Enervis Battery Storage Index: Revenue growth continues in April
Since the first quarter of 2025, we at enervis 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 April 2025
In April 2025, achievable revenues amounted to around €15,000/MW, representing an increase of 32% compared to March 2025 and 13% compared to April 2024. As was already the case in March, PV feed-in was particularly high and even set new records for the month of April in Germany. This strong PV production led to large price spreads in the day-ahead and intraday markets. At the same time, prices for primary control reserve (FCR) and secondary control reserve (aFRR) showed an upward trend and remained at a comparatively high level. These market conditions largely explain the revenue increase observed in our calculations.
General trends
Achievable monthly revenues have shown significant variation over the past 13 months. The peak was reached in June 2024, at just under €18,000 per megawatt per month, while the lowest value was observed in February 2025 at €6,770 per megawatt. 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. This seasonal pattern is not unique to Germany and can be observed in other markets as well. On average, battery storage systems generated just over €12,600 per megawatt per month in the past year, amounting to approximately €151,000 per megawatt annually.
Current Expected Revenues 2025
In line with the historical methodology, the enervis Battery Storage Index also provides a forward-looking view of revenue expectations for the current year. Based on enervis’ latest electricity price forecasts for the intraday and balancing power markets, the operation of a typical stand-alone battery storage system in 2025 has been modelled.
The achievable revenues for the full year 2025 are still based on our Current Efforts Scenario Q2/2025; no update to the scenario was made this month. The currently projected revenues amount to €147,800/MW/year.
The projected revenues for 2025 remain slightly below the average achievable revenues of the past twelve months, at €147,800/MW/year. However, they are still within the same order of magnitude as shown in the enervis Battery Storage Index. The storage parameters have remained 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 Q2/2025.
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 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.“
Would you like to meet the enervis team? Enervis consultants will be speaking at the Battery Business & Development Forum in Frankfurt on July 16, organized in partnership between Conexio, Solar Power Europe and pv magazine. This one-day forum is tailored for professionals planning or investing in large-scale battery energy storage systems, offering insights into key topics such as grid connection, permitting, technical planning, trading, financing, and regulatory developments. The program will feature market deep-dives into Germany and Italy, alongside broader coverage of the European landscape. Join us for a dedicated networking reception on the evening of July 15, where you can connect with project developers, investors, and industry experts.
For more information, and to register for the event, click here.
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