Right now
The story
Five chapters on whether renewables can now keep the lights on without fossil fuels.
1Coal is goneCoal was Britain's biggest source of power in 2012. Now it makes none.
Where Britain's power comes from
Share of generation each year. The last bar is the past 365 days.
2Low carbon overtakes fossilWind, solar, nuclear and hydro now generate more than gas and coal in most months.
3More hours on almost no fossil fuelEach year the grid spends more hours running on very little gas.
Hours each year with gas and coal together under 10, 5 and 1 GW. The last bar is the past 365 days.
4Batteries are comingGrid batteries barely registered a few years ago. Now they cover gigawatts at the evening peak.
Battery output over time
Daily mean battery output on a log scale, where each step up the axis is a doubling or more. The bands show the range of daily means over a rolling year.
Charging and discharging
Above the line, batteries are feeding the grid; below it, they're charging.
About the battery data
No single public feed sees all of Great Britain's batteries yet, so the chart shows three side by side.
| Source | What it measures | Delay | Charging? | Coverage |
|---|
Battery units
Elexon has no battery fuel type, so units are matched by name (battery, BESS, storage) or by National Grid's naming convention for battery units, where the unit both imports and exports. Batteries connected to local networks outside the Balancing Mechanism are not visible in any of these feeds.
Where battery power comes from
Batteries don't make electricity, they move it in time, so their output is only as clean as what charged them. This treats the whole fleet as one store that empties first in, first out: energy taken in each half hour is tagged with that half hour's grid mix, and comes back out in the order it went in. It's an experiment, so it only runs when you ask.
How the attribution works, and its limits
5Could solar and batteries do it alone?What a steady megawatt from sun and storage alone would cost, compared with gas.
Solar is the cheapest power ever built, and batteries have followed it down. But the grid needs power at night and in December too. What would it cost to get one steady megawatt, every half hour of the year, from solar panels and batteries alone, and how does that compare with gas?
Panels and batteries keep getting cheaper
Installed cost of large solar farms and grid batteries, in 2024 pounds.
A grid battery lasts about 15 years, slowly losing capacity, so it is bought twice over a solar farm's 30 years and needs topping up along the way. Those costs are included below.
What one firm megawatt takes
The cost of a firm megawatt
Cost per MWh of power delivered around the clock, all year, in 2024 pounds.
What the answer depends on
How this is worked out, and sources
About the data
Generation by fuel comes from NESO's historic generation mix, half-hourly since 2009 and updated hourly. It includes wind and solar on local networks, which NESO estimates. Fossil fuels here are gas and coal; oil is too small to report separately and sits in "Other".
Battery data comes from Elexon's Insights Solution: each battery unit's Physical Notifications (its planned output, published in real time) and its B1610 metered output (published about five days later). NESO also counts battery discharge inside its "Other" category, and plans to publish batteries separately.
A spell is a run of consecutive half hours that meet the threshold. Gaps in the data of up to an hour are bridged when the half hours either side qualify; longer gaps end the spell.
Inspired by Kate Morley's National Grid: Live. Built by Alex, and the source code is on GitHub.
Contains BMRS data © Elexon Limited copyright and database right 2026. Contains data from the National Energy System Operator, licensed under the NESO Open Data Licence.