WASHINGTON — Tens of thousands of new electric cars are zipping into traffic this year, and with them come a trunkful of strategies about how to recharge them.
There are at least four ways to go: recharging slowly through a standard 120-volt wall socket, the type a consumer would use for a hair dryer; buying a faster 240-volt home charger, about the size of a garden gnome, for several thousand dollars; plugging into the same 240-volt charger in a public parking space but paying a price; or using a $30,000 superspeedy public charger that takes only minutes but is not widely available.
The only consensus is that the more opportunities there are to recharge, the better the sales of the vehicles; they can generally go fewer than 100 miles between charges.
Not surprisingly, the chief executive of a company that has bought up thousands of high-voltage devices thinks they are the best way to recharge. The CarCharging Group, based in Miami, has quietly purchased four companies with networks of chargers, 13,430 in all.
CarCharging has installed the high-voltage devices, some dressed up to mimic a gasoline pump, in underground parking garages, where drivers plug in and pay for the electricity through a device that resembles a credit card. But the price, 49 cents a kilowatt-hour — roughly four times what people pay for electricity in their homes — often makes the electric car more expensive per mile than the gasoline car it replaced.
The high-voltage devices, though, take less than an hour to charge a car that has been driven 20 miles from home to office, enabling garage valets who park the cars to move them around, charging several during the day.
Such public charging has an advantage over the 240-volt charger that a car owner can install in a garage or car port, said Michael Farkas, the founder and chief executive of the CarCharging Group, because in a private home, the charger is typically used for just one car. “We're able to amortize it over several users,” Farkas said.
The smaller home chargers typically take two or more hours to recharge a car.
Another company, ChargePoint, manufactures the devices (including some for CarCharging) and sells them, usually to landlords, to use as they please.
Strategies differ, said Dimitrios Papadogonas, vice president of marketing for ChargePoint. “It's not surprising that there's some confusion, because it's a new industry and it's getting sorted out.”
Stepping into this picture, eight states announced a joint effort last month to bolster electric cars, partly by requiring the installation of chargers in certain categories of buildings, like multifamily apartment structures.
But it is a tough business. Last month, CarCharging bought the Blink network's 12,450 chargers because its owner, Ecotality, had gone bankrupt despite $114.8 million from the Energy Department to help build the network. (Blink had trouble keeping its chargers in good repair.)
In February, CarCharging bought Beam Charging, which has contracts with 400 parking garages. In April, it bought EVPass, with chargers in New York, and 350Green, with 600 installations in the Midwest and California.
But Farkas acknowledged that 49 cents a kilowatt-hour was equivalent to the cost of gasoline at current prices for a car that gets 21 mpg, a substandard rate in 2013.
A cheaper way to use electricity to save gasoline, said Jeremy Michalek, author of a Carnegie Mellon study, is a plug-in hybrid, a car with a small battery pack that could be recharged from a standard 120-volt outlet and would switch to gasoline when that charge was exhausted.
Some experts say that the 240-volt chargers are not needed, since most electric cars are used for commuting and are parked most of the day. Standard AC outlets would be perfectly adequate even though charging takes hours, these experts say.
Oregon is encouraging big retailers to set up the speediest type of chargers in parking lots and offer the electricity free. Giving away power is a good way to lure shoppers, one official said.