Zero prices (bank holiday weekend sun)
Research notes
Figures are for London unless they say otherwise.
What happened
- Sat 27 May: London reached 0p at 13:30 (1.5 hours at 0p in all); average 14.4p, peak 28.8p at 17:00; all 14 regions at 0p or below; lowest 0.0p in Eastern England.
Likely causes
- Mon 29 May 2023 was the spring bank holiday, so this was the start of a long weekend; solar was 10.6GW at the 0p half-hour. (confirmed by data; the holiday from GOV.UK bank holidays)
- Sat 27 May, 13:30 (London's lowest half-hour): wind 6.1GW (19% of supply), solar 10.6GW, gas 3.4GW (11%), imports 5.5GW, total supply 31.3GW. Over the day wind averaged 5.2GW; the 2023 average was 9GW (29%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
- The low came around midday on Sat 27 May, with solar at 10.6GW. (inference from NESO data)
- Sat 27 May was at the weekend, when demand is lower. (inference)
- Elexon market index: Sat 27 May averaged £52.42/MWh with a low of −£22.26 at 14:00. Source: Elexon market index, Sat 27 May. (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
Medium. The grid figures fit the prices, but no report found names a cause for 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.