Test of the European Joint Research Centre performance model for c-Si PV modules

The performance of ten c-Si PV modules is studied at different levels of illumination and module temperatures and is modeled in terms of relative efficiency with respect to Standard Testing Conditions (STC). A recently proposed model is tested in Nordic conditions for generic mono- and mc-Si devices with screen-printed cells as well as for some high-efficiency cell designs. Two of the modules are field aged. Averaged model coefficients are derived and compared to values found in the literature. Irradiance and module temperatures measured in 2011 are then used to estimate the expected annual energy yields. The measured yields equal the predicted ones within 1.6% (mean bias error -1.0%) which suggests good modeling accuracy. The annual average relative efficiency of new c-Si modules for the test site in Southern Norway is 0.95, among the highest values in Europe. It is attributed to cool ambient air and frequent windy conditions. A theoretical relationship is derived between the first coefficient of the performance model and I-V curve model parameters. Fitted and predicted values agree well for most of the tested devices. The equation may be used by module manufacturers as a quantitative guideline for designing products with superior energy yields.