The photovoltaic industry is experiencing rapid growth. Industry analysts project that photovoltaic sales will increase from their current $1.5 billion level to over $27 billion by 2020, representing an average growth rate of 25%. (Cook et. al. 2000)[1]. To date, the vast majority of sales have been for navigational signals, call boxes, telecommunication centers, consumer products, off-grid electrification projects, and small grid-interactive residential rooftop applications. Building integrated photovoltaics, the integration of photovoltaic cells into one or more of the exterior surfaces of the building envelope, represents a small but growing photovoltaic application. In order for building owners, designers, and architects to make informed economic decisions regarding the use of building integrated photovoltaics, accurate predictive tools and performance data are needed. A building integrated photovoltaic test bed has been constructed at the National Institute of Standards and Technology to provide the performance data needed for model validation. The facility incorporates four identical pairs of building integrated photovoltaic panels constructed using single-crystalline, polycrystalline, silicon film, and amorphous silicon photovoltaic cells. One panel of each identical pair is installed with thermal insulation attached to its rear surface. The second paired panel is installed without thermal insulation. This experimental configuration yields results that quantify the effect of elevated cell temperature on the panels’ performance for different cell technologies. This paper presents the first set of experimental results from this facility. Comparisons are made between the electrical performance of the insulated and non-insulated panels for each of the four cell technologies. The monthly and overall conversion efficiencies for each cell technology are presented and the seasonal performance variations discussed. Daily efficiencies are presented for a selected month. Finally, plots of the power output and panel temperatures are presented and discussed for the single-crystalline and amorphous silicon panels.

1.
Cook, G., David, R., Gwinner, D., and Hicks, A., 2000, Photovoltaics; Energy for the New Millennium, 1-17, 1-1-2000, NREL, Golden, CO, Department of Energy.
2.
Schoen, T. J., 1999, “Information,” Renewable Energy World, 2, No. 5, p. 84.
3.
King, D. L., Dudley, J. K, and Byoson, W. E., 1997, “PVSIM: A Simulation Program for Photovoltaic Cells, Modules, and Arrays,” Proc. of 26th IEEE Photovoltaics Specialists Conf., Anaheim, CA.
4.
1999, Photovoltaic Analysis and TrAnsient Simulation Method (PHANTASM), Building Integrated Photovoltaic Simulation Software, Solar Energy Laboratory, University of Wisconsin, Madison, WI.
5.
ENERGY-10, V1.3, 2000, “A Tool for Designing Low Energy Buildings,” Sustainable Buildings Energy Council, Washington, D.C.
6.
IV Curve Tracer, Solar Design Studio, v4.0, Maui Solar Energy Software Corp., Haiku, I, October 2000.
7.
King, D. L., 1997, “Photovoltaic Module and Array Performance Characterization methods for all System Operating Conditions,” Proc. of NREL/SNL Photovoltaics Program Review Meeting, Nov. 1996, Lakewood, CO, AIP Press, New York.
8.
Fanney, A. H., and Dougherty, B. P., 2000, “Building Integrated Photovoltaic Test Facility,” Proc. of Solar 2000: Solar Powers Life, Share the Energy, June, Madison, WI, ASME, New York.
9.
NIST R-Matic Test Report R000420 B, April 20, 2000.
10.
Raydec, 1988, “Photovoltaic Operations and Maintenance Manual,” Ver. 4.0.
11.
King, D. L, Kratochvil, J. A., and Boyson, W. E., 1997, “Measuring Solar Spectral and Angle-of-Incidence Effects on Photovoltaic Modules and Solar Irradiance Sensors,” 26th IEEE Photovoltaic Specialists Conf., Anaheim, CA.
12.
Davis, M. W., Fanney, A. H., and Dougherty, B. P., 2001 “Prediction of Building Integrated Photovoltaic Cell Temperatures,” Proc. of Forum 2001, Solar Energy: The Power to Choose, April 2001, ASES, Washington, DC.
You do not currently have access to this content.