Numerical model for the thermal yield estimation of unglazed photovoltaic-thermal collectors using indoor solar simulator testing

In this paper a method is proposed to estimate the real thermal performance of unglazed PVT collectors, by using a compact indoor solar simulator testing in combination with a detailed steady state numerical PVT collector model. The numerical model takes into account the physical and spectral attributes of the solar simulator and is used to correct for the unwanted phenomena to derive the actual outdoor collector performance. The resulting numerical model also offers detailed understanding of the collector and can therefore be used to optimise the design of the collector. Furthermore, this model is used to derive thermal performance characteristics of the unglazed PVT collector as defined by solar thermal testing standards, which can be used in system simulation tools (E.g. TRNSYS models) to obtain annual collector and system yields.