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France S2 2025 Price Forecast released
October 17, 2025 Clean Horizon’s team is pleased to share the latest update of the Storage Index, offering comprehensive insights into the performance and revenue trends of BESS across Europe.
The Day-Ahead spread rose from €160/MWh to €200/MWh in September, mainly due to the EstLink 1 outage (cutting imports with Finland) and a 50% drop in Latvia’s hydropower production, increasing reliance on fossil generation.
As a result, trading revenues for BESS are at their highest level since the opening of the ancillary services markets in February 2025, even though they still represent a minority share.
Estonia
Overall, there was a slight decrease in revenues of around -14% for 2-hour BESS compared to August. This decline is mainly due to a drop in aFRR capacity revenues, which were cut in half as aFRR capacity prices fell from €116/MW/h to €75/MW/h.
This decrease was partially offset by higher FCR revenues, with FCR prices increasing from €70/MW/h in August to €115/MW/h in September.
Latvia
Revenues remained stable compared to August. The decrease in revenues caused by lower aFRR capacity prices was offset by higher mFRR capacity revenues.
Lithuania
Revenues increased, particularly for 1-hour BESS (+20% compared to August), driven by a sharp rise in mFRR capacity prices, which more than tripled since August (from €30 to €108/MW/h, up + down), as well as by an increase in the aFRR energy spread.
In September, the market values for aFRR capacity and aFRR energy (PICASSO) remained in line with previous months, reflecting stable index performance.
PICASSO spreads closed the month at €250/MWh, with aFRR capacity prices at €51/MW/4h for UP and €47/MW/4h for DOWN.
Day-ahead spreads also held steady at €120/MWh, mirroring the levels observed in recent months.
The decrease in aFRR capacity prices during September, combined with lower volatility in the Day-Ahead market, led to a drop in revenues — particularly for 4-hour batteries.
In contrast to DK1, both Day-Ahead and aFRR energy market volatility slightly increased. This uptick in volatility resulted in a significant improvement in revenues for 4-hour batteries compared to the previous month.
In September, revenues dropped across all BESS durations. Both reservation and activation prices decreased, with an average rate of 31% for primary reserves and 12% for the secondary and tertiary reserves.
On the activation side, low mFRR down prices led to high spreads on this market, averaging €523/MWh this month.
In September, BESS revenues in France declined slightly compared to August, mainly due to a decrease in aFRR capacity reservation prices by 20%.
Revenues in September were significantly higher than in the previous month, with all BESS sizes recording increases of over 33%.
This trend is driven by the net rise in aFRR reservation prices, which have returned to summer levels, averaging over €27/MW/h for each UP and DOWN auction.
Additionally, spreads on the aFRR energy market and Day-Ahead market have risen, with 1-hour and 2-hour BESS benefiting more from these opportunities than the 4-hour BESS.
In September, BESS revenues in Italy saw an increase across all durations, driven by higher volatility in the energy markets within the SUD zone in the country.
Storage revenues remain high on ancillary services, with prices at an average of €36/MW/h on the FCR, €59/MW/h on the aFRR, and €56/MW/h on the mFRR.
The Day-Ahead spread is still skyrocketing in Poland, with an average of €215/MWh in September, offering additional opportunities for storage systems.
In September, the BESS revenues increased by 7% on average for all durations. This revenue augmentation is mainly explained by the increase in the aFRR reservation down prices by 38%, as well as the increase in the aFRR activation (+45%), balancing mechanism (+44%), and DA (+15%) spreads respectively.
In parallel, the aFRR reservation prices up have decreased by 7%.
This month, the 1-hour BESS revenues have increased by 6% compared to last month, while 2-hour and 4-hour BESS revenues are stable.
BESS benefits from good opportunities on FCR-N, with multiple time slots above €60/MW/h, leading to a growing share of the stack coming from this revenue stream.
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