Virtual energy rating: a method for optimizing module performance through cell-to-module analysis

The implementation of energy rating of photovoltaic modules based on IEC-61853 imposes new costs and challenges to developers of PV module technology. In response, we present how a validated, simulation-based, and thus more cost-effective Cell-to-Module (CTM) analysis methodology, adapted for non-STC conditions, can be used to obtain all information needed for determination of a climate specific virtual energy rating (CSER), namely: a power matrix, the spectral response, the angular loss, and the heat transfer coefficients. A conventional full-cell module and a “butterfly” half-cell topology are used to exemplify how the proposed method can be used to identify gain and loss factors of a module design affecting the performance of each module in terms of rated energy yield per area and climate specific energy rating (CSER). Recommendations for improving the module design module are ranked and discussed, based on a sensitivity analysis on eleven parameters.