Background: A Vision First Sparked by a Tzero

Modern Vehicle-to-Grid (V2G) technology can be traced back to at least the late 1990s, with its roots in the pioneering work of EV advocate Tom Gage. With Tom as CEO and Alan Cocconi as the brain trust, the team at AC Propulsion developed the Tzero—a hand-built electric sports car that was either the precursor to the Tesla Roadster or inspired it at the very least, all depending on whose version of events you subscribe to. What isn’t quite as well known is that the Tzero was also a platform for V2G.  The team at AC Propulsion intuitively knew that cars sit an average of 96% of the time, and boast impressive amounts of energy storage.

These early EV pioneers were among the first to demonstrate the promise of two-way charging; not just drawing electricity from the grid, but sending it back. In fact, Gage is credited with coining the term “V2G” and helped show that EVs could do more than drive—they could support the energy grid.

Since then, the concept has evolved from a boutique demonstration to a serious feature under consideration by automakers and utilities. But while the promise of V2G is well understood — EVs acting as mobile batteries that stabilize the grid, support homes during outages, or share power with other vehicles — the rollout has been slow and fragmented.

Definitions: V2X and Its Many Flavors

Let’s set the stage for more in-depth discussion by defining some terms. Two-way charging is often lumped under the umbrella term “V2X”—where “X” can stand for Load, Home, Grid, or Vehicle. Each has different implications for the hardware, regulations, and partnerships required to bring it to life:

V2L (Vehicle-to-Load)

The simplest form. A car with a built-in or adapter-supported outlet (known in North America as the NEMA 5-15 plug, or more universally recognized as a ubiquitous standard 120V wall socket) can power small appliances, such as microwaves or laptops. Many EVs already support this feature, including the Hyundai Ioniq 5, Tesla Cybertruck, and Rivian R1 models (click here for a hopefully comprehensive list). It’s useful for tailgating or emergencies, and it requires no home installation or utility coordination. Therefore, EV manufacturers can install them with impunity from regulatory bodies like utilities, and no standards are required, aside from getting the plug right.

V2V (Vehicle-to-Vehicle)

A niche use case where one EV charges another. It’s technically just an application of V2L, but it requires specific hardware and typically only offers Level 2 AC charging. The Lucid Air is one example that supports this today.

V2H (Vehicle-to-Home)

The EV serves as a backup power source for a home during power outages. Ford’s F-150 Lightning currently leads the field here, with a fully integrated consumer-facing system that includes a bi-directional charger and a transfer switch. A fully charged F-150 can power a typical home for days. V2H is very close to V2G in terms of technical requirements—many systems that support V2H are 90% ready for V2G. However, transitioning from home backup to grid support presents a host of new challenges.

The Tesla Cybertruck also offers V2H, as do several current  GM vehicles.  But the implementation differs between all of these implementations, and this is an issue for universal deployment, as I will discuss shortly.

I also need to give a nod to the OG of V2H, the Nissan Leaf.  While never commercially deployed in North America, the Leaf still enjoys fairly widespread acceptance as a viable V2H solution in its native Japan.  But with CCS and later the J3400 (NACS) standards, the CHAdeMO-based Nissan V2H was doomed in the North American market.

Eaton demonstrates its Vehicle-to-Home charging capabilities at CES 2025. (Source: Eaton)

V2G (Vehicle-to-Grid)

This is the V2x holy grail. EVs don’t just store energy—they provide grid services like demand balancing, peak shaving, or emergency response. While utilities and researchers have run promising pilot programs, no mainstream EV today offers full V2G capability in a consumer-friendly package. That’s not because it is a technical leap—it’s a regulatory and business model that auto manufacturers are, for now at least, ill-suited to tackle.

Why Is It Taking So Long?

The delay in V2G rollout isn’t because the technology is unsolved. It’s because the hardest part isn’t engineering—it’s everything else.

Warranty Issues

Automakers are hesitant to offer V2G without clear standards and liability protections. They worry that the battery, designed for the light-duty consumer use of propelling an automobile, will wear far faster when pressed into service for grid stability.  Who is liable for accelerated battery wear in this case? The EV manufacturer? The consumer? The utility? Warranty claims and the legal complexities of converting a consumer vehicle into a utility asset are new territory for EV manufacturers and utilities alike. V2L is an easy “yes.” Even V2H, for occasional use to cover a utility blackout, is a straightforward sell to the mahogany row of publicly traded EV manufacturers.  But V2G?  Not so fast.

Utility Partnerships

V2G necessitates collaboration among automakers, homeowners, and electric utilities — many of whom still operate under outdated regulatory frameworks.

Exporting power to the home while it is isolated from the grid is one thing, but to export power to a grid-tied home takes frequency and phase matching.  Known in the solar industry as Grid Synchronization, this refers to a set of hardware and standards that grid-tied solar PV systems utilize every day.

But in the EV world, manufacturers currently lack the standards that would allow grid-tied V2G from any EV (GM, Ford, Tesla, BMW, etc.) to any utility (PG&E, Con Edision, LAPW, just to name a few of the more than 3,000 utilities in the US alone).

The lack of these standards and acceptance leads to obvious pain points for consumers, who face expensive hardware for the V2G system, with the prospect of owning several different cars over the course of decades in the same home.

Charging Standards in Flux

North America’s charging ecosystem is currently undergoing a major upheaval, as the industry shifts from the Combined Charging System (CCS) to Tesla’s North American Charging Standard (NACS), now formalized as SAE J3400.

While CCS already includes support for two-way power flow, which is what is implemented on Ford’s F-150, NACS — at least in its current standard — does not.

It is no mistake that the 2025 F-150 still uses the CCS plug, despite Ford being the first to adopt the NACS in time for its 2024 models. That’s because Ford simply didn’t have a two-way standard to deploy on a NACS-equipped F-150, and they still don’t.

The lack of two-way charging via the NACS didn’t stop Tesla from implementing the feature on the Cybertruck.  But it is instructive to note that Tesla’s current implementation differs fundamentally from Ford’s.  The Cybertrucks implementation exports AC Power, whereas Ford’s exports DC power.  The obvious difference is that there is far greater capability to export power over the DC pins than AC, but also that if DC power is exported, the conversion to AC for home or grid use must therefore be off-board the vehicle.

Tesla appears to recognize that the future will likely involve exporting DC power, as the Cybertruck, along with the off-board Powershare module, currently only supports exporting AC power. However, current Cybertrucks also support exporting DC power.

My “informed speculation” is that automakers are focusing their engineering resources on adapting to J3400 and on the standard supporting two-way charging before making further investments in V2G functionality.

Until the J3400 fully supports two-way charging, V2G and V2H are likely to remain sidelined. Automakers are prioritizing what consumers care about now — access to Tesla’s charging network — rather than a feature that only a minority of buyers currently demand.

A Cadillac LYRIQ charging with its V2H GM Energy Home System bundle in a residential garage. (Source: GM)

Looking Ahead: Still on the Horizon, But Getting Closer

The tide may be turning. Consumer interest in energy resilience is increasing, particularly in regions prone to wildfires, hurricanes, or power grid instability. When the lights go out, the ability to power your home from your car becomes a compelling selling point. Ford and Tesla have tapped into this sentiment with their V2H-capable F-150 Lightning and Cybertruck offerings. Others will follow — especially as standards mature, so someone who invests in a V2H home powered by, say, a Ford F-150 will not have to get all new homeside hardware when the upgrade to a Lucid Gravity.  (Yes, I did show my bias there, didn’t I?)

As for true V2G? That may take longer. The hardware is largely in place, but the legal, financial, and institutional infrastructure is not. Until utilities, automakers, and regulators align on standards, roles, and incentives, EVs will remain underutilized as grid-stabilizing assets.

But don’t count it out. If EV adoption continues to climb and utilities continue to face strain from heatwaves, wildfires, and the integration of renewables, the value of V2G will only grow. It may have taken 20 years to get from the Tzero to the Lightning, but the next leap could come faster.