Why plugging in all those EVs could actually save the power grid

California faces a significant challenge as it increases its use of renewable energy sources like solar and wind power. Intermittency is a problem because the sun doesn't always shine and the wind doesn't always blow, leading to periods when no electricity is generated. To address this issue, the state has been rapidly expanding its battery storage capacity, with capacity increasing by 2,100 percent between 2019 and 2025.

However, there is another untapped resource for energy storage within the state: electric vehicles (EVs). Many EV models are equipped with vehicle-to-grid (V2G) technology, which allows them to send power back into the electrical grid during times of high demand. According to a new report, if just 10 percent of EV owners in California participate in V2G programs by 2036, they could provide one-third of the state's targeted long-duration energy storage.

Pete Skala, vice president of professional and advisory services at the grid software company Kevala, explained that this would significantly reduce the need for costly grid-scale storage purchases. Ideally, V2G should be combined with other flexible load devices that can discharge power to the grid or shift their electricity usage, thereby spreading demand more evenly throughout the day.

The report highlights that California has a tremendous opportunity to accelerate the transition to renewables, enhance the electrical system, and reduce costs for everyone involved, not just EV owners who can provide extra power when needed. Several challenges are facing grid systems nationwide, including a growing demand for electricity due to the shift from fossil fuels to electric appliances and the increasing presence of data centers, as well as rising temperatures that necessitate the use of air conditioning.

Traditionally, utilities could predict demand for power by generating additional energy using natural gas power plants. However, with more solar power in the mix, the sun is setting while people are turning on their air conditioning and other appliances, leading to a need for large battery facilities that are expensive to build.

By utilizing the existing pool of idle EVs, which are often plugged in at home or work, utilities could tap into a valuable resource without incurring additional costs. The report notes that determining an appropriate compensation structure for EV owners to provide backup power is crucial, as paying too much could drive up costs for everyone.

While a fraction of California's EV owners would need to participate, the greater the number of vehicles available for use, the less energy each utility would need to draw from grid-scale storage facilities. EV owners wouldn't need to worry about their batteries draining entirely, as they can specify when they need their cars fully charged.

Even those without EVs would benefit, as rates would not increase if utilities could avoid building extra infrastructure. The report emphasizes the importance of setting incentives at levels that benefit everyone, ensuring that the rollout of V2G occurs in conjunction with efforts to reduce overall demand. Utilities are already implementing strategies such as remotely adjusting smart thermostats.

In these opt-in programs, homeowners agree to slightly raise their indoor temperature during heat waves, reducing the need for air conditioning and lessening stress on the grid during peak hours. Implemented together, V2G and demand response programs can encourage the transition to renewables and make electricity cheaper for all consumers.