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 ISC (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 ISC 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.