California needs to charge electric vehicles during day, not night, to save grid, study says
California is trying to find a way to make it cheaper for cars to run on electricity at night, and thus on the grid. The state has said it will require new cars that are produced today to be equipped with so-called fast-charging stations.
Fast-charging stations can charge electric cars in 15 minutes or less.
In a study on grid resilience published this month by Cambridge University, a California research center, California Energy Commission and the University of California San Diego, researchers identified how electric vehicles could be used to shift the electricity market away from supply-dependency during night hours, which are peak times during the day when the grid is overloaded.
During that shift, a car powered by electricity would not need to be plugged into a regular grid connection for recharging. Instead, the vehicle would be plugged into a fast-charging station, like a home computer that can be used to charge a laptop or a phone.
The researchers found that the shift could have three significant benefits:
Power for electric vehicles could be generated more cost-effectively during peak times by having the grid supply the vehicles directly.
Transmission lines for transporting electricity could be made more efficient, and energy storage systems could be added to reduce the need for transmission lines.
More efficient electricity use could be achieved through better utilization of solar and wind power.
The study, published in the journal Energy Policy, found that electric vehicles and the fast-charging stations that would be needed to run them could reduce the overall level of grid inefficiency if used to shift peak demand from power-production during the day to power-consumption during the night.
Grid reliability has become more and more important as the average size and cost of electric cars has increased over the last two decades, from 4 in 1998 to 13 in 2011, according to the report, the findings of which were based on state-of-the-art computer modeling and a review of the energy use and cost data for the California energy market.
“We would see a huge reduction in the number of times that the grid would have to step in to manage grid disruptions,” said Alan G. MacRobert, a visiting assistant professor of applied mathematics and a research associate at the UCLA Center for Sustainable Energy Economics, which sponsored the study.
The study looked at all electricity