Which came first: the electric car or the infrastructure needed to power the electric car? That's one of the key questions that carmakers will have to answer if they ever hope to fill up the freeways with their plug-in vehicles.

Finding an answer won't be easy. Most drivers are hesitant, for the time being, to buy electric vehicles for a number of reasons. For one, even when these cars roll out in volume next year, they'll cost $7,000 to $20,000 more than comparable vehicles with internal combustion gas engines, according to business consulting firm PricewaterhouseCoopers.

There's also no guarantee that carmakers won't abandon their electric-car customers (remember General Motors' EV-1?) and move on to some other promising green technology. Energy Secretary Steven Chu may have cut funding for the research and development of hydrogen fuel cells, but Congress could still vote to restore funding. It's also unlikely that Toyota, GM and other companies who've invested in hydrogen technology will want to abandon it at this point.

But perhaps the biggest question for electric vehicles (and hydrogen cars as well) relates to infrastructure. How and where will drivers be able to recharge their all-important lithium-ion batteries, particularly if those drivers venture far from home? In most cases, this means they plan to drive farther than the 160 to 240 kilometers they'll get from a fully charged battery. PricewaterhouseCoopers estimated in a report last month that by 2020, purely electric vehicles could represent between 2 and 5 percent of the total output of light vehicles. While certain types of electric vehicles, such as GM's Chevrolet Volt, include range-extending gasoline engines that act as battery chargers, purely electric vehicles, such as Nissan's Leaf, would be solely reliant on the driving range that their battery pack provides.

"Inadequate infrastructure…will delay a widespread shift to electric vehicles," Steve D'Arcy, PricewaterhouseCoopers' global auto leader, said in a prepared statement released along with the company's report. "The lack of an available network of charging stations restricts drivers to short commutes, while it can take several hours to fully recharge an electric vehicle. The space required to place charging stations, coupled with a suitable means for consumers to pay for the electricity they use while charging their vehicles, are open issues."

Fast-charge kiosks
Electric vehicles are propelled by one or more electric motors powered by rechargeable battery packs, which convert 75 percent of the chemical energy from the batteries to power the wheels. (Internal combustion engines convert 20 percent of the energy stored in gasoline.) However, there are relatively few recharging stations in place across the U.S. at this time, with only the state of California having more than 400, and most states having none.

Several companies are vying for an opportunity to put to rest this last concern, which they refer to as "range anxiety." While plug-in hybrids could be successful recharging via a 220-volt outlet, or even a standard 110-volt connection, Monrovia, Calif.-based AeroVironment, Inc., is betting that all-electric vehicles will need their own fast-charging infrastructure in order to be successful. Such an infrastructure would include kiosks that look something like today's gas pumps but could produce 400 to 600 volts, enough electricity to recharge an electric vehicle battery pack in minutes, says Kristen Helsel, AeroVironment's director of electric vehicle chargers.

AeroVironment has met with some success in its plans to develop these kiosks. The U.S. Patent and Trademark Office earlier this week granted the company a patent for technology designed to gather data from an electric car or its charger and use the data to determine whether the rate of charge is optimized for the vehicle's performance, the battery's long-term health and the local utility company's power availability. In May, Washington, D.C.'s Department of Transportation, Nissan North America and AeroVironment announced a partnership that they expect will lead to at least 100 fast-charging kiosks throughout D.C. by 2011. The district is also pledging to add Nissan's Leaf to its fleet.

AeroVironment, which helped GM design the ill-fated EV-1, thinks the time is right for electric vehicles and is even working with GM again, this time to develop its all-electric Impact vehicle ("Impact" was also the pre-production name for the EV-1). "Working in electric vehicles' favor this time around is a political environment that appears to be encouraging the use of greener modes of transportation," Helsel says.

Battery swaps
Palo Alto, Calif.-based Better Place promises a different approach to creating an electric car infrastructure by proposing to build drive-through battery exchange stations that use robots on an automated track that slide under the car to swap out weak batteries for newly charged ones within minutes. (The company has produced a video demonstrating this procedure.) Better Place would own the batteries and be responsible for recharging them, taking that responsibility out of drivers' hands, says Sven Thesen, director of Better Place's utility operations and sustainability strategy. According to the company's plan, a driver would sign up for access to this service at the time he or she purchases an electric vehicle and would be charged for a plan similar to the way cell phone services are structured.

Better Place also sells charging posts that could be installed at homes or businesses. "We, as the infrastructure provider, will own and operate these charge stations and swap stations," Thesen says. He claims that the company has already installed 1,000 charge posts in Israel and signed up 30 companies, including IBM and Nike, in that country to provide its charging services to their employees. Israel Railways earlier this month announced that it will install 220 Better Place charging stations at various train stations throughout the country.

Hard Sell
Despite the effort that AeroVironment, Better Place and others are putting into selling the idea of electric cars, "the electric vehicle business is a little premature at the moment," says Andrew Frank, a University of California, Davis, professor of mechanical and aeronautical engineering, adding that the main reason for this is the lack of a sufficient charging infrastructure and an unclear plan for who will end up paying for it. Frank cautions that car companies should not expect the public to pitch in. One way to kill the electric car (again) is to ask the public to invest a lot of money in the infrastructure, he says.

Even though Better Place's battery-swap strategy doesn't need to tap into the grid, it still suffers from a lack of resources, namely batteries, Frank says. For Better Place to offer the battery swap-out stations that they're proposing, they're going to need a lot of batteries, he adds, and these batteries will need to fit a variety of car makes and models.

The U.S. Department of Energy (DOE) has taken steps to alleviate the battery backlog, this month awarding $2.4 billion in funds for 48 advanced battery and electric drive projects. Johnson Controls, Inc., based in Milwaukee, Wisc., is getting nearly $300 million to make nickel-cobalt-metal battery cells and packs. On the infrastructure side, the DOE is giving $99.8 million to a project led by Electric Transportation Engineering Corporation (eTec), a subsidiary of Scottsdale, Ariz.-based ECOtality, for installation of up to 12,750 charging stations across five markets: Tennessee, Oregon, San Diego, Seattle and the Phoenix/Tucson, Ariz., region. The project also includes the deployment of up to 1,000 Nissan Leaf electric vehicles in each market.

Despite these gestures, Frank is outspoken in his support for plug-in gas-electric hybrids in the near term because they will cut fuel consumption without requiring a massive charging infrastructure. The prime alternative to the high-power, quick-charging stations that AeroVironment and others propose is to use the existing infrastructure of 110-volt outlets that offer low power and take much longer to charge, a situation that fits very well with the current crop of hybrid cars already on the road, Frank says, adding, "plug-in hybrids are good for the short term, which could be 50 years."