Negative prices (lockdown, record low demand)
Sun 28 Jun · Mon 29 Jun
Research notes
Figures are for London unless they say otherwise.
What happened
- Sun 28 Jun: London was below zero for 7.5 hours (longest spell 5 hours from 03:00), min −3.8p at 05:00; average 3.9p, peak 19.0p at 18:30; all 14 regions at 0p or below; lowest −4.5p in Northern Scotland.
- Mon 29 Jun: London was below zero for 3 hours from 02:30, min −3.7p at 03:30; average 5.9p, peak 19.9p at 17:30; all 14 regions at 0p or below; lowest −4.4p in Northern Scotland.
Likely causes
- Electric Insights: demand "fell to its lowest levels this century, falling below 17 GW on the 28th of June". Source: Electric Insights, Power system records (Q2 2020). (confirmed by source)
- Sun 28 Jun, 05:00 (London's lowest half-hour): wind 10GW (48% of supply), solar 0.1GW, gas 4.8GW (23%), imports 0.4GW, total supply 20.7GW. Over the day wind averaged 11.5GW; the 2020 average was 7.8GW (25%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
- Mon 29 Jun, 03:30 (London's lowest half-hour): wind 10.5GW (50% of supply), solar 0GW, gas 4.6GW (22%), imports 0.3GW, total supply 21.1GW. Over the day wind averaged 12.7GW; 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 28 Jun and Mon 29 Jun, when demand is at its lowest (total supply as low as 20.7GW, against a 2020 average of 31.4GW). (inference)
- Sun 28 Jun was at the weekend, when demand is lower. (inference)
- Elexon market index: Sun 28 Jun averaged −£12.54/MWh with a low of −£47.90 at 04:30; Mon 29 Jun averaged £21.34/MWh with a low of −£10.47 at 02:30. Source: Elexon market index, Sun 28 Jun. (confirmed by source; a short-term index, not the day-ahead auction Agile follows)
Wider context that week
- The first national lockdown in England began on 23 Mar 2020 ("stay at home"); people who couldn't work from home were asked to return from 10 May, non-essential shops reopened on 15 Jun, and pubs and restaurants on 4 Jul. Source: GOV.UK, timeline of COVID-19 restrictions in 2020 (PDF). (confirmed by source)
- Elexon found that GB electricity demand was 19% lower in Apr and May 2020 than a year earlier, "driven by the COVID-19 lockdown measures", and that 83% of the year's negative system prices to June fell in April and May. Source: Elexon: negative system prices during COVID-19, last updated 29 Jun 2020. (confirmed by source; these are system prices, not the day-ahead prices Agile follows)
Confidence
High. A published record low for demand on the day itself, with half the power from wind overnight.
Gaps
- Elexon's system warnings feed has no entries before mid-2023, so warnings for these days couldn't be checked there.