Can I power my house with an electric car?

Vehicle to home technology could help keep the lights on

Electric vehicles

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Updated

My daughters got some light, and at least the illusion of heat, from candles during the Feb. 2021 blackout.

My family lost power and heat for three days during winter storm Uri in 2021. It was a pretty lousy experience and we struggled to stay warm as temperatures dropped to single digits outside. We moved all our food from our refrigerator into our cold garage to keep it from spoiling. We also struggled to keep our phones charged so we could communicate with family, figure out when power would come back, and try to keep my young daughters entertained. Our solution was to run an extension cord from our electric car into the house. That kept our devices charged, but could electric cars also power our furnace, refrigerator and more during blackouts?

The answer is not yet, but they could.

Electric vehicles (EVs) are essentially batteries on wheels. You can store energy in those batteries, and if EVs are equipped with something called vehicle-to-grid or vehicle-to-home technology, they can also be used to keep the lights on in emergencies. The technology allows the energy being stored in an EV battery to be pushed back into the grid or into buildings to provide power.

Electric car batteries hold an average of 69.5 kilowatt hours (kWh) of energy, enough to provide back-up power to an average U.S. household for two days. Larger electric vehicles like buses and trucks have even bigger batteries and can provide more power. The American company Proterra produces electric buses that can store up to 675kWh of energy. Electric garbage trucks and even big-rigs, with bigger batteries, are becoming a reality too.

If equipped with vehicle-to-grid (V2G) or vehicle-to-home technology, those cars, buses and trucks could prove invaluable during future blackouts. People could rely on their cars to power their houses. Municipalities, transit agencies and school districts could send out their fleets to the areas most in need. We could power homes, shelters and emergency response centers — and could keep people warm, healthy and comfortable until power could be restored.

In October 2018, the Pecan Street, Inc. started integrating the first V2G vehicle in Texas. The pilot project used a 2019 Nissan Leaf with a 40kWh battery in Austin’s Mueller neighborhood and “during the first year of the demonstration phase, Pecan Street was able to have the vehicle participate as a Behind the Meter (BTM) asset to aid Austin Energy in reducing its peak load during ERCOT’s 4CP events. Additionally, during that first year, Pecan Street did not see major battery degradation from daily charge/discharge events requested by the utility.”

Since then, the popularity of EVs has only grown. In 2023, the U.S. witnessed the historic sale of one million fully electric vehicles, the first time that number of EVs were purchased in a single year in the U.S. This surge in adoption underscores a notable shift in consumer preferences and perhaps thanks to various factors, including advancements in battery technology, expanded charging infrastructure, and a heightened awareness of environmental concerns. 

One noteworthy addition to the EV market is Ford’s electric F-150 Lightning. Upon its release, Ford highlighted the truck’s capacity to provide power to a household during a blackout. Ford says that the vehicle with the extended-range battery can power a house for about three days when using 30 kilowatt-hours (kWh) of electricity per day. But having a car with bidirectional capability is only part of the equation. You also need a special charger that allows energy to flow both ways. The Home Integration System, purchased through Ford’s partner Sunrun, includes a power inverter, transfer switch, and battery to start the system, which enables two-way power flow.

We are seeing more bidirectional chargers coming into the market. In June 2023, Montreal-based dcbel announced that its r16 Home Energy Station had become the first bidirectional EV charger certified for residential use in the US. This certification is a significant milestone, signifying that bidirectional EV charging technology is not merely a concept but a practical reality ready for integration into everyday life. 

Another bidirectional charger, the Quasar 2 from Wallbox, will be available for the Kia EV9 in the first half of 2024. Quasar 2 is an 11.5 kW bidirectional Level 2 charger. A Kia EV9 can hold between 76 and 100 kWh of energy, enough to power a typical household for up to four days

Pilot programs have also since been launched: California’s Pacific Gas and Electric, the largest utility in the U.S., has started enrolling customers in an $11.7 million pilot program.  

Under the plan, residential customers will receive up to $2,500 toward the cost of installing a bidirectional charger. They will then be compensated for discharging excess electricity from their bidirectional chargers back to the grid during periods of anticipated energy shortages. This compensation model not only provides financial benefits to participating consumers but also positions them as active contributors to the resilience and efficiency of the broader energy grid.

PG&E has initiated a pilot initiative tailored for its business clientele, offering incentives of up to $5,000. The suitability of V2G technology is particularly ideal for commercial vehicles, given their adherence to schedules and centralized oversight by decision-makers.

School buses in particular embody the ideal scenario for Vehicle-to-Grid (V2G) implementation, boasting sizable batteries and extensive idle periods during daylight hours. In a groundbreaking move, San Diego Gas & Electric pioneered the inaugural V2G program in the United States in July 2022. This initiative utilized eight electric buses stationed in El Cajon, California, to feed electricity back into the grid, effectively providing power to over 450 homes during a blistering heat wave.

The passage of Proposition 7 on the November 2023 ballot in Texas created the Texas Energy Fund, and although the majority of the $10 billion fund will go into low interest loans and incentives to power companies to build methane gas power plants, it also includes $1.8 billion to support backup power or microgrids at critical facilities like hospitals or police stations. Electric buses will be eligible for funding through this program. 

The potential for EVs to transform our energy landscape continues to grow, promising a future where electric vehicles not only transport us but also power our homes and contribute to a more resilient and sustainable energy grid.

To support widespread adoption of electric vehicles, we need to invest in the charging infrastructure necessary to accommodate explosive growth. We also need to make sure that as EV adoption increases, the vehicles and infrastructure are set up to use the power-transfer technology. Nissan already does this with its Leaf-to-home system. Proterra offers transit buses equipped with the technology. Dominion Energy in Virginia is working with school bus manufacturers to develop and operationalize a large-scale school bus vehicle-to-grid program.

The surge in EV popularity, coupled with the certification of bidirectional chargers and the initiation of pilot programs, marks a pivotal moment. The integration of Vehicle-to-Grid (V2G) and Vehicle-to-Home (V2H) technologies positions EVs not just as vehicles but as mobile energy solutions, capable of addressing power outages and actively participating in grid management. As the vision of a more resilient and sustainable energy future begins to materialize, it becomes increasingly clear that the reality of EVs revolutionizing our approach to power emergencies is well underway.

EV plugged in during Texas blackout
Luke Metzger | TPIN
Luke Metzger's Chrysler Pacifica plug-in hybrid powered his family's phones during the blackout.
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Luke Metzger

Executive Director, Environment Texas Research & Policy Center

As the executive director of Environment Texas, Luke is a leading voice in the state for clean air and water, parks and wildlife, and a livable climate. Luke recently led the successful campaign to get the Texas Legislature and voters to invest $1 billion to buy land for new state parks. He also helped win permanent protection for the Christmas Mountains of Big Bend; helped compel Exxon, Shell and Chevron Phillips to cut air pollution at four Texas refineries and chemical plants; and got the Austin and Houston school districts to install filters on water fountains to protect children from lead in drinking water. The San Antonio Current has called Luke "long one of the most energetic and dedicated defenders of environmental issues in the state." He has been named one of the "Top Lobbyists for Causes" by Capitol Inside and received the President's Award from the Texas Recreation and Parks Society for his work to protect Texas parks. He is a board member of the Clean Air Force of Central Texas and an advisory board member of the Texas Tech University Masters of Public Administration program. Luke, his wife, son and daughters are working to visit every state park in Texas.