So far, garage is hub of EV charging action
Photo credit: COURTESY AEROVIRONMENT, INC.
Outside the home, more charging stations are being built, but locations are still widely scattered. In the long run, experts say, the basic charging technology being used to launch tiny volumes of EVs today probably will predominate in the near future.
"Most of the technology issues are minimal," says Phil Gott, director of automotive consulting for IHS Global Insight in Lexington, Mass.
Global Insight's main concern about electric vehicles is consumer resistance because of the limited range of EVs, Gott says. A widespread charging structure -- particularly high-voltage, fast-charging stations -- could overcome that objection.
But the consensus is that the majority of initial EV owners will recharge overnight at home using slower, comparatively low-voltage charging stations. High-voltage charging stations will top off the battery during the day if necessary, at locations such as shopping malls or at recharging stations along highways.
Home is where the charger is
Most home charging uses a Level 2 charging station. According to Coulomb Technologies Inc. in Campbell, Calif., which makes charging stations, the most common Level 2 in-home installation will require 240 volts.
Older homes may need a bigger electrical panel, but most homes built since the 1980s probably can accommodate a home charging dock, says Kristen Helsel, vice president of EV solutions at AeroVironment Inc. in Monrovia, Calif., another manufacturer of charging stations.
It takes two to six hours to recharge a car with a Level 2 station, depending on how far the battery is depleted. AeroVironment says a Level 2 setup costs $2,000 to $4,200. Local labor rates account for much of the difference, the company says.
Level 1 charging uses a standard 110-volt household electrical outlet, Helsel says. Because that takes at least twice as long to charge as a Level 2 setup, manufacturers expect consumers to use household outlets only as a last resort.
Hypothetically, home charging stations alone would be enough to accommodate most commuters. According to AeroVironment, 85 percent of U.S. drivers commute 50 miles or fewer each day round trip. That's easily within the 100-mile range on battery power that now is considered practical for electric vehicles and for plug-in hybrids using battery power alone.
But some driver requirements are psychological as well as physical, says Gott of Global Insight.
He says that in test fleets, drivers with home charging stations want charging stations away from home, even when their round-trip daily commute is within the range of their EV.
Gott says researchers found that when EV drivers were aware that charging stations were available away from home, they drove more and came home with their batteries closer to fully depleted.
In other words, even if they didn't use the charging stations away from home, having them available made them more confident that their EVs wouldn't strand them.
The fast track
Besides topping off commuters, high-voltage fast charging would be essential for long trips between cities.
Level 3 fast charging requires 480 volts -- more than a private home could handle, says Helsel of AeroVironment. A fast charging station costs an estimated $110,000 to $160,000, according to AeroVironment.
The company says studies have found that the number of publicly accessible fast charging stations should be about 10 to 30 percent of the total number of gas stations. That would mean about 150 to 400 fast-charge stations in the Washington area, the company says; 250 to 750 in the Los Angeles area; and 450 to 1,300 in the New York City area.
Helsel wouldn't disclose how many charging stations AeroVironment has contracted to build, but the recharging industry has a long way to go to approach those levels.
For instance, to support about 4,700 Nissan Leaf EVs, Electric Transportation Engineering Corp. says that last fall it received a U.S. Department of Energy grant of $99.8 million to build 10,950 Level 2 chargers plus 260 Level 3 chargers in five states: Arizona, California, Oregon, Tennessee, and Washington. ETec is a subsidiary of publicly traded ECOtality Inc. in Scottsdale, Ariz.
A commonly quoted rule of thumb is that a fast charging station provides an 80 percent charge in 20 minutes. Helsel of AeroVironment says there are a lot of variables, especially the fact that different EVs can recharge at different rates.
Unfortunately for EVs, Americans expect electric cars to be "transparent" to the user, says Global Insight's Gott.
The 'Ewww' factor
"It needs to be able to do at least as much as a conventionally fueled car of a similar size," he says. "People realize that a Smart car can't substitute for a big SUV, but an electric Smart ought to be at least as capable as a gasoline one."
Gott says fast charging also shortens battery life if used too often. Helsel disputes that.
"Our belief is that the people who build the cars and the batteries make sure that the charging is designed to last many, many, many years, and they have certainly factored in that there's going to be a mix" of fast and slow charging, she says.
Nevertheless, Gott says that when you add in the potential drawbacks of EVs, "All of a sudden, people say, 'Ewww.' "
Craig Giffi, vice chairman and leader of the U.S. automotive practice at Deloitte, based in Cleveland, says car companies should pay closer attention to customer expectations. Selling EVs to the wrong customers at startup could create bad word of mouth, he says. The right customers would have reasonable expectations of EVs and understand charging options.
Says Giffi: "If customers get stranded, if there are issues with charging, that's going to clearly slow the adoption regardless of whether the technology is useful."
You can reach Jim Henry at email@example.com.