Storage
Storage covers pumped hydro and battery systems. Positive figures mean storage is discharging (generating); negative figures mean it is charging (consuming power to store for later).
- Current output
- 0.79GW
- Share of generation
Breakdown
| Source | GW | % |
|---|---|---|
| Pumped hydro | 0.79 | 2.7 |
| Battery | - | - |
Battery charge/discharge over the last 24 hours
Positive values mean batteries are discharging onto the grid; negative values mean they're charging up, usually when power is cheap or abundant.
History
Storage output
Share of total generation
Storage output and share of total generation over the selected range.
About storage
Pumped hydro stations, such as Dinorwig in Wales, pump water uphill when power is cheap or abundant, then release it through turbines within seconds when demand spikes - acting as a giant battery for the grid.
Dinorwig and the birth of grid-scale storage
Dinorwig power station, built inside a mountain in Snowdonia and completed in 1984, remains one of the most remarkable feats of British energy engineering. Nicknamed "Electric Mountain", it can go from a standing start to generating 1.7GW of power in under 16 seconds, historically used to cover the sudden surges in demand that occur, famously, when millions of kettles are switched on during breaks in televised events. Britain's other major pumped storage sites - Ffestiniog (1963), Cruachan in Scotland (1965), and Foyers (1974) - are older still, built as some of Europe's earliest large-scale grid storage.
The rise of batteries
Grid-scale battery storage is far newer, with the first significant projects connecting in the mid-2010s as lithium-ion battery costs fell sharply. Battery capacity has since grown far faster than pumped hydro ever could, because battery sites can be built in months rather than the decade-plus required for a new pumped storage scheme, and can be sited almost anywhere on the network.
Batteries typically discharge for shorter bursts than pumped hydro - commonly half an hour to two hours - making them well suited to smoothing short-term mismatches between renewable output and demand, and to providing fast frequency response that keeps the grid stable moment to moment.
The Elexon Insights Solution currently only reports battery discharging, not charging. Charging figures aren't shown here to avoid double-counting generation elsewhere on the system; giving a fuller picture of battery storage, including charging, is one of this site's future plans.
The Elexon Insights Solution currently only reports battery discharging, not charging. Charging figures aren't shown here to avoid double-counting generation elsewhere on the system; giving a fuller picture of battery storage, including charging, is one of this site's future plans.
With the toggle above switched on, this shows a combined view: battery output swinging between charging (drawing power to store, shown as negative) and discharging (feeding power back out, shown as positive) across the day. Reporting charging live safely, without double-counting generation recorded elsewhere, needs a second data source alongside Elexon - most likely each battery operator's own metering, or a market-wide feed such as Modo Energy - which is why this view is still a placeholder rather than a live feed.
Sources
- Dinorwig Power Station, Ffestiniog, Cruachan and Foyers - Wikipedia.
- Elexon - on current battery-discharge-only reporting in the Balancing Mechanism.
Records
The Dinorwig facts below are real and sourced, hand-checked periodically against the sources below (see "Last checked") rather than computed live from this site's own stored history, which for a fresh install would only cover a few days or weeks rather than a full year.
- Highest pumped storage discharge (this year)2.7GW - 8 January 2026
- Dinorwig start-to-full-power timeunder 16 seconds
- Dinorwig opened1984
Source: National Energy System Operator (Elexon BMRS for the "this year" figure) and First Hydro Company, Dinorwig Power Station. Last checked: 4 September 2026.