Southern California Edison on Tuesday issued its first report on how the growth in the use of electric vehicles in its territory has affected its grid, and the news — at least according to the investor-owned utility — is good.
Despite initial fears that the popularity of the plug-in vehicles might overtax the utility's grid, that has not yet happened.
It's a remarkable finding given that fully 10 percent of the nation's electric vehicle stock plugs in somewhere in So Cal Edison's territory.
The conclusions were contained in a white paper titled “Charged Up: Southern California Edison’s Key Learnings about Electric Vehicles, Our Customers and Grid Reliability" (it's embedded below). Among the key findings:
- Edison has made nearly 400 upgrades to circuits in its system since 2010, but the additional power demands of electric vehicles required only 1 percent of those upgrades.
- Edison's grid managed to avoid undue burdens on its system attributable to electric vehicle recharging because vehicle owners used automated timers that randomized the time of recharging, preventing a large number of vehicles from trying to recharge simultaneously and averting power-load spikes.
- Electric vehicle users' behavior was consistent and predictable.
Edison’s Director of Electric Vehicle Readiness, Ed Kjaer, said that most electric cars plug in at night. That's helped the utility cope with new demand.
The randomized timing was a key finding, Kjaer said.
“If everybody programmed their car to come on or to start charging at 9 o'clock at night, we would see this instant spike in terms of demand,” Kjaer said. “Whereas, if everybody programs their car to be done by a certain time in the morning, the shape of the load, the ramp-up of the load, is much more shallow.”
Despite the generally rosy assessment, there are still a few problems meeting the needs of electric vehicles.
Kjaer says apartment buildings and condos still aren’t great places to recharge an electric vehicle. "Despite high interest in EVs from condominium and apartment dwellers, fewer than 5 percent of building owners or condominium associations are even considering installing the necessary charging infrastructure," Edison found.
Installing a recharging station in a single family house also remains troublesome. There are more than 180 cities within Edison’s jurisdiction, each with its own process for permitting and construction.
One solution? Edison and other utilities are pushing for more charging stations at the other place people spend at least 8 hours a day: work.
Edison also reported a few surprises.
Initially, Kjaer's team projected that about 70 percent of electric vehicles in Edison territory would be hybrids, in which a gasoline-fueled engine takes over once a vehicle's electric battery is exhausted.
But the actual percentage is a bit lower than that, with all-electric vehicles representing a larger than expected share. The reason: The popularity of the high-end battery electric cars made by Tesla, as well as the Nissan LEAF.
Southern California still has twice as many plug-in hybrids as battery electric cars – and far more than in northern California, where all-battery cars are dominant. “Our commuting distances are probably further here in Southern California than in northern California” Kjaer says. “That makes a difference.”
The white paper was based in part on information Kjaer’s team analyzed based on what electric vehicle owners report to the utility, although fewer than half of electric vehicle owners in the region volunteer to Edison what they’re doing.
Kjaer said that information is also useful for future planning: About 12,000 electric vehicle owners live in Edison’s service area now, but the utility anticipates as many as 350,000 electric vehicles in the region within seven years.
This story has been corrected to reflect the fact that no utility has yet been able to access DMV data.