Enervis Battery Storage Index: Revenues plunge to winter lows in November

Since the first quarter of 2025, at Enervis, we have been publishing a monthly Battery Storage Index based on historical market data. The first publication of the index was presented in an initial article in March 2025. The index illustrates revenue opportunities for battery storage systems by accounting for participation in both the intraday and balancing power markets. It provides an overview of achievable revenues for each of the past 13 months.

New revenue figures for November 2025

Achievable BESS revenues in November amounted to around €7,100 per megawatt, falling to the lowest levels observed since February 2025. This corresponds to a 47% decrease compared with October and stands 24% below November 2024. In November, average price levels remained relatively elevated overall, with only a few pronounced price spikes, except during November 25–26. In parallel, ancillary services prices continued their downward trend, reaching levels comparable to those seen towards the end of last winter, further underscoring the limited revenue opportunities.

General trends

The monthly achievable revenues have fluctuated significantly over the past 13 months. They ranged from a low of €6,800 per megawatt per month in February 2025 to a peak of €19,100 per megawatt per month, reached in May 2025. Revenues tend to be higher during the summer months, largely due to strong PV generation combined with relatively low overall electricity demand. In addition, conventional generation capacity is typically lower during summer, partly because of scheduled maintenance and, in the case of gas-fired power plants, potentially reduced efficiency under high ambient temperatures. Wind generation availability also tends to decline in summer compared to autumn and winter. As a result, short-term fluctuations or forecast errors in PV feed-in lead to increased market volatility during these months reflected in more dynamic activity on the intraday market. On average, battery storage systems generated almost €12,780 per megawatt per month in the last twelve months, amounting to approximately €153,400 per megawatt annually.

Expected revenues for 2026

Analogous to the approach used for the historical analysis, the Enervis Battery Storage Index also provides a forward-looking perspective. Based on our current power price forecasts, the operation of a typical stand-alone battery storage system is modelled for the year 2026.

The achievable revenues projected for 2026 continue to be based on our Current Efforts scenario Q4/2025, as the scenario was not updated this month. Forecast revenues currently amount to €149,600 per megawatt per year.

With annual revenues of €149,600 per megawatt, the 2026 forecast lies slightly below the average achievable revenues of the past twelve months, but remains within a comparable range, as shown in our Battery Storage Index. The storage parameters were kept unchanged.

Methodological explanation: The Enervis Battery Storage Index shows the monthly net revenues that can be achieved historically and in the future in Germany for a 1 megawatt capacity and 2 megawatt hours storage volume (2 hours) battery storage system. The storage system was modeled with a use restriction of 1.5 cycles per day, a maximal depth of discharge of 90%, a technical availability of 97% and a round-trip efficiency of 87%. The index takes into account participation in the following markets: Intraday, Frequency Containment Reserve (FCR) and automatic Frequency Restoration Reserve (aFRR). Imperfect foresight and no revenues from aFRR energy are modeled. The respective prices of the markets for the historical analysis are taken from publications of the transmission system operators and EPEX-Spot. The future outlook is based on the same modeling and parameters and prices from the current Enervis power price scenario Current Efforts Q4/2025.

Further information:

If you are interested in a more detailed analysis and the full report, you can request it here.

Authors:

Mirko Schlossarczyk – Managing Director of enervis energy advisors is an experienced energy market expert. His consulting focus is on electricity price forecasts, electricity market scenarios and the asset valuation of BESS.

Jonas Anthonioz – Consultant at the energy economics consultancy enervis energy advisors, where he is responsible for battery storage-related topics. In addition to his usual tasks in revenue assessment and profitability analysis of battery storage projects, he developed the enervis BESS Index and the associated BESS Index Report.