Will electric cars wreck the grid?
Aug 13, 2009 - Colin Sullivan - Scientific American
PLUG-IN PROBLEM?: Some power generators worry that too many electric cars could wreak havoc on local electric grids. © GM Corp.
LONG BEACH, Calif. -- Plug-in electric cars could destabilize the distribution of power, a utility executive cautioned at a conference here this week.
Ed Kjaer, director of Southern California Edison's electric transportation advancement program, said plug-in manufacturers, designers and component makers are poised to capitalize on a "perfect storm" that could push electric cars into the mainstream. Kjaer noted that 10 to 12 carmakers are ready to launch plug-in models between 2010 and 2012, creating a sense of "incredible excitement" around a sector that has seen its fair share of false starts.
But Kjaer warned that consumer demand for electric cars is still unproven. He also said he wants infrastructure planners to focus on how a flood of plug-in cars would drain the power grid at the most local level.
"The realities are, this is not a done deal," Kjaer told the "Plug In 2009" conference and exhibition. "We have a lot of challenges before us to help make this market a reality."
Chief among those challenges is how thousands of power-hungry vehicles would tax distribution transformers at the local level. Such transformers have historically handled electricity load for about 10 average-size homes each.
Adding a plug-in car to the grid is equal to about a third of a house, Kjaer said. And because early adopters are likely to spring up in geographic concentrations, that could mean overloaded transformers at the distribution level or plug-in cars potentially causing power outages.
"The worst imaginable situation you could have is your neighbor yelling at you because you blacked out the neighborhood," Kjaer said.
Kjaer is less concerned about transmission or generation being overtaxed, as long as consumers are taught to charge their plug-in cars at night, during off-peak demand periods, to smooth the load. Kjaer said improving distribution is the key infrastructure challenge for utilities, aside from creating a network of charging stations.
"We're talking about the last 10 feet" between the house and the transformer, he said. "It's the last 10 or 20 feet that we've got to work on. We're got to work on it really hard, really quickly, because these cars are coming."
Volt makes splash
The big news at this year's Plug In conference was General Motors Corp.'s announcement that test models of the Chevrolet Volt, a plug-in hybrid, are surpassing 230 miles per gallon in the city, as rated by a U.S. EPA system for measuring energy consumption. If confirmed by EPA, that means the Volt would be the first model to exceed triple-digit gas mileage when introduced in showrooms in late 2010.
Tony Posawatz, GM's vehicle line director for the Volt, told attendees here that the Volt will go into pre-production between March 2010 and August 2010, with commercially available cars set to roll out the following November. He added that GM engineers had just returned from a trip to the desert, where they tested a liquid-cooled battery with positive results.
"This really is breakthrough news," Posawatz said.
James Boyd, a former chief of the California Air Resources Board, said the announcement had him praising GM for perhaps the first time in his career.
"Can you believe the company ... that led the campaign to kill the electric car has released a plug-in hybrid?" Boyd said. "This is my first public congratulatory statement to General Motors ever."
Still, Boyd, now a commissioner at the California Energy Commission, cautioned that the infrastructure issues standing in the way of real commercial viability are likely to block further progress if government officials do not start taking some risks to encourage planting charging stations in home residences and elsewhere.
Among the obstacles are building out charging sockets in homes and permitting them through local authorities, in addition to mapping a future network of charging stations. The process for residential construction can sometimes take months, which would likely deter buyers. And limited range means charging stations away from the home are a must.
Mark Perry, director of product planning at Nissan North America, said Nissan is preparing to launch its own plug-in, zero-emissions model -- the Leaf -- in 14 months' time, but executives there are urging governments to get involved in infrastructure planning. The subject is their top focus.
"There are a lot of jigsaw pieces that have to come together in 14 months," Perry said. "It's not financial; it's manpower, time and work."
Perry said Nissan has signed agreements with San Diego, Sonoma County, Phoenix, Raleigh, Seattle and the state of Oregon to develop launch markets. In San Diego, $100 million in stimulus funding will be spent on developing a test market and charging stations, and Nissan is working with the city to get there.
Other deals with test markets are expected soon, Perry said.
"We're playing a pathfinder role here," he added. "We're coming, GM is coming, and there are going to be a lot of others."