THERMAL REGULATION OF PHOTOVOLTAIC CLADDING

In the use of photovoltaic cladding for walls and roofs of buildings, the PV components can experience temperatures high enough to reduce th e electrical output well below the rated value. It is shown that reduc tions in temperature of up to 20 K can be obtained by heat transfer to an air flow induced by buoyancy in a duct behind the PV component, wi th a significant increase in the electrical output and reduction of he at gain into the building. Practical PV roof installations have been i mplemented, on the basis of measurements with a fun-scale roof specime n. A numerical model is used, which enables basic design data for PV w alls and roofs to be obtained, such as the effects of the depth of the cooling duct on the thermal and electrical performance of the system. The model predictions are confirmed by measurements on a purpose-buil t test rig and simulations using CFD. (C) 1997 Elsevier Science Ltd.