Three-hour battery storage system boosts security of supply in Hesse

With an output of 6.4 MW and a capacity of 21.6 MWh, Stadtwerke Hünfeld operates what is currently the largest battery storage system in Hesse. As a so-called three-hour system, the storage facility is particularly well suited to responding to short-term fluctuations in the power grid – a feature that is becoming increasingly important as the share of renewable energies rises.

The trading is carried out through Cross-Market-Optimisation, which specifically includes all relevant markets – including balancing energy (FCR and aFRR) as well as day-ahead and intraday markets. Entelios is responsible for the technical integration and implementation of central grid-side processes such as prequalification, balancing group management, redispatch and pooling.

In addition, the storage facility will provide important system services that are of utmost importance for the safe operation of supra-local electricity grids. Its capacity is theoretically sufficient to completely supply all household customers in the Hünfeld urban area with electricity for several hours.

With this project, Stadtwerke Hünfeld is demonstrating its pioneering spirit: it is showing how municipal energy suppliers can fulfil their system responsibilities through powerful battery storage systems while at the same time exploiting economic opportunities in dynamic electricity markets.