​An unconstrained two-hour battery in Germany could have earned €149k/MW/yr in October 2026. That is down 33% from €223k/MW/yr in September, and the lowest since February. Lower aFRR capacity revenue drove most of the fall. Revenues also sat 49% below October 2025, when aFRR capacity paid around three times as much.

The fall is largely seasonal: October marked the switch from a solar-dominated to a wind-dominated system. Solar output fell 42% from September, removing the daily midday troughs that paid batteries all summer. Instead, wind spells now set prices, and they last for days rather than hours. A two-hour battery cycles daily, so it cannot earn as much from a price swing that plays out over a week.

Notably, this happened while gas prices kept rising. TTF front-month averaged €87/MWh in October, up 14% from €76/MWh in September. Higher gas should lift both spreads and ancillary prices. It did neither. Wind explains the spreads; a growing battery fleet explains ancillary prices.

Key takeaways

• An unconstrained two-hour battery could have earned €149k/MW/yr in October, down 33% on September and 49% below October 2025's €294k/MW/yr.
• aFRR capacity revenue fell €39k/MW/yr month-on-month, the largest driver. aFRR-down prices dropped 56% to €6.9/MW/h as the midday solar surplus shrank.
• FCR revenue roughly halved to €18k/MW/yr, as FCR prices fell 30% to €15.7/MW/h, back to their level of a year ago.
• Day-ahead TB2 spreads narrowed 31% to €152/MWh, even as TTF gas rose 14% to an average €87/MWh. Multi-day wind spells pushed prices down for days at a time, which a daily-cycling battery cannot exploit.
• aFRR-up prices in the 16:00 to 20:00 block fell 57% year-on-year, despite higher gas. Procured volumes were flat, so more batteries competed for the same reserve.
• Energy trading made up 37% of the stack, up from 32% in September and 1% a year ago, because ancillary revenue fell faster.

Revenues fell to €149k/MW/yr, the lowest since February

aFRR capacity remained the largest stream, at €78k/MW/yr. Day-ahead trading followed at €47k/MW/yr, then FCR at €18k/MW/yr. Intraday added €7k/MW/yr.

However, the mix looks very different from a year ago. In October 2025, aFRR capacity supplied almost all of the €294k/MW/yr total. This October, day-ahead and intraday together supplied 37%. That shift reflects ancillary price compression as more batteries prequalify, buoyed by stronger wholesale energy earnings.

aFRR capacity and FCR drove the month-on-month fall

Revenues fell in every market from September to October, with the largest signals from aFRR capacity (around €40k/MW/yr) and FCR (€20k/MW/yr).

Notably, most of the aFRR capacity loss came from the downward leg. aFRR-down capacity revenue roughly halved, from €62k to €32k/MW/yr. In contrast, aFRR-up held up better, falling 16% to €46k/MW/yr.