In the Dutch WenSDak project, eight companies and three research institutes worked together on the (further) development of five concepts for integrating solar heat and power production into one roof. The performance of the ventilated PV, uncovered PVT and solar thermal collectors was evaluated in a field test and with a solar simulator indoors. In this paper, we focus on three types of uncovered PVT collectors. There is a large difference between the measured thermal performance of the three different collectors. These differences can be explained by the PVT collector design. The absorption of all PVT modules is quite good (0.9 – 0.94). A good heat conduction from the PV cells to a metal absorber leads to a high peak collector efficiency, while insulation at the back of the PVT module improves the performance at higher temperatures. Performance of some collectors can be improved by e.g. heat conducting paste, however, this is also more expensive. System simulations with PVT as part of a solar heating system are carried out in TRNSYS and will yield valuable information on the annual yield for a specific system
