Negative prices (Storm Dennis)
Research notes
Figures are for London unless they say otherwise.
What happened
- Sun 16 Feb: London was below zero for 4 hours from 02:00, min −3.2p at 03:30; average 5.8p, peak 23.6p at 17:30; all 14 regions at 0p or below; lowest −3.8p in Northern Scotland.
Likely causes
- Storm Dennis affected the UK on 15 and 16 Feb 2020, according to the Met Office's list of named storms for 2019/20. Source: Met Office, UK storm season 2019/20. (confirmed by source; its link to the prices is inference)
- Electric Insights: wind farms supplied a record average of 12.3GW through February 2020, and February was the first month on record when wind produced more electricity than any other source. Sources: Electric Insights, Power system records (Q1 2020), Electric Insights, Wind power surges to new records (Q1 2020). (confirmed by source)
- Sun 16 Feb, 03:30 (London's lowest half-hour): wind 12.6GW (49% of supply), solar 0GW, gas 3.4GW (13%), imports 1GW, total supply 25.5GW. Over the day wind averaged 14.8GW; the 2020 average was 7.8GW (25%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
- The low came overnight on Sun 16 Feb, when demand is at its lowest. (inference)
- Sun 16 Feb was at the weekend, when demand is lower. (inference)
- Elexon market index: Sun 16 Feb averaged £22.49/MWh with a low of −£7.11 at 09:00. Source: Elexon market index, Sun 16 Feb. (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. A named storm on the day, in the windiest month on record to then, on a Sunday night.
Gaps
- Elexon's system warnings feed has no entries before mid-2023, so warnings for these days couldn't be checked there.