The most expensive days of the period
Sun 13 Sep · Mon 14 Sep · Tue 15 Sep · Wed 16 Sep
Research notes
Figures are for London unless they say otherwise.
What happened. Sun 13 Sep averaged 35.5p (min 29.1p). Mon 14 Sep averaged 37.3p, the highest daily average of the period (min 28.7p, max 56.6p at 17:00). Tue averaged 32.4p, Wed 33.2p. Peaks 53p to 57p in London, 62p to 66p in Northern Scotland.
Likely causes
- Gas at its highest. NBP day-ahead 198.80p (11 Sep), 207.35p (14 Sep, the period's high), 197.50p (15 Sep), 193.60p (16 Sep). Drivers named: Norwegian maintenance taking out "roughly 12% to 19%" of capacity, a new Nyhamna outage cutting 38.8 mcm/day and unplanned work at Troll cutting 25 more, "postponed talks between Iran and Gulf states and further attacks near two of the region's main oil transit routes", Brent at $108.75, and no LNG heading for Britain (confirmed by source) Catalyst 15 Sep, Catalyst 16 Sep, Catalyst weekly, 9 to 15 Sep
- Sun 13 Sep was nearly windless and dull. Wind fell from 6.8 GW at midnight to 0.5 GW by late afternoon (average 2.0 GW); solar peaked at only 6.8 GW; gas plant ran at 9 to 13 GW from mid-morning on, unusually high for a Sunday. Catalyst had forecast Sunday's wind and solar "well under a seasonal norm" (confirmed by data and by source) Elexon FUELHH 13 Sep, Catalyst 11 Sep
- Mon 14 Sep: wind only 3 to 5 GW until mid-afternoon, gas plant 10 to 12 GW most of the day (average 10.3 GW), and Hartlepool 2 went offline that day, taking nuclear outages to 2,725 MW across five units (confirmed by data and by source) Elexon FUELHH 14 Sep, Catalyst 14 Sep
- Tue 15 and Wed 16 Sep were windier but still dear. Day-ahead baseload £166.56 (for 15 Sep) and £171.17 (for 16 Sep). On 15 Sep wind held at 10 to 13 GW, yet gas plant still ramped to 10.6 GW for the evening. On 16 Sep wind sagged to 4 GW at midday. A wind forecast for 16 Sep was cut overnight from 14,800 to about 10,200 MWh, and the peak contract settled above baseload "for the first time since 28 August" (confirmed by source and by data) Catalyst 16 Sep, Elexon FUELHH 15 to 16 Sep
- This was not a cold snap: temperatures ran about 3°C above normal all week. Catalyst: "What a business pays for gas this winter is being set by supply risk, not by today's weather" (confirmed by source, Catalyst 15 Sep).
Wider context that week. Reuters on 16 Sep: EU storage at a record low for the date, LNG executives warning about winter Reuters via BOE Report. Energy Live News ran the record balancing-cost story on 14 Sep. TTF was near €80/MWh (search snippet from Trading Economics: EU natural gas; I did not open the page) against about €50 in mid-Jul (Oilprice via Yahoo Finance). Saudi Arabia was reported to be offering extra crude on 16 Sep, easing oil slightly.
Confidence. High for the overall cause. Medium for the exact split on 13 and 14 Sep, because Catalyst gives no day-ahead figure for Sunday or Monday delivery.
Gaps. No day-ahead settlement for delivery on 13 or 14 Sep. No NESO margin notice found for these days (I looked only indirectly; none is mentioned in Catalyst's reports).