Negative prices (record January wind)
Sat 7 Jan · Sun 8 Jan · Tue 10 Jan · Wed 11 Jan · Thu 12 Jan
Research notes
Figures are for London unless they say otherwise.
What happened
- Sat 7 Jan: London was below zero for half an hour from 23:30, min −0.9p at 23:30; average 22.7p, peak 35.8p at 16:00; all 14 regions at 0p or below; lowest −1.1p in Northern Scotland.
- Sun 8 Jan: London was below zero for 4 hours (longest spell 2 hours from 04:30), min −4.6p at 02:30; average 16.2p, peak 35.8p at 16:00; all 14 regions at 0p or below; lowest −5.6p in Northern Scotland.
- Tue 10 Jan: London was below zero for half an hour from 23:30, min −4.2p at 23:30; average 25.0p, peak 35.8p at 07:30; all 14 regions at 0p or below; lowest −5.0p in Northern Scotland.
- Wed 11 Jan: London was below zero for 1.5 hours (longest spell half an hour from 00:00), min −4.2p at 00:00; average 20.5p, peak 35.8p at 16:00; all 14 regions at 0p or below; lowest −5.0p in Northern Scotland.
- Thu 12 Jan: London was below zero for 1.5 hours (longest spell half an hour from 00:00), min −2.1p at 00:00; average 21.3p, peak 35.8p at 16:30; all 14 regions at 0p or below; lowest −2.5p in Northern Scotland.
Likely causes
- Electric Insights: wind produced "more than 20 GW sustained over a whole day on 11 January", in "an exceptionally windy January". Sources: Electric Insights, Power system records (Q1 2023), Electric Insights, Wind becomes our largest electricity source (Q1 2023). (confirmed by source)
- Sat 7 Jan, 23:30 (London's lowest half-hour): wind 20.4GW (66% of supply), solar 0GW, gas 3.6GW (12%), imports 0.4GW, total supply 31.1GW. Over the day wind averaged 17.8GW; the 2023 average was 9GW (29%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
- Sun 8 Jan, 02:30 (London's lowest half-hour): wind 19.5GW (64% of supply), solar 0GW, gas 4.2GW (14%), imports 0.4GW, total supply 30.7GW. Over the day wind averaged 17.8GW; the 2023 average was 9GW (29%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
- Tue 10 Jan, 23:30 (London's lowest half-hour): wind 20.8GW (63% of supply), solar 0GW, gas 4.1GW (12%), imports 0.3GW, total supply 32.9GW. Over the day wind averaged 18.6GW; the 2023 average was 9GW (29%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
- Wed 11 Jan, 00:00 (London's lowest half-hour): wind 20.6GW (64% of supply), solar 0GW, gas 4GW (12%), imports 0.3GW, total supply 32.4GW. Over the day wind averaged 20GW; the 2023 average was 9GW (29%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
- Thu 12 Jan, 00:00 (London's lowest half-hour): wind 15.6GW (54% of supply), solar 0GW, gas 2.9GW (10%), imports 2.8GW, total supply 28.9GW. Over the day wind averaged 17.2GW; 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 Sat 7 Jan, Sun 8 Jan, Tue 10 Jan and Wed 11 Jan (20.4GW, 19.5GW, 20.8GW and 20.6GW, against 9GW for the year). (inference from NESO data)
- The low came overnight on Sat 7 Jan, Sun 8 Jan, Tue 10 Jan, Wed 11 Jan and Thu 12 Jan, when demand is at its lowest. (inference)
- Sat 7 Jan and Sun 8 Jan were at the weekend, when demand is lower. (inference)
- Elexon market index: Sat 7 Jan averaged £66.62/MWh with a low of −£24.08 at 03:30; Sun 8 Jan averaged £99.33/MWh with a low of £6.73 at 05:30; Tue 10 Jan averaged £122.85/MWh with a low of −£12.99 at 23:30; Wed 11 Jan averaged £98.27/MWh with a low of −£12.47 at 01:30; Thu 12 Jan averaged £108.75/MWh with a low of £7.53 at 03:30. Source: Elexon market index, Sat 7 Jan. (confirmed by source; a short-term index, not the day-ahead auction Agile follows)
Wider context that week
- The Energy Price Guarantee began on 1 Oct 2022, setting household electricity unit rates at 34.0p/kWh. Source: Solar Power Portal, 2022. Octopus applied it to Agile by charging 34p for any half-hour priced 34p to 52p before VAT and taking 17p off anything above, which is why so many half-hours from then to 30 Jun 2023 sit at exactly 35.8p (34p with VAT) and the highest at 82.1p. (confirmed by data in the site's store; see
src/lib/events.mjs)
Confidence
High.
Gaps
- Elexon's system warnings feed has no entries before mid-2023, so warnings for these days couldn't be checked there.