EXECUTIVE SUMMARY

As Germany continues expanding battery energy storage to support a renewable-based power system, market-driven business models are becoming increasingly important for improving the commercial value of standalone storage assets. Reflecting this trend, MaxSolar and BKW have signed their first battery energy storage tolling contract for the Darstadt/Stalldorf battery energy storage system (BESS), marking the beginning of their collaboration in market-based battery optimisation. The agreement covers the Darstadt/Stalldorf battery energy storage system (BESS), which will have a power capacity of 10 MW and an energy storage capacity of 40 MWh. The project is scheduled to enter commercial operation during the first quarter of 2027.

Under the tolling agreement, BKW will be responsible for optimising and marketing the battery storage system across electricity markets. Through this arrangement, the company will manage the charging and discharging strategy of the battery to maximise its value while providing flexibility services that respond to changing market conditions.

Both the Darstadt/Stalldorf BESS and the Darstadt solar farm shall be connected to the same substation as that of the existing Darstadt solar park, hence sharing the same grid connection point. But the battery energy storage system shall run independently of the photovoltaic system from technical and commercial perspectives. This arrangement allows the battery to be active in the power market irrespective of solar energy production.

MaxSolar said the project represents one of its early steps in integrating standalone battery storage into commercial electricity markets through dedicated marketing models. The company views tolling agreements as an important component of its strategy to diversify revenue streams while expanding its independent power producer (IPP) business.

BKW, which specialises in energy market services and flexibility optimisation, will apply its expertise in battery trading and market participation to maximise the value of the storage asset. The agreement also extends BKW's battery storage portfolio with another standalone project in Germany.

Battery energy storage systems are becoming increasingly important as renewable energy penetration grows across Europe. Flexible storage assets help balance electricity supply and demand, reduce network congestion, improve grid stability and enable greater integration of variable renewable generation. Market-based optimisation models such as tolling contracts also create predictable commercial frameworks that support investment in standalone storage infrastructure.

The agreement establishes the foundation for broader cooperation between MaxSolar and BKW in battery storage. By combining storage development with professional market optimisation, the companies aim to support Germany's evolving electricity market while improving the commercial performance of grid-scale battery energy storage projects.