BMW and E.ON are now offering German iX3 owners up to €720 per year to let their car act as a grid battery. The technology is real. The number sounds attractive. But the gap between the marketing promise and what a private owner can actually achieve today is wider than most buyers assume.
The €720 pitch, broken down
E.ON pays €0.24 for every hour the iX3 is connected to a bidirectional wallbox. That is not energyexported, it is a capacity payment: the car is available as grid storage, and the owner gets a small hourly reward. The maths is simple. To earn the full €720 per year, an owner needs 3,000 connected hours annually: €720 ÷ €0.24 = 3,000 hours That is 8.2 hours per day, every single day, with the car plugged in and available to the grid. For a private car used for commuting, school runs and shopping, that is an aggressive assumption. It means the vehicle has to be at home, connected, and not being driven for more than eight hours a day. Put the earnings in a family budget context. A typical European family EV consumes around 18 kWh per 100 km in real-world use. If you drive 15,000 km per year, you need roughly 2,700 kWh of electricity. At a home tariff of €0.30 per kWh, that is €810 per year in charging costs. In other words, the best-case V2G payment of €720 almost covers the entire home charging bill. That is genuinely interesting. But it only works if the car, the wallbox, the tariff, the smart meter and the grid connection all line up — and the owner hits the full 3,000 hours. Our charging cost calculator shows how quickly charging spend adds up, and why the V2G pitch should be treated as a rebate on a very specific set of conditions, not a guaranteed income.Why real-world adoption is still tiny
BMW has not broken out iX3 V2G participation numbers. If the €720 offer were being taken up at scale, we would likely hear about it. Instead, the market is stuck in a loop of pilots, press releases and proof-of-concept projects. One number explains part of the problem. According to the Bundesnetzagentur, only 5.5% of German households have an intelligent metering system — a digital electricity meter with an internet connection. Germany is embarrassingly far behind the rest of Europe on smart-meter rollout. Without a smart meter gateway, bidirectional charging cannot be billed correctly, the grid operator cannot see the flexibility, and the business case collapses. But the smart meter is only one bottleneck. Markus Hackmann, managing director at P3 Group, describes the wider issue as a “discrepancy between theoretical potential and lived reality”. The causes include fragmented standardisation, battery-warranty risk for carmakers, and the absence of scalable business models beyond isolated projects. Standardisation is messy. ISO 15118-20 still has 57 of 186 parameters marked as optional in the dynamic mode. The IEA’s Task 53, led by Marco Piffaretti, is pushing for multiparty interoperability and wants to reduce the parameter count to 153 while removing ambiguities. The goal is a system where any V2G-ready car can work with any wallbox and any energy tariff, rather than closed ecosystems where one brand’s car, wallbox and electricity contract must all come from the same provider.Lock-in and internal competition
Piffaretti is blunt: bidirectional charging “cannot currently scale to benefit customers because we lack multiparty interoperability”. Today, most solutions require a specific combination of EV, wallbox and electricity tariff. That locks the customer into one provider and removes the flexibility that V2G is supposed to enable. The Volkswagen Group shows how fragmented even a single corporate strategy can be. VW is pushing V2G-ready hardware, including the new small cars from Polo to Skoda Epiq. Yet two Group companies — Elli and Moon — are effectively competing in the same space. Customers can register with Elli to earn up to €720 per year, echoing BMW’s offer, while Skoda has announced a separate product with Moon. That is not a clear path to scale. There is also an economic competitor that has quietly improved: stationary home storage. Ankersolix, for example, offers a plug-and-play inverter with 5 kWh of storage for €1,599 and 10 kWh for €2,698. For household solar shifting and backup, a fixed battery in the garage is simpler than using the car, with no battery-warranty risk and no requirement for 3,000 hours of annual availability. The conversation is no longer just “car as battery” versus nothing; it is car as battery versus a cheap dedicated battery.Where the early money actually is
Private passenger cars are the hardest V2G use case: unpredictable schedules, variable mileage and battery-warranty concerns. Commercial fleets are easier. Haulage, logistics and taxi operators have predictable routes, high energy volumes and vehicles that sit idle at depots overnight. That is exactly the profile needed to monetise bidirectional charging without asking a commuter to keep their car plugged in for eight hours a day. We saw the same pattern in Asia: GAC delivered 115 Aion EVs to Grab Thailand as the electric taxi share hit 61%. High-utilisation fleets concentrate charging demand, and they are the natural first customers for grid services. In Europe, the equivalent will likely be municipal depots, logistics hubs and corporate car pools — not private homes first. The charging market is also consolidating and rebundling in ways that matter. Earlier this year, E.ON and Clever split a 157-point Scandinavian fast-charging network, showing how quickly partnerships in the charging space change. Bidirectional charging will face the same churn as players compete for the home wallbox and tariff relationship.What a buyer should do today
Do not buy a car because of a V2G revenue promise. Buy it because it is a good electric car, and treat bidirectional capability as a possible future benefit. If you are seriously interested, check three things before signing anything: 1. Is the car V2G-ready? Many newer models are — VW’s small EVs and the Skoda Epiq are mentioned as V2G-ready — but the wallbox and tariff must also match. 2. Do you have a smart meter? In Germany, the rollout is only at 5.5%. If your home does not have an intelligent metering system, the bidirectional offer is not yet real for you, regardless of what the car can do. 3. What is the lock-in? If the contract forces you into one car brand, one wallbox brand and one electricity tariff, calculate the total cost before comparing it with a simple stationary storage system. Our EV tariff calculator can help you judge whether the combined package is worth it.Bottom line
Bidirectional charging is not a hardware problem. The car battery can absorb and release energy today. The blockers are software, standards, smart meters, warranty risk and fragmented business models. The foundations are being laid — ISO 15118-20 work, AFIR guidelines, China’s GB/T and Japan’s CHAdeMO experience — but the payoff is years away. Our supercharger database currently tracks 483 locations across Europe. That is public fast charging. Bidirectional charging lives at the private wallbox, and it is still mostly invisible in real-world data. The honest timeline is not “next year”; several industry figures point toward 2030 before V2G gains meaningful traction in Europe. Until then, the €720 promise is a useful laboratory test of how the energy transition might work — not a reason to buy an EV.Source: https://www.electrive.com/2026/08/19/from-promise-to-reality-the-state-of-bidirectional-charging/
