Germany’s operating batteries, 4.3 GW, are now larger than all three reserve markets the grid buys, about 3.2 GW.
Until recently Germany’s large batteries were built almost entirely to hold reserve for the grid, as RWTH Aachen’s Battery Charts records. The fleet passed the combined size of those markets in April 2026. A battery that cannot win reserve has the day-ahead and intraday markets left, and the day-ahead spread is the public measure of what those pay. This page shows both from public data, and says what it cannot show.
The fleet against the reserve markets
Operating battery power by the month each unit was commissioned, units of a megawatt or more that operate today, from the register’s export of 15 October 2026; 1.1 GW was commissioned before 2023. The dashed line adds the three reserve markets below. A battery can hold several products in turn, and other plants compete for them, so the line shows the size of the markets for comparison.
| Reserve market | What the grid buys |
|---|---|
| FCR | the German share of the 3 GW the continental grid holds, 562 MW in 2021 and adjusted each year Next Kraftwerke |
| aFRR | about 2 GW, as currently dimensioned BayWa r.e., March 2026, from the transmission companies’ figures |
| mFRR | about 0.6 GW, as currently dimensioned BayWa r.e., March 2026, from the transmission companies’ figures |
Batteries prequalified to offer reserve already exceed what the grid buys of the fastest product. On 1 January 2026 the transmission companies listed 1.35 GW of batteries prequalified for FCR, 1.20 GW for upward and 1.20 GW for downward aFRR, and 0.37 and 0.36 GW for mFRR (regelleistung.net, prequalified capacity in Germany by technology).
The day-ahead spread, month by month
The two hour spread in Germany and Luxembourg: each day, the average of the eight dearest quarter hours of the day-ahead auction less the average of the eight cheapest, in euros per megawatt hour, averaged over the month. It is what a two hour battery is paid to buy low and sell high once a day, before losses. October 2026 is to 17 October 2026 and drawn paler. Source: Bundesnetzagentur | SMARD.de, CC BY 4.0. Every country, day by day.
Over the twelve full months to September 2026 the spread averaged €141 per megawatt hour. It ran from €62 in December 2025 to €219 in September 2026: wide in the months of strong sun, narrow in winter.
What reserve capacity paid
The transmission companies publish every reserve auction result on regelleistung.net, and its terms ask for written consent before the results are reproduced. We have not yet asked, so this page quotes a published summary of them.
| Product | 2024, € per MW | 2025, € per MW |
|---|---|---|
| FCR | 143,046 | 142,401 |
| aFRR, upward | 115,428 | 120,162 |
| aFRR, downward | 95,258 | 94,161 |
| mFRR, downward | 70,163 | 69,956 |
| mFRR, upward | 30,159 | 32,687 |
Capacity payments over a whole year for one megawatt held every hour, as summarised by BayWa r.e., March 2026 from the transmission companies’ results. Energy payments for reserve actually used come on top and are not included.
What this page cannot show
Intraday prices are sold by the exchange, EPEX SPOT, and are not public. No German battery’s output is published, so what any one battery earned is unknown; the battery pages say so one by one. This page therefore shows what the markets offer.