Negative prices (overnight)
Research notes
Figures are for London unless they say otherwise.
What happened
- London below zero for two separate half-hours before dawn (03:30 and 04:30), min −1.4p at 04:30. Daily average 15.5p. All 14 regions at or below zero.
Likely causes
- Windy night with low overnight demand. NESO data: wind peaked at 16.7GW at 00:30 and was 15.7GW (60% of supply) at 04:30, when total supply was only 26.2GW and gas was down to 3.9GW. Source: NESO historic generation mix. Figures (confirmed by source); link to prices (inference).
Wider context that week
- Same week as the 14 Oct capacity market notice above. Two days apart the system went from too little power to too much, which is a fair illustration of how much wind now drives GB prices. (inference)
Confidence
Medium. Data fits neatly; nothing in the press about this night. This was a midweek night, not a weekend, so wind rather than low demand is doing most of the work.
Gaps
Looked for weather reports or market coverage for 15 to 16 Oct. Found nothing specific.