There were 30 continuous periods of 24+ hours where wind generation stayed below 5GW. These low wind events totaled 1,862.7 hours (77.6 days) across 2025.
Notable Extended Low Wind Events
The longest continuous low wind period lasted 180.4 hours (7.5 days) from October 10-18, 2025, with generation dropping to just 0.38 GW at its lowest point. Other significant extended events include:
- August 14-19: 121.4 hours (5.1 days), minimum 1.23 GW
- July 8-12: 105.6 hours (4.4 days), dropping to 0.00 GW
- January 18-23: 105.0 hours (4.4 days), minimum 0.08 GW
- August 21-25: 95.5 hours (4.0 days), minimum 0.65 GW
Severity Analysis
Several periods saw wind generation fall to near-zero levels:
- July 8-12: Complete calm (0.00 GW)
- September 28-30: Another complete calm event (0.00 GW)
- January 18-23: Nearly zero at 0.08 GW
This demonstrates the critical challenge of “Dunkelflaute” (dark doldrums) periods that your renewable energy monitoring work has tracked – extended periods when wind (and often solar) provide minimal contribution to the grid, requiring substantial backup capacity or storage to maintain supply security.