Enervis Battery Storage Index: Revenues rise in March

Energy economics consultancy enervis has been publishing a monthly “Battery Storage Index,” based on historical market data, since the first quarter of 2025. The first publication of the index came in an article on March 13. The index illustrates revenue opportunities for battery energy storage systems, 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.

March revenue figures

Following the initial publication in March, the modeled revenue figures for that month are now available as well as an updated annual forecast for 2025. In March, achievable revenue was €11,300 ($12,900) per megawatt of project scale, slightly above the level of October 2024. Enervis believes this increase is mainly due to high PV feed-in, which has led to increased price spreads in the day-ahead and intraday markets. At the same time, an increase in prices for grid primary control reserve and negative secondary control reserve was observed.

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/MW/month, while the lowest value was observed in March 2024, at €6,750/MW. 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 output 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 energy storage systems generated just under €12,500/MW/month in the past year, amounting to approximately €150,000/MW annually.

Updated revenue potential

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 standalone battery energy storage system in 2025 has been modeled.

The underlying electricity price scenario from enervis was updated to the Q2/2025 scenario for achievable revenue in 2025 as a whole. Compared to the previous, Q1, 2025 scenario, this results in an increase of approximately €13,000/MW/year, bringing the forecast annual revenue to €147,800/MW. Enervis believes this increase is due in particular to an increase in the average daily day-ahead spreads in the model, which are around €10/MWh higher than in the previous scenario.

Despite this update, the projected revenues for 2025 remain slightly below the average values observed over the past 12 months but are still within the same overall range reflected in the enervis “Battery Storage Index.” The modeling parameters for the storage system have remained unchanged.

Methodology: The enervis “Battery Storage Index” shows the monthly net revenues that can be achieved historically, and in the future in Germany, for a 1 MW/2 MWh battery energy 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 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 electricity transmission system operators and the European Power Exchange SE market. 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:

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.“