Photovoltaic roof systems for educational buildings

A roof photovoltaic system (PVS) for power supply to a university building is being considered. The large roof areas of these buildings make it possible to fully meet the needs of electricity and a large part of the heat demand during the heating season. During the autumn-winter season, electricity from the PV system is used to charge the rechargeable battery (RB) for lighting and to supply air-water heat pumps to the heating installation. The electricity produced during the spring-summer season is sold to the energy system. The funds received cover a large part of winter heating costs. A small lithium-ion RB is provided to align the daily load schedule. The proposed model provides minimum energy costs annually and is planned to be implemented as a training center at TU-Sofia under OPIC Operational Program, proposal “Optimization of operating costs of building lighting and heating through the use of renewable energy sources”