Eco Stor inaugurates 238 MWh German battery, may have saved customers €36/MWh during ’24 lull

Eco Stor’s battery energy storage system (BESS) in Bollingstedt, in the German state of Schleswig-Holstein, has been online since April but its official inauguration took place on Thursday in the presence of Tobias Goldschmidt, state minister for energy transition, climate protection, environment, and nature.

The 103.5 MW/238 MWh project, one of the largest BESS in Germany, was built by Eco Stor with project developer EPW and is near a substation and wind farms. The site comprises 64 lithium-ion battery containers and 32 inverter and transformer containers.

Despite numerous grid connection requests for the large-scale batteries needed to help stabilize volatile German energy prices, few projects have taken shape thus far and Eco Stor said the Bollingstedt BESS could have saved bill payers €36/MWh of electricity during a price peak on December 12.

“After deducting the prices for charging during the preceding night hours, the German economy could have saved around €1 million in electricity costs during this one hour of dark lull alone,” said the Oslo-based developer, adding the site will shave around €4 million per year off the surcharge applied to electricity bills to fund more renewables generation capacity.

Eco Stor said the battery is operating on day-ahead and intraday wholesale energy markets and also earning revenue from supplying primary and secondary control power to the grid. The developer said it uses a digital twin of the electricity network to determine periods when it would be unfavorable to grid operations to discharge energy into, or withdraw electricity from the network.

The developer said its 1.2 ha Bollingstedt BESS will be the first of many, including a similarly-scaled site in the neighboring municipality of Schuby.

“The battery [energy] storage facility in Bollingstedt marks the beginning of the energy storage revolution,” said Eco Stor Managing Director (MD) Georg Gallmetzer. “We now have the technology to shift valuable solar power to the evening hours, curb prices, and further reduce electricity from gas and coal. Until now, the energy transition has been on one foot. With battery storage facilities of this size, we can bring it into balance.”

From pv magazine Deutschland.