Enervis Battery Storage Index: Slight recovery in January, but still weak winter levels

Since the first quarter of 2025, Enervis has been publishing a monthly Battery Storage Index based on historical market data, reflecting revenue opportunities for battery storage systems. The index is based on historical market data and illustrates revenue potential from participation in both the intraday market and the balancing power markets. For each month of the past 13 months, the respective achievable revenues are reported.

Source: Enervis

New revenue figures for January 2026

Achievable BESS revenues in January recovered following the historic low reached in December 2025. Revenues increased to approximately €7,000 per megawatt, representing a 40% rise compared with December, but remaining 19% below January 2025 levels. Spreads in the spot markets remained relatively weak but were on average higher than in December, mainly driven by two pronounced day-ahead price peaks on 8 and 20 January, which temporarily widened spreads and modestly improved arbitrage opportunities for battery storage systems. At the same time, ancillary services prices remained at low levels, continuing to constrain overall revenue potential.

General trends

Monthly achievable revenues have fluctuated considerably over the past 13 months. The maximum was reached in May 2025 at €19,100 per megawatt per month, while the minimum occurred in December 2025 at €5,000 per megawatt per month.

Battery revenues tend to be higher during the summer months. This is primarily due to strong photovoltaic generation during these months combined with comparatively lower overall electricity demand. In addition, conventional generation capacity is seasonally less available during summer, partly due to maintenance activities and potentially lower efficiency of gas-fired power plants at high temperatures. Wind availability is also typically lower during summer compared to winter or autumn months. As a result, short-term feed-in fluctuations or forecast deviations in PV generation during summer months lead to greater market volatility. This is directly reflected in more intensive trading activity in the intraday market.

Over the past twelve months, battery storage revenues averaged just above €12,230 per megawatt per month (approximately €146,800 per megawatt on an annual basis).

Expected revenues 2026

Similar to our approach to historical data, the Enervis Battery Storage Index also offers a glimpse into the future. Based on our current electricity price forecasts, the deployment of a typical stand-alone storage system is modelled for the year 2026.

The projection of achievable revenues continues to be based on our Current Efforts Q1/2026 scenario; no update of the scenario was carried out this month. The forecast revenues currently amount to €145,900 per megawatt per year. This is slightly below the average achievable revenues of the past twelve months, but still within a comparable range, as shown in the Enervis Battery Storage Index. Storage parameters were kept unchanged.

Methodological Explanation: The Enervis Battery Storage Index shows the historically and future achievable monthly net revenues (contribution margins) in Germany for a 1-megawatt capacity battery storage system with a 2-megawatt-hour operating volume (2 hours). The storage system was modeled with an operating restriction of 1.5 cycles per day, a depth of discharge of 90 percent, a technical availability of 97 percent, and a cycle efficiency of 87 percent. The index considers participation in the following revenue markets: intraday, primary control reserve, and secondary control reserve. Imperfect forecasting is used, and revenues from the marketing of secondary control reserve are not included. The respective market prices for the historical analysis are derived from publications by the transmission system operators and EPEX Spot. The future outlook is based on the same modeling, parameters, and prices from the current Enervis electricity price scenario, Current Efforts Q1/2026.

Further information:

More detailed analysis and the full report can be requested here.

About the 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 is a consultant at enervis energy advisors, where he is responsible for battery energy storage related topics. In addition to his tasks in revenue assessment and profitability analysis of battery energy storage projects, he developed the enervis “BESS Index” and the associated “BESS Index Report.“