generated to be applied to the f-Chart method to produce more accurate and useful results for hybrid systems.

  11. Performance of commercially available Passive Integrated Transponder (PIT) tag systems used for fish identification and interjurisdictional fisheries management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Passive integrated transponder (PIT) tag systems are commonly used for identification and monitoring programs with fisheries applications. Transponders of different frequencies, sizes, and code formats are available from numerous manufacturers, and there is an increasing concern regarding the need ...

  12. Alphabus Solar Array- Versatile and Powerful Solar Arrays for Tomorrow's Commercial Telecom Satellites

    NASA Astrophysics Data System (ADS)

    Pfefferkorn, T.; Oxynos, C.; Greff, P.; Gerlach, L.

    2008-09-01

    After the successful series of Eurostar 3000 and Spacebus 4000 satellites and due to the demand of satellite operators for even larger and more powerful satellites, ESA decided to co-fund the development of a new satellite platform which covers the market segment beyond the upper limits of both satellite families.The new satellite bus family Alphabus is developed in the frame of ARTES 8 project by a joint project team of ASTRIUM and TAS, whereas the solar array is developed by ASTRIUM GmbH.The main approaches in this design phase for the Alphabus solar array were to find a standardized and scaleable design to production and to use qualification heritage from former projects, especially Eurostar 3000, as far as possible. The main challenges for the solar array design and test philosophy were the usage of lateral deployment and related sequential deployment and the bus voltage of 102,5V and related ESD precautions.This paper provides an overview of the different configurations, their main design features and performance parameters. In addition it summarizes the development and verification approach and shows the actual qualification status.

  13. Building with passive solar: an application guide for the southern homeowner and builder

    SciTech Connect

    1981-03-01

    This instructional material was prepared for training workshops for builders and home designers. It includes: fundamental definitions and equations, climate and site studies, building components, passive systems and techniques, and design tools. (MHR)

  14. Economic analysis of solar assisted absorption chiller for a commercial building

    NASA Astrophysics Data System (ADS)

    Antonyraj, Gnananesan

    Dwindling fossil fuels coupled with changes in global climate intensified the drive to make use of renewable energy resources that have negligible impact on the environment. In this attempt, the industrial community produced various devices and systems to make use of solar energy for heating and cooling of building space as well as generate electric power. The most common components employed for collection of solar energy are the flat plate and evacuated tube collectors that produce hot water that can be employed for heating the building space. In order to cool the building, the absorption chiller is commonly employed that requires hot water at high temperatures for its operation. This thesis deals with economic analysis of solar collector and absorption cooling system to meet the building loads of a commercial building located in Chattanooga, Tennessee. Computer simulations are employed to predict the hourly building loads and performance of the flat plate and evacuated tube solar collectors using the hourly weather data. The key variables affecting the economic evaluation of such system are identified and the influence of these parameters is presented. The results of this investigation show that the flat plate solar collectors yield lower payback period compared to the evacuated tube collectors and economic incentives offered by the local and federal agencies play a major role in lowering the payback period.

  15. Passive solar heating and natural cooling of an earth-integrated design

    SciTech Connect

    Barnes, P.R.; Shapira, H.B.

    1980-01-01

    The Joint Institute for Heavy Ion Research is being designed with innovative features that will greatly reduce its energy consumption for heating, cooling, and lighting. A reference design has been studied and the effects of extending the overhang during summer and fall, varying glazing area, employing RIB, and reducing internal heat by natural lighting have been considered. The use of RIB and the extendable overhang increases the optimum window glazing area and the solar heating fraction. A mass-storage wall which will likely be included in the final design has also been considered. A figure of merit for commercial buildings is the total annual energy consumption per unit area of floor space. A highly efficient office building in the Oak Ridge area typically uses 120 to 160 kWhr/m/sup 2/. The Joint Institute reference design with natural lighting, an annual average heat pump coefficient of performance (COP) equal to 1.8, RIB, and the extendable overhang uses 71 kWhr/m/sup 2/. This figure was determined from NBSLD simulations corrected for the saving from RIB. The internal heat energy from lighting and equipment used in the simulation was 1653 kWhrs/month (high natural lighting case) which is much lower than conventional office buildings. This value was adopted because only a portion of the building will be used as office space and efforts will be made to keep internal heat generation low. The mass-storage wall and ambient air cooling will reduce energy consumption still further. The combined savings of the innovative features in the Joint Institute building are expected to result in a very energy efficient design. The building will be instrumented to monitor its performance and the measured data will provide a means of evaluating the energy-saving features. The efficiency of the design will be experimentally verified over the next several years.

  16. Improvement of the SiOx passivation layer for high-efficiency Si/PEDOT:PSS heterojunction solar cells.

    PubMed

    Sheng, Jiang; Fan, Ke; Wang, Dan; Han, Can; Fang, Junfeng; Gao, Pingqi; Ye, Jichun

    2014-09-24

    Interfacial properties currently hinder the performance of Si/organic heterojunction solar cells for an alternative to high-efficiency and low-cost photovoltaics. Here, we present a simple and repeatable wet oxidation method for developing the surface passivation layer, SiOx, on the Si surface for the fabrication of high-efficiency Si/poly(3,4-ethylene-dioxythiophene):polystyrenesulfonate (PEDOT:PSS) heterojunction solar cells. The uniform and dense SiOx thin layer introduced by the oxidizing aqueous solution of H2O2 or HNO3 provided the better surface passivation and stronger wettability of the Si surface, compared to those in the native oxide case. These two types of progress helped create a lower defect density at the Si/PEDOT:PSS interface and thus a high-quality p-n junction with a lower interface recombination velocity. As a result, the HNO3-oxidized device displayed better performance with a power conversion efficiency (PCE) of 11%, representing a 28.96% enhancement from the PCE of 8.53% in the native oxide case. The effects on the performance of the Si/PEDOT:PSS hybrid solar cells of the wet oxidation treatment procedure, including the differences in surface roughness and wettability of the Si substrate, the quality and thickness of the SiOx, etc., were explored extensively. Such a simple and controllable oxidizing treatment could be an effective way to promote the interfacial properties that are an important cornerstone for more efficient Si/organic hybrid solar cells. PMID:25157634

  17. Toward a national plan for the accelerated commercialization of solar energy: the implications of a national commitment

    SciTech Connect

    Bennington, G.; Bohannon, M.; Gerstein, R.; Hartzler, R.; Kannan, N.; Miller, G.; Rebibo, K.; Shulman, M.; Spewak, P.; Taul, J.

    1980-01-01

    This report analyzes the expected benefits, costs, and implications of three levels of federal commitment and subsidy for the accelerated commercialization of solar energy. It includes estimates of potential solar use representing 16 to 23 percent of the nation's energy supply in the year 2000. Projections are based on data available as of early 1979.

  18. Study of surface passivation as a function of InP closed-ampoule solar cell fabrication processing variables

    NASA Technical Reports Server (NTRS)

    Faur, Mircea; Faur, Maria; Jenkins, Phillip; Goradia, Manju; Goradia, Chandra; Bailey, Sheila; Weinberg, Irving; Jayne, Douglas

    1990-01-01

    The effects of various surface preparation procedures, including chemical treatment and anodic or chemical oxidation, closed-ampoule diffusion conditions, and post-diffusion surface preparation and annealing conditions, on the passivating properties of InP have been investigated in order to optimize the fabrication procedures of n(+)p InP solar cells made by closed-ampoule diffusion of sulfur into p-type InP. The InP substrates used were p-type Cd-doped to a level of 1.7 x 10 to the 16th/cu cm, Zn-doped to levels of 2.2 x 10 to the 16th and 1.2 x 10 to the 18th/cu cm, and n-type S-doped to 4.4 x 10 to the 18th/cu cm. The passivating properties have been evaluated from photoluminescence (PL) and conductance-voltage (G-V) data. Good agreement was found between the level of surface passivation and the composition of different surface layers as revealed by X-ray photoelectron spectroscopy (XPS) analysis.

  19. Evaluation of a commercially available passively Q-switched Nd:YAG laser with LiF: F2- saturable absorber for laser-induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Carson, Cantwell G.; Goueguel, Christian L.; Sanghapi, Hervé; Jain, Jinesh; McIntyre, Dustin

    2016-05-01

    Interest in passively Q-switched microchip lasers as a means for miniaturization of laser-induced breakdown spectroscopy (LIBS) apparatus has rapidly grown in the last years. To explore the possibility of using a comparatively UV-vis transparent absorber, we herein present the first report on the evaluation of a commercially available flash lamp-pumped passively Q-switched Nd:YAG laser with LiF: F2- saturable absorber as an excitation source in LIBS. Quantitative measurements of barium, strontium, rubidium and lithium in granite, rhyolite, basalt and syenite whole-rock glass samples were performed. Using a gated intensified benchtop spectrometer, limits of detection of 0.97, 23, 37, and 144 ppm were obtained for Li, Sr, Rb, and Ba, respectively. Finally, we discuss the advantages of using such a laser unit for LIBS applications in terms of ablation efficiency, analytical performances, output energy, and standoff capabilities.

  20. LiBr treated porous silicon used for efficient surface passivation of crystalline silicon solar cells

    NASA Astrophysics Data System (ADS)

    Zarroug, Ahmed; Haddadi, Ikbel; Derbali, Lotfi; Ezzaouia, Hatem

    2015-04-01

    A simple but effective passivation method of both front and rear surfaces using porous silicon (PS) has been developed. This paper investigates the effect of LiBr on the passivation of PS. The immersion of as-etched PS in dilute LiBr solution followed by an annealing in an infrared furnace, under a controlled atmosphere at different temperatures, led to the passivation of the PS layer and the improvement of the electronic properties of the crystalline silicon substrates. The influence of substrate temperature was investigated, since the processed wafers were found to be sensitive to heat, which in turn was optimized to have a gettering effect. The bromide of lithium can effectively saturate dangling bonds and hence contributed to the formation of a stable passivation film, at both front and back surfaces. Such a reaction was found to have a beneficial effect on the passivation process of the PS layer grown on both sides. The obtained results exhibited a significant improvement of the minority carrier lifetime, which is an important parameter that defines the quality of crystalline silicon substrates, and an apparent enhancement of its photoluminescence (PL). The internal quantum efficiency was investigated and found to be significantly improved. The qualitative effect of the above-mentioned procedure proved a significant enhancement of the electronic quality of the treated substrates.

  1. Carrier Selective, Passivated Contacts for High Efficiency Silicon Solar Cells based on Transparent Conducting Oxides

    DOE PAGESBeta

    Young, David L.; Nemeth, William; Grover, Sachit; Norman, Andrew; Yuan, Hao-Chih; Lee, Benjamin G.; LaSalvia, Vincenzo; Stradins, Paul

    2014-01-01

    We describe the design, fabrication and results of passivated contacts to n-type silicon utilizing thin SiO2 and transparent conducting oxide layers. High temperature silicon dioxide is grown on both surfaces of an n-type wafer to a thickness <50 Å, followed by deposition of tin-doped indium oxide (ITO) and a patterned metal contacting layer. As deposited, the thin-film stack has a very high J0,contact, and a non-ohmic, high contact resistance. However, after a forming gas anneal, the passivation quality and the contact resistivity improve significantly. The contacts are characterized by measuring the recombination parameter of the contact (J0,contact) and the specificmore » contact resistivity (ρcontact) using a TLM pattern. The best ITO/SiO2 passivated contact in this study has J0,contact = 92.5 fA/cm2 and ρcontact = 11.5 mOhm-cm2. These values are placed in context with other passivating contacts using an analysis that determines the ultimate efficiency and the optimal area fraction for contacts for a given set of (J0,contact, ρcontact) values. The ITO/SiO2 contacts are found to have a higher J0,contact, but a similar ρcontact compared to the best reported passivated contacts.« less

  2. Long-term measurement of indoor thermal environment and energy performance in a detached wooden house with passive solar systems

    SciTech Connect

    Ishikawa, Yoshimi; Yoshino, Hiroshi; Sasaki, Chikashi

    1998-07-01

    The indoor thermal environment, energy performance and energy consumption for a detached wooden house equipped with two passive solar systems, were investigated over a period of three years. The house with a floor area of 188 m{sup 2} was constructed in the autumn of 1993 in Sendai, Japan; and was well insulated and very airtight compared with other houses in Japan. There are six occupants. Heating equipment is comprises of a thermal storage space heater using night-time electricity and a vented firewood furnace on the first floor. Each room is ventilated all day by a central ventilation system. Two passive solar systems were incorporated: a concrete floor in the southern perimeter of the living room as a direct gain system, and an earth tube embedded around the circumference of the house to supply fresh air. The principal results obtained are as follows: (1) The indoor environment during the heating season was more thermally comfortable, compared with that or ordinary houses in Japan. (2) The concrete floor played a role of thermal storage, which absorbed and released heat for decreasing the fluctuation of room temperature. (3) The earth tube supplied air with lower temperature in the summer and higher temperature in the winter to the room, that the outdoor air temperature. This thermal performance did not decrease in spite of the long-term use. (4) The annual amount of energy consumption of this house was less than that of ordinary houses in the northern part of Japan.

  3. Barriers to commercialization of large-scale solar electricity: Lessions learned from the LUZ experience

    SciTech Connect

    Lotker, M. , Westlake Village, CA )

    1991-11-01

    This report discusses the economic and policy factors leading to the initial successful introduction of Luz International Limited's Solar Electric Generating Systems (SEGS). It then addresses the wide range of barriers to continued SEGS commercialization, including state and federal tax policy, avoided cost energy pricing, artificial size limitations under the Public Utility Regulatory Policies Act (PURPA), the loss of effectiveness of PURPA itself, the lack of incentives available to utilities as owners of solar electric plants, and the limited ways in which the environmental benefits of this technology have been recognized. The way in which each of these barriers contributed to the suspension of new LUZ projects is highlighted. In addition, mitigation approaches to each of these barriers are suggested.

  4. Barriers to commercialization of large-scale solar electricity: Lessions learned from the LUZ experience

    SciTech Connect

    Lotker, M.

    1991-11-01

    This report discusses the economic and policy factors leading to the initial successful introduction of Luz International Limited`s Solar Electric Generating Systems (SEGS). It then addresses the wide range of barriers to continued SEGS commercialization, including state and federal tax policy, avoided cost energy pricing, artificial size limitations under the Public Utility Regulatory Policies Act (PURPA), the loss of effectiveness of PURPA itself, the lack of incentives available to utilities as owners of solar electric plants, and the limited ways in which the environmental benefits of this technology have been recognized. The way in which each of these barriers contributed to the suspension of new LUZ projects is highlighted. In addition, mitigation approaches to each of these barriers are suggested.

  5. Benefits of the integrated solar upper stage (ISUS) to commercial space systems

    NASA Astrophysics Data System (ADS)

    Malloy, John; Miles, Barry

    1997-01-01

    The Integrated Solar Upper Stage (ISUS) is a solar thermal system that provides both propulsion and electric power. Using hydrogen as the propellant, ISUS can provide average specific impulses between 750 and 800 seconds. Once in final orbit, the stage uses thermionic diodes to produce electricity for the satellite payload throughout its operating lifetime. Because of its high specific impulse, ISUS can increase the total mass delivered to GEO by any launch vehicle by up to 250%. ISUS can provide benefits to commercial system in lower orbits as well. These orbits are particularly demanding on battery system because of the short orbit periods and the resulting number of battery cycles. Thermal storage in the ISUS receiver can accommodate these cycles without increasing system mass. ISUS also provide more efficient propulsion for station keeping and for separation of satellites when multiple satellites are launched for a single launch vehicle.

  6. Module greenhouse with high efficiency of transformation of solar energy, utilizing active and passive glass optical rasters

    SciTech Connect

    Korecko, J.; Jirka, V.; Sourek, B.; Cerveny, J.

    2010-10-15

    Since the eighties of the 20th century, various types of linear glass rasters for architectural usage have been developed in the Czech Republic made by the continuous melting technology. The development was focused on two main groups of rasters - active rasters with linear Fresnel lenses in fixed installation and with movable photo-thermal and/or photo-thermal/photo-voltaic absorbers. The second group are passive rasters based on total reflection of rays on an optical prism. During the last years we have been working on their standardization, exact measuring of their optical and thermal-technical characteristics and on creation of a final product that could be applied in solar architecture. With the project supported by the Ministry of Environment of the Czech Republic we were able to build an experimental greenhouse using these active and passive optical glass rasters. The project followed the growing number of technical objectives. The concept of the greenhouse consisted of interdependence construction - structural design of the greenhouse with its technological equipment securing the required temperature and humidity conditions in the interior of the greenhouse. This article aims to show the merits of the proposed scheme and presents the results of the mathematical model in the TRNSYS environment through which we could predict the future energy balance carried out similar works, thus optimizing the investment and operating costs. In this article description of various technology applications for passive and active utilization of solar radiation is presented, as well as some results of short-term and long-term experiments, including evaluation of 1-year operation of the greenhouse from the energy and interior temperature viewpoints. A comparison of the calculated energy flows in the greenhouse to real measured values, for verification of the installed model is also involved. (author)

  7. Evaluating the Performance and Economics of Transpired Solar Collectors for Commercial Applications: Preprint

    SciTech Connect

    Kozubal, E.; Deru, M.; Slayzak, S.; Norton, P.; Barker, G.; McClendon, J,

    2008-07-01

    Using transpired solar collectors to preheat ventilation air has recently become recognized as an economic alternative for integrating renewable energy into commercial buildings in heating climates. The collectors have relatively low installed costs and operate on simple principles. Theory and performance testing have shown that solar collection efficiency can exceed 70% of incident solar. However, implementation and current absorber designs have adversely affected the efficiency and associated economics from this initial analysis. The National Renewable Energy Laboratory has actively studied this technology and monitored performance at several installations. A calibrated model that uses typical meteorological weather data to determine absorber plate efficiency resulted from this work. With this model, an economic analysis across heating climates was done to show the effects of collector size, tilt, azimuth, and absorptivity. The analysis relates the internal rate of return of a system based on the cost of the installed absorber area. In general, colder and higher latitude climates return a higher rate of return because the heating season extends into months with good solar resource.

  8. Si surface passivation by SiOx : H films deposited by a low-frequency ICP for solar cell applications

    NASA Astrophysics Data System (ADS)

    Zhou, H. P.; Wei, D. Y.; Xu, S.; Xiao, S. Q.; Xu, L. X.; Huang, S. Y.; Guo, Y. N.; Khan, S.; Xu, M.

    2012-10-01

    Hydrogenated silicon suboxide (SiOx : H) thin films are fabricated by a low-frequency inductively coupled plasma of hydrogen-diluted SiH4 + CO2 at a low temperature (100 °C). Introduction of a small amount of oxygen into the film results in a predominantly amorphous structure, wider optical bandgap, increased H content, lower conductivity and higher activation energy. The minority carrier lifetime in the SiOx : H-passivated p-type Si substrate is up to 428 µs with a reduced incubation layer at the interface. The associated surface recombination velocity is as low as 70 cm s-1. The passivation behaviour dominantly originates from the H-related chemical passivation. The passivation effect is also demonstrated by the excellent photovoltaic performance of the heterojunction solar cell with the SiOx : H-based passivation and emitter layers.

  9. Commercial-scale process design for thin-film solar cells

    NASA Astrophysics Data System (ADS)

    Russell, T. W. F.; Baron, B. N.; Rocheleau, R. E.

    Process and manufacturing costs for commercial-scale production of thin-film solar cells are examined from the viewpoint of the chemical process industry, with emphasis on CdS/Cu2S cells. The cells comprise opaque contact, collector/converter, absorber/generator, transparent contact, and encapsulation/antireflective coating layers. Each layer is deposited as a separate unit operation, through either continuous or batch processing methods. The scale-up of laboratory-verified cell manufacturing steps to commercial processing is detailed from the choice of a Zn-plated copper foil substrate to the bonding of a 1/16 in. tempered glass protective layer with polyvinyl butyral. The total product cost is calculated as a sum of raw materials, utilities, labor, and capital investment costs, using a cost/W for a 1 GW plant. Continuous processing results in a $0.50/W cell with raw materials accounting for 38% of the total product cost.

  10. On the performance limiting behavior of defect clusters in commercial silicon solar cells

    SciTech Connect

    Sopori, B.L.; Chen, W.; Jones, K.; Gee, J.

    1998-09-01

    The authors report the observation of defect clusters in high-quality, commercial silicon solar cell substrates. The nature of the defect clusters, their mechanism of formation, and precipitation of metallic impurities at the defect clusters are discussed. This defect configuration influences the device performance in a unique way--by primarily degrading the voltage-related parameters. Network modeling is used to show that, in an N/P junction device, these regions act as shunts that dissipate power generated within the cell.

  11. Excellent Passivation and Low Reflectivity Al2O3/TiO2 Bilayer Coatings for n-Wafer Silicon Solar Cells: Preprint

    SciTech Connect

    Lee, B. G.; Skarp, J.; Malinen, V.; Li, S.; Choi, S.; Branz, H. M.

    2012-06-01

    A bilayer coating of Al2O3 and TiO2 is used to simultaneously achieve excellent passivation and low reflectivity on p-type silicon. This coating is targeted for achieving high efficiency n-wafer Si solar cells, where both passivation and anti-reflection (AR) are needed at the front-side p-type emitter. It could also be valuable for front-side passivation and AR of rear-emitter and interdigitated back contact p-wafer cells. We achieve high minority carrier lifetimes {approx}1 ms, as well as a nearly 2% decrease in absolute reflectivity, as compared to a standard silicon nitride AR coating.

  12. Interface engineering for the passivation of c-Si with O3-based atomic layer deposited AlOx for solar cell application

    NASA Astrophysics Data System (ADS)

    Lee, Hyunju; Tachibana, Tomihisa; Ikeno, Norihiro; Hashiguchi, Hiroki; Arafune, Koji; Yoshida, Haruhiko; Satoh, Shin-ichi; Chikyow, Toyohiro; Ogura, Atsushi

    2012-04-01

    We have investigated the effects of deposition temperature and post-annealing on the passivation performance of AlOx films deposited by O3-based atomic layer deposition for crystalline Si. We found that the dramatic enhancement in the passivation performance of room-temperature deposited AlOx films by post-annealing is due to the phase transformation of aluminum silicate to mullite in an AlOx interlayer and the resulting self-aligned AlOx/SiOx interface. This result is interesting for the fabrication of high-performance silicon solar cells with AlOx passivation layers.

  13. Carrier Selective, Passivated Contacts for High Efficiency Silicon Solar Cells based on Transparent Conducting Oxides

    SciTech Connect

    Young, David L.; Nemeth, William; Grover, Sachit; Norman, Andrew; Yuan, Hao-Chih; Lee, Benjamin G.; LaSalvia, Vincenzo; Stradins, Paul

    2014-01-01

    We describe the design, fabrication and results of passivated contacts to n-type silicon utilizing thin SiO2 and transparent conducting oxide layers. High temperature silicon dioxide is grown on both surfaces of an n-type wafer to a thickness <50 Å, followed by deposition of tin-doped indium oxide (ITO) and a patterned metal contacting layer. As deposited, the thin-film stack has a very high J0,contact, and a non-ohmic, high contact resistance. However, after a forming gas anneal, the passivation quality and the contact resistivity improve significantly. The contacts are characterized by measuring the recombination parameter of the contact (J0,contact) and the specific contact resistivity (ρcontact) using a TLM pattern. The best ITO/SiO2 passivated contact in this study has J0,contact = 92.5 fA/cm2 and ρcontact = 11.5 mOhm-cm2. These values are placed in context with other passivating contacts using an analysis that determines the ultimate efficiency and the optimal area fraction for contacts for a given set of (J0,contact, ρcontact) values. The ITO/SiO2 contacts are found to have a higher J0,contact, but a similar ρcontact compared to the best reported passivated contacts.

  14. Enhanced photovoltaic performance of inverted pyramid-based nanostructured black-silicon solar cells passivated by an atomic-layer-deposited Al2O3 layer.

    PubMed

    Chen, Hong-Yan; Lu, Hong-Liang; Ren, Qing-Hua; Zhang, Yuan; Yang, Xiao-Feng; Ding, Shi-Jin; Zhang, David Wei

    2015-10-01

    Inverted pyramid-based nanostructured black-silicon (BS) solar cells with an Al2O3 passivation layer grown by atomic layer deposition (ALD) have been demonstrated. A multi-scale textured BS surface combining silicon nanowires (SiNWs) and inverted pyramids was obtained for the first time by lithography and metal catalyzed wet etching. The reflectance of the as-prepared BS surface was about 2% lower than that of the more commonly reported upright pyramid-based SiNW BS surface over the whole of the visible light spectrum, which led to a 1.7 mA cm(-2) increase in short circuit current density. Moreover, the as-prepared solar cells were further passivated by an ALD-Al2O3 layer. The effect of annealing temperature on the photovoltaic performance of the solar cells was investigated. It was found that the values of all solar cell parameters including short circuit current, open circuit voltage, and fill factor exhibit a further increase under an optimized annealing temperature. Minority carrier lifetime measurements indicate that the enhanced cell performance is due to the improved passivation quality of the Al2O3 layer after thermal annealing treatments. By combining these two refinements, the optimized SiNW BS solar cells achieved a maximum conversion efficiency enhancement of 7.6% compared to the cells with an upright pyramid-based SiNWs surface and conventional SiNx passivation. PMID:26243694

  15. Solar paint of ZnO/CdS and ZnO/CdSe based on commercial ZnO

    NASA Astrophysics Data System (ADS)

    Guo, Yi; Zhang, Xiang; Li, Yanhong; Li, Yanmei; Hu, Chunli; Zhou, Xingfu

    2016-03-01

    We report a facile and cheap route to the fabrication of ZnO/CdS and ZnO/CdSe based on commercial ZnO particles. The obtained product can be directly brush printed as solar paint. The results show that the solar cell based on the mixture of ZnO/CdS and ZnO/CdSe have a better light absorption and electron transport ability, and a high power conversion efficiency (PCE) of 1.36% was obtained, which is the highest PCE reported for inorganic paint-based solar cells to date. This method greatly simplifies the process of the solar cell fabrication and opens a door toward the cheap and printable solar paint based on commercial available materials.

  16. The design of a solar energy collection system to augment heating and cooling for a commercial office building

    NASA Technical Reports Server (NTRS)

    Basford, R. C.

    1977-01-01

    Analytical studies supported by experimental testing indicate that solar energy can be utilized to heat and cool commercial buildings. In a 50,000 square foot one-story office building at the Langley Research Center, 15,000 square feet of solar collectors are designed to provide the energy required to supply 79 percent of the building heating needs and 52 percent of its cooling needs. The experience gained from the space program is providing the technology base for this project. Included are some of the analytical studies made to make the building design changes necessary to utilize solar energy, the basic solar collector design, collector efficiencies, and the integrated system design.

  17. Establish feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

    1987-01-01

    Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some application.

  18. Establish feasibility for providing passive cooling with solar updraft and evaporate downdraft chimneys

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

    1987-01-01

    Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some applications.

  19. Hydrogen passivation of n+p and p+n heteroepitaxial InP solar cell structures

    NASA Technical Reports Server (NTRS)

    Chatterjee, B.; Ringel, S. A.; Hoffman, R., Jr.

    1995-01-01

    High-efficiency, heteroepitaxial (HE) InP solar cells, grown on GaAs, Si or Ge substrates, are desirable for their mechanically strong, light-weight and radiation-hard properties. However, dislocations, caused by lattice mismatch, currently limit the performance of the HE cells. This occurs through shunting paths across the active photovoltaic junction and by the formation of deep levels. In previous work we have demonstrated that plasma hydrogenation is an effective and stable means to passivate the electrical activity of dislocations in specially designed HE InP test structures. In this work, we present the first report of successful hydrogen passivation in actual InP cell structures grown on GaAs substrates by metalorganic chemical vapor deposition (MOCVD). We have found that a 2 hour exposure to a 13.56 MHz hydrogen plasma at 275 C reduces the deep level concentration in HE n+n InP cell structures from as-grown values of approximately 10(exp 15)/cm(exp -3), down to 1-2 x 10(exp 13)/cm(exp -3). The deep levels in the p-type base region of the cell structure match those of our earlier p-type test structures, which were attributed to dislocations or related point defect complexes. All dopants were successfully reactivated by a 400 C, 5 minute anneal with no detectable activation of deep levels. I-V analysis indicated a subsequent approximately 10 fold decrease in reverse leakage current at -1 volt reverse bias, and no change in the forward biased series resistance of the cell structure which indicates complete reactivation of the n+ emitter. Furthermore, electrochemical C-V profiling indicates greatly enhanced passivation depth, and hence hydrogen diffusion, for heteroepitaxial structures when compared with identically processed homoepitaxial n+p InP structures. An analysis of hydrogen diffusion in dislocated InP will be discussed, along with comparisons of passivation effectiveness for n+p versus p+n heteroepitaxial cell configurations. Preliminary hydrogen-passivated

  20. Grain Boundary Passivation of Multicrystalline Silicon Using Hydrogen Sulfide as a Sulfur Source

    NASA Astrophysics Data System (ADS)

    Saha, Arunodoy

    Hydrogen sulfide (H2S) has been identified as a potential ingredient for grain boundary passivation of multicrystalline silicon. Sulfur is already established as a good surface passivation material for crystalline silicon (c-Si). Sulfur can be used both from solution and hydrogen sulfide gas. For multicrystalline silicon (mc-Si) solar cells, increasing efficiency is a major challenge because passivation of mc-Si wafers is more difficult due to its randomly orientated crystal grains and the principal source of recombination is contributed by the defects in the bulk of the wafer and surface. In this work, a new technique for grain boundary passivation for multicrystalline silicon using hydrogen sulfide has been developed which is accompanied by a compatible Aluminum oxide (Al2O3) surface passivation. Minority carrier lifetime measurement of the passivated samples has been performed and the analysis shows that success has been achieved in terms of passivation and compared to already existing hydrogen passivation, hydrogen sulfide passivation is actually better. Also the surface passivation by Al 2O3 helps to increase the lifetime even more after post-annealing and this helps to attain stability for the bulk passivated samples. Minority carrier lifetime is directly related to the internal quantum efficiency of solar cells. Incorporation of this technique in making mc-Si solar cells is supposed to result in higher efficiency cells. Additional research is required in this field for the use of this technique in commercial solar cells.

  1. Design and application of ion-implanted polySi passivating contacts for interdigitated back contact c-Si solar cells

    NASA Astrophysics Data System (ADS)

    Yang, Guangtao; Ingenito, Andrea; van Hameren, Nienke; Isabella, Olindo; Zeman, Miro

    2016-01-01

    Ion-implanted passivating contacts based on poly-crystalline silicon (polySi) are enabled by tunneling oxide, optimized, and used to fabricate interdigitated back contact (IBC) solar cells. Both n-type (phosphorous doped) and p-type (boron doped) passivating contacts are fabricated by ion-implantation of intrinsic polySi layers deposited via low-pressure chemical vapor deposition and subsequently annealed. The impact of doping profile on the passivation quality of the polySi doped contacts is studied for both polarities. It was found that an excellent surface passivation could be obtained by confining as much as possible the implanted-and-activated dopants within the polySi layers. The doping profile in the polySi was controlled by modifying the polySi thickness, the energy and dose of ion-implantation, and the temperature and time of annealing. An implied open-circuit voltage of 721 mV for n-type and 692 mV for p-type passivating contacts was achieved. Besides the high passivating quality, the developed passivating contacts exhibit reasonable high conductivity (Rsh n-type = 95 Ω/□ and Rsh p-type = 120 Ω/□). An efficiency of 19.2% (Voc = 673 mV, Jsc = 38.0 mA/cm2, FF = 75.2%, and pseudo-FF = 83.2%) was achieved on a front-textured IBC solar cell with polySi passivating contacts as both back surface field and emitter. By improving the front-side passivation, a VOC of 696 mV was also measured.

  2. Electromagnetic Fields Associated with Commercial Solar Photovoltaic Electric Power Generating Facilities.

    PubMed

    Tell, R A; Hooper, H C; Sias, G G; Mezei, G; Hung, P; Kavet, R

    2015-01-01

    The southwest region of the United States is expected to experience an expansion of commercial solar photovoltaic generation facilities over the next 25 years. A solar facility converts direct current generated by the solar panels to three-phase 60-Hz power that is fed to the grid. This conversion involves sequential processing of the direct current through an inverter that produces low-voltage three-phase power, which is stepped up to distribution voltage (∼12 kV) through a transformer. This study characterized magnetic and electric fields between the frequencies of 0 Hz and 3 GHz at two facilities operated by the Southern California Edison Company in Porterville, CA and San Bernardino, CA. Static magnetic fields were very small compared to exposure limits established by IEEE and ICNIRP. The highest 60-Hz magnetic fields were measured adjacent to transformers and inverters, and radiofrequency fields from 5-100 kHz were associated with the inverters. The fields measured complied in every case with IEEE controlled and ICNIRP occupational exposure limits. In all cases, electric fields were negligible compared to IEEE and ICNIRP limits across the spectrum measured and when compared to the FCC limits (≥0.3 MHz). PMID:26023811

  3. Development of Performance Acceptance Test Guidelines for Large Commercial Parabolic Trough Solar Fields: Preprint

    SciTech Connect

    Kearney, D.; Mehos, M.

    2010-12-01

    Prior to commercial operation, large solar systems in utility-size power plants need to pass a performance acceptance test conducted by the EPC contractor or owners. In lieu of the present absence of engineering code developed for this purpose, NREL has undertaken the development of interim guidelines to provide recommendations for test procedures that can yield results of a high level of accuracy consistent with good engineering knowledge and practice. The fundamental differences between acceptance of a solar power plant and a conventional fossil-fired plant are the transient nature of the energy source and the necessity to utilize an analytical performance model in the acceptance process. These factors bring into play the need to establish methods to measure steady state performance, potential impacts of transient processes, comparison to performance model results, and the possible requirement to test, or model, multi-day performance within the scope of the acceptance test procedure. The power block and BOP are not within the boundaries of this guideline. The current guideline is restricted to the solar thermal performance of parabolic trough systems and has been critiqued by a broad range of stakeholders in CSP development and technology.

  4. Metal insulator semiconductor solar cell devices based on a Cu{sub 2}O substrate utilizing h-BN as an insulating and passivating layer

    SciTech Connect

    Ergen, Onur; Gibb, Ashley; Vazquez-Mena, Oscar; Zettl, Alex; Regan, William Raymond

    2015-03-09

    We demonstrate cuprous oxide (Cu{sub 2}O) based metal insulator semiconductor Schottky (MIS-Schottky) solar cells with efficiency exceeding 3%. A unique direct growth technique is employed in the fabrication, and hexagonal boron nitride (h-BN) serves simultaneously as a passivation and insulation layer on the active Cu{sub 2}O layer. The devices are the most efficient of any Cu{sub 2}O based MIS-Schottky solar cells reported to date.

  5. Low-cost foil metallization using arc discharge for passivated emitter and rear solar cells

    NASA Astrophysics Data System (ADS)

    Kurimoto, Yuji; Yamasaki, Ichiro

    2016-04-01

    For the cost reduction of passivated emitter and rear cells (PERC), we propose a new rear contact formation method, in which an aluminum foil and an arc discharge system are used. The arc discharge system consists of inexpensive parts and does not contain any sophisticated part such as a laser ablation apparatus. Therefore, this system can save the cost of the rear contact forming process. We applied this technique to a test production of PERC. It is found that the arc discharge system can provide a similar performance to that attained by a conventional PERC production method.

  6. Establishing feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.

    1986-01-01

    At the present time all experimental towers (chimneys) are completed and operating. This consists of both a solar updraft and a natural-evaporative downdraft tower retrofitted to an existing residence structure and a greenhouse. The residential, experimental, natural-draft cooling system was completed in May, 1985, and five months of summer data on a Hewlet Packard 85 data acquisition computer with a digital voltmeter were acquired. The cooling tower and solar chimney on the experimental greenhouse became operational in September of 1985. A conceptual drawing of both the greenhouse and the residence natural-draft towers is included in the appendix along with the September 85 progress report.

  7. Process heat in California: Applications and potential for solar energy in the industrial, agricultural and commercial sectors

    NASA Technical Reports Server (NTRS)

    Barbieri, R. H.; Bartera, R. E.; Davis, E. S.; Hlavka, G. E.; Pivirotto, D. S.; Yanow, G.

    1978-01-01

    A summary of the results of a survey of potential applications of solar energy for supplying process heat requirements in the industrial, agricultural, and commercial sectors of California is presented. Technical, economic, and institutional characteristics of the three sectors are examined. Specific applications for solar energy are then discussed. Finally, implications for California energy policy are discussed along with recommendations for possible actions by the State of California.

  8. Passivation properties of aluminum oxide films deposited by mist chemical vapor deposition for solar cell applications

    NASA Astrophysics Data System (ADS)

    Miki, Shohei; Iguchi, Koji; Kitano, Sho; Hayakashi, Koki; Hotta, Yasushi; Yoshida, Haruhiko; Ogura, Atsushi; Satoh, Shin-ichi; Arafune, Koji

    2015-08-01

    Aluminum oxide (AlOx) films were deposited by mist chemical vapor deposition (MCVD) in air for p-type crystalline silicon, and the effects of the deposition temperature (Tdep) and AlOx film thickness on the maximum surface recombination velocities (Smax) were evaluated. It was found that Smax was improved with increasing Tdep. The AlOx film deposited at 400 °C exhibited the best Smax value of 2.8 cm/s, and the passivation quality was comparable to that of AlOx deposited by other vacuum-based techniques. Smax was also improved with increasing film thickness. When the film thickness was above 10 nm, Smax was approximately 10 cm/s. From the Fourier transform infrared spectra, it was found that the AlOx films deposited by MCVD consisted of an AlOx layer and a Si-diffused AlOx layer. In addition, it is important for the layers to be thick enough to obtain high-quality passivation.

  9. Back-side hydrogenation technique for defect passivation in silicon solar cells

    DOEpatents

    Sopori, Bhushan L.

    1994-01-01

    A two-step back-side hydrogenation process includes the steps of first bombarding the back side of the silicon substrate with hydrogen ions with intensities and for a time sufficient to implant enough hydrogen atoms into the silicon substrate to potentially passivate substantially all of the defects and impurities in the silicon substrate, and then illuminating the silicon substrate with electromagnetic radiation to activate the implanted hydrogen, so that it can passivate the defects and impurities in the substrate. The illumination step also annihilates the hydrogen-induced defects. The illumination step is carried out according to a two-stage illumination schedule, the first or low-power stage of which subjects the substrate to electromagnetic radiation that has sufficient intensity to activate the implanted hydrogen, yet not drive the hydrogen from the substrate. The second or high-power illumination stage subjects the substrate to higher intensity electromagnetic radiation, which is sufficient to annihilate the hydrogen-induced defects and sinter/alloy the metal contacts.

  10. Back-side hydrogenation technique for defect passivation in silicon solar cells

    DOEpatents

    Sopori, B.L.

    1994-04-19

    A two-step back-side hydrogenation process includes the steps of first bombarding the back side of the silicon substrate with hydrogen ions with intensities and for a time sufficient to implant enough hydrogen atoms into the silicon substrate to potentially passivate substantially all of the defects and impurities in the silicon substrate, and then illuminating the silicon substrate with electromagnetic radiation to activate the implanted hydrogen, so that it can passivate the defects and impurities in the substrate. The illumination step also annihilates the hydrogen-induced defects. The illumination step is carried out according to a two-stage illumination schedule, the first or low-power stage of which subjects the substrate to electromagnetic radiation that has sufficient intensity to activate the implanted hydrogen, yet not drive the hydrogen from the substrate. The second or high-power illumination stage subjects the substrate to higher intensity electromagnetic radiation, which is sufficient to annihilate the hydrogen-induced defects and sinter/alloy the metal contacts. 3 figures.