vehicle-to-grid V2G – A US pilot suggests electric vehicle owners may earn up to thousands by selling stored power to stabilize grids as renewables rise—if standards and tariffs catch up.
Electric cars spend most of their lives parked. With a shift in how electricity flows, that idle time could become a revenue stream—and a grid-smoothing tool—for millions of drivers.
The challenge is familiar: electricity from solar and wind is clean, but it’s also variable. When the sun disappears or the wind drops, supply can swing quickly. Renewable-heavy grids need flexibility, and researchers increasingly see EVs as a large, underused source of that flexibility.
A pilot in Delaware points to how that could work through vehicle-to-grid, or V2G.. In the project. four Ford electric vehicles owned by Delmarva Power were retrofitted so they could send electricity back to the power system.. Researchers monitored V2G performance across 2025. and reported that—based on the amount of electricity the cars supplied—each EV could have earned as much as $3. 359 annually if that energy had been sold at market price.
On paper, the logic is straightforward: many EVs are plugged in most of the day.. Some estimates suggest the average EV drives only a small fraction of the time. leaving a large window when a car is connected to charging infrastructure but not actively being used.. In that state, the vehicle becomes less like a passenger transport device and more like a distributed battery.. Utilities can draw from that stored energy when demand peaks in the morning and evening. while the cars recharge during periods of higher renewable supply.
The appeal isn’t only about paying drivers.. It’s also about cost and reliability.. The pilot’s lead researcher. Willett Kempton at the University of Delaware. argues that using parked EVs can reduce the need for expensive. centralized battery storage—potentially lowering costs for grid stability while increasing the grid’s ability to integrate more renewables.. In other words, V2G is not just “more batteries,” but a different way to distribute them.
Still. the path from pilots to widespread adoption looks less like a single breakthrough and more like a stack of hard engineering decisions and market rules.. One of the biggest issues is power conversion.. Most power grids operate on alternating current (AC). while EVs convert incoming AC into direct current (DC) to charge their batteries.. For an EV to supply electricity back to the grid. that flow must reverse—and the vehicle needs to convert stored DC back into AC safely.
Safety standards turn this conversion problem into a commercial one.. Reversible energy flow requires V2G components built to meet strict electrical protections.. In the simplest setups available today. a wall charger can handle the conversion. including converting DC to AC in a way that fits established standards used for solar systems.. But those chargers can be expensive—often costing thousands—so the industry is pushing toward EV designs that can convert DC to AC internally.. If that becomes widespread. researchers expect V2G could cost less to deploy. adding only a few hundred dollars rather than thousands.
That “how” matters because standards are currently competing.. Some companies pursue DC-based V2G approaches, while others lean toward AC-based systems.. The situation has been compared to the VHS-versus-Betamax era: different technologies can both work. but the market’s long-term winner depends on cost. safety certification. and how easily drivers and utilities can roll out compatible hardware.. Alex Schoch of Octopus Energy describes the likely reality as a period where more than one standard coexists—until scaling forces alignment.
For drivers, even a technically capable car doesn’t automatically turn into a paycheck.. The missing piece is incentive design.. V2G only becomes attractive when there’s a clear buyback tariff—so owners are paid for the energy they provide at times when the grid values it most.. The UK has begun experimenting: Octopus launched the first V2G tariff there in 2024, though uptake remains limited.. Partnerships. such as those that pair vehicles and chargers via leases. are another way the market is trying to reduce upfront costs and lower the friction for consumers.
There’s also a systems-level twist that’s easy to miss: V2G can relieve pressure when managed well. but it can also add complexity as more vehicles participate.. If many cars respond simultaneously—especially during charging windows—the grid could face new peaks and stresses.. That means V2G is likely to accelerate grid modernization. including upgrades that allow for greater control. communication. and power handling across distribution networks.
Researchers examining the long-term outlook argue that power systems can’t afford to treat V2G as a gradual patchwork.. One analysis concluded that it may be more economical for countries to upgrade their grids in a coordinated way rather than incrementally as V2G grows.. The message is blunt: while V2G can look like a “silver bullet. ” it doesn’t eliminate the need for infrastructure investment.. The gap is significant, and grids must be prepared early to avoid bottlenecks.
For now. the Delaware pilot shows the direction of travel: EVs can act as a practical. distributed energy resource when the hardware. safety rules. and market incentives line up.. If the industry can converge on interoperable standards—particularly around AC versus DC conversion—and if tariffs make participation rewarding for everyday drivers. vehicle-to-grid may move from demonstrations to a mainstream feature of the clean-energy transition.
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