Environmental impact assessments of hybrid photovoltaic-thermal (PV/T) systems - A review

In a hybrid photovoltaic-thermal (PV/T or PVT) module, electricity and thermal energy are generated simultaneously in the same module. By combining a PV module and a solar thermal collector, more of the solar radiation can be harvested, and the total efficiency of the module is increased. The combination of two technologies in one module also has the potential to reduce the use of materials and the required space. In order to assess and quantify these possibilities, several research groups have presented life cycle assessments (LCA) of different PV/T concepts and installations. This paper presents a review of the published results, and aims to find a common ground. In general, the payback time for both energy and greenhouse gas emissions of the PV/T systems are much shorter than their expected lifetime. However, due to the use of different methods and unclear data sources, it is difficult to make any wide-ranging conclusions about the environmental impact of PV/T modules.