German Grid Operator Uses Battery Storage to Avoid Substation Upgrade

A Bavarian electricity network company is deploying large-scale battery storage to sidestep a planned substation reinforcement, illustrating how flexibility assets can substitute for conventional grid investment.

E.ON subsidiary Bayernwerk Netz is running a procurement for a 20 MW battery with a minimum capacity of 80 MWh to serve the Bayreuth area. The system will connect directly to the Speichersdorf substation, where long-term planning had identified a need for traditional capacity upgrades. Chief Executive Nick Sieger said the battery will produce the same grid effect as that scheduled reinforcement — and can be brought online faster.

Sieger added that the strategy shows how flexibility solutions can raise the utilisation of existing infrastructure and, in certain cases, temporarily or permanently replace conventional expansion works. The battery is designed to absorb surplus power during high solar output periods and release it when demand peaks, responding dynamically to network conditions.

The contract bundle covers equipment supply, system operation, and grid-support services delivered as a flexibility product. Only a closed group of pre-qualified companies may submit offers.

The company ran an earlier procurement for a smaller 5 MW unit in the Ham district, where Maxsolar emerged as the winner. Both batteries are configured to operate under regional distribution network rules rather than chasing wholesale market signals, distinguishing them from standard commercial storage assets.

The new grid connection at Speichersdorf is scheduled to become available by the close of 2027.

Source: ESS News (pv magazine)