What is Bidirectional Charging or “V2G" Technology?

The Nissan LEAF is able to support the grid by storing energy for later use and absorbing demand fluctuation.

What is “V2G” and how does it work? What is bidirectional charging? What cars enable bidirectional charging? 

“V2G” stands for “vehicle-to-grid”, a charging technology that allows energy in an electric car battery to be pushed back into the electrical grid. It can also be referred to as bidirectional charging because of the two-way flow of electrical energy. The idea is similar to smart charging where charging power is increased or decreased as necessary, but V2G goes one step further and allows the charged power to be pushed back to the power grid to balance energy consumption and production variations when necessary.  

When plugged into a V2G charger, EV drivers can choose to either charge up their cars from the grid or sell back stored energy from their car to the grid. V2G charging allows EV batteries to be used much more efficiently than traditional unidirectional charging and is important for fighting climate change and moving away from fossil fuels. Renewable energy like wind and solar can’t be produced on demand and needs to be either used immediately when it becomes available or stored somewhere for later use. EV batteries provide a perfect place to store this energy, and once stored, it can be pushed back into the grid during peak demand times and to help avoid blackouts or power surges without the use of fossil fuels.  

The most important aspect of V2G charging is making sure that the battery is charged enough when the car needs to be driven, something easily solved using phone apps that allow you to choose what charge you need at any given time. That way, when the car is helping balance the grid, it only uses some of the energy from the vehicle and keeps the charge within a set tolerance. Since cars are plugged in 90% of the time, it makes sense to use the batteries to balance the grid when they’re not in use.  

The only vehicles out right now that have V2G capabilities are the Nissan Leaf and the Nissan e-NV200, but other manufacturers aren’t far behind. Ford has made vehicle-to-home (V2H) capabilities for the F-150 Lightning electric pickup and may add V2G charging in the future. Volkswagen has announced that all their ID. branded vehicles will have V2G capabilities starting in 2022 and EV Connect, leading provider of EV charging solutions, is already running trials on V2G technology in the U.S. 

The Ford F-150 Lightning has V2H "vehicle to home" capabilities allowing it to be used as a power source in the case of blackouts or disasters, and is expected to have V2G tech in the future.