Revenues in Great Britain fell 6% month-on-month to £69k/MW/year in April 2026, down from £74k/MW/year in March, and 4% below April 2025's £72k/MW/year. The headline decline masked a shift in how batteries earned: April featured no distinct bias between markets, with wholesale arbitrage and the Balancing Mechanism contributing positive revenues to the revenue stack.

That balance is a return to normal after March and February's bias towards wholesale imports and Balancing Mechanism exports.

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

• A breakdown of revenue changes across each service
• How record solar generation impacted wholesale spreads
• Why Balancing Mechanism revenues fell so drastically from March
• Reserve revenues rising in April
• A data download of all charts

Wholesale and the Balancing Mechanism contributed evenly to the stack

April's revenue stack reflected a more typical month, compared to the wholesale-import, Balancing Mechanism-export bias seen in March and February. Wholesale revenues averaged £23k/MW/year.

The Balancing Mechanism is structurally the most volatile market in Great Britain, and the most valuable when batteries sell power. In April, Balancing Mechanism revenue reduced by £35k/MW/year, wholesale revenue rose to compensate, but the net result was a £5k/MW/year loss reduction.

Frequency Response revenues lifted slightly, supported by the introduction of Slow Reserve, which reduced overall saturation across the ancillary stack. Reserve revenues rose £0.8k/MW/year MoM on the back of higher Quick Reserve prices and the new Slow Reserve service.

Wholesale Market revenues

Intraday spreads hit 11-month high

Average daily intraday spreads widened to £97/MWh in April, up from £94/MWh in March. Day-ahead spreads compressed 11% to £79/MWh from March's £89/MWh, leaving an £18/MWh premium between intraday and day-ahead.