The effect of storage and interconnection on the optimal mix of intermittent renewables in Europe

Abstract

Due to their intermittent nature, wind and solar power are difficult to integrate in the European electricity system. In this thesis the potential benefits for grid integration of choosing an optimal mix and distribution of wind and solar power were studied. The effect of interconnection on the capacity credit and curtailment of intermittent renewables was studied for a scenario for 2050 developed by Greenpeace. The effects of interconnection and storage on the optimal distribution of wind and solar capacity were studied as well. The study was based on high resolution reanalysis weather data and a method to generate wind and solar production profiles based on reanalysis weather data was demonstrated. The optimal mix of wind and solar power in a copper plate Europe consists of 74% wind energy and 26% solar energy for a combined total of 78% intermittent renewables in total annual production. Without interconnection, the share of wind decreases and the share of solar energy increases, indicating that interconnection favors wind power which is reflected in the lower cross-border correlations in wind power, particularly between countries on different latitudes. Increasing volumes of high power storage favors solar power, until the ratio in production from intermittent renewables is then 60% wind to 40% solar. Storage increases the capacity credit of renewables in an optimal distribution of capacity only when there is interconnection. As long as there is enough interconnection, choosing an optimal mix of intermittent renewables makes them easier to integrate on the grid, improves their capacity credit and reduces curtailment of their output.