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Summary
This study analyzes the impact of variable renewable energy (VRE) droughts on long-duration storage needs in a fully renewable European power system, considering different interconnection levels across countries.
Highlights
- VRE droughts define operational and investment needs for long-duration storage in a European power sector with high shares of wind and solar power.
- Major discharge periods of long-duration storage coincide with the most pronounced drought periods identified in the data.
- Interconnection among European countries significantly reduces the requirement for long-duration energy storage.
- Firm renewable energy sources, such as hydro reservoirs or bioenergy, mitigate long-duration storage needs for dealing with extreme droughts.
- The most pronounced pan-European renewable drought identified in the VRE drought analysis leads to the highest long-duration storage need.
- The storage-mitigating effect of interconnection for dealing with very pronounced renewable droughts is limited.
- Long-duration storage needs vary across weather years, emphasizing the significance of accounting for extreme renewable droughts when planning renewable energy systems.
Key Insights
- The study reveals a positive correlation between extreme drought events and optimal storage energy capacity investments for many European countries and weather years, highlighting the critical role of long-duration storage in coping with VRE droughts.
- Interconnection levels, as foreseen in the TYNDP scenarios, mitigate the storage needs for extreme drought events only to a limited extent, indicating the need for higher interconnection levels or alternative flexibility options.
- The analysis suggests that the need for long-duration storage capacities ranges between 67 and 351 TWh, equivalent to 1.4-7.1% of the yearly European electricity demand, under policy-oriented interconnection levels.
- Even under the assumption of a perfectly interconnected Europe, coping with the most pronounced drought in the data would require 159 TWh of long-duration storage, corresponding to around 3% of yearly electric load.
- The study proposes refining the Dunkelflaute notion to focus on extended (winter) periods where renewable energy falls short of electricity demand, which ultimately define the energy capacity and the operation of long-duration storage.
- The results emphasize the importance of considering multiple weather years for identifying weather-resilient system configurations, particularly those with the most pronounced drought events.
- The analysis highlights the need for early action to enable rapid scaling to realize the ambitious hydrogen storage investments determined in the study, considering the long lead times due to supply chain and permitting bottlenecks.
Mindmap
Citation
Kittel, M., Roth, A., & Schill, W.-P. (2024). Coping with the Dunkelflaute: Power system implications of variable renewable energy droughts in Europe (Version 2). arXiv. https://doi.org/10.48550/ARXIV.2411.17683