Negative prices
Research notes
Figures are for London unless they say otherwise.
What happened. London down to −4.2p at 12:30, below zero for 5.5 hours from 10:30, average 16.0p.
Likely causes
- Mostly solar: peak about 14.2 GW with only moderate wind (6.6 GW average) (confirmed by data) PV_Live 8 Aug, Elexon FUELHH 8 Aug
- Catalyst's Monday report: Friday's day-ahead peak settled at £53.35 against baseload £91.07, and the balancing market's system price went as low as −£14.47/MWh on Saturday and −£14.07 on Sunday. It adds that by Monday "negative pricing has stopped, and it stopped abruptly" (confirmed by source) Catalyst 10 Aug
- Saturday demand (inference).
Wider context that week. Hartlepool 2 went off for a planned 16-day outage on 7 Aug. Talks between Iran and Oman on shipping lanes were going on with conditions attached. This was the last cheap weekend before the mid-Aug heatwave.
Confidence. High.
Gaps. Sunday 9 Aug isn't in the data file as a negative day even though the balancing price went negative; that is the balancing market, not day-ahead, so no conflict.