Initial stabilization of a statistical sample of forty-four monocrystalline photovoltaic modules

The paper discusses the methodology and presents the results of the stabilization process for a statistic of forty-four monocrystalline silicon photovoltaic (PV) modules. The modules have been exposed to real sunlight in three different sessions and have been measured prior exposure and after each exposure session using a pulsed sun simulator. The first session of exposure shows the highest power loss in the modules, with an average 1.8%. During this initial stabilization step, 17 modules had a loss in the maximum power above 2% (registered losses from 2.1% to a maximum of 2.8%). The overall power losses are in the range 1.7–3.4%, with an average loss of 2.4% for the considered module population. Visual inspection and the analysis of the measured I–V curves revealed some imperfections in the modules. However, those imperfections do not impact on the actual performance at the present time. After the stabilization, the modules have been installed in the Northeast Solar Energy Research Center (NSERC) array, located at Brookhaven National Laboratory. The array will be used to analyze module degradation in the Northeast environmental conditions and to study the grid impact of utility-level PV plants.