Zelestra, Centrica Sign Toll Deal for 99MW/297MWh BESS in Germany

IPP Zelestra has agreed a long-term toll for a 99MW/297MWh BESS project in Germany with the trading arm of UK-based power group Centrica.

The tolling agreement covers the 99MW/297MWh standalone Hilgermissen battery energy storage system (BESS) and enables Zelestra to proceed to construction. It is located in Lower Saxony, northwest Germany.

Zelestra will build, own and operate the system while Centrica Energy will trade and optimise the contracted capacity, in return for paying Zelestra a fixed fee. It effectively sees Centrica Energy rent the capacity from Zelestra.

Construction will start in 2027 for full operations in the second half of 2028.

Germany has a growing renewable energy fleet which is creating huge opportunities in its wholesale energy market, Europe’s deepest, while ancillary services are also a meaningful revenue source. Zelestra is also deploying solar and wind in Germany.

Large-scale BESS activity has ramped up in the country after regulators confirmed a 4 August 2029 deadline for projects to come online and avoid charge-discharge grid fees, though there are still numerous policy questions to be ironed out. That includes the long-term grid fee situation.

These will be discussed at the Energy Storage Summit Germany 2026, which runs on 15-16 September 2026 in Berlin (use our code ESN20 for a 20% discount on tickets).

It is the latest in a series of recent announcements for BESS offtake deals for both companies across Europe.

Zelestra has secured tolls for two BESS projects in Italy at the end of July, with offtakers Axpo and EnBW. In April, it secured a power purchase agreement (PPA) for a solar-and-storage project in Spain, with Portugal-based power group EDP. And in May it energised a solar-and-storage project Chile, which already had a long-term PPA in place.

Zelestra executives discussed the companies tolling and PPA activity in Italy and Spain for a Q&A piece in the Energy Storage Report 2026, published earlier this year.

For its part, Centrica Energy has secured optimisation deals for BESS for project owners Aukera and Renner Energies in Belgium, and Wood & Co and for its parent company Centrica in Sweden.