Stem has expanded its role in Hungary’s renewable energy market after Solarmarkt Group selected its PowerTrack Energy Management System to hybridise two operating utility-scale solar plants with battery storage.
Under a five-year agreement, Solarmarkt and engineering, procurement and construction partner Pannonwatt Energetikai Megoldások will deploy PowerTrack EMS across solar facilities in Szihalom and Hódmezővásárhely. Each 60MWp solar plant will receive a 40MW/80MWh battery energy storage system, adding 160MWh of storage capacity across the two sites.
Stem previously supplied power plant control capabilities for the facilities during 2025 and 2026 using its hybrid-ready PowerTrack architecture. The expanded deployment will integrate solar generation, storage, grid interconnection and market dispatch through one software and controls platform.
PowerTrack EMS will coordinate battery dispatch, solar output, grid constraints and market instructions while supporting compliance with E.ON distribution requirements. The initial commercial strategy will target Hungary’s automatic Frequency Restoration Reserve market, with future support planned for Frequency Containment Reserve services and cross-border value stacking.
Matt Tappin, President of Software, Stem, said the project showed how existing solar plants could become hybrid assets without replacing their controls foundation.
The projects will also support Solarmarkt’s Green Cloud Platform, which connects renewable generation with corporate energy consumers. Stem said combining storage with advanced controls could make renewable electricity more flexible, controllable and commercially valuable as Central and Eastern European power markets become increasingly interconnected.
Pannonwatt said the deployment could establish a technical benchmark for European hybridisation.
