UL Solutions opens certification for AC bidirectional EV chargers, four months after the standard was issued
A published standard does not let anyone sell anything; a certification route does. AC bidirectional charging has until now been gated by certifying each vehicle and charger as one tested system, which effectively hands the decision about what your car is allowed to do to whichever manufacturers agree to pair with each other. Certifying the charger alone against a vehicle standard breaks that pairing, and it is the specific step that decides whether a parked car becomes a battery its owner can actually dispatch rather than a feature waiting on a partnership announcement. The trade worth naming is that component certification rests the safety case on a standard being right rather than on two vendors having tested their combination, which is the ordinary price of an open interface.
UL Solutions opens certification for AC bidirectional EV chargers, four months after the standard was issued
The route to market for AC vehicle-to-grid hardware no longer runs through a matched vehicle-and-charger pair.
UL Solutions began offering testing and certification of bidirectional electric vehicle supply equipment against UL 1741 Supplement SC on 14 September 2026, at its facilities in Fremont, California and Northbrook, Illinois, according to pv magazine USA. The supplement was issued by UL Standards & Engagement in May 2026 and covers AC bidirectional supply equipment for vehicles whose onboard inverters are designed and tested to SAE J3072, as reported by Charged EVs on 31 July 2026.
Two architectures compete for the job of pushing energy out of a car. In the DC approach, the inverter sits in the wall box, offboard the vehicle; this is what suppliers including dcbel, Sigenergy and Wallbox ship today. In the AC approach, the inverter is the one already built into the car, and the wall box becomes what UL describes as the oversight supervisor of the connection between the vehicle and the grid. The second architecture means the owner is not buying a second inverter. pv magazine USA reports that AC equipment is expected to be significantly less expensive than the DC products now on the market; no figures were attached to that expectation, and it is a reasonable inference rather than a measured one. [NEEDS DATA: installed price of AC bidirectional EVSE against a comparable DC unit]
The certification route is the part that changes what can be sold. Before Supplement SC, utilities in California and Maryland worked from a UL 1741 Certification Requirement Decision combined with UL 9741, the standard for electric vehicle power export equipment, which certified a specific vehicle and a specific charger together as one matched multipiece system. That structure made interoperability a commercial negotiation: your car could export only into hardware whose manufacturer had agreed to be tested alongside it. Supplement SC certifies the charger on its own, against the general requirement that the vehicle's onboard inverter complies with SAE J3072, which was finalised in 2024 and made the supplement possible.
Zach Woogen, executive director of the Vehicle Grid Integration Council, said the standard and the work following it "may catalyze a new market for low-cost, scalable" AC vehicle-to-grid.
Why it matters
A published standard authorises nothing by itself. A test lab willing to issue certificates against it is the point at which a product can be specified, permitted and connected, and that is what opened on 14 September.
The specific thing dissolved here is a pairing requirement, and pairing requirements are how control gets held at the centre of a supply chain. When a car may only export through hardware its maker has agreed to be certified with, the decision about whether a parked battery can earn anything belongs to two manufacturers negotiating, not to the person who paid for the battery. Certifying the charger against a standard rather than against a partner moves that decision to the owner, which is the whole difference between a feature and an asset.
The same move has a cost worth naming. Component-level certification puts the burden of correct behaviour on a standard being right, rather than on two vendors having tested their combination in a lab. That is the ordinary trade in open interfaces, and it usually pays; it is not free.
Wesley Kwok, vice president and general manager of the Energy and Industrial Automation group at UL Solutions, said in the company's announcement that "Electric vehicles spend much of their time parked", creating an opportunity to do more than transport. The same announcement cites an E3 study commissioned by General Motors estimating that vehicle-to-grid could deliver 5 to 15 times more per-vehicle value than one-way managed charging in many markets. That is a figure produced for an interested party, quoted by another interested party, and the study itself was not read here. [UNVERIFIED: the E3 for General Motors 5 to 15 times per-vehicle value estimate, and the market conditions it assumes]
What is still unknown
No list of products certified to Supplement SC has been published, and the launch of a certification programme implies there is nothing on it yet rather than proving it. UL Solutions has not disclosed what certification costs or how long it takes, and no manufacturer has been named as having entered testing. It is also unclear whether utility interconnection processes will accept a Supplement SC certificate on its own, or continue to ask for a paired vehicle and charger review out of habit; the standard can only do its work if the interconnection desk agrees. Nor is the addressable fleet established: the number of vehicles on American roads today with a J3072-compliant onboard inverter is the figure that decides whether this matters in 2027 or in 2031. [NEEDS DATA: count of J3072-compliant vehicle models sold in the United States] Finally, no other test laboratory has been identified offering the same programme, so for now this is a single-supplier route.
Sources
- pv magazine USA, 14 September 2026: https://pv-magazine-usa.com/2026/09/14/ul-solutions-launches-ac-bidirectional-ev-charger-certification-program/
- Charged EVs, 31 July 2026: https://chargedevs.com/newswire/ul-releases-an-important-new-v2g-standard/
- UL Solutions announcement, Business Wire, 14 September 2026, as carried by EC&M: https://www.ecmweb.com/electric-vehicles/news/55404877/ul-solutions-launches-certification-program-for-vehicle-to-grid-technologies-to-enhance-grid-resilience
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