Price spike and the winter's first capacity market notice
Research notes
Figures are for London unless they say otherwise.
What happened
- London peaked at 65.3p at 18:30 with a daily average of 24.9p. Highest anywhere was 75.9p in Northern Scotland.
- This came the day after negative prices, so the swing in under 48 hours was from −1.1p to 65.3p.
Likely causes
- NESO issued an electricity capacity market notice at 11:04 for 15:30 onwards, the first in almost two years. It was cancelled at 13:05. Source: Elexon system warnings feed, also Nuclear Industry Association statement, 14 Oct. (confirmed by source)
- Timera Energy's write-up gives the reasons margins were thin: about 4GW of interconnector capacity out (3GW to France across IFA1, IFA2 and ElecLink, 1.4GW to Norway on NSL), peak demand of about 37GW which was the highest since the previous winter, Sizewell B (1.2GW nuclear) and Damhead Creek (812MW gas) on outage, and the recent closure of the last coal plant. Source: Timera Energy. (confirmed by source)
- Timera also reports that NESO's interconnector trades reached £1,030/MWh for 16:00 to 17:00 UTC and the intraday weighted average peaked near £677/MWh. The notice was withdrawn once NESO's trades reversed flows from Belgium, the Netherlands and Denmark. Source: Timera Energy. (confirmed by source)
- Very little wind. NESO data: wind averaged 4.3GW (13% of supply) across the day and was 2.8GW at 16:30 and 3.5GW at 18:30, with gas running at 20.6GW. Source: NESO historic generation mix. Figures (confirmed by source); Timera does not list low wind among its reasons, so the weight given to it is (inference).
- The Elexon Market Index Price peaked at £605/MWh for the half-hour starting 18:30 UK time, the same half-hour as Agile's peak. Source: Elexon market index, 14 Oct. (confirmed by source)
Wider context that week
- The Nuclear Industry Association used the notice to argue for new nuclear, pointing to stations due to retire by 2026 and 2028. NIA
- New Civil Engineer ran an explainer on why the "blackout prevention system" was activated (page blocked to my fetcher, so not read). New Civil Engineer, 23 Oct
Confidence
High. The notice, its timing and the outage list are all documented, and the generation and price data line up to the half-hour.
Gaps
Could not find the day-ahead auction price itself for 14 Oct in any free source. Could not read the New Civil Engineer or New Power articles (blocked).