Depending on who you ask, renewable energy and electric vehicles are seen either as a threat to the electric grid or its saviors. While it’s true that solar energy isn’t always plentiful and wind is inconsistent, gas-fired power plants can generate electricity whenever needed. Critics fear that as more Americans transition to electric vehicles, the increased demand will further strain a grid that’s already under pressure.
However, this concern overlooks a crucial innovation: large batteries. Solar and wind facilities are increasingly incorporating significant energy storage systems to tackle their inherent intermittency. (Engineers are even exploring ways to turn the Earth into an even more extensive battery.) Plus, a growing array of electric cars now features vehicle-to-grid (V2G) technology, allowing them to draw renewable power during peak generation and send surplus energy back to utility companies, helping to stabilize the grid’s reliability rather than detract from it. Studies indicate that globally, less than one-third of EV owners would need to participate in this system to satisfy the increasing demand for energy storage.
Traditionally, we’ve interacted with utilities as mere customers receiving power, but a new era is emerging where individuals actively contribute to the grid by offloading excess energy. A significant step in this direction is happening in Maryland, where last month, Baltimore Gas and Electric teamed up with Sunrun, a solar and battery provider, and Ford, the maker of the electric F-150 Lightning, to launch the nation’s first residential V2G pilot project.
“This is the first occasion that actual customers have transferred energy from their electric vehicles to the grid during peak demand periods in the evening,” explained Chris Rauscher, Sunrun’s vice president of grid services. “This action helps alleviate grid stress and demand spikes — effectively flattening the load curve, which contributes to lower costs for all consumers.”
To appreciate this technology, think of EVs as massive mobile batteries. For instance, the battery in the Lightning is ten times larger than a typical residential battery, noted Rauscher. “Currently, there’s more energy capacity in electric vehicle batteries on the roads in the U.S. than in total stationary batteries combined,” he remarked, highlighting its potential. This resource is expected to grow; the Natural Resources Defense Council predicts that if California facilitates V2G connections for all 14 million EVs projected by 2035, they could supply power to every home in the state for three days.
Presently, only a limited number of vehicle models support V2G technology, but this is changing as the technology becomes more common. The system operates with a specialized charger that charges the vehicle’s battery and can either supply power to homes in vehicle-to-home setups or return energy to the grid in vehicle-to-grid configurations.
Utilities will need to establish channels of communication with program participants, possibly through an app that allows users to set parameters, such as keeping their vehicle’s charge above a certain level. Additionally, each utility will need to determine compensation rates to entice participation, similar to net metering schemes where solar homeowners are credited for energy returned to the grid. “We’re still in the early phases of this initiative,” said Divesh Gupta, director of clean energy solutions at Baltimore Gas and Electric, noting the need for improvements in customer engagement.
Moreover, this battery power doesn’t have to return to the grid to benefit utilities. Ford Lightning truck owners have been using their vehicles to power their homes for some time. The extended-range version of the Lightning can cover over 300 miles, and supplying a house with energy uses only about five to six miles of that range per hour.
Consider an owner who returns at 6 PM, a peak time for electricity demand due to widespread use of cooling systems and appliances as people arrive home. During this increased consumption, electricity prices rise. A Lightning owner can avoid these costs by using their truck’s battery to power their home for five hours, using about 25 to 30 miles of range. As Ryan O’Gorman, Ford’s business lead for vehicle-to-grid and vehicle-to-home technology, stated, “It essentially makes the house disappear from the grid.”
Afterward, the owner can recharge at a lower demand time, for example, during the day when solar energy generation is robust.
Expanding the use of EV batteries for home energy also reduces pressures on the grid, particularly during heatwaves when air conditioning use spikes. As these heatwaves increase, so do the challenges for utilities in maintaining reliable service, especially with growing energy consumption from data centers pushing grids to their limits. Infrastructure must also support other critical decarbonization efforts like heat pumps and induction stoves, which are vital for phasing out fossil fuels.
Instead of idly depreciating in a garage, V2G technology transforms EVs into valuable resources for enhancing grid stability and reducing household energy costs. “Vehicles spend over 22 hours a day parked,” O’Gorman pointed out. “If we consider the benefits of an EV, it can provide savings and potential earnings for the owner.” Interestingly, electric trains, too, can contribute energy back to the grid thanks to regenerative braking, as demonstrated by the Caltrain system in the Bay Area, which reduced its annual power costs from $19.5 million to $16.5 million through this method.
The V2G initiative in Baltimore builds upon various experiments across the country with larger vehicles. For example, in Oakland, California, Pacific Gas and Electric collaborated with electric bus provider Zum to implement vehicles that transport students home in the afternoon, charge overnight, and then return surplus power to the grid during peak demand periods. Their substantial battery capacity allows them to easily send additional energy back to utilities.
Commercial fleets may prove to be more advantageous for V2G than private vehicles, as their reliable schedules make them predictable for utilities needing to draw power. School buses, for instance, are parked at specific times, making them available for grid support, especially during summer months. Other fleets, such as delivery trucks and governmental vehicles, also adhere to consistent timetables.
Fleet managers can invest in numerous compatible charging stations, facilitating system integration more feasibly compared to individual homeowners acquiring just one. “In the near term, we view commercial-scale V2G applications as more practical due to infrastructure issues, although affordable residential solutions are likely to emerge as the market develops and demand grows,” a representative from Nissan stated, referencing their electric Leaf that has long included bidirectional charging.
Utilities are still working on coordinating the complex interactions between vehicles, chargers, and the grid on a larger scale. However, the potential benefits are considerable as the existing EV infrastructure could mitigate the need for new dedicated storage plants for renewable energy. Fewer constructions would ultimately translate to reduced rates for consumers, allowing utilities to store electricity locally rather than sourcing it from distant regions during high-demand periods.
This advancement in technology could lead to lower energy bills for consumers while enhancing energy storage options. “It seems fair to conclude that employing V2G technology will likely be more economical than establishing stationary battery facilities serving solely as backup for grid support in critical moments,” said Rudi Halbright, product manager of VGI pilot implementation at Pacific Gas and Electric. “This is because stationary batteries remain unused at times and lack the additional functions of being mobile.”
Nevertheless, human factors complicate the integration of EVs into V2G schemes. Many individuals prefer the convenience of charging their vehicles at their leisure and may not fully grasp how electricity prices fluctuate throughout the day, observed David Victor, a professor at the University of California, San Diego, who studies EV driver behaviors. Many drivers appreciate the assurance of always having a fully charged vehicle. “This suggests that V2G implementation will be particularly challenging for private users who do not have professionally managed fleets that can reliably be available when the grid requires additional energy,” Victor noted.
Nonetheless, considering the volume of EVs, only a small percentage of owners need to engage for a significant impact. Furthermore, residential and commercial V2G systems can effectively complement each other, supporting a utility’s larger energy storage strategies—a diversified approach that could foster renewable energy adoption. “I firmly believe that when bidirectional electric vehicles become commonplace, they’ll be seen as a transformative technology that suddenly everyone utilizes,” Rauscher concluded. “Once we enroll enough customers and deploy them broadly, the participation rate won’t be as critical to achieving our goals.”
