Toyota Industries Verifies AC-Based Vehicle-to-Grid Technology with Bidirectional On-Board Charger

Toyota Industries Corporation announced on July 13 that it successfully completed hardware verification of vehicle-to-grid (V2G) technology using its bidirectional on-board charger. The verification established an important technological foundation for expanding V2G deployment by confirming that electricity stored in an electric vehicle battery can be converted into alternating current (AC) on the vehicle itself and supplied back to the power grid. The demonstration was conducted in accordance with the requirements of the international ISO 15118-20 standard, validating the system's capability for bidirectional energy transfer.

The verification project was carried out in collaboration with the Research Institutes of Sweden (RISE) and DEFA, a charger manufacturer based in Norway. Toyota Industries supplied its V2G-compatible bidirectional on-board charger, DEFA contributed its newly developed charging and discharging equipment known as DEFA Power, while RISE created the dedicated testing environment required to validate system performance under the ISO 15118-20 specifications.

Traditional V2G systems primarily rely on direct current (DC), where electricity stored inside an electric vehicle must first be converted from DC to AC using external charging and discharging equipment installed at homes or other facilities before being delivered to the power grid. This additional conversion hardware increases system complexity and contributes to higher installation costs for infrastructure deployment.

In contrast, the AC-based V2G approach verified during this project uses a bidirectional on-board charger capable of converting electricity between DC and AC directly within the vehicle. Because the vehicle itself performs the conversion, AC power can be supplied straight to the grid without requiring external conversion equipment. This architecture simplifies charging and discharging infrastructure, reduces implementation costs, and supports broader deployment of V2G technology as electric vehicle adoption continues to expand.

Frequently Asked Questions

What did Toyota Industries verify through its latest V2G demonstration?
Toyota Industries verified that its bidirectional on-board charger can convert electricity stored in an electric vehicle battery into alternating current and supply it directly to the power grid in compliance with ISO 15118-20. The project was completed together with RISE and DEFA, confirming the technical feasibility of AC-based vehicle-to-grid operation while demonstrating a solution that simplifies charging infrastructure, lowers implementation costs, and supports the broader adoption of V2G technology in future electric mobility ecosystems.