5. Influence Effect of Energy Roof on PV Efficiency: A Case Study

Increasingly there is a need for high-performance (sustainable) buildings. Even in a country with as little solar radiation as the Netherlands, the application of so-called solar energy roofs is becoming more popular. Already some different concepts exist, and one of the latest developments is the use of the roof as combined solar thermal collector and photovoltaic (PV) laminate. This chapter presents the results of research on the energy roof of a school in the Netherlands. The school was designed as an energy-plus school, and the energy roof, in combination with the PV laminate, plays a significant role in this project. The aim of this research was to determine the added value of the combined concept of PV and thermal collector in the total performance of the energy roof. It was expected that cooling of the PV laminate would have a positive effect on the electrical efficiency of this PV as the thermal collector absorbed heat from the overlying PV laminate. The producers of the PV laminate claim it has higher efficiencies. This claim was examined by studying the correlation of efficiency and the thermal gain of the roof in three different situations. The results showed no clear positive effect of the energy roof on the average efficiency of the PV laminate.