Reference module selection criteria for accurate testing of photovoltaic (PV) panels

It is shown that for accurate testing of PV panels the correct selection of reference modules is important. A detailed description of the test methodology is given. Three different types of reference modules, having different I-SC (short circuit current) and power (in Wp) have been used for this study. These reference modules have been calibrated from NREL. It has been found that for accurate testing, both I-SC and power of the reference module must be either similar or exceed to that of modules under test. In case corresponding values of the test modules are less than a particular limit, the measurements may not be accurate. The experimental results obtained have been modeled by using simple equivalent circuit model and associated I-V equations. (C) 2009 Elsevier Ltd. All rights reserved.