Europe's Battery Boom Has a Dirty Secret

October 14, 2026-Europe's battery energy storage market is expanding rapidly. Battery energy storage systems (BESS) can absorb surplus solar and wind power when electricity prices are low and discharge electricity during periods of high demand. This helps reduce price volatility and improve the integration of renewable energy into the power grid. However, the market's rapid growth has exposed a contradiction: in some electricity markets, battery storage profitability still depends on price spikes driven partly by coal and natural gas generation.

According to SolarPower Europe, Europe added approximately 36 GWh of battery storage capacity in 2025, bringing its cumulative capacity to more than 100 GWh, roughly ten times the level recorded a decade earlier. The association expected annual additions to exceed 50 GWh in 2026. Germany, Bulgaria and Italy have emerged as important markets for battery storage deployment.

One of the main benefits of battery storage is its ability to address the so-called “duck curve.” During the day, abundant solar generation can exceed electricity demand, pushing wholesale prices toward zero or even into negative territory. In the evening, solar output declines while electricity consumption rises, often causing prices to increase. Battery systems can charge during low-price periods and discharge when prices are higher, helping narrow price differences across the day and reduce renewable energy curtailment.

Bulgaria provides an example of this market dynamic. Analysis of data from the Bulgarian Independent Energy Exchange has indicated that storage operators can capture electricity price spreads exceeding €100 per megawatt-hour during certain periods. Over the preceding six months, Bulgarian electricity prices reportedly declined by around 15% relative to neighboring markets. Other European countries, including Spain, Portugal, Italy, the United Kingdom and Germany, are also deploying storage to make better use of renewable electricity that might otherwise be curtailed.

Despite these benefits, the economics of battery storage remain closely linked to the structure of Europe's electricity markets. Evening peak prices are still influenced by the costs of gas- and coal-fired generation. As a result, storage operators can earn revenue by buying electricity when prices are low and selling it when prices rise. In some markets, this means that the profitability of battery storage remains partly dependent on the continued presence of fossil-fuel generation.

Government policies also play an important role. Capacity mechanisms are designed to ensure sufficient electricity supply and maintain grid reliability, but they can also provide financial support to conventional power plants and extend their operating lives. In September 2026, the European Commission approved a German capacity mechanism worth approximately €35.2 billion over 15 years. Italy's capacity mechanism, meanwhile, involved payments of around €1.8 billion in 2025.

These arrangements highlight a broader challenge for Europe's energy transition: ensuring reliable electricity supply while accelerating the retirement of fossil-fuel power plants. Battery storage can help balance intermittent renewable generation, but many conventional battery systems can discharge at full power for only two to three hours. They may therefore be insufficient during prolonged periods of low wind and solar output.

Long-duration energy storage technologies, including iron-air and flow batteries, could help address this limitation. Expanding wind and solar capacity, strengthening electricity grids and improving market incentives for flexible power resources will also be important.

Ultimately, battery storage is expected to become an increasingly important component of Europe's energy system. However, ensuring that storage genuinely accelerates the phase-out of fossil fuels will require coordinated progress in technology, market design, financing and energy policy.