Report from LA: The Grid Easily Handles Lots of Electric Cars

By · August 06, 2013

Chevy Volt charging up

Southern California Edison studied EV charging and its impact on the grid.

Electric car detractors, especially of the Henny-Penny variety, worry that too many EVs plugging in at the same time will knock out the electric grid. Well, that hasn’t been the case in Southern California, the largest market for plug-in electric vehicles in the country. The grid has easily handled the demand, said Ed Kjaer, director of Transportation Electrification at Southern California Edison. “What we are finding is, almost 13,000 plug-in electric vehicle customers have been connecting to system seamlessly for the most part,” he said. “We are not seeing significant challenges.”

That the grid can handle the demand is one conclusion of “Charged Up,” a just-released white paper by Southern California Edison. The utility presented the paper’s findings today. Another finding: Level 1 110-volt charging is more popular than SoCal Edison thought it would be. Also, having drivers program their charging with a set “End Time”—an hour at which a full charge is completed, rather than a set start time for beginning to charge—is good for plug-in customers and their neighbors.

The “end charge time” is better for grid reliability because it staggered charge times. Drivers program charging to be completed by a certain time, usually the wee hours of the morning. Since batteries are different sizes and take juice at different charge levels, this randomized the load on the grid and avoided power spikes.

The Grid Adapts Faster Than Cars Are Added

When SoCal Edison started research for its white paper in 2009, the utility didn’t know how the grid would respond to this new demand, said Kjaer. Some even suggested the transformers would blow up. But the billions of dollars that the electric utility industry is investing in modernizing its grids seems to be paying off. “The grid is adapting faster than the deployment of the vehicles themselves,” said Kjaer.

SoCal Edison also found that range anxiety concerns were short-lived among customers that owned battery-electric vehicles. Plug-in vehicle owners exhibit “consistent and predictable” behavior, according to the study.

About 65 percent of SoCal Edison’s EV customers own plug-in hybrids—and 35 percent own pure battery electric cars. Plug-in hybrids can fully charge on less voltage then a pure electric vehicle. Northern California, which is served by other utilities, has more pure electric customers, said Kjaer, perhaps because commutes tend to be shorter there.

SCE specifically studied 92 owners of Nissan LEAF pure electric vehicles. It found that any “range anxiety” before the purchase went away. Other findings:

  • The average daily miles driven was 35 miles
  • Drivers mostly charged at home overnight
  • Most driving was on weekdays
  • The types of trips driven in the LEAF didn’t differ from those of other vehicles, besides fewer long trips as expected.

California is the largest market for plug-in electric vehicles in the country, representing 35 percent of all sales. SoCal Edison’s service territory covers 40 percent of all EV sales in California, and 11 percent nationwide, said Kjaer. The utility plans to do a similar study regularly to share its experiences. “We are a bit of a roadmap for other markets on how (electric) vehicles are deployed and connected to the energy system,” said Kjaer. As vehicles and the grid get smarter, customers will have more tools and ability to shape their energy use, he said. “Plug-in vehicles will have a tremendous role to play in the future,” said Kjaer. “They are the gift that keeps on giving.”


New to EVs? Start here

  1. Seven Things To Know About Buying a Plug-In Car
    A few simple tips before you visit the dealership.
  2. Incentives for Plug-in Hybrids and Electric Cars
    Take advantage of credits and rebates to reduce EV costs.
  3. Buying Your First Home EV Charger
    You'll want a home charger. Here's how to buy the right one.