Hybrid Solar Storage Retrofits

Solarmarkt Group selected Stem’s Stem PowerTrack Hungary energy management system to hybridize two operating utility-scale solar plants in Szihalom and Hódmezővásárhely. The projects will add 40 MW/80 MWh of battery storage to existing 60 MWp facilities, with commercial operation of the fully hybridized assets expected by September 2026.

The five-year agreement expands Stem’s existing power plant control work at both sites. A single integrated platform will coordinate solar generation, battery dispatch and grid interconnection while supporting Solarmarkt Group’s Green Cloud Platform, which connects renewable generation with corporate energy buyers seeking traceable, auditable green energy.

The initial commercial strategy will target Hungary’s automatic Frequency Restoration Reserve market, with Frequency Containment Reserve support planned later. The projects highlight how hybrid solar-storage assets can provide additional grid services as Central and Eastern European power markets become more interconnected.

Image Credit: