A battery in Scotland charges six times as often as it discharges
Elexon publishes every accepted bid and offer in the balancing mechanism with the price it was accepted at. Reading a full year of it, unit by unit, shows that a battery in Scotland and a battery in England are doing two different jobs.
| Where | Discharging | Charging | Offer revenue |
|---|---|---|---|
| Scotland, 396 MW placed | 90 h/y | 535 h/y | £10.15/kW/y |
| England and Wales, 2,010 MW placed | 226 h/y | 204 h/y | £24.73/kW/y |
Measured as full power hours a year. Eastern Grampian and Tayside is the extreme: 878 hours a year charging against 84 discharging, better than ten to one.
What the system is using the asset for
In Scotland the balancing mechanism is using batteries as a sink for wind that cannot get south. In England it is calling them up as a resource and paying them to deliver. The same equipment, two different jobs, decided by which side of the constraint it sits.
That sits underneath a fact about the queue: roughly three quarters of the Gate 2 storage book is Scottish. Whether that is a mispricing or a correct read of a future in which the Scottish constraint is worth more than the English one is a commercial judgement. The tool presents both and resolves neither.
The number is one revenue line, not profit
A battery charges through balancing bids and sells that energy in the wholesale market. The cost leg shows in this data and the income leg does not, so net balancing cash is negative for many assets and that is a purchase rather than a loss. Offer revenue, what the system paid to have the asset discharge, is the clean comparable figure and it is the one reported.
How it was checked before it was published
Summing every unit in the market for 6 to 8 August 2026 gives £43.66m against NESO's published balancing cost of £44.83m for the same three days, a ratio of 0.97. The 3% gap is the non balancing mechanism services NESO's total includes and the settlement stack does not. Across the full year the market paid £2,682m in balancing offers, of which batteries took £227.9m, 8.5%.