ABSTRACT
Purpose of this work is to improve accuracy of already available simulation tools for prediction of a PV-array performance within grid-connected or stand-alone systems. The mathematical model applied is based on the double-diode PV-cell model. The model is incorporated in the TRNSYS program as one of the components. In that sense, already available components of the TRNSYS program may be used (solar air-collector and liquid collectors, building model, etc.) enabling simulation of hybrid systems including building-integrated PV-arrays. Special attention has been devoted to evaluate and identify the dependence of PV-energy output on (i) irradiation level, (ii) incident angle of irradiance and (iii) a part of diffuse irradiance in a hemispherical irradiance. The accuracy of the simulation results has been analysed using measurement data. The verification has been carried out by measurement data of Sol garden-system situated in Kolding, Denmark. Solgarden system consists of 846 PV modules with approx. 90 kWp power roof mounted and 16.5 kWp integrated in the facade. It is shown that the introduction of correction functions improves the accuracy of long-term energy predictions of PV-array performance. This may be especially relevant for PV-arrays situated in the climate zones (like e.g. northern part of Europe) with a considerable part of diffuse irradiation.
