Electric Vehicles Can Give Power Back to the Grid—Or Your Home During a Blackout

The Washington Post sent up alarms earlier this month with a story that concluded the grid won’t be ready for all the electric vehicles that will be wanting to plug in. “Making America’s cars go electric is no longer primarily a story about building the cars,” the article said. “America’s electric grid will be sorely challenged by the need to deliver clean power to those cars. It barely functions in times of ordinary stress, and fails altogether too often for comfort, as widespread blackouts in California, Texas, Louisiana and elsewhere have shown.”

But what if the battery-powered cars, trucks, and buses could help out by delivering power back to our beleaguered grid when it needs it most? That’s the premise of V2G, or vehicle to grid, which posits that when electric vehicles (EV) are idle, as they will be 95% of the time, they can be grid-connected and (by agreement between power provider and vehicle owner) upload electricity. After all, reports Moixa, 10 new Nissan Leafs can store as much energy as 1,000 homes typically consume in an hour.

The concept goes back to the early 2000s when EVs were still embryonic. At the University of Delaware, Professor Willet Kempton set up test programs with Mini-E electrics. “You need a technology that can come online fast, safely and in a balanced way to replace say, solar, if the sun didn’t shine this afternoon, or wind if it was a windless day. V2G can do that,” Kempton said.

V2G has been promising for a while, but commercial applications have been slow to get off the ground. It’s mostly pilot programs, as in a 50-vehicle test in Australia. But that’s changing. Over the summer in Beverly, Massachusetts, a Thomas Built electric school bus powered by Proterra (with a 226-kilowatt-hour battery pack) delivered power back to the grid for more than 50 hours. The utility took in almost three megawatt-hours of power during 30 upload events. The average American home uses 11 megawatt-hours a year. 

The program was in conjunction with Highland Electric Fleets and National Grid. Proterra developed the bidirectional charging system that’s on the bus. V2G is green in this case because the bus power was drawn down in periods of high demand. One bus won’t make a huge difference, but a fleet of them could make it unnecessary to turn on fossil-fueled “peaker” plants. 

“By delivering stored clean energy back to the grid when it’s needed most, electric school buses can help create a more resilient local power system and reduce the dependence on expensive fossil-fuel power plants,” said Gareth Joyce, president of Proterra. School buses sit around a lot, typically transporting students for six hours a day, 200 days annually. And they take the summer off. That’s when there’s a huge demand for air conditioning. 

In March, Volkswagen said its new EVs will have bi-directional charging from 2022 onwards. Bloomberg says that with 10 million EVs on the road, their combined 296 gigawatt-hours of lithium-ion batteries have eight times the capacity of the stationary grid-scale batteries currently installed around the world. 

Consumers who give power back to the grid will be compensated for it, but the revenue stream is not likely to be a major selling point. According to Gizmodo, the EVs in the Australian V2G program will upload power a few dozen times over the course of a year, for not more than 15 minutes each time, earning the owners about Australian $1,000 ($747) annually. 

Something else might get buyers more excited, V2H, or vehicle to home. The new Ford F-150 Lightning electric truck is capable of powering a work site, or a home experiencing a power outage. To get that capability, owners will have to pass on the base $40,000 vehicle and buy the extended-range version with a dual onboard charging system, capable of recharging at 19.2 kilowatts. If fast charged, it will be able to add 54 miles of range in 10 minutes. For home use, Ford’s 80-amp Charge Station Pro bi-directional unit will have to be installed. 

In the Lightning’s forward “frunk” are four 120-volt plugs and two USBs, with a total of 2.4 kilowatts. The 20 amps of 120-volt power can run all the power tools you want. The outlets in the pickup bed offer 7.2 kilowatts, which Motor Trend says is enough to power a welder or a home air conditioner. And using the Charge Station Pro means the dark house can benefit from a full 9.6 kilowatts of power. The car can keep the lights on for about three days. 

In April, a Montreal-based company called Dcbel showed a $5,000 system, the r16, that can charge two EVs at a time using solar power, but can also tap into bi-directional cars (the Nissan Leaf, the Kia EV6, the Mitsubishi Outlander, and those future VWs) as a home backup source. Tesla’s Powerwall battery storage can also be a home blackout bailout. 

When Texas experienced its blackout last February (the one that sent Senator Ted Cruz sprinting to Cancun), resourceful homeowners used their F-150 PowerBoost hybrids as backup power—they also have 120- and 240-volt chargers in their beds. As climate change intensifies, causing more flooding, heat waves, and power outages, V2H is an idea whose time has come. Anyway, they’re happy in Beverly, Massachusetts. “We look forward to taking full advantage of the economic, environmental and operational benefits that V2G technology offers,” said Beverly Mayor Mike Cahill.