Negative prices (New Year's Day)
Research notes
Figures are for London unless they say otherwise.
What happened
London went to −1.4p at 03:30, below zero for 4.5 hours overnight (longest spell 1.5h from 02:30). All 14 regions hit 0p or below, lowest −1.6p in Northern Scotland. Daily average 13.4p, evening peak 38.7p.
Likely causes
- Very windy night. Transmission-metered wind was 15.8GW at midnight and averaged 13.5GW across the day, while gas fell as low as 1.8GW. GB was exporting up to 5.1GW over the interconnectors around 05:00, which is what a surplus looks like. (confirmed by source: grid data) Elexon FUELHH 1 Jan 2025
- The Met Office had yellow wind warnings across England and Wales for 1 Jan with gusts of 65 to 75mph in exposed places, after 70mph gusts further north on New Year's Eve, as a run of low pressure systems crossed the country. This was not a named storm. (confirmed by source) Met Office, 29 Dec 2024
- Edinburgh's outdoor Hogmanay events were cancelled because of the weather. (confirmed by source) Yahoo News live coverage
- Bank holiday, and the negative half-hours fell in the small hours when demand is at its lowest. Low demand plus high wind is the usual recipe. (inference)
Wider context that week
- Russian gas stopped flowing through Ukraine on 1 Jan when the five-year transit deal expired. The market had largely priced it in, and gas prices rose only slightly. CNBC, 1 Jan 2025 · Bruegel analysis
- The Ofgem price cap rose 1.2% to £1,738 a year for a typical dual-fuel household on 1 Jan. Ofgem
- The Met Office published "2025 begins with a cold snap" the same day: the wind died away and cold air moved in from 2 Jan, which sets up the spikes a week later. Met Office, 1 Jan 2025
Confidence
High. Grid data and Met Office warnings agree, and the pattern (windy bank-holiday night) is textbook.
Gaps
No news report found that mentions negative wholesale prices on 1 Jan 2025 specifically. No NESO statement about wind output that night. The 22.4GW wind record widely reported around then was 18 Dec 2024, not this date.