Vehicle-to-grid (V2G) technology is gradually making the transition from pilots to commercial applications.

At the moment, a few automakers, including GM, Ford and Nissan, offer bidirectional charging features, but these require proprietary charging hardware, and are limited to applications such as backup power (V2H). True V2G functionality requires a utility interconnection, and for this, up-to-date standards will be critical.

In May, UL Standards & Engagement released the UL 1741 Supplement SC for AC Bidirectional Electric Vehicle Supply Equipment for EVs with SAE J3072 Bidirectional Onboard Inverters.

Zach Woogen, Executive Director of the Vehicle Grid Integration Council (VGIC), a national smart EV charging advocacy group, explains in a recent blog post, “This long-awaited standard, and the resulting developments now underway, may catalyze a new market for low-cost, scalable vehicle-to-grid alternating current (V2G AC) by supporting interoperability.”

V2G systems come in two flavors: DC (inverter functions are offboard the EV); and AC (inverter functions are onboard the EV). Several US utilities have adopted or proposed updates to their rules to incorporate both DC and AC V2G applications.

Regulators and utilities in California, Maryland, New York, Massachusetts and Connecticut have clarified the treatment for V2G DC systems under existing or modified interconnection rules.

As for V2G AC systems, utility rules in California and Maryland define a certification pathway under the relevant UL 1741 Certification Requirement Decision (CRD) for multipiece distributed energy resource (DER) systems in combination with UL 9741. This approach applies to matched, multipiece DER systems, where a specific vehicle model and charger are certified for V2G AC operation using existing published requirements. Utilities in Nevada and Connecticut have pending proposals to establish this same certification pathway.

The May 2026 publication of UL 1741 SC offers a new certification pathway for V2G AC systems. The standard supports the interconnection of a charger as an “oversight supervisor” for a vehicle designed and tested to meet SAE J3072. Because this certification pathway does not rely on certifying a given vehicle-charger pair as a single system, industry stakeholders view it as a key step toward widespread interoperability of AC bidirectional charging.

Source: VGIC