Variability of wind and solar power – An assessment of the current situation in the European Union based on the year 2014

• Measured times series of wind and solar power production in the EU were collected.
• The data covers 90.1% of wind power production and 86.0% of solar power production.
• The analysis reveal a significant smoothing effect for wind power production in the EU.
• Reduced magnitude and frequency of high wind and solar power variations are observed on EU level.

The growth of wind and solar power in the EU (European Union) poses several challenges for its integration in the electricity system like short-term balancing, back-up power and overproduction. The present study quantifies the current variations and production characteristics of wind and solar power based on measured time series of the year 2014, collected from the EU transmission system operators. The data is covering 90.1% of wind power production and 86.0% of solar power production with a time resolution of 15 min in most cases. A significant smoothing effect due to geographical spreading is observed for wind power production in the EU with a base-load share of 4% of installed capacity and even 9% during winter season. Wind power shows high peak values of short-term variations on a national level while on an EU level, variations are below ±3% of installed capacity per 15 min. The maximum coverage of load by wind and solar power was 32% for the EU while in Denmark overproduction already occurred with a temporal share of 119% of load.