250 MW grid booster battery breaks ground in Germany

A landmark energy storage project announced in 2022 has moved closer to realization with the official opening of the construction site in Kupferzell, in the German state of Baden-Württemberg.

The 250 MW / 250 MWh Netzbooster (Grid Booster) project is a storage as transmission assset (SATA) and represents a relatively new and not widely known battery energy storage system (BESS) application. 

SATA projects are utility-scale batteries operated to mimic transmission line flows by injecting and absorbing power. They can be used to reinforce or even replace existing power lines, thus offering infrastructure planners an alternative solution for transmission transition.

TransnetBW’s Netzbooster is expected to reduce the need for grid expansion and ease bottlenecks stemming from transporting wind energy from Germany’s north to the country’s southern load centers. The project proponents anticipate it will reduce the number of required preventive measures in system operation, thereby lowering operating costs of Germany’s transmission system.

“By using this technology in innovative ways we can increase capacity in the existing electricity grid and integrate more renewable energy. The Netzbooster is thus making an important contribution towards the energy transition,” Werner Götz, TransnetBW CEO, said at the groundbreaking ceremony on Monday.

A suite of complex services

To support the transmission network, the system will deliver a suite of complex services, including synthetic inertia, dynamic voltage control, contingency support, and congestion management, among others. For instance, in case of contingency events, the system will operate at full capacity for one hour, giving the transmission system operator sufficient time to ramp conventional generation up or down.

The Netzbooster initiative was first introduced in 2019 as an innovative concept under the 2030 German grid development plan. TransnetBW’s Netzbooster is meant as an initial deployment to gain experience with this type BESS application.

Importance of the project for the municipality of Kupferzell

Christoph Spieles, Mayor of Kupferzell, also emphasized the importance of the project for the municipality of Kupferzell: “The construction of the grid booster is an opportunity for us in Kupferzell to be at the forefront of climate protection and to become known nationwide as an energy transition community. Even if there were concerns and critical questions in the run-up to a project of this magnitude, these could be dispelled thanks to the intensive and transparent dialog with TransnetBW,” he said.

In parallel, Fluence is working on two more grid booster projects in Germany in collboration with transmission system operator TenneT. The two 100 MW/100 MWh SATA projects announced last year will be located in Audorf Süd in Schleswig-Holstein and Ottenhofen in Bavaria.

Globally, SATA projects are expected to make inroads in the years to come as the rapid expansion of renewable energy sources increases grid congestion. Research group S&P Global forecasts 17 GW / 50 GWh of energy storage systems to be deployed globally through 2030 to enhance or defer investment into upgrading existing electricity network infrastructure.