REXEV launches FIT-to-FIP switch, BESS retrofit service for high-voltage solar, eyes expansion to low-voltage

September 22, 2025
Solar Power
REXEV plans to apply its EV energy management know-how to solar-plus-storage assets.

REXEV launched a service to support solar power plant owners with feed-in-tariff (FIT) to feed-in-premium (FIP) conversions and battery storage retrofits, the electric vehicle (EV) solution provider announced on September 18, 2025.

According to the statement, the company plans to apply its EV-based expertise in battery control, forecasting, and markets to solar power plants, initially focusing on high-voltage assets operating under 32 yen per kWh and higher FIT contracts. REXEV plans to offer a turnkey service, supporting customers with sourcing and retrofitting their project with BESS and aggregating the asset after its conversion to FIP.

Under the service, generation asset owners can choose to either invest in the retrofit project directly or add batteries under a third-party ownership model.

REXEV said its first project is underway with FIP operations expected to begin within 2025. The company plans to commission more projects gradually from April 2026. In the future, it also aims to offer a similar service for low-voltage (sub-50kWAC) assets, pairing them with either stationary batteries or EV-plus-V2X (vehicle-to-everything) systems.

Founded in 2019, REXEV primarily focuses on supporting businesses and municipalities with electrifying their fleets and provides EV-related energy management services. It joins a growing list of companies such as U-POWER and Green Growth offering FIT solar power plant operators support with BESS retrofits and conversions to FIP amid increasing curtailment, in Kyushu in particular.

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