The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

Ryne P Raffaelle - One of the best experts on this subject based on the ideXlab platform.

  • Space Solar Cells and Arrays
    Handbook of Photovoltaic Science and Engineering, 2011
    Co-Authors: S. G. Bailey, Sheila Bailey, Ryne P Raffaelle
    Abstract:

    This chapter contains sections titled: * The History of Space Solar Cells * The Challenge for Space Solar Cells * Silicon Solar Cells * III–V Solar Cells * Space Solar Arrays * Future Cell and Array Possibilities * Power System Figures of Merit * Summary * References

  • Thin-Film Solar Array Earth Orbit Mission Applicability Assessment
    2002
    Co-Authors: David J. Hoffman, Thomas W. Kerslake, Aloysius F. Hepp, Ryne P Raffaelle
    Abstract:

    This is a preliminary assessment of the applicability and spacecraft-level impact of using very lightweight thin-film Solar Arrays with relatively large deployed areas for representative Earth orbiting missions. The most and least attractive features of thin-film Solar Arrays are briefly discussed. A simple calculation is then presented illustrating that from a Solar array alone mass perspective, larger Arrays with less efficient but lighter thin-film Solar cells can weigh less than smaller Arrays with more efficient but heavier crystalline cells. However, a proper spacecraft-level systems assessment must take into account the additional mass associated with Solar array deployed area: the propellant needed to desaturate the momentum accumulated from area-related disturbance torques and to perform aerodynamic drag makeup reboost. The results for such an assessment are presented for a representative low Earth orbit (LEO) mission, as a function of altitude and mission life, and a geostationary Earth orbit (GEO) mission. Discussion of the results includes a list of specific mission types most likely to benefit from using thin-film Arrays. NASA Glenn's low-temperature approach to depositing thin-film cells on lightweight, flexible plastic substrates is also briefly discussed to provide a perspective on one approach to achieving this enabling technology. The paper concludes with a list of issues to be addressed prior to use of thin-film Solar Arrays in space and the observation that with their unique characteristics, very lightweight Arrays using efficient, thin-film cells on flexible substrates may become the best array option for a subset of Earth orbiting missions.

  • Chemical vapor deposition for ULTR-lightweight thin-film Solar Arrays for space
    2002 37th Intersociety Energy Conversion Engineering Conference (Iecec), 2002
    Co-Authors: Aloysius F. Hepp, Michael H Jin, J.E. Lau, J. E. Cowen, Kulbinder K. Banger, Ryne P Raffaelle, J D Harris, Stan A. Duraj
    Abstract:

    The development of thin-film Solar cells on flexible, lightweight, space-qualified substrates provides an attractive cost solution to fabricating Solar Arrays with high specific power, (W/kg). The use of a polycrystalline chalcopyrite absorber layer for thin film Solar cells is considered as the next generation photovoltaic devices. A key technical issues outlined in the 2001 US Photovoltaic Roadmap, is the need to develop low cost, high throughput manufacturing for high-efficiency thin film Solar cells. At NASA GRC we have focused on the development of new single-source-precursors (SSP's) and their utility to deposit the chalcopyrite semi-conducting layer (CIS) onto flexible substrates for Solar cell fabrication. The syntheses and thermal modulation of SSP's via molecular engineering is described. Thin-film fabrication studies demonstrate the SSP's can be used in a spray CVD process, for depositing CIS at reduced temperatures, which display good electrical properties, suitable for PV devices.

  • Chemical vapor deposition for ultralightweight thin-film Solar Arrays
    IECEC '02. 2002 37th Intersociety Energy Conversion Engineering Conference, 2002., 2002
    Co-Authors: Aloysius F. Hepp, Michael H Jin, J.E. Lau, J. E. Cowen, Kulbinder K. Banger, Ryne P Raffaelle, J D Harris, Stan A. Duraj
    Abstract:

    The development of thin-film Solar cells on flexible, lightweight, space-qualified substrates provides an attractive cost solution to fabricating Solar Arrays with high specific power, (W/kg). The use of a polycrystalline chalcopyrite absorber layer for thin film Solar cells is considered as the next generation photovoltaic devices. A key technical issues outlined in the 2001 US Photovoltaic Roadmap, is the need to develop low cost, high throughput manufacturing for high-efficiency thin film Solar cells. At NASA GRC we have focused on the development of new single-source-precursors (SSP's) and their utility to deposit the chalcopyrite semiconducting layer (CIS) onto flexible substrates for Solar cell fabrication. The syntheses and thermal modulation of SSP's via molecular engineering is described. Thin-film fabrication studies demonstrate the SSP's can be used in a spray CVD process, for depositing CIS at reduced temperatures, which display good electrical properties, suitable for PV devices.

David Banks - One of the best experts on this subject based on the ideXlab platform.

  • use of the wind tunnel test method for obtaining design wind loads on roof mounted Solar Arrays
    Journal of Structural Engineering-asce, 2013
    Co-Authors: Gregory A Kopp, David Banks
    Abstract:

    AbstractASCE 7 does not provide design wind loads for roof-mounted Solar panels. This paper discusses the use of the wind tunnel test method, called Method 3 in ASCE 7-05, which was originally intended for obtaining design wind loads for individual buildings. Because roof-mounted Solar Arrays are generally mounted in many configurations on many buildings of many different shapes, additional requirements are necessary to use Method 3 in this situation. The paper describes these additional requirements.

Gregory A Kopp - One of the best experts on this subject based on the ideXlab platform.

  • use of the wind tunnel test method for obtaining design wind loads on roof mounted Solar Arrays
    Journal of Structural Engineering-asce, 2013
    Co-Authors: Gregory A Kopp, David Banks
    Abstract:

    AbstractASCE 7 does not provide design wind loads for roof-mounted Solar panels. This paper discusses the use of the wind tunnel test method, called Method 3 in ASCE 7-05, which was originally intended for obtaining design wind loads for individual buildings. Because roof-mounted Solar Arrays are generally mounted in many configurations on many buildings of many different shapes, additional requirements are necessary to use Method 3 in this situation. The paper describes these additional requirements.

  • aerodynamic mechanisms for wind loads on tilted roof mounted Solar Arrays
    Journal of Wind Engineering and Industrial Aerodynamics, 2012
    Co-Authors: Gregory A Kopp, Steve Farquhar, Murray J Morrison
    Abstract:

    Abstract A wind tunnel study has been performed on roof-mounted Solar Arrays of two different panel tilt angles. One of the Arrays was also placed on the ground in order to distinguish array generated aerodynamic effects from building generated effects. It is shown that there are two main mechanisms causing the aerodynamic loads: (i) turbulence generated by the panels and (ii) pressure equalization. For higher tilt angles, significant array generated turbulence increases the net wind loads, while for low tilt angles, pressure equalization dominates. In addition, it is observed that the presence of the building changes the aerodynamic loads substantially compared to ground-mounted systems. There is a complex interaction between building generated vortices and the flow induced by the array, which depends on building height, the setback of the array from the roof edge, and other building parameters.

Ewald F. Fuchs - One of the best experts on this subject based on the ideXlab platform.

  • microprocessor controlled new class of optimal battery chargers for photovoltaic applications
    IEEE Transactions on Energy Conversion, 2004
    Co-Authors: Mohammad A. S. Masoum, Seyed Mahdi Mousavi Badejani, Ewald F. Fuchs
    Abstract:

    A simple, fast and reliable technique for charging batteries by Solar Arrays is proposed. The operating point of a battery is carefully forced near the maximum power point of Solar cells under all environmental (e.g., insolation, temperature, degradation) conditions. Optimal operation of Solar Arrays is achieved using the Voltage-Based Maximum Power Point Tracking (VMPPT) technique and the charger operating point is continuously adjusted by changing the charging current. An optimal Solar battery charger is designed, simulated and constructed. Experimental and theoretical results are presented and analyzed. The main advantages of the proposed Solar battery charger as compared with conventional ones are shorter charge time and lower cost.

  • Microprocessor-controlled new class of optimal battery chargers for photovoltaic applications
    IEEE Transactions on Energy Conversion, 2004
    Co-Authors: Mohammad A. S. Masoum, Seyed Mahdi Mousavi Badejani, Ewald F. Fuchs
    Abstract:

    Summary form only given. A simple, fast and reliable technique for charging batteries by Solar Arrays is proposed. The operating point of a battery is carefully forced near the maximum power point of Solar cells under all environmental (e.g., insolation, temperature, degradation) conditions. Optimal operation of Solar Arrays is achieved using the voltage-based maximum power point tracking (VMPPT) technique and the charger operating point is continuously adjusted by changing the charging current. An optimal Solar battery charger is designed, simulated and constructed. Experimental and theoretical results are presented and analyzed. The main advantages of the proposed Solar battery charger as compared with conventional ones are shorter charge time and lower cost.

Stan A. Duraj - One of the best experts on this subject based on the ideXlab platform.

  • Chemical vapor deposition for ULTR-lightweight thin-film Solar Arrays for space
    2002 37th Intersociety Energy Conversion Engineering Conference (Iecec), 2002
    Co-Authors: Aloysius F. Hepp, Michael H Jin, J.E. Lau, J. E. Cowen, Kulbinder K. Banger, Ryne P Raffaelle, J D Harris, Stan A. Duraj
    Abstract:

    The development of thin-film Solar cells on flexible, lightweight, space-qualified substrates provides an attractive cost solution to fabricating Solar Arrays with high specific power, (W/kg). The use of a polycrystalline chalcopyrite absorber layer for thin film Solar cells is considered as the next generation photovoltaic devices. A key technical issues outlined in the 2001 US Photovoltaic Roadmap, is the need to develop low cost, high throughput manufacturing for high-efficiency thin film Solar cells. At NASA GRC we have focused on the development of new single-source-precursors (SSP's) and their utility to deposit the chalcopyrite semi-conducting layer (CIS) onto flexible substrates for Solar cell fabrication. The syntheses and thermal modulation of SSP's via molecular engineering is described. Thin-film fabrication studies demonstrate the SSP's can be used in a spray CVD process, for depositing CIS at reduced temperatures, which display good electrical properties, suitable for PV devices.

  • Chemical vapor deposition for ultralightweight thin-film Solar Arrays
    IECEC '02. 2002 37th Intersociety Energy Conversion Engineering Conference, 2002., 2002
    Co-Authors: Aloysius F. Hepp, Michael H Jin, J.E. Lau, J. E. Cowen, Kulbinder K. Banger, Ryne P Raffaelle, J D Harris, Stan A. Duraj
    Abstract:

    The development of thin-film Solar cells on flexible, lightweight, space-qualified substrates provides an attractive cost solution to fabricating Solar Arrays with high specific power, (W/kg). The use of a polycrystalline chalcopyrite absorber layer for thin film Solar cells is considered as the next generation photovoltaic devices. A key technical issues outlined in the 2001 US Photovoltaic Roadmap, is the need to develop low cost, high throughput manufacturing for high-efficiency thin film Solar cells. At NASA GRC we have focused on the development of new single-source-precursors (SSP's) and their utility to deposit the chalcopyrite semiconducting layer (CIS) onto flexible substrates for Solar cell fabrication. The syntheses and thermal modulation of SSP's via molecular engineering is described. Thin-film fabrication studies demonstrate the SSP's can be used in a spray CVD process, for depositing CIS at reduced temperatures, which display good electrical properties, suitable for PV devices.