Vehicle to Grid Charging Could Change the Game for Fleet Owners

Using your electric vehicle to power your home is an exciting concept, but it's not just for consumers. Fleet owners may soon be some of the biggest early adopters of bidirectional charging technology, which allows a vehicle to convert its stored direct current energy into alternating current electricity. The vehicle can then feed power back to the home as a backup option during outages or back to the grid. 

Here's how vehicle to grid, or "V2G," bidirectional charging could change the game for fleet owners. 

How a UPS warehouse is using bidirectional charging 

The future of bidirectional charging for fleet owners may look an awful lot like this UPS warehouse that uses a bidirectional charging system for its trucks in a vehicle-to-grid setup. 

"We partnered with UPS [and] we did a bidirectional charging wireless power transfer system for one of the UPS trucks," said Omer Onar, research and development staff at Oak Ridge National Laboratory in Tennessee. "[With] that system, you can not only charge wirelessly, but also provide power back to the grid. The reason for that is that UPS is doing a lot of investments in the microgrid at their large facilities so that they can reduce their dependency on the power grid." 

Onar pointed to natural disasters like hurricanes as an example of how a functioning microgrid can help UPS continue operations where other package delivery companies may suffer from delays or lost packages. "They are investing a lot in on-site generation, including solar rooftop panels, on-site energy generation systems and energy storage systems, and having a number of [EV] trucks provides a lot of flexibility in their microgrid operations." 

It's easy to see other fleets like school buses, car rental companies and public transit taking advantage of this kind of microgrid setup for both redundancy and cost savings. "The idea is that when these trucks get back to the facility with 30% state of charge, they can provide power back to the grid," said Onar. "They offset the power demand of the sorting facilities and after midnight, when the electricity is much cheaper and demand is very, very low, they can charge back." 

Predictability matters in V2G 

This microgrid setup can technically work for anyone with a large fleet, including school buses, churches, car rentals, trucking companies, public transit and more. These larger fleets operate on a controlled and predictable schedule, and predictability is valuable for V2G programs. 

On top of this, fleet vehicles like school buses, delivery vans and trucks tend to have much bigger batteries. A school bus may only get used a few hours a day, picking kids up and dropping them off at school or home. Between dropoffs, it's usually sitting idle. By connecting it to a V2G program, the school bus can offer between 130 and 150 kilowatt-hours of energy. 

"You can do a lot with that kind of capacity multiplied by a fleet's size," said Thomas Martin, director of sales engineering at Swtch, a company that offers EV charging solutions for multitenant buildings. "The trick is to ensure there's adequate incentive to get fleets to participate. This could include payments for contributions during peak electricity hours or discounted electricity rates. There are lots of options, but figuring this out could unlock a lot of value in the coming years."

In this regard, the challenges are fairly similar to the ones that exist for consumers. There's significant variation across state lines between utilities. Some states allow net metering, letting you be compensated for excess energy produced by solar panels. Other states may limit energy arbitrage and capacity arbitrage, which is payments for when your home battery or EV returns power to the grid. 

Despite these regulatory hurdles, 2025 may be the year we see more widespread adoption of EVs for bidirectional charging by both consumers and fleet owners.