Zero prices (overnight)
Sat 30 Oct · Mon 1 Nov
Research notes
Figures are for London unless they say otherwise.
What happened
- Sat 30 Oct: London reached 0p at 03:30 (1.5 hours at 0p in all); average 23.4p, peak 35.0p at 16:00; all 14 regions at 0p or below; lowest 0.0p in Eastern England.
- Mon 1 Nov: London reached 0p at 01:30 (1.5 hours at 0p in all); average 20.4p, peak 35.0p at 16:30; all 14 regions at 0p or below; lowest 0.0p in Eastern England.
Likely causes
- Sat 30 Oct, 03:30 (London's lowest half-hour): wind 12.6GW (49% of supply), solar 0GW, gas 3.4GW (13%), imports 1.7GW, total supply 25.6GW. Over the day wind averaged 11.1GW; the 2021 average was 7.1GW (22%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
- Mon 1 Nov, 01:30 (London's lowest half-hour): wind 13.5GW (54% of supply), solar 0GW, gas 2.7GW (11%), imports 1.5GW, total supply 25GW. Over the day wind averaged 13.7GW; the 2021 average was 7.1GW (22%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
- Wind was well above its yearly average at the lowest half-hour on Mon 1 Nov (13.5GW, against 7.1GW for the year). (inference from NESO data)
- The low came overnight on Sat 30 Oct and Mon 1 Nov, when demand is at its lowest (total supply as low as 25GW, against a 2021 average of 32.5GW). (inference)
- Sat 30 Oct was at the weekend, when demand is lower. (inference)
- Elexon market index: Sat 30 Oct averaged £114.65/MWh with a low of £55.29 at 05:00; Mon 1 Nov averaged £99.52/MWh with a low of −£20.19 at 03:30. Source: Elexon market index, Sat 30 Oct. (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
Medium. The grid figures fit the prices, but no report found names a cause for 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.
- Elexon's system warnings feed has no entries before mid-2023, so warnings for these days couldn't be checked there.