Negative prices (overnight)
Sun 15 Nov · Mon 16 Nov
Research notes
Figures are for London unless they say otherwise.
What happened
- Sun 15 Nov: London reached 0p at 03:30 (2.5 hours at 0p in all); average 8.2p, peak 29.2p at 17:00; all 14 regions at 0p or below; lowest 0.0p in Eastern England.
- Mon 16 Nov: London was below zero for half an hour from 02:30, min −0.2p at 02:30; average 8.9p, peak 28.7p at 17:30; all 14 regions at 0p or below; lowest −0.3p in Northern Scotland.
Likely causes
- Sun 15 Nov, 03:30 (London's lowest half-hour): wind 13.2GW (54% of supply), solar 0GW, gas 3.9GW (16%), imports 0.3GW, total supply 24.6GW. Over the day wind averaged 13.2GW; the 2020 average was 7.8GW (25%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
- Mon 16 Nov, 02:30 (London's lowest half-hour): wind 13.6GW (54% of supply), solar 0GW, gas 3.4GW (14%), imports 0.9GW, total supply 25.1GW. Over the day wind averaged 13.6GW; 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 15 Nov and Mon 16 Nov, when demand is at its lowest (total supply as low as 24.6GW, against a 2020 average of 31.4GW). (inference)
- Sun 15 Nov was at the weekend, when demand is lower. (inference)
- Elexon market index: Sun 15 Nov averaged £23.54/MWh with a low of −£7.32 at 08:00. Source: Elexon market index, Sun 15 Nov. (confirmed by source; a short-term index, not the day-ahead auction Agile follows)
Wider context that week
- England's second lockdown ran from 5 Nov to 2 Dec 2020. Source: GOV.UK, timeline of COVID-19 restrictions in 2020 (PDF). (confirmed by source)
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.
- Elexon's system warnings feed has no entries before mid-2023, so warnings for these days couldn't be checked there.