Photovoltaic / thermal system for stand-alone operation

The growing demand for the utilization of clean energy resources requires consideration of more efficient and economical ways in the usage of available resources and technologies. In the field of solar energy both the efficiency and the economics, i.e. the payback times are crucial questions for a more widespread application of this resource in the future. A novel solution and system are proposed in the paper aimed at enhancing the amount of energy that can be harvested from solar radiation in the same area. The basis of the method presented is a special construction of combined Photovoltaic / Thermal panels that can generate heat power to produce hot water, while the photovoltaic part provides electric power for covering the electric power consumption of loads, to supply its own electronic control units and to operate pump drives etc. The theoretical predictions of the electric part of the system are confirmed by laboratory test results. The system and the overall control structure, including the MPPT control, are presented assuming stand-alone operation but parallel operation is also possible.