Energy was last better‑than‑free: yesterday Next

On the Agile Octopus tariff, customers get paid to use electricity when there’s too much in the grid.

That’s cheaper than Octopus Energy paying to store it.

The price changes every half-hour.

How free electricity works

Region

Price spike (at the cap)

Research notes

Figures are for London unless they say otherwise.

What happened

  • Tue 13 Mar: London peaked at 35.0p at 18:00 (Agile's 35p cap), average 16.4p, lowest 9.7p at 22:30; highest anywhere 35.0p in Eastern England.

Likely causes

  • Tue 13 Mar, 18:00 (London's peak): wind 1.3GW (3% of supply), solar 0GW, gas 21.6GW (48%), imports 2.1GW, total supply 45.5GW. Over the day wind averaged 2.3GW; the 2018 average was 5.8GW (17%). 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 Tue 13 Mar (1.3GW, against 5.8GW for the year), so gas made up the gap. (inference from NESO data)
  • The peak came in the early evening on Tue 13 Mar, when demand is highest and there is no solar. (inference)
  • Elexon market index: Tue 13 Mar averaged £61.31/MWh with a high of £100.84 at 18:30. Source: Elexon market index, Tue 13 Mar. (confirmed by source; a short-term index, not the day-ahead auction Agile follows)

Wider context that week

  • Nothing notable found for that week.

Confidence

Medium. The grid figures fit the prices, but no report found names a cause for this date.

Gaps

  • No news report or official write-up found that ties this date to a cause; the causes above are from the data.
  • Elexon's system warnings feed has no entries before mid-2023, so warnings for these days couldn't be checked there.

More notable days

Half-hourly prices

Tuesday 13 Mar 2018 · half-hourly prices

South Eastern England

2am 4am 6am 8am 10am 12pm 2pm 4pm 6pm 8pm 10pm Now

Stats for Tuesday 13 Mar 2018

10.6p

Cheapest half-hour 10.30pm – 11pm

35.0p

Dearest half-hour 6pm – 6.30pm

0 hours

Negative prices none on 13 Mar 2018

12.8p avg

Cheapest 3 hours 3am – 6am

17.7p

Average price on 13 Mar 2018

Show as a table
TimePrice
12am – 12.30am15.0p
12.30am – 1am16.7p
1am – 1.30am14.3p
1.30am – 2am13.1p
2am – 2.30am13.1p
2.30am – 3am13.1p
3am – 3.30am12.9p
3.30am – 4am12.7p
4am – 4.30am12.7p
4.30am – 5am12.7p
5am – 5.30am12.7p
5.30am – 6am12.9p
6am – 6.30am18.5p
6.30am – 7am17.3p
7am – 7.30am15.0p
7.30am – 8am16.4p
8am – 8.30am20.8p
8.30am – 9am20.7p
9am – 9.30am22.1p
9.30am – 10am21.5p
10am – 10.30am17.1p
10.30am – 11am15.9p
11am – 11.30am15.0p
11.30am – 12pm14.7p
12pm – 12.30pm14.1p
12.30pm – 1pm13.9p
1pm – 1.30pm13.9p
1.30pm – 2pm13.1p
2pm – 2.30pm14.8p
2.30pm – 3pm14.4p
3pm – 3.30pm13.5p
3.30pm – 4pm14.1p
4pm – 4.30pm30.7p
4.30pm – 5pm31.9p
5pm – 5.30pm32.2p
5.30pm – 6pm33.4p
6pm – 6.30pm35.0p
6.30pm – 7pm35.0p
7pm – 7.30pm26.6p
7.30pm – 8pm25.4p
8pm – 8.30pm18.0p
8.30pm – 9pm14.6p
9pm – 9.30pm14.0p
9.30pm – 10pm12.7p
10pm – 10.30pm12.1p
10.30pm – 11pm10.6p
11pm – 11.30pm14.6p
11.30pm – 12am16.2p