Negative prices (Storm Gerrit)
Tue 26 Dec · Wed 27 Dec · Thu 28 Dec · Fri 29 Dec
Research notes
Figures are for London unless they say otherwise.
What happened
- Tue 26 Dec: London was below zero for 2.5 hours (longest spell half an hour from 00:00), min −4.2p at 06:00; average 12.7p, peak 34.8p at 16:30; all 14 regions at 0p or below; lowest −5.0p in Northern Scotland.
- Wed 27 Dec: London was below zero for half an hour from 23:30, min −0.4p at 23:30; average 11.9p, peak 28.8p at 16:30; all 14 regions at 0p or below; lowest −0.5p in Northern Scotland.
- Thu 28 Dec: London was below zero for 4 hours (longest spell 1 hour from 04:30), min −2.1p at 22:30; average 7.6p, peak 28.9p at 18:00; all 14 regions at 0p or below; lowest −2.5p in Northern Scotland.
- Fri 29 Dec: London was below zero for 4 hours (longest spell 3 hours from 02:30), min −3.8p at 06:00; average 11.8p, peak 33.3p at 17:30; all 14 regions at 0p or below; lowest −4.5p in Northern Scotland.
Likely causes
- Storm Gerrit affected the UK on 27 and 28 Dec 2023, according to the Met Office's list of named storms for 2023/24. Source: Met Office, UK storm season 2023/24. (confirmed by source; its link to the prices is inference)
- Tue 26 Dec 2023 was the Boxing Day bank holiday. Source: GOV.UK bank holidays. (confirmed by source)
- Tue 26 Dec, 06:00 (London's lowest half-hour): wind 15.4GW (59% of supply), solar 0GW, gas 3GW (11%), imports 0.3GW, total supply 26.3GW. Over the day wind averaged 9.2GW; the 2023 average was 9GW (29%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
- Wed 27 Dec, 23:30 (London's lowest half-hour): wind 20.4GW (66% of supply), solar 0GW, gas 3.1GW (10%), imports 0.1GW, total supply 30.7GW. Over the day wind averaged 18.5GW; the 2023 average was 9GW (29%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
- Thu 28 Dec, 22:30 (London's lowest half-hour): wind 19.2GW (63% of supply), solar 0GW, gas 2.5GW (8%), imports 1.9GW, total supply 30.8GW. Over the day wind averaged 20.1GW; the 2023 average was 9GW (29%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
- Fri 29 Dec, 06:00 (London's lowest half-hour): wind 19.4GW (66% of supply), solar 0GW, gas 2.5GW (8%), imports 0.5GW, total supply 29.6GW. Over the day wind averaged 16.6GW; the 2023 average was 9GW (29%). 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 Wed 27 Dec, Thu 28 Dec and Fri 29 Dec (20.4GW, 19.2GW and 19.4GW, against 9GW for the year). (inference from NESO data)
- The low came overnight on Tue 26 Dec, Wed 27 Dec, Thu 28 Dec and Fri 29 Dec, when demand is at its lowest. (inference)
- Tue 26 Dec was a bank holiday (Boxing Day), when demand is lower. (inference)
- Elexon market index: Tue 26 Dec averaged £51.73/MWh with a low of −£17.98 at 05:00; Wed 27 Dec averaged £42.63/MWh with a low of −£3.10 at 23:30; Thu 28 Dec averaged £20.42/MWh with a low of −£10.78 at 23:00; Fri 29 Dec averaged £60.15/MWh with a low of −£4.31 at 00:00. Source: Elexon market index, Tue 26 Dec. (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
High.
Gaps
- None beyond what is said above.