When discussing EVs, you sometimes see the claim that they have "already become an indispensable part of the grid." But to state the present accurately: they are "becoming one (adoption is early-stage)." Separating potential (direction) from deployed (current adoption) is especially important in this area.
The tectonic shift underneath in the power system is real. With the rapid expansion of solar and wind, surplus power is frequent in Europe and the hours when prices fall below zero are increasing. The value of flexibility — absorbing this surplus and releasing it at peak — is rising, and EV batteries are a candidate to provide it.
The Tectonic Shift Underneath the Power System
First, confirm with data that the change is real.
Rapid expansion of grid-scale storage
According to the IEA, global battery storage additions grew 40% year-on-year to 108 GW in 2025. China accounted for about 60% of additions. Utility-scale made up about 87 GW — roughly 80% of the total — and is becoming the core of grid flexibility.
Negative power prices become routine
In Europe, renewables reached 47% of the mix in 2024 and solar overtook coal for the first time, so surplus during low-demand hours pushes wholesale prices to zero or below more often — raising demand for flexibility to absorb surplus power.
Progress on standardization
ISO 15118-20, the communication protocol enabling bidirectional charging, is finalized and being implemented. The EU is moving to require all new public chargers to support it by 2027, laying the technical foundation for smart charging and V2G.
These point to a direction in which EVs shift from being "loads that only charge" to "distributed energy assets that can charge and discharge." Smart charging (optimizing charge timing) is already implemented in places, and V2G (vehicle-to-grid power feed) lies beyond it.
V2G Is Still at the "Pilot Stage"
That said, commercial V2G deployment remains early-stage. The current state is pilot-centric, with carsharing-linked pilots such as the Netherlands' "Utrecht Energized" as leading examples. The market is estimated at about USD 6 billion in 2025 and is expected to grow more than 27% annually, but the absolute scale is still small.
The barriers to adoption are not only technical.
Battery warranty and degradation concerns
The effect of frequent charge/discharge on battery life and the treatment of maker warranties are unsettled. The economic incentive for users to participate and the allocation of degradation risk are unclear.
Regulation and market design
The schemes and tariff structures to trade vehicle batteries as grid services are immature country by country. Frameworks for aggregator-mediated participation and metering/billing of bidirectional power are not in place.
Economics and OEM readiness
Bidirectional-capable onboard units and chargers add cost, and OEM support is limited. Diffusion of ISO 15118-20-capable equipment will take time, so for now smart charging (one-way optimization) is the realistic mainstay.
Separating Potential from Deployed
For strategy, it is essential to assess this area by splitting it into "direction" and "current state." As direction, three things align — renewable expansion, the surge in grid-scale storage, and progress on standardization — making the energy-asset transformation of EVs highly likely. As deployment, however, V2G is at the pilot stage, and full commercial rollout must clear four barriers: battery warranty, regulation, economics, and standards readiness.
This view is falsifiable. If the number of commercial V2G cases and the diffusion of ISO 15118-20-capable equipment accelerate, the distributed-energy-asset transformation will advance faster than expected. Conversely, if grid-scale storage (BESS) satisfies flexibility needs without EV participation, V2G's grid value will stay limited. What to watch is not "V2G's potential" but "the number of commercial pilots, regulatory development, and the diffusion speed of capable equipment."
The battery-cost dynamics underpinning EV adoption are covered in Battery at USD 108/kWh: The BEV Cost Crossover, and the market-wide picture in Global EV Sales 2026: A Bifurcating Market.
Reference FactCards
> Source: IEA (global battery storage capacity 108 GW / +40% in 2025, utility-scale ~87 GW, China 63 GW+, cost down 90%+ from 2010 to 2025), Ember European Electricity Review (EU renewables 47% in 2024, solar overtaking coal, 66 GW of new solar). Negative power prices, ISO 15118-20, and V2G market size are referenced in the text from public sources. FactCards are unified on primary sources (IEA / Ember).