Wind and solar push Agile prices below zero: 10 October
Wind and solar Agile prices fell below zero on Saturday 10 October 2026, the first plunge of the month. In London, Agile Octopus was negative for 22 half-hours, bottoming out at -3.64p/kWh at 11:30am. Strong winds had been building since Thursday, and a sunny late morning added to the surplus.
What happened
Great Britain's wind farms ran hard from Thursday night into Saturday. Elexon's half-hourly generation data shows wind averaging about 16.5GW on Friday 9 October, against 2.2GW on Tuesday 6 October.
By 11:30am on Saturday, wind was producing 17.8GW and solar about 7.9GW. Demand on the national grid was only 18.9GW, because Saturday mornings are quiet and rooftop solar cuts what homes draw from it.
With more power than the country needed, gas plants were turned down to 2.6GW. Britain also sent about 4.8GW abroad through its undersea cables, and pumped-storage hydro (reservoirs that pump water uphill to store energy) soaked up another 1.1GW.
| Half-hour starting | Wind | Solar | Gas | London Agile price |
|---|---|---|---|---|
| Tuesday 6 October, 12pm | 1.5GW | 6.6GW | 12.9GW | 23.26p/kWh |
| Saturday 10 October, 11:30am | 17.8GW | 7.9GW | 2.6GW | -3.64p/kWh |
The solar figure on Tuesday is the day's peak, not the exact half-hour. The point is the swing in wind and gas, not the sunshine alone.
How Agile prices responded
Agile prices follow the wholesale market every half hour, so the windy spell showed up straight away. London's daily average fell from 32.73p/kWh on Tuesday to 10.18p/kWh on Friday and 7.43p/kWh on Saturday.
Saturday had two separate plunges in London. Prices dipped just below zero overnight, between 12:30am and 6am. They then went negative from 9:30am to 3:30pm, when solar output added to the wind.
Prices still rose at teatime. London reached 43.55p/kWh at 6:30pm, as solar faded and demand climbed. You can see today's and tomorrow's Agile prices half-hour by half-hour.
How the regions compared
Every region went negative on 10 October, at the same 11:30am low. This table uses Octopus's published prices up to 10:30pm, since the last two half-hours of the Agile day come out with tomorrow's prices.
| Region | Negative half-hours | Lowest price |
|---|---|---|
| London, East Midlands, Yorkshire | 22 | -3.64p/kWh |
| Eastern, West Midlands, North Eastern, North Western, Southern England, Southern Scotland | 18 | -3.65p/kWh |
| Merseyside and North Wales, South Eastern England, South Wales | 15 | -3.67p/kWh |
| South Western England | 14 | -3.68p/kWh |
| Northern Scotland | 12 | -3.70p/kWh |
Regions where Agile is usually dearer had fewer negative half-hours, but slightly deeper lows. You can compare Agile prices across all 14 regions for any day.
What a windy day is worth
Take a 7kW electric car charger in London, run from 11am to 1pm. That adds 14kWh. On Saturday 10 October, the four half-hours averaged -3.24p/kWh, so the driver was paid about 45p.
| Charge from 11am to 1pm, London | Average price | Cost of 14kWh |
|---|---|---|
| Tuesday 6 October (calm) | 23.57p/kWh | £3.30 |
| Saturday 10 October (windy) | -3.24p/kWh | 45p credit |
That is a swing of about £3.75 for the same charge, just from the weather. Home batteries, hot water cylinders and storage heaters on a timer can gain in the same way.
Plunges rarely last a whole day, so timing matters. Wattly's cheapest time to use electricity finder picks the cheapest block for a task of any length.
Will it happen again?
Autumn and winter tend to be windier than summer, so more plunges are likely, though less sunshine means more of them may come overnight. September 2026 had nine plunge days, while London had none from 1 to 9 October.
Octopus says Agile customers get an alert when prices drop below zero. Wattly's Agile price history shows how windy spells change prices from month to month.
FAQ
Why does wind make Agile prices cheaper? Wind costs almost nothing to run once built. When it covers most of the country's demand, fewer gas plants are needed and wholesale prices fall, which Agile passes through.
How low did Agile go on 10 October 2026? The lowest price was -3.64p/kWh in London and -3.70p/kWh in Northern Scotland, both at 11:30am.
Do I get paid when Agile prices are negative? Yes. On Agile Octopus you are credited for electricity you use during a negative half-hour, which Octopus calls Plunge Pricing.
Why were prices still high in the evening? Solar output drops away by late afternoon and demand peaks around 4pm to 7pm. Even on a windy day, that pushes teatime prices up.