Negative prices (weekend)
Research notes
Figures are for London unless they say otherwise.
What happened
- Sun 30 Jul: London was below zero for 5 hours (longest spell 3.5 hours from 12:00), min −4.2p at 09:00; average 9.9p, peak 30.1p at 16:30; all 14 regions at 0p or below; lowest −5.0p in Northern Scotland.
Likely causes
- Sun 30 Jul, 09:00 (London's lowest half-hour): wind 15.5GW (54% of supply), solar 4GW, gas 4.2GW (15%), imports 1.1GW, total supply 28.7GW. Over the day wind averaged 13.1GW; the 2023 average was 9GW (29%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
- Sun 30 Jul was at the weekend, when demand is lower. (inference)
- Elexon market index: Sun 30 Jul averaged £46.93/MWh with a low of −£3.69 at 11:00. Source: Elexon market index, Sun 30 Jul. (confirmed by source; a short-term index, not the day-ahead auction Agile follows)
Wider context that week
- Nothing notable found for that week.
Confidence
Low. Neither the grid figures nor any report found clearly explain this date.
Gaps
- No news report or official write-up found that ties this date to a cause; the causes above are from the data.