Peak shaving with photovoltaic-battery systems

With the steady growth of the photovoltaic market over the last decade, the feed-in of photovoltaic-generators may strain the electricity grid, especially in rural areas. Storage devices are expected to smooth over the non-simultaneous production of volatile renewable energies and their consumption. In this paper, we investigate to what extent domestic photovoltaic-battery systems can compensate the capping of the feed-in power by buffering the peak energy. The Fraunhofer Institute for Solar Energy Systems (ISE) in Freiburg, Germany, has developed a novel forecast-based control scheme for photovoltaic-battery systems. It estimates the photovoltaic excess energy and derives a charging schedule for the battery to store the energy from the photovoltaic peak-production. The maximal self-consumption of the locally produced renewable energy is thereby not affected. We show that the maximal photovoltaic feed-in power can be reduced from 70 % to 60 % of the nominal photovoltaic power without losses.