Germany approved thousands of new batteries last year, with capacity comparable to pumped-storage plants

German grid operators last year concluded grid connection agreements for large battery storage facilities with capacity approaching the total storage capacity of Germany’s pumped-storage power plants. However, these projects currently exist only on paper, and it is uncertain how many will ultimately be delivered. The rapid growth of the battery storage sector is not only increasing pressure on grid capacity, but also on the economics of new investments. The Czech market faces a similar test.

German grid operators according to Clean Energy Wire last year concluded nearly 2,000 grid connection agreements for battery storage facilities with 54.2 GW of power and 142.4 GWh of capacity. The volume of approved capacity thus shows how quickly battery storage is moving to the forefront of Germany’s power sector transformation.

The scale of the newly concluded agreements is particularly striking compared with Germany’s pumped-storage power plants. The country operates 28 pumped-storage facilities with a combined capacity of 6.2 GW and storage capacity of around 147 GWh. The capacity of batteries with connection agreements from last year alone therefore almost matches the long-established storage capacity of pumped-storage facilities.

At present, approximately 1,300 battery projects with 6.2 GW of power and around 6 GWh of capacity are connected to Germany’s distribution and transmission grids. The connection agreements therefore primarily represent an exceptionally large project pipeline, rather than a picture of the future system.

Negative prices increase the value of flexibility

The economic basis of the battery boom is being strengthened by volatility in the German market. Wholesale electricity prices in Germany were negative for 573 hours last year, or 6.5% of the time. During these periods, storage operators can buy cheap or negatively priced electricity and sell it later at higher prices, for example during evening demand peaks, when photovoltaic generation falls sharply.

The pace of new applications is not slowing either. By the beginning of April this year, transmission system operators alone had concluded 64 new agreements for projects with 24.7 GW of power and 55.4 GWh of capacity.

Alongside genuine investment plans, however, speculative projects are also burdening the system. The German regulator recorded more than 10,000 applications to connect battery storage facilities last year at the high-voltage level, with combined power of around 400 GW and capacity of 661 GWh. Such a volume far exceeds both the needs of the German system and the market’s investment capacity.

Batteries are not the only ones competing for grid capacity

Pressure on grid capacity does not concern battery storage facilities alone. Data centres, industrial electrification projects, large heat pumps and charging infrastructure operators are also competing for connections. German transmission system operators therefore want to abandon the first-come, first-served system and plan to assess applications in regular rounds.

Decisions are to be based on transparent criteria, such as the status of the permitting process, land secured, the technical readiness of the connection and the project’s benefit to the system. The aim is to prevent capacity from being blocked by speculative applications while favouring projects with a genuine chance of being delivered.

The Czech market faces a similar test

For Czechia, both the pace of battery storage deployment and how quickly new capacity will affect electricity market prices are key. According to data from the AKU-BAT association, 318 MWh of battery storage capacity was commissioned in Czechia during the first half of 2026.

Domestic electricity distribution companies are also recording a substantial volume of connection applications from battery storage facilities. For example, ČEZ Distribuce had recorded requests for battery capacity totalling 258 GWh by the end of last November. E.GD is also seeing strong interest in connecting battery storage facilities, having recorded more than 2,000 applications with total storage capacity of roughly 38 GW by the end of last year.