Could Vehicle-to-Grid Technology Help Smooth the Transition to All-Electric?

All major automakers have gone all-in on an all-electric future. But can the U.S.’s aging grid handle the upcoming surge in demand for charging? And what about resiliency during power outages when you have less access to fossil-fueled generators?

Industry experts point to vehicle-to-grid (V2G) technology as a potential solution to help address these concerns and smooth the transition to electrification.

By enabling electric vehicles with V2G capabilities, fleet managers can work with local utilities on demand response and position their EV fleets as a potential backup power source during outages.

Consider these stats:

• One V2G-enabled Nissan LEAF can provide enough power for two days’ worth of household electricity, according to a recent report by the Electrification Coalition and SAFE (formerly Securing America’s Future Energy).
• One electric school bus can store enough energy to power the equivalent of five operating rooms for more than eight hours, and a single operating room for 43 hours, according to that same report.
• V2G could provide $1 billion in annual grid benefits in California alone if the state reaches its goal of 5 million EVs by 2030 and half of the EVs are V2G enabled, according to the Electric Power Research Institute.

What exactly is V2G? The California Joint Agencies Vehicle-Grid Integration Working Group defines V2G as two-way, bidirectional charging and discharging between EVs and the grid. Associated terms include vehicle-to-home (V2H) and vehicle-to-building (V2B), where the EV battery provides power directly to the property. In those cases, the power is “islanded” and not discharged back to the grid.

For simplicity and clarity, this article will use V2G as a catchall term to include V2H and V2B. And we’ll use V2G and “bidirectional charging” interchangeably.

So, what needs to change in EVs and charging stations to make them V2G-enabled? How could V2G improve resiliency in storm response situations? And what will drive mainstream adoption?

UFP recently spoke with Ladeene Freimuth, senior advisor, Grid Security Project at SAFE (https://secureenergy.org), and Katherine Stainken, vice president of policy at the Electrification Coalition (www.electrificationcoalition.org). We talked about the current state of V2G technology and what the future holds. Here is an edited version of our conversation.

UFP: What makes bidirectional charging happen? Does it initiate from the EV itself, or does it depend on the charger?

Katherine Stainken: It depends on where the power conversion and the smart functions occur, which can either be on the vehicle itself, built into the charging station or split between both.

UFP: What do you think will be more common? Will OEMs build more inverters for V2G? Or do you think the charging providers will take on more responsibility?

Stainken: We’ll likely see both happening, at least for now. That’s because it depends on the vehicle and battery size, particularly for the mobile power use case. For example, electric trucks with large batteries, like the Ford F-150 Lightning, offer the option of built-in bidirectional charging, perfect for use as a mobile power unit. But sedans would likely need the power conversion and smart functions built into the charging stations because the batteries on those vehicles are smaller, meaning you would rotate through those vehicles providing power more quickly, so it’s more cost effective to have the bidirectionality functions in the charging stations versus the added cost to each vehicle.

UFP: Is there a minimum charging level – such as Level 2 or Level 3 fast charging – for V2G?

Ladeene Freimuth: Bidirectional charging typically uses direct current charging or converts AC to DC for charging. An inverter also is required.

UFP: How would you envision V2G improving resiliency in storm response situations for utility fleets?

Stainken: Electric school buses have huge batteries that can provide significant backup power. Or it could be an electric concrete mixer or any big truck with large batteries. You could also generate power with a large fleet of electric sedans – say, a municipal fleet of 50 to 100 vehicles just sitting in the parking lot at the facility. You could set up a bank of V2G chargers on-site to send power back to the grid or direct to a building.

UFP: What do you think will drive mainstream adoption of V2G?

Freimuth: Greater awareness of the value and benefits that V2G can create will help. On the policy front, the Bipartisan Infrastructure Law and the recently signed Inflation Reduction Act also should help drive adoption of electric vehicles and V2G. For instance, several programs in the BIL are intended to facilitate the wider and faster adoption of V2G, from the National EV Charging Initiative aimed at expanding charging infrastructure across major highway corridors and in underserved communities, including V2G, to Energy Department grid modernization or smart grid investment grants for which V2G technologies are eligible. The Inflation Reduction Act includes a tax credit for electric vehicle charging infrastructure, known as the Section 30C tax credit, which explicitly makes bidirectional charging equipment eligible for this credit. The IRA also contains credits for light-duty electric vehicles and for medium- and heavy-duty EVs.

Stainken: If California reaches its goal of 5 million EVs by 2030, and half of the EVs are V2G enabled, that could generate a potential $1 billion annual grid benefit. That’s significant money. And as more studies show these economic benefits, that will help drive more and more of the market towards V2G.

Also, in California, a comprehensive working group concluded that there were about 320 different use cases for bidirectional charging. So, it’s up to the state, the utilities commission and other stakeholders to prioritize which use cases to focus on.

We’re shifting towards 100% clean energy. But wind power is intermittent. And solar has peak times. So how do you store that energy for when you need it? Electric vehicles with V2G technology could serve as battery storage.

And there are different business models to consider that could drive adoption. For example, you could imagine that the electric school bus provider would get paid for supplying power back to the grid.

UFP: To clarify, you’re saying that V2G technology could create a potential revenue stream for EV owners who supply power back to the grid?

Freimuth: Yes, it is conceivable – depending on the vehicle ownership model and other factors – that V2G could create a potential revenue stream for the grid services provided by a vehicle.

UFP: I imagine a lack of universal technical standards for bidirectional charging hardware and software would hinder widespread adoption. How far away are we from having a uniform set of standards?

Freimuth: Efforts are under way to establish uniform technical standards so that there are not different sets of technical standards across the states.