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Oct 16, 2023

Vehicle

Related Video Electric vehicles offer many benefits: no more expensive gas to

Related Video

Electric vehicles offer many benefits: no more expensive gas to pump, reduced greenhouse emissions, priority parking, and HOV-lane access. Another one EV makers and advocates are touting is the promise of vehicle-to-grid (V2G) charging, the ability to have an EV's battery to send power to utilities, which has advantages ranging from financial incentives for EV owners to helping fortify the electric grid.

EVs currently can stress the electric grid rather than strengthen it. For example, last year the governor of California requested that EV owners reduce charging during a heatwave to keep from straining the state's power grid. But if you think of EVs as large batteries with motors and wheels—essentially energy storage devices—tapping their power to bolster the electric grid makes sense. It could also create cash for EV owners by sending—and getting paid for—power stored in their batteries back to the grid when utilities need it.

But as with most things EV, from supply chain issues to lack of public charging infrastructure, V2G is a complex challenge due to a variety of factors—and is at best several years away from being viable. It will require extensive coordination between and investment by electric utilities, automakers, and EV owners, and standards for the technology are still evolving. Automakers and utilities are making the initial steps to facilitate V2G since it not only enables symbiotic support for EVs but has the potential along with renewable and other dedicated energy storage means to reshape the electric grid.

"Vehicle to grid has the potential to transform huge swathes of the energy infrastructure," said Scott Hinson, CTO for Pecan Street, an Austin, Texas-based nonprofit research organization that focuses on clean energy and smart grid technologies. "We've never added a load to the electrical grid that's as flexible as the electric vehicle," he added.

For example, during a heatwave, people can't just turn off their air conditioning to avoid a blackout. "If you turn off the A/C for long enough in some areas, people can die," Hinson said. "But an electric vehicle doesn't care when it's charged, and with V2G you have a whole new order of magnitude of flexibility."

EVs are typically cheaper to charge during early-morning hours when the demand on the grid is low and electricity rates subsequently decrease—and most EVs are parked. So they're a much more manageable load for the grid compared to air conditioners running 24/7 in Arizona or Florida in summer.

The building blocks for V2G—including managed charging, wherein an EV charger can communicate with a utility and vehicle-to-home (V2H) charging that allows an EV battery to power a house—are already in place. The next steps and EVs that support V2G are being developed.

To enable V2G, an EV needs bidirectional charging: the ability to both receive power from or send it to the electric grid. Currently very few cars—including the GMC Hummer, Ford F-150 Lightning, Mitsubishi Outlander PHEV, Nissan Leaf, and Volvo EX90—have bidirectional charging. But more are on the way, such as the Chevy Silverado EV and EVs from the Volkswagen Group that use the company's MEB electric platform architecture.

"You need bidirectional charging along with the software in the vehicle to pull the energy off and either put it into your home for V2H or into the grid for V2G," explained Mark F. Bole, head of V2X and battery solutions for GM Energy, a new business unit the automaker launched last year. "Later this year we will take the first step, which is vehicle-to-home, or V2H," Bole added.

This first step will be the Chevy Silverado RST EV slated for release in November, along with a bidirectional charger and the hardware necessary for V2H. "Once you get power off the vehicle for V2H, it's a natural next step to go to V2G" Bole said. "But V2G is most likely not going to come in a broad sense until 2025."

GM and other automakers including Ford, Volkswagen, and Toyota are running V2G pilot programs with utilities to integrate systems and establish protocols. "We need to interface with the utilities, and that's going to take a bit of time," Bole said. "There are more than 1,500 utilities in the U.S., and they are all very different, and they all have their own systems."

GM Energy is currently running more than 20 V2G pilot programs, Bole added. "We're starting out with a managed-charging program and piloting V2H, and once we have bidirectionality, that's where we'll really help the electric grid and generate value," he said. "When standards are in place, we'll start to see more mass-production vehicles with V2G capabilities."

Ford is also laying the groundwork for V2G with its F-150 Lightning EV pickup and its V2H capability. But as with the upcoming Chevy Silverado EV, to enable V2H and subsequently V2G, the F-150 Lightning requires expensive equipment purchases on the EV owner's part. An EV owner also typically needs to be a homeowner, which leaves out renters and many who live in multi-unit dwellings, although it may be possible for them to participate in a V2G program if, for example, they work for a company that enables the technology at an office or for a fleet.

The F-150 Lightning requires the Intelligent Backup Power feature that's standard on the upper trims and allows V2H capability. An F-150 Lightning owner also needs a Level 2/240-volt, 80-amp Ford Charge Station Pro home charger, which is standard with an extended-range battery, and a Home Integration System developed by Ford and Sunrun, Ford's preferred installation partner.

"For V2G, the utility will need to offer the consumer a program to enable that capability, which Ford is currently testing with multiple utilities across the U.S.," said Dave Hurst, energy services manager for Ford. He added that Ford is currently collaborating with multiple utilities to test V2G, including managed charging programs with Xcel Energy in Colorado, DTE Energy in Michigan, and SMUD in California. The company is also studying the transition from V2H to V2G with PG&E in California and Duke Energy in multiple states, and using the F-150 Lightning to test V2G.

General Motors is taking a much broader approach exemplified by GM Energy's three divisions—residential, commercial, and charging—all under the Ultium brand. GM Energy's portfolio includes everything from V2G to stationary energy storage to a cloud-based system that combines software and data to tie everything together. "We're thinking very comprehensively about opportunities to help people manage their energy," Bole said.

GM Energy's Ultium Home line includes a V2H-capable bidirectional charger, a controller, a stationary battery called Powervault similar to Tesla's Powerwall, and solar through its partner SunPower. Bole said these products will debut with the launch of the 2024 Chevrolet Silverado EV but didn't reveal pricing.

GM is pitching Ultium Home not just to keep the lights on at home during a power outage or EV charging via solar, but eventually to allow consumers to sell electricity from their EV batteries back to utilities. GM hasn't finalized how or if it will compensate consumers for the energy they supply to utilities, Bole said. "But we may say to customers, 'You can get $20 a month off your monthly lease payment or we may share savings,'" he added.

"The difficult part is it's different in every state and with every utility," Bole said. "But we'll use data from the Energy Services Cloud we're putting together and say to customers, 'This is the amount of money you can save by managing your energy through us with these products and services.' That will be coming by the end of this year," he added.

Pecan Street's Hinson said that while V2G is being proven in pilot programs and many electric utilities are onboard, a major obstacle is establishing standards. "Technology-wise it's doable," he said. "The connectivity is already there. Standards are not." Bole acknowledged that there aren't yet standards on communication protocols between the EV and a bidirectional charger but added that they're being quickly developed.

Hinson said a walled-garden approach of proprietary standards could hamper V2G and that universal standards need to be established. "Auto manufacturers tend to be fairly protective," he added. "They want to hold onto this potential value stream as part of their future business models."

When Chevy rolls out the Silverado EV and its V2H technology in November, owners will need hardware provided by General Motors, Bole said. Ford and other automakers also offer proprietary systems. "Today you can't go to the store and buy a bidirectional charger," Bole added.

But Bole said as standards evolve, "You will be able to plug a Tesla into a GM charger and work with GM to aggregate your energy. Obviously, we want to sell as many GM EVs as we can, but I'd be foolish if I thought that our EV customers will just buy GM vehicles. They may have a Tesla sitting in their garage, too," he added.

"Once these standards are set, which will be more into 2025, there will be the ability for GM Energy to aggregate energy from a Tesla or a Ford or a stationary storage system as well as a GM EV," Bole said. "We're building an agnostic, broad system. Not all automakers are approaching it that way, but going forward there will be more plug-and-play opportunities for consumers."

EV owners will, of course, need to be onboard and purchase the equipment required for V2G to reap the rewards, but it will also have to be seamless. "From a consumer perspective, it has to be transparent and easy," said Andrew Meintz, chief engineer of EV charging and grid integration at the federally funded National Renewable Energy Laboratory. "That's going to require the utility or vehicle OEM to understand how owners use their vehicles."

This has already started with managed charging pilots, Bole said. "We can do that today through vehicle telematics and working with the utility," he added. "Say a utility sends us a demand response for tomorrow at 3 a.m. and asks us to send a stop charge command to the EV with the customer's agreement and knowledge. We then text our customers using that utility and ask, 'Can you not charge between 3 to 5 a.m. tomorrow, and will you allow us to turn off charging? If you accept, here's $20. '"

Bole said GM Energy currently has three such pilot programs in place in the U.S. "It's less than 400 vehicles that are enrolled because we're still learning, the utility is still learning, and our customers are still learning," he added. "Part of our go-to-market strategy, which we're still developing, will be if a consumer buys the equipment—given where they live and their driving habits—we'll estimate their energy savings. We'll say, 'This will be your payback for that investment.' Plus, they now have a generator in their garage."

GM Energy isn't actively promoting V2G to consumers because the products and services aren't yet publicly available, Bole said. "We don't want to get too far in front of ourselves because we don't have something to sell today," he added. "But we are actively talking about what we're doing with utilities because we think it's part of the education process."

Hinson says automakers also need to communicate to customers any possible impact V2G and related energy-extraction technologies have on an EV battery and its warranty. Several studies have been conducted on how V2G affects an EV's battery, with one from 2017 by the University of Warwick showing that it could actually extend the life of batteries.

"Part of GM's Energy Services Cloud is monitoring the health of the battery," Bole said. "Who better to trust than the company that made the battery and warranties it."

Although the ideal is for large numbers of EVs to send power to the grid, just a few vehicles can make an impact, Meintz said. Bole added that GM is working with the clean-energy nonprofit Rocky Mountain Institute and several utilities on what he called virtual powerplants, which is taking individual EVs and aggregating their energy.

Hinson said that although V2G tech still has a way to go on several fronts, he's hopeful it will have a future. "There's more work that needs to be done to understand what the value will be," Hinson said. "And how V2G will play in the market against competing technologies that provide the same resource, such as stationary batteries that have 100 percent availability and are always plugged into the grid. But with V2G," he said, "the vehicle can become an energy asset in ways people are not yet comprehending or contemplating."