We investigated the relationship of power plant mix and required energy storage capacity with a computer model based on global weather data. We focus on energy storage requirements of an electricity supply for Europe by wind and solar power (PV). The minimum required energy storage capacity for a 100% renewable (wind and PV) electricity supply occurs at »30% wind and »70% PV installed capacity. A transition of today’s European electricity supply to a 100% renewable scenario would rise the required energy storage capacity exponentially to about 150 TWh (3.8% of the annual electricity demand). However the installation of excess wind and PV power plant capacity is shown to drastically reduce the required energy storage. For instance 10% excess capacity cut the required storage capacity in half, higher excess capacities lead to further, significant reduction of storage requirements. Furthermore, storage can be separated into daily (short term) storage and seasonal (long term) storage. Seasonal storage capacity has to be about two orders of magnitude larger than storage for the daily cycle, however, the annual sum of stored energy is nearly equal for both types of storage. In summary, an electricity supply by only wind and PV power is shown to be perfectly feasible with respect to the required energy storage capacity and required land area for power plants, and offers competitive electricity generating cost.
© 2015 Optical Society of AmericaPDF Article