Trams could store energy when there is excess supply, and return it to the grid when demand peaks, generating thousands of euros a year. But manufacturers disagree on the best way to do this — in a war of concepts like the one that pitted Betamax against VHS in the 1980s.

At least 90% capacity of electricity generation that is currently being built is renewable. But solar and wind farms only produce electricity when the sun shines and the wind blows, so energy supply fluctuates more.

A pilot project in the US state of Delaware showed that electric vehicle (EV) owners could gain thousands of dollars per year by allowing their cars to function as part of a gigantic collective drums which stores electricity when supply is high and distributes it when demand is high.

Some data suggest that an average VE only runs about 5% of the time. The rest of the time, the vehicle is frequently parked and connected to the gridnote to .

This means that instead of building huge battery farms, electricity companies could balance the grid by taking energy from these cars when consumption reaches morning and evening peaksand then recharging them during the day, explains Willett Kemptonfrom the University of Delaware, who led the .

EV owners could sell electricity at a premium price and even so, save money to the network. “An electric vehicle connected to the mains for 95% of the time it is not driving can provide storage to the grid at about a tenth of the cost of building batteries,” says Kempton.

“This could help increase the reliability of any electrical system and increase our ability to integrate more and more renewable energy in the system”, he adds.

In the project, four trams from the energy company Delmarva Power were adapted to supply electricity back to the system through charging vehicle-to-grid (V2G)a system that allowed, for example, on the day of the blackout on April 28th last year, when the whole country was in the dark, .

Kempton and his colleagues monitored V2G charging throughout 2025. Taking into account the amount of electricity the cars supplied to the grid, each EV could have yielded up to $3,359, about 2,850 euros, per yearif this energy were sold at the market price.

When Kempton became one of the first to research V2G in 1997, the concept made so much sense that thought it would become a commercial reality in a few years. But almost 30 years laterV2G exists primarily in a handful of test programs in the US, Europe, Japan and China.

A fundamental reason for this inertia is that reverse the flow of energy from the network to the car is surprisingly complexbecause it requires manufacturers, utility companies, and governments to change the way you view EVsexplains Kempton.

The biggest obstacle is that electrical networks work mostly or exclusively with alternating current (AC)while most household devices, including EVs, convert this AC into direct current (DC) when drawing power from an outlet. For an EV to supply power to the grid, it needs to convert the power back to AC.

Do this without electrocuting anyone requires that V2G components be built to safety standards. The simplest way to configure V2G currently is install a wall charger that converts DC to AC to standards designed to allow solar panels to power the grid.

Some manufacturers, including a Volkswagen e a Nissanhave been offering wall chargers with this feature in certain markets. But these wall chargers can cost thousands of euros.

Companies like Tesla, BYD and Renault began to develop EVs that convert DC to AC in the vehicle itselfand Kempton and others have been working on new safety standards for AC chargers.

If this technology becomes widespread, it could make V2G viable by adding just a few hundred euros to the cost of the car, says Kempton.

There is currently a rivalry between V2G in DC, like Volkswagen, and V2G in AC, like Tesla. This is similar to the format war between cassettes VHS and Betamax in the 1980sexplains Alex Schochfrom British electricity retailer Octopus Energy.

At the time, the Betamax offered better quality, similar to DC chargers, which are more efficient. But VHS players were much cheaper, as did AC chargers, and VHS ended up dominating the market.

“Our perspective is that there is a period where the market can handle two different standards, but to really scale and reach the mass market, it is I need to align in one”says Schoch. “We are firmly on team…CA.”

“Many manufacturers are already putting EVs on the road that are already V2G compatible, or the next generation arriving today or tomorrow will be,” says Schoch. “And suddenly, we will have gigawatts of distributed capacity on all sides.”

But so that owners want to spend even just a few hundred dollars on a V2G system, there needs to be a buyback fee that allows them to make money by supplying energy to the grid.

In 2024, the Octopus launched the UK’s first V2G tariffalthough for now few car owners can take advantage of it. In this sense, it also established a partnership with BYD to allow consumers rent a charger and an electric vehicle equipped for V2G in AC.

And this modality represents, in practice, a new business model for any consumer, who could now rent equipment, buy cheap energy (or charge their vehicle at no cost, if they can) and sell it at a profit margin.

Owning an electric vehicle (or renting one) is apparently about to become a sole proprietorship energy arbitration business… which generates an interesting income, practically alone, while the car is parked.

Trams could store energy when there is excess supply, and return it to the grid when demand peaks, generating thousands of euros a year. But manufacturers disagree on the best way to do this — in a war of concepts like the one that pitted Betamax against VHS in the 1980s.

At least 90% capacity of electricity generation that is currently being built is renewable. But solar and wind farms only produce electricity when the sun shines and the wind blows, so energy supply fluctuates more.

A pilot project in the US state of Delaware showed that electric vehicle (EV) owners could gain thousands of dollars per year by allowing their cars to function as part of a gigantic collective drums which stores electricity when supply is high and distributes it when demand is high.

Some data suggest that an average VE only runs about 5% of the time. The rest of the time, the vehicle is frequently parked and connected to the gridnote to .

This means that instead of building huge battery farms, electricity companies could balance the grid by taking energy from these cars when consumption reaches morning and evening peaksand then recharging them during the day, explains Willett Kemptonfrom the University of Delaware, who led the .

EV owners could sell electricity at a premium price and even so, save money to the network. “An electric vehicle connected to the mains for 95% of the time it is not driving can provide storage to the grid at about a tenth of the cost of building batteries,” says Kempton.

“This could help increase the reliability of any electrical system and increase our ability to integrate more and more renewable energy in the system”, he adds.

In the project, four trams from the energy company Delmarva Power were adapted to supply electricity back to the system through charging vehicle-to-grid (V2G)a system that allowed, for example, on the day of the blackout on April 28th last year, when the whole country was in the dark, .

Kempton and his colleagues monitored V2G charging throughout 2025. Taking into account the amount of electricity the cars supplied to the grid, each EV could have yielded up to $3,359, about 2,850 euros, per yearif this energy were sold at the market price.

When Kempton became one of the first to research V2G in 1997, the concept made so much sense that thought it would become a commercial reality in a few years. But almost 30 years laterV2G exists primarily in a handful of test programs in the US, Europe, Japan and China.

A fundamental reason for this inertia is that reverse the flow of energy from the network to the car is surprisingly complexbecause it requires manufacturers, utility companies, and governments to change the way you view EVsexplains Kempton.

The biggest obstacle is that electrical networks work mostly or exclusively with alternating current (AC)while most household devices, including EVs, convert this AC into direct current (DC) when drawing power from an outlet. For an EV to supply power to the grid, it needs to convert the power back to AC.

Do this without electrocuting anyone requires that V2G components be built to safety standards. The simplest way to configure V2G currently is install a wall charger that converts DC to AC to standards designed to allow solar panels to power the grid.

Some manufacturers, including a Volkswagen e a Nissanhave been offering wall chargers with this feature in certain markets. But these wall chargers can cost thousands of euros.

Companies like Tesla, BYD and Renault began to develop EVs that convert DC to AC in the vehicle itselfand Kempton and others have been working on new safety standards for AC chargers.

If this technology becomes widespread, it could make V2G viable by adding just a few hundred euros to the cost of the car, says Kempton.

There is currently a rivalry between V2G in DC, like Volkswagen, and V2G in AC, like Tesla. This is similar to the format war between cassettes VHS and Betamax in the 1980sexplains Alex Schochfrom British electricity retailer Octopus Energy.

At the time, the Betamax offered better quality, similar to DC chargers, which are more efficient. But VHS players were much cheaper, as did AC chargers, and VHS ended up dominating the market.

“Our perspective is that there is a period where the market can handle two different standards, but to really scale and reach the mass market, it is I need to align in one”says Schoch. “We are firmly on team…CA.”

“Many manufacturers are already putting EVs on the road that are already V2G compatible, or the next generation arriving today or tomorrow will be,” says Schoch. “And suddenly, we will have gigawatts of distributed capacity on all sides.”

But so that owners want to spend even just a few hundred dollars on a V2G system, there needs to be a buyback fee that allows them to make money by supplying energy to the grid.

In 2024, the Octopus launched the UK’s first V2G tariffalthough for now few car owners can take advantage of it. In this sense, it also established a partnership with BYD to allow consumers rent a charger and an electric vehicle equipped for V2G in AC.

And this modality represents, in practice, a new business model for any consumer, who could now rent equipment, buy cheap energy (or charge their vehicle at no cost, if they can) and sell it at a profit margin.

Owning an electric vehicle (or renting one) is apparently about to become a sole proprietorship energy arbitration business… which generates an interesting income, practically alone, while the car is parked.

Trams could store energy when there is excess supply, and return it to the grid when demand peaks, generating thousands of euros a year. But manufacturers disagree on the best way to do this — in a war of concepts like the one that pitted Betamax against VHS in the 1980s.

At least 90% capacity of electricity generation that is currently being built is renewable. But solar and wind farms only produce electricity when the sun shines and the wind blows, so energy supply fluctuates more.

A pilot project in the US state of Delaware showed that electric vehicle (EV) owners could gain thousands of dollars per year by allowing their cars to function as part of a gigantic collective drums which stores electricity when supply is high and distributes it when demand is high.

Some data suggest that an average VE only runs about 5% of the time. The rest of the time, the vehicle is frequently parked and connected to the gridnote to .

This means that instead of building huge battery farms, electricity companies could balance the grid by taking energy from these cars when consumption reaches morning and evening peaksand then recharging them during the day, explains Willett Kemptonfrom the University of Delaware, who led the .

EV owners could sell electricity at a premium price and even so, save money to the network. “An electric vehicle connected to the mains for 95% of the time it is not driving can provide storage to the grid at about a tenth of the cost of building batteries,” says Kempton.

“This could help increase the reliability of any electrical system and increase our ability to integrate more and more renewable energy in the system”, he adds.

In the project, four trams from the energy company Delmarva Power were adapted to supply electricity back to the system through charging vehicle-to-grid (V2G)a system that allowed, for example, on the day of the blackout on April 28th last year, when the whole country was in the dark, .

Kempton and his colleagues monitored V2G charging throughout 2025. Taking into account the amount of electricity the cars supplied to the grid, each EV could have yielded up to $3,359, about 2,850 euros, per yearif this energy were sold at the market price.

When Kempton became one of the first to research V2G in 1997, the concept made so much sense that thought it would become a commercial reality in a few years. But almost 30 years laterV2G exists primarily in a handful of test programs in the US, Europe, Japan and China.

A fundamental reason for this inertia is that reverse the flow of energy from the network to the car is surprisingly complexbecause it requires manufacturers, utility companies, and governments to change the way you view EVsexplains Kempton.

The biggest obstacle is that electrical networks work mostly or exclusively with alternating current (AC)while most household devices, including EVs, convert this AC into direct current (DC) when drawing power from an outlet. For an EV to supply power to the grid, it needs to convert the power back to AC.

Do this without electrocuting anyone requires that V2G components be built to safety standards. The simplest way to configure V2G currently is install a wall charger that converts DC to AC to standards designed to allow solar panels to power the grid.

Some manufacturers, including a Volkswagen e a Nissanhave been offering wall chargers with this feature in certain markets. But these wall chargers can cost thousands of euros.

Companies like Tesla, BYD and Renault began to develop EVs that convert DC to AC in the vehicle itselfand Kempton and others have been working on new safety standards for AC chargers.

If this technology becomes widespread, it could make V2G viable by adding just a few hundred euros to the cost of the car, says Kempton.

There is currently a rivalry between V2G in DC, like Volkswagen, and V2G in AC, like Tesla. This is similar to the format war between cassettes VHS and Betamax in the 1980sexplains Alex Schochfrom British electricity retailer Octopus Energy.

At the time, the Betamax offered better quality, similar to DC chargers, which are more efficient. But VHS players were much cheaper, as did AC chargers, and VHS ended up dominating the market.

“Our perspective is that there is a period where the market can handle two different standards, but to really scale and reach the mass market, it is I need to align in one”says Schoch. “We are firmly on team…CA.”

“Many manufacturers are already putting EVs on the road that are already V2G compatible, or the next generation arriving today or tomorrow will be,” says Schoch. “And suddenly, we will have gigawatts of distributed capacity on all sides.”

But so that owners want to spend even just a few hundred dollars on a V2G system, there needs to be a buyback fee that allows them to make money by supplying energy to the grid.

In 2024, the Octopus launched the UK’s first V2G tariffalthough for now few car owners can take advantage of it. In this sense, it also established a partnership with BYD to allow consumers rent a charger and an electric vehicle equipped for V2G in AC.

And this modality represents, in practice, a new business model for any consumer, who could now rent equipment, buy cheap energy (or charge their vehicle at no cost, if they can) and sell it at a profit margin.

Owning an electric vehicle (or renting one) is apparently about to become a sole proprietorship energy arbitration business… which generates an interesting income, practically alone, while the car is parked.