A study of double facades with phase-change storage and photovoltaics

This paper considers a double facade for preheating of fresh air, generation of electricity with integrated photovoltaic panels and storage of solar energy in phase-change material - butyl stearate absorbed in gypsum board. A simple transient numerical control volume model is developed for the heat transfer in the PCM. Different facade systems are studied with computer simulations and full scale experiments. Combinations with photovoltaics are then considered. Solar utilization efficiencies of up to 70% are obtained.