Vehicle-to-grid charging: What you need to know

Electric vehicles (EVs) can save you money in more ways than one. Compared to gas-powered cars, it’s already cheaper to fuel an EV (usually). Thanks to bidirectional charging, you can use that cost-effective “fuel” from your EV battery to power your devices, your home, and even send power back to the electric grid. 

Vehicle-to-grid is a type of bidirectional charging, an emerging technology that enables EVs to take a charge and send power out. As its name implies, vehicle-to-grid technology allows you to draw power from the electric grid and supply electricity back to it. Although bidirectional charging is still in its infancy and not yet regulated or widely available in current car models, it’s a promising avenue to maximize the value of your EV and your solar investments. 

With more homeowners pairing solar panels with energy storage systems and more car purchasers opting for electric vehicles, bidirectional charging is a natural companion feature. Eventually, you’ll be able to charge your EV with your home solar panel system, store your unused energy, and use your car to power your home or the grid when necessary. Let’s dive deeper into how vehicle-to-grid technology works and explore the EV models currently leading the bidirectional charge.

Vehicle-to-grid (V2G) technology allows you to take the electricity stored in your electric vehicle's (EV) battery and send it back to the grid, as you would with a net metered solar panel system.

As a refresher, net metering empowers you to send electricity generated by your home solar panel system to the grid in exchange for credits on your electric bills. Vehicle-to-grid technology extends this concept to electric vehicles. With V2G, EV batteries both accept and send electricity to the grid, which can reduce stress on the grid during peak demand hours and boost the value of your EV investment by using your EV to earn electric bill credit. 

While V2G charging isn't widely available yet, many automakers are actively exploring and testing its functionality.

V2G technology creates a mobile energy storage device on wheels, allowing you to integrate more renewable energy into the grid and into your home. 

Imagine a future where you drive your EV to work and park it in a parking lot covered by solar canopies. You and all of your coworkers' EVs charge during the day. When electricity prices increase in the mid-day summer heat, these EVs respond and pump that stored, clean solar energy back into the grid (and get paid to do so). Since it's a Wednesday, your EV knows that you go to the grocery store and lead pickup from after-school activities. It stops discharging to the grid to leave more than enough charge in your battery to run your errands and keep you moving if any unexpected errands arise. 

Additionally, V2G technology can improve the financials of going solar. If you’re subject to time-of-use rates or you don't have one-to-one net metering (where every unit of electricity you put onto the grid is credited as one full unit of electricity you can use from the grid later), V2G charging can help make up the difference. 

One of the only downsides of bidirectional charging is the potential for battery degradation. Frequently charging and discharging your battery can contribute to a shorter lifespan.

V2G technology is only just gaining traction. To really take off, it needs the foundational policy that other programs like net metering have established. 

The shift to bidirectional charging is underway, but only a few EV options with any kind of bidirectional charging technology are available today. If you’re keen on becoming a V2G early adopter, check out the Nissan Leaf.

Interested in the benefits of vehicle-to-grid technology but can't wait for it to become more commercially available? A great place to start is by checking out solar plus storage on EnergySage. Investing in a solar battery solution for your home is a great way to provide backup power for outages that is cleaner and more affordable in the long run than a backup generator. To receive custom solar and storage quotes for your home, register for an account on the EnergySage Marketplace.