Revenues in Great Britain fell 13% to £56k/MW/year in August 2026, down from £65k/MW/year in July and 7% below August 2025's £61k/MW/year. Wholesale revenues climbed to their highest since September 2021 while the Balancing Mechanism fell to its worst revenues on record, as batteries continued the trading behaviour seen in July.

Gas rose to its highest monthly average since December 2022, pulling day-ahead prices to £128/MWh and keeping spreads among the widest of the past twelve months.

Dispatch in the Balancing Mechanism went the other way. NESO took 5% of the battery offers that were in merit in August, less than half the rate of a year ago and the lowest in at least twelve months, even though those offers undercut gas by £35/MWh. NESO is trying to improve battery dispatch, but it’s getting worse.

For subscribers to Modo Energy's Research, this article will also cover:

• A breakdown of revenue changes across each service
• Why higher wholesale prices did not produce higher revenues
• Why the strongest wholesale revenues since 2021 and the worst Balancing Mechanism revenues on record are two halves of one trade
• Why NESO dispatched 5% of the battery offers that were in merit, against 12% a year ago
• A data download of all charts

Batteries continued to trade between wholesale and the Balancing Mechanism

Wholesale revenues reached £44k/MW/year in August, £2k above July and their highest since September 2021. The Balancing Mechanism dropped a further £4k to -£17k/MW/year.

Batteries charge on Balancing Mechanism bids and discharge into the wholesale market, so the cost lands in one market and the revenue in the other. It is an increasingly common trade, and a continuation of the one we ran through in detail in July.

Elsewhere, Frequency Response fell £2k to £16k/MW/year and Imbalance £3k to £4k/MW/year, though the Imbalance figure is likely to rise slightly once further settlement runs are calculated. Reserve and the Capacity Market barely moved, at £3k and £6k/MW/year.

Wholesale Market revenues

Day-ahead spreads reached £81/MWh, the third widest in twelve months

Average daily day-ahead spreads widened to £81/MWh in August, up from £78/MWh in July, with intraday spreads at £96/MWh. Only June and March this year beat August on the day-ahead spread, against a twelve-month average of £68/MWh.

Batteries sell into the top of the curve, and gas is what sets it, so the widest months of the past year have been the expensive-gas months.