Utilizing managed charging, which allows electric vehicles (EVs) to charge at different times of the day to avoid energy-use spikes, and bi-directional charging, which allows EVs to discharge energy to the grid, could increase grid reliability, decrease transportation-sector emissions and reduce California's electricity system costs by almost $12 billion, according to a Union of Concerned Scientists (UCS) analysis released today.
“Our research shows that EVs can be a valuable asset to electricity grid operations,” said lead report author and UCS Electric Vehicle Infrastructure Senior Manager Samantha Houston, “By using managed and bidirectional charging, we can avoid costly infrastructure upgrades, make the air cleaner and lower electricity system costs.”
The report, “Harnessing the Power of Electric Vehicles”, finds that although both managed charging and bidirectional charging reduce peak electricity demand and offset the need for additional grid infrastructure and the use of fossil fuels, bidirectional charging provides significantly more benefits. Although the analysis is based on California, its findings can inform how EVs could support the electricity grid in states across the nation.
For example, high levels of grid-connected bidirectional charging could lower net peak electricity demand in California by as much as 33% in residential areas and save the state $11.7 billion annually by 2045.
Since cars are parked far more hours per day than they are driven and only a fraction of vehicles must participate at any given time, these results could be achieved without altering driving behavior.
Maximizing the benefit of bidirectional charging, the report says, requires preparing the grid with technological advancements that allow real-time grid-EV coordination, implementing incentives for participation, requiring bidirectional capability in all new light-duty EVs and updating battery warranties to ensure bi-directional charging users are covered.
“Bidirectional charging will allow EVs to serve as energy storage that can provide enormous value to everyone,” said Houston. “With smart planning and policies, EVs can play a major role in making the electricity system cleaner, more affordable and more reliable.”