About a tenth of electric vehicles operating in the United States are charged up by power provided by Southern California Edison (SCE), according to a whitepaper the utility released Tuesday. The whitepaper, a slick if wonky piece of PR, details how SCE is trying to ready itself to serve an estimated 350,000 plug-in electric vehicles by 2020.
According to the whitepaper, "Charged Up," 12,000 of its current customers either own or lease electric cars, so increasing that number to 350,000 in the next six and a half years will take some doing. Of special importance will be making sure the utility's distribution grid can handle the increase in power demand at odd hours.
That's going to take some work,, as there are parts of SCE's grid that need some attention, and that extends to more than upgrading transformers to meet voltage demand. On July 31, SCE released a safety study in which the utility revealed that somewhere between 292,000 and 333,800 of the 1.4 million transmission and distribution poles in SCE's service area are beneath the company's safety standards in terms of potential failure. To SCE's credit, the standards it used in the survey exceed those mandated by the State of California. Still, that's a lot of substandard power poles. When people depend on electrical power not just to wake them up and make them coffee but to get them to work, an outage due to a broken power pole will be even more disastrous.
According to SCE, charging an electric vehicle can use as much power as the rest of the household uses in a typical day. If homeowners with electric cars opt to install a higher-voltage Level 2 charger, the resulting increase in instantaneous power demand can tax the local grid. But SCE says it's finding that about half of its customers with EVs use Level 1 chargers, which use regular 120-volt house current. "We're seeing a much lower impact on our grid distribution circuits than if more customers charged at the higher Level 2." The utility says that only about 1 percent of the transformer upgrades it's performed in the last few years have stemmed from demand for charging EVs.
Also of interest: SCE says it's gotten a lot of slack from customers with programmable car chargers who use the "end charge time" function, which instructs the charger to have the car's charged finished by a certain point. Using this function rather than the similar "start charge time" command means that vehicles don't all hit the system demanding juice when everyone gets home from work. Instead, the demand on the grid is spread out depending on each vehicle battery's individual charge level.
It's not all rosy in SCE's analysis. For one thing, people who live in multiple-unit dwellings still have trouble getting access to chargers. For another, SCE admits that people may start converting to electric cars more quickly than the utility anticipates, which might mean the company will have to work hard to upgrade its local circuits to handle the demand.
One factor that may cause that last scenario to come true: SCE reports that early-adopter electric car users it surveyed said their fears about being stranded with a tapped battery pretty much vanished after a short time in their new vehicle. Nissan Leaf owners surveyed generally charged their cars only once daily, generally at home, and they drove an average of 35 miles per day. Once that news gets around, electric cars may well get a lot more popular.