Building energy modelling was conducted using TRNSYS and the equation based IDA Indoor Climate and Energy (ICE) building energy simulation programs. TRNSYS was used as a PVT component Type 567 was available as part of the Green Building Component Library and this component interfaces with the Type 56 Multi-zone building. The key parameters and inputs used for simulating the PVT system in TRNSYS are outlined in Table 1. The PV efficiency modifier parameter is used to account for a reduction in the power output of the PV due to an operating

temperature above the standard 25 °C test conditions. IDA ICE was also used to create a model of the house and determine the heating energy requirement. TMY2 weather data for Sydney was used for simulations in both programs.

The HDD method was used to conduct a simple analysis of the building heating energy requirement. Equations detailed by Eicker [7] for evaluation of the temperatures and performance of building integrated photovoltaic facades and solar collectors were followed to validate the simulated thermal energy output results from TRNSYS.

Table 1. Key parameters and inputs used for simulation of the PVT system in TRNSYS