Comparison of Photovoltaic Module Performance Measurements

Computer simulation tools used to predict the energy production of photovoltaic systems are needed in order to make informed economic decisions. These tools require input parameters that characterize module performance under various operational and environmental conditions. Depending upon the complexity of the simulation model, the required input parameters can vary from the limited information found on labels affixed to photovoltaic modules to an extensive set of parameters. The required input parameters are normally obtained indoors using a solar simulator or flash tester, or measured outdoors under natural sunlight. This paper compares measured performance parameters for three photovoltaic modules tested outdoors at the National Institute of Standards and Technology (NIST) and Sandia National Laboratories (SNL). Two of the three modules were custom fabricated using monocrystalline and silicon film cells. The third, a commercially available module, utilized triple-junction amorphous silicon cells. The resulting data allow a comparison to be made between performance parameters measured at two laboratories with differing geographical locations and apparatus. This paper describes the apparatus used to collect the experimental data, test procedures utilized, and resulting performance parameters for each of the three modules. Using a computer simulation model, the impact that differences in measured parameters have on predicted more » energy production is quantified. Data presented for each module includes power output at standard rating conditions and the influence of incident angle, air mass, and module temperature on each module's electrical performance. Measurements from the two laboratories are in excellent agreement. The power at standard rating conditions is within 1% for all three modules. Although the magnitude of the individual temperature coefficients varied as much as 17% between the two laboratories, the impact on predicted performance at various temperature levels was minimal, less than 2%. The influence of air mass on the performance of the three modules measured at the laboratories was in excellent agreement. The largest difference in measured results between the two laboratories was noted in the response of the modules to incident angles that exceed 75 deg. « less

[1]  Mark W. Davis,et al.  Measured Performance of Building Integrated Photovoltaic Panels , 2001 .

[2]  N. Martín,et al.  Annual angular reflection losses in PV modules , 2005 .

[3]  David L. King,et al.  Photovoltaic module and array performance characterization methods for all system operating conditions , 1996 .

[4]  J. E. Rumburg,et al.  ''AM/PM'' -- all-day module performance measurements , 1982 .

[5]  Carl R. Osterwald,et al.  Procedure for determining the uncertainty of photovoltaic module outdoor electrical performance ‡ , 2001 .

[6]  D. L. King,et al.  Sandia National Laboratories , 2000 .

[7]  Kenji Yamamoto,et al.  Spectral Effects of a Single-Junction Amorphous Silicon Solar Cell on Outdoor Performance , 2004 .

[8]  D. L. King,et al.  Analysis of factors influencing the annual energy production of photovoltaic systems , 2002, Conference Record of the Twenty-Ninth IEEE Photovoltaic Specialists Conference, 2002..

[9]  Mark W. Davis,et al.  Prediction of Building Integrated Photovoltaic Cell Temperatures , 2001 .

[10]  A. T. Young,et al.  Revised optical air mass tables and approximation formula. , 1989, Applied optics.

[11]  B. Marion.  A method for modeling the current–voltage curve of a PV module for outdoor conditions , 2002 .

[12]  D. L. King,et al.  Temperature coefficients for PV modules and arrays: measurement methods, difficulties, and results , 1997, Conference Record of the Twenty Sixth IEEE Photovoltaic Specialists Conference - 1997.

[13]  William E. Boyson,et al.  Photovoltaic array performance model. , 2004 .

[14]  D. L. King,et al.  Measuring solar spectral and angle-of-incidence effects on photovoltaic modules and solar irradiance sensors , 1997, Conference Record of the Twenty Sixth IEEE Photovoltaic Specialists Conference - 1997.

[15]  Mark W. Davis,et al.  Evaluating building integrated photovoltaic performance models , 2002, Conference Record of the Twenty-Ninth IEEE Photovoltaic Specialists Conference, 2002..

[16]  R. Bird,et al.  Terrestrial solar spectral modeling , 1982 .

[17]  B. Marion,et al.  Validation of a Photovoltaic Module Energy Ratings Procedure at NREL , 1999 .

[18]  W. Beckman,et al.  Solar Engineering of Thermal Processes , 1985 .

[19]  A. Hunter Fanney,et al.  BUILDING INTEGRATED PHOTOVOLTAIC TEST FACILITY , 2000 .

[20]  B. Kroposki,et al.  Comparison of Module Performance Characterization Methods for Energy Production , 2000 .

[21]  Daryl R. Myers,et al.  Terrestrial solar spectral modeling tools and applications for photovoltaic devices , 2002, Conference Record of the Twenty-Ninth IEEE Photovoltaic Specialists Conference, 2002..

[22]  Mark W. Davis,et al.  Measured Performance of Building Integrated Photovoltaic Panels: Round 2 , 2004 .

[23]  M.W. Davis,et al.  Performance and characterization of building integrated photovoltaic panels , 2002, Conference Record of the Twenty-Ninth IEEE Photovoltaic Specialists Conference, 2002..

[24]  B. Marion,et al.  Current–voltage curve translation by bilinear interpolation , 2004 .