V2G Grows Up

Vehicle-to-grid (V2G) is hot. In the past few months E.ON Germany announced a V2G tariff x dance-routine combo, VW did the same (without the dancing), Hyundai expanded their V2X support, and Nissan announced a V2G partnership with Motability Operations.

But for the old hands out there, this feels like groundhog day; Nissan rolled out a V2G proposition 10 years ago, and mainstream V2G has been billed as ‘just around the corner’ ever since.

So what’s changed — and why does 2026 feel different? And what’s the big fuss about, anyway?

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What is V2G?

V2G is vehicle-to-grid: sending electricity from an EV’s battery back out into the grid (V2H is vehicle-to-home: sending electricity from an EV’s battery into the home, but not into the grid).

As grids decarbonise, they need more flexibility; we can’t change when the sun shines or the wind blows, so we need to be able to move around electricity demand to match electricity generation.

The vast majority of EVs are unidirectional; they can charge from the grid, but they can’t discharge back the other way.

Unidirectional EV charging is still massively valuable to the grid; by shifting charging based on the needs of the grid, EVs can decrease (pricey) peak electricity demand, increase utilisation of the physical infrastructure, and take advantage of the cheapest energy, which lowers costs for everyone.

V2G (also called bidirectional charging) supercharges this. A bidirectional EV can charge fully from cheap & clean solar, export energy back to the grid in the evening (when the grid is dirtiest, priciest, and most strained), and then charge up again with cheap and clean wind overnight.

This can create substantial financial value for the EV driver, whilst lowering energy system costs and carbon.

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Why it matters

EV batteries are huge, and there are already a lot of them.

The typical stationary home battery in Europe is 5 to 10 kWh. These are typically designed to charge from excess solar, which the home then uses after the sun sets.

An EV battery is ~10x larger; typically 50+ kWh. And there are more EVs than home batteries. Take the UK, which is about average in home battery penetration. The UK has installed roughly 200K home batteries, and 2M EVs.

10x the size times 10x the count? 100x the storage capacity, just sitting in our driveway.

The 2M EVs in the UK have a total storage capacity of ~100 GWh; that’s ~8 times larger than the utility-scale battery fleet.

This isn’t an apples-to-apples comparison, because EVs aren’t always available to help the grid. They’re typically parked at home for 12 hours a day. That brings the effective capacity down to 50 GWh - which still dwarfs utility-scale storage.

That 50 GWh could power the entire country for hours, day after day.

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Why aren’t we doing it?

V2G has been in pilot-hell for over a decade. Rationally minded economists and engineers have long agreed that from a system perspective, the opportunity is very compelling: EV batteries are large, connected, and increasingly available as flexible assets.

V2G hasn’t been held up by a single barrier; instead, it’s been the complexity of the system-level interactions, with diverging incentives amongst key stakeholders.

Carmakers

Carmakers need to allow this to happen, and they’ve historically been hesitant. The battery is the most valuable part of an EV, and they needed enough data to build confidence this doesn’t worsen battery degradation.

Carmakers are in the business of building cars, not ‘non-stationary grid-supporting systems’. They don’t want to degrade the driver experience, or hand over control to someone who might.

Costs

Bidirectional charging also has higher upfront costs. Electricity from the grid is AC, and that stored in the battery is DC. To go back to the grid, there needs to be an inverter (either in the car or in the charger) to go from DC back to AC. Carmakers and charger manufacturers haven't been aligned on where this inverter should live, and so we've got a mixture of DC (in the charger) and AC (in the car) V2G solutions, which reduces compatibility and increases complexity.

Grids

Grids also won’t accept any old electricity. It must be frequency-matched (50 Hz, in Europe) and phase-matched. So even if the EV has a built-in inverter, you need a special AC bidirectional EV charger, with the electronics and software to meet the grid’s requirements.

Today, most grids require that the combined system (car plus charger combination) undergoes extensive testing before it can be used for V2G; this adds costs and complexity, and hampers interoperability. And even if the system is approved, the grid operator may still reject the request for bidirectional charging on a site level.

Interoperability

If the charger meets the grid’s requirements, and the grid accepts it, and the car allows for it, the car might not play nice with the charger. Today, you can plug (pretty much) any charger into (pretty much) any EV, and it’ll charge. That’s thanks to common standards. Until recently, we didn’t have widely accepted common standards for bidirectional charging. And even with those standards, not everyone will play ball.

Energy markets

This is only worthwhile if we can put that big juicy battery to good use helping the grid. And traditionally, energy markets (where flexibility can get compensated for helping the grid) were limited to large-scale assets, like power plants. It’s only been in the past few years, with companies like Axle, that there’s a viable path to monetising smaller devices like EVs.

Consumer proposition

Last but not least is the EV driver. Drivers will only do this if the offer and experience are compelling. Once we overcome the added CAPEX, compatibility and setup challenges, we have the day-to-day value proposition: what's in it for me as a driver? Will I save/earn enough money to make all of this worthwhile? And will I be able to get the benefits without having to change my behaviour and being inconvenienced?

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Why is 2026 any different?

There hasn’t been a silver bullet, just a whittling away of the key barriers, and it's all coming together to make the next year very interesting:

1. Carmakers are now taking the lead: they’re more confident that this won’t jeopardise the battery warranty, and many see this as a compelling and differentiated customer offering in an increasingly competitive EV market.
2. Grids are more willing to play ball: as EV and renewables penetration increases, the value V2G can provide is increasinglly relevant to regulators and grid operators.
3. We have standards: OCPP 2.1 and ISO 15118-20 standardise the communication between the car, the charger, and the user, although manufacturers are still implementing these standards idiosyncratically.

It’ll still take a bit of time before a consumer can pick an EV of their choice, install any home charger, choose an electricity tariff, and it all just works, like it does for unidirectional charging.

But we’re getting there. V2G is fast becoming a meaningful differentiator, and it’s not long before it’ll be table stakes. We’re already hearing carmakers worried about being left behind, which is a notable shift from even a year ago.

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What’s next?

At Axle, we’re actively working with leading carmakers and EV charger manufacturers to bring the first V2G propositions to the mass-market (public announcements coming soon). We will continue to focus on delivering great value and compelling user experiences. A unidirectional EV can earn the driver hundreds of pounds each year from helping the grid, and V2G is able to deliver substantially more value.

We don’t believe any one player can solve every challenge, but together the dream is achievable: no added upfront cost, a simple and enjoyable user experience, and fantastic value, for the driver, the grid, and the planet.

This is the year that drivers will see the benefits of V2G in the form of commercial propositions. If you are carmaker, charger manufacturer, or energy supplier interested in V2G: Come by for a chat → hello@axle.energy

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