Energy was last better‑than‑free: yesterday Next

Research notes

Figures are for London unless they say otherwise.

What happened

• Mon 28 Nov: London peaked at 82.1p at 16:30 (the Energy Price Guarantee ceiling), average 44.1p, lowest 28.6p at 00:00; highest anywhere 82.1p in Eastern England.
• Tue 29 Nov: London peaked at 82.1p at 16:30 (the Energy Price Guarantee ceiling), average 52.0p, lowest 35.8p at 00:00; highest anywhere 82.1p in Eastern England.
• Wed 30 Nov: London peaked at 82.1p at 16:30 (the Energy Price Guarantee ceiling), average 52.7p, lowest 35.8p at 00:00; highest anywhere 82.1p in Eastern England.
• Thu 1 Dec: London peaked at 82.1p at 16:30 (the Energy Price Guarantee ceiling), average 53.5p, lowest 35.8p at 00:00; highest anywhere 82.1p in Eastern England.

Likely causes

• Bloomberg headline, 29 Nov 2022: "High Power Prices Persist in UK as Wind Power Output Slumps". (confirmed by source, headline only; paywalled)
• Electric Insights says gas prices "started heading back upwards at the end of November". Source: Electric Insights, Power prices ease going into winter (Q3 2022). (confirmed by source)
• Mon 28 Nov, 16:30 (London's peak): wind 0.7GW (2% of supply), solar 0GW, gas 22.9GW (57%), imports 5.6GW, total supply 40.2GW. Over the day wind averaged 3GW; the 2022 average was 8.8GW (27%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
• Tue 29 Nov, 16:30 (London's peak): wind 1.3GW (3% of supply), solar 0GW, gas 22.9GW (56%), imports 6.2GW, total supply 41GW. Over the day wind averaged 1.2GW; the 2022 average was 8.8GW (27%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
• Wed 30 Nov, 16:30 (London's peak): wind 3.4GW (8% of supply), solar 0GW, gas 22.5GW (54%), imports 4.5GW, total supply 41.4GW. Over the day wind averaged 3.1GW; the 2022 average was 8.8GW (27%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
• Thu 1 Dec, 16:30 (London's peak): wind 2.7GW (6% of supply), solar 0GW, gas 22.5GW (54%), imports 5GW, total supply 41.9GW. Over the day wind averaged 3GW; the 2022 average was 8.8GW (27%). Source: NESO historic generation mix. (figures confirmed by source; link to prices is inference)
• Wind was less than half its yearly average at the peak on Mon 28 Nov, Tue 29 Nov, Wed 30 Nov and Thu 1 Dec (0.7GW, 1.3GW, 3.4GW and 2.7GW, against 8.8GW for the year), so gas made up the gap. (inference from NESO data)
• The peak came in the early evening on Mon 28 Nov, Tue 29 Nov, Wed 30 Nov and Thu 1 Dec, when demand is highest and there is no solar. (inference)
• Elexon market index: Mon 28 Nov averaged £272.45/MWh with a high of £508.42 at 17:30; Tue 29 Nov averaged £340.02/MWh with a high of £486.48 at 16:30; Wed 30 Nov averaged £325.64/MWh with a high of £439.12 at 17:00; Thu 1 Dec averaged £338.60/MWh with a high of £440.67 at 18:00. Source: Elexon market index, Mon 28 Nov. (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)
• A week earlier, on Tue 22 Nov 2022, National Grid issued a tight electricity margin notice for the evening as temperatures dropped and wind fell to about 4GW. Source: The National, 22 Nov 2022. (confirmed by source)

Confidence

High. Wind under 3.5GW at every peak, a press report of high prices as wind slumped, and every day at the 82.1p ceiling.

Gaps

• Elexon's system warnings feed has no entries before mid-2023, so warnings for these days couldn't be checked there.