Monthly BESS revenues and market trends, Q2 2026

METHODOLOGICAL UPDATE PORTFOLIO PERFORMANCE

To provide a portfolio performance view that is neutral to asset availability, we introduced methodological updates. Firstly, it applies a data-quality filter to exclude days where an asset was not operational for more than four hours. As a result, revenues from wholesale, aFRR, and FCR on these partial-availability days are removed, which can lead to slightly lower total revenues. However, the same filtering is also applied to the calculation of average marketable power (MW) and energy (MWh), meaning that averages are computed only on fully operational days. This creates a more representative performance metric.

Secondly, duration clustering has been refined. The 2h segment is now defined as 1.51-2.5h rather than extending to 3.5h. This change was requested by asset owners and market participants to create a cleaner benchmark that more closely represents a true 2h asset. The cluster description now also focuses on P10/P90 ranges rather than minimum/maximum values, reducing the influence of outliers.

However, when adjusting for these composition effects, the underlying performance remained nearly identical, confirming that the new methodology improves consistency and robustness rather than materially changing economic outcomes.

Scroll to market updates May 2026 →

Scroll to market updates April 2026 →

Market evolution and BESS revenues June 2026

The 1-hour BESS portfolio generated annualized revenues of EUR 169.3k per marketable MW, representing a 9.0% decrease compared with May. This decline was primarily driven by a 25.3% reduction in aFRR revenues, while FCR revenues remained broadly stable and wholesale revenues increased moderately.

The 2-hour BESS portfolio generated EUR 262.8k per marketable MW per year, an increase of 4.5% month-on-month. The improvement was supported by higher aFRR and FCR contributions, which more than offset a moderate reduction in wholesale-market revenues. Wholesale market conditions strengthened during June:

• Average day-ahead prices increased by 6.8%.
• Intraday VWAP increased by 9.5%.
• All intraday auction prices moved higher, with ID auction 3 increasing by 20.4%.
• The 1-hour and 2-hour day-ahead swap proxies increased by approximately 22%.
• Although the number of negative-price periods declined significantly, overall daily price dispersion increased, indicating that arbitrage opportunities were increasingly driven by intraday price swings rather than extreme negative-price events.

Fundamental conditions were also supportive of higher market activity. Average solar generation increased by 5.0%, average wind generation increased by 4.9%, and average load increased by 8.2%. Ancillary-service prices showed mixed developments:

• aFRR up capacity prices increased by 55.9%.
• aFRR down capacity prices decreased by 18.4%.
• FCR capacity prices increased by 6.6%.

June demonstrated that improving wholesale opportunities alone does not determine portfolio performance. The ability to dynamically allocate capacity between wholesale, FCR and aFRR remained the primary driver of realized revenues.

Key month-on-month market indicators

Key month-on-month portfolio indicators 2-hour BESS (1.51-2.5h)

Key month-on-month portfolio indicators 1-hour BESS (0.9-1.5h)

Portfolio performance: 2-hour BESS portfolio

The 1.51–2.5-hour portfolio generated EUR 262.8k per marketable MW per year in June, compared with EUR 251.6k in May. This represents an increase of 4.5% month-on-month and places the 2-hour portfolio approximately 55% above the 1-hour portfolio in annualized revenue terms. The improvement was primarily driven by ancillary services:

• FCR revenues increased by 57.4%, although FCR remained a relatively small revenue stream for the longer-duration portfolio.
• Wholesale revenues decreased slightly by 3.2%, from EUR 55.9k to EUR 54.0k per marketable MW per year.
• Average cycling increased from 1.24 to 1.36 FCE per day, indicating more intensive utilization during June. Average utilized duration remained stable at approximately 2.07 hours per day.

aFRR remained the dominant revenue stream, accounting for approximately 76% of total June portfolio revenues. Wholesale markets contributed approximately 21%, while FCR represented around 3%.

Portfolio performance: 1-hour BESS portfolio

The 0.9–1.5-hour portfolio generated EUR 169.3k per marketable MW per year in June, compared with EUR 186.0k in May. The portfolio therefore recorded a 9.0% month-on-month decline, despite improving wholesale arbitrage conditions. The decrease was mainly attributable to aFRR:

• aFRR revenues declined from EUR 73.1k to EUR 54.6k per marketable MW per year.
• This represents a reduction of 25.3%.
• FCR revenues remained broadly unchanged at approximately EUR 95.2k per marketable MW per year.
• Wholesale revenues increased by 7.7%, from EUR 18.2k to EUR 19.6k per marketable MW per year.

The portfolio’s average cycling increased from 0.81 to 0.94 FCE per day, consistent with the improvement in wholesale-market spreads and swap proxies. Average utilized duration remained stable at approximately 1.18 hours per day. FCR continued to represent the largest revenue contribution for the 1-hour portfolio, accounting for approximately 56% of June revenues, compared with around 32% from aFRR and 12% from wholesale markets.

Wholesale markets

German wholesale electricity prices increased across all observed reference markets during June. The average day-ahead price rose from EUR 102.50/MWh to EUR 109.50/MWh, an increase of 6.8%. Intraday prices increased even more strongly:

• ID VWAP: +9.5%
• ID auction 1: +10.4%
• ID auction 2: +10.6%
• ID auction 3: +20.4%

ID auction 3 recorded the strongest increase and became the highest-priced monthly reference market in June, averaging EUR 119.11/MWh. The day-ahead swap proxies confirm that arbitrage conditions improved:

• The 1-hour, one-cycle proxy increased from EUR 181.48 to EUR 221.25 per MW per day.
• The 2-hour, one-cycle proxy increased from EUR 337.20 to EUR 411.82 per MW per day.

Both indicators increased by approximately 22%, suggesting that the theoretical value of shifting energy between the lowest- and highest-priced hours strengthened materially. This improvement was reflected in higher cycling rates for both portfolio groups. However, the impact on realized wholesale revenues differed:

• The 1-hour portfolio increased its wholesale revenues by 7.7%.
• The 2-hour portfolio recorded a 3.2% decrease in wholesale revenues.

The difference illustrates that realized portfolio performance depends not only on observable wholesale spreads, but also on capacity allocation, ancillary-service commitments, asset constraints, and the timing of available trading opportunities.

Ancillary services and balancing markets

aFRR up

Average aFRR up capacity prices increased from EUR 10.05 to EUR 15.66 per MW per day, representing a strong 55.9% recovery. This indicates tighter conditions for upward reserve procurement during June. Potential drivers include higher system load, changing renewable production patterns, reduced availability of flexible upward capacity and periods of tighter residual system margins.

aFRR down

Average aFRR down capacity prices decreased from EUR 22.10 to EUR 18.04 per MW per day, a decline of 18.4%. Despite the decrease, aFRR down prices remained above aFRR Up prices on average. The decline suggests that downward flexibility was comparatively more available or less scarce during June.

FCR

Average FCR prices increased from EUR 22.71 to EUR 24.22 per MW per day, representing a 6.6% month-on-month increase. The impact on the two portfolios differed substantially:

• The 1-hour portfolio’s FCR revenue remained nearly unchanged.
• The 2-hour portfolio’s FCR revenue increased by 57.4%, although from a relatively low base.

Portfolio implications

The 2-hour portfolio continued to derive most of its value from aFRR, generating more than EUR 200k per marketable MW per year from aFRR energy and capacity revenues. For the 1-hour portfolio, lower realized aFRR revenues outweighed improving aFRR Up market prices. This indicates that market average prices should not be interpreted as a direct predictor of portfolio revenue. Results also depend on accepted volumes, directional allocation, asset availability, activation volumes, bidding strategy and opportunity costs relative to other markets.

Fundamentals: renewables and load

Average renewable generation increased during June:

• Solar generation increased by 5.0%, from 58.46 GW to 61.36 GW.
• Wind generation increased by 4.9%, from 7.94 GW to 8.33 GW.

At the same time, average load increased substantially from 48.39 GW to 52.34 GW, representing growth of 8.2%. The stronger increase in electricity demand partly offset the additional renewable generation, contributing to firmer wholesale prices. Instead, average prices increased across both day-ahead and intraday markets. Higher solar production can create lower midday prices and steeper evening ramps, while stronger load can support higher peak-hour prices. This combination is generally favorable for battery arbitrage when it widens the difference between charging and discharging periods.

Market evolution and BESS revenues May 2026

May delivered another strong month for battery storage optimization in Germany, with both 1-hour and 2-hour BESS portfolios maintaining annualized revenues above EUR 180k/MW/year and EUR 250k/MW/year respectively. Wholesale power prices recovered significantly compared with April. German day-ahead prices increased by 39.2% month-on-month to EUR 102.50/MWh, while intraday VWAP increased by 34.8% to EUR 102.88/MWh. However, higher average price levels did not translate into stronger arbitrage conditions for storage assets.

Compared with April, May recorded fewer negative-price events and lower average price spread. Negative day-ahead quarter-hours declined by 36.0% month-on-month (492 to 315), while the daily price-spread proxy decreased by 16.0%. As a result, the number of attractive charge-discharge opportunities was lower, particularly for longer-duration assets. Both 1-hour and 2-hour assets continued to benefit from:

• Strong participation opportunities in balancing and reserve markets
• Recurring negative-price periods during high-solar production hours
• Solar-driven intraday price spreads and evening ramping events
• Continued demand for system flexibility and reserve capacity

These conditions reinforced the value of flexible storage assets capable of dynamically allocating capacity between wholesale and ancillary service markets. While average market prices increased significantly, portfolio performance remained primarily driven by the availability of spread opportunities and ancillary-service revenues rather than outright power price levels.

Key month-on-month market indicators

Note: Daily price-dispersion proxy = max(DA auction, ID VWAP, ID Auction 1, ID Auction 2, ID Auction 3) minus min of the same daily reference prices. Values are monthly averages of daily spreads.

Key month-on-month portfolio indicators

Portfolio performance

The 1-hour portfolio achieved its strongest performance of 2026 to date, increasing annualized revenues from EUR 180k/MW/year to EUR 186k/MW/year (+3.1% MoM). Importantly, this revenue growth was achieved despite lower cycling intensity. Average throughput decreased from 1.08 to 0.98 FCE/day (-9.7%), while average operating duration increased slightly from 1.17h/day to 1.19h/day (+2.0%). This indicates that revenue quality improved during May, with each cycle capturing more value.

Although average wholesale prices increased significantly in May, the market offered fewer high-value arbitrage opportunities for longer-duration assets. The frequency of negative-price events declined materially, with negative day-ahead quarter-hours falling by 36% month-on-month (492 to 315), while the daily price-dispersion proxy decreased by 16%. As a result, the number of economically attractive charge-discharge opportunities was lower than in April, reducing average cycling from 1.42 to 1.24 FCE/day. Consequently, annualized revenues declined modestly by 2.2% to EUR 251.6k/MW/year.

Day-ahead and intraday markets

Wholesale price levels rebounded in May. Average day-ahead rose from 73.64 to 102.50 EUR/MWh (+39.2%), while ID VWAP increased from 76.31 to 102.88 EUR/MWh (+34.8%). ID Auction 3 had the sharpest recovery, rising from 55.44 to 98.89 EUR/MWh (+78.4%).

Despite higher average prices, daily cross-reference price dispersion moderated during May. The daily dispersion proxy declined from EUR 164k/MW/year in April to EUR 138k/MW/year in May (-16.0% MoM). At the same time, negative day-ahead price periods became less frequent, with negative quarter-hours falling by 36.0% MoM. This reduced the number of high-value charging opportunities available to storage assets, helping explain why battery revenues did not increase in line with wholesale price levels.

The reduction of the SDAC day-ahead price floor from -500 EUR/MWh to -600 EUR/MWh highlights the growing influence of solar-driven oversupply events in European power markets. Although May recorded fewer negative-price periods than April, the new price boundary increases the potential value of future extreme charging opportunities for battery storage assets.

Ancillary services and balancing markets

Capacity prices were mixed. aFRR up decreased from 10.96 to 10.05 EUR/MW/day (-8.3%), aFRR down increased from 21.54 to 22.10 EUR/MW/day (+2.6%), and FCR slipped from 23.72 to 22.71 EUR/MW/day (-4.2%). The two duration buckets responded differently to May's market conditions. The 1-hour portfolio achieved a modest increase in annualized revenues despite fewer negative-price events, supported by strong participation in ancillary service markets. The 2-hour portfolio maintained annualized revenues above EUR 250k/MW/year, although total revenues declined slightly as fewer high-value opportunities resulted in lower cycling activity (1.24 FCE/day versus 1.42 FCE/day in April). Across both duration buckets, aFRR capacity revenues remained the largest contributor to total portfolio revenues, providing a stable revenue foundation alongside wholesale market optimization opportunities.

Extreme price events and special days

May remained supportive for battery optimization, although negative-price events were less frequent than in April. Germany recorded 315 negative day-ahead quarter-hours (78.8 hours) during May, compared with 492 quarter-hours (123.0 hours) in April, representing a 36.0% month-on-month decline. Despite the reduction in negative-price frequency, solar-driven midday price depressions continued to create attractive charging opportunities for BESS assets. These low-price periods were frequently followed by stronger evening price recovery, allowing optimized portfolios to capture value from within-day volatility. The strongest trading day of the month occurred on 27 May, EUR 674.71/MW/day for 1-hour assets and EUR 802.56/MW/day for 2-hour assets, highlighting the continued value of storage duration during periods of elevated price dispersion.

Fundamentals (renewables, load) and key takeaways

May moved further into the solar-heavy spring regime. Average solar generation increased from 13,562 to 14,615 MW (+7.8%), while wind declined from 13.5GW to 9.13 MW (-29.5%). Average load fell from 50,783 to 48,387 MW (-4.7%). As renewable penetration continues to increase, the ability to dynamically allocate capacity between wholesale and ancillary-service markets remains a key driver of value creation for battery storage assets. While May contained fewer negative-price events and narrower average spreads than April, optimized portfolios continued to benefit from recurring low-price charging opportunities, evening demand ramps, and robust reserve-market revenues.

Market evolution and BESS revenues April 2026

For the 1.51-2.5h BESS portfolio in Germany, annualized PnL increased from EUR 180,795.30 per marketable MW in March to EUR 257,383.45 in April (+42.4%). Average daily cycling rose from 1.39 to 1.42 FCE/day. For the 0.9-1.5h BESS portfolio in Germany, annualized PnL increased from EUR 136,496.87 per marketable MW in March to EUR 180,345.68 in April (+32.1%). Average daily cycling was broadly stable at 1.08 FCE/day.

April extended the March recovery rather than reversing it. The uplift was no longer driven by higher outright wholesale prices: Average day-ahead and intraday reference prices fell month-on-month. Instead, realized battery revenues were supported by stronger reserve capacity prices, higher aFRR energy monetization, and wider intraday dispersion linked to high solar output, low wind, and lower system demand.

Key month-on-month market indicators

Key month-on-month portfolio indicators

Wholesale markets (DA and ID)

Wholesale price levels weakened in April even as battery revenue remained strong. The average German day-ahead price declined from EUR 99.25/MWh in March to EUR 78.52/MWh in April (-20.9%). ID VWAP (Intraday volume-weighted average price) declined from EUR 98.80/MWh to EUR 79.79/MWh (-19.2%). The sharpest move was in ID auction 3, which fell from EUR 103.63/MWh to EUR 59.25/MWh (-42.8%).

However, price dispersion improved. A simple daily spread proxy across day-ahead, ID VWAP, and ID auction references increased from EUR 20.70/MWh in March to EUR 25.64/MWh in April (+23.9%). The maximum daily proxy widened to EUR 95.52/MWh on 2026-04-25, confirming that the month contained deeper short-term dislocations despite lower average price levels.

Ancillary services and balancing markets

The balancing complex was again the main source of support. Average daily aFRR capacity revenue increased from EUR 3,071/MW/day in March to EUR 3,493/MW/day in April (+13.7%). Average daily energy arbitrages revenue increased from EUR 272/MW/day to EUR 554/MW/day (+103.4%), making activation energy a much larger contributor than in March.

At the product level, aFRR up capacity prices increased from EUR/MW/day 10.27 to 11.16 (+8.6%), aFRR down capacity increased from EUR/MW/day 11.83 to 20.47 (+73.1%), and FCR capacity increased from EUR/MW/day 16.64 to EUR 22.95 (+37.9%).

Extreme price events and special days

The stronger April revenue profile was mainly linked to structural changes in renewable generation and system balance. Wind generation remained relatively subdued during several high-value periods, tightening the system and increasing scarcity in the balancing market. At the same time, solar output increased materially versus March, creating deeper midday price depressions followed by steeper evening ramps. This widened intraday spreads and improved arbitrage opportunities for BESS assets.

The exceptional peak on 26 April was likely driven by a combination of low residual load flexibility, sharp renewable ramps, and elevated reserve-capacity prices. High solar penetration during daytime hours compressed midday prices, while weaker wind and stronger evening demand recovery generated significant upward price corrections later in the day. These conditions typically increase both wholesale spread capture and ancillary-service revenues simultaneously.

Fundamentals: renewables and load

Fundamentals shifted further into a spring solar regime. Average solar generation increased from 9,664 MW in March to 13,367 MW in April (+38.3%), while average wind generation fell from 3,118 MW to 2,535 MW (-18.7%). Average load declined from 54,335 MW to 51,379 MW (-5.4%).

The combination of materially higher solar, lower wind, and lower demand created deeper daytime charging opportunities and steeper residual-load ramps. Lower wind also supported reserve scarcity conditions. The result was a market environment in which average wholesale prices fell, but batteries still captured stronger spread, balancing, and reserve monetization opportunities.