Jumping from a system of transportation based on petroleum to one that's primarily electric is exciting to consider, but a lot of small steps will be required to get from here to there, with other nonelectric fuels playing a part.
"We're going to have to adopt a multipronged approach to transportation starting now if we want to have a sustainable future," Anne Tazewell says.
In North Carolina, biofuels will play a substantial role, adds Tazewell, the N.C. Solar Center's transportation program manager, along with compressed natural gas, liquefied natural gas (propane) and ethanol. Each one can fill a niche. On the electric side, too, there are different kinds of EVs—electric vehicles—for different places and purposes.
Biofuels: The state-funded Biofuels Center of N.C., based in Oxford, set an ambitious goal of replacing 10 percent of the state's liquid fuels with biofuels—that's about 600 million gallons a year by 2017. Biofuels can be burned in any diesel engine. Feedstocks would be such things as switchgrasses, sorghum and other easy-to-grow, highly renewable crops. The center works closely with the state's farmers.
Ethanol: Currently, it's the most widely available biofuel. A dozen stations in the Triangle sell E-85, which is mostly ethanol. E-10 blends are ubiquitous and can be used in any engine. The downside of ethanol is that it requires fossil fuels to make it.
Natural Gas: It's clean-burning, relatively abundant and widely used in Europe, where it's called Autogas. There are 11 million natural gas vehicles in the world, according to NGVAmerica, a trade group, but just 110,000 in the U.S., most of them trucks and buses.
Electric Vehicles: Packing a 24-kwh lithium-ion battery, the Nissan Leaf will hit the U.S. market in about six months with a promised range of 100 miles between charges. It will be all electric—no gas engine. Reducing the size, weight and cost of such batteries, while adding more power to them, is what the FREEDOM Systems Center at N.C. State is focused on.
Hybrid Electric Vehicles: Hybrids like the Toyota Prius and Ford Escape SUV have a small electric battery that works with—and is charged by—a gasoline engine. The battery boosts gas mileage, but vehicles don't go far, or fast, running on the battery power alone.
Plug-in Hybrid Electric Vehicles: PHEVs, as they're called, are stock hybrids to which a more powerful lithium-ion battery pack has been added. Running on the combined electric power, such cars can go 40 miles between charges and up to 30–40 mph, so if your trips are mostly short hops, you burn little or no gasoline. Hybrids don't require a plug-in charge, but the battery packs do; they plug into any electric outlet.
Neighborhood Electric Vehicles: The GEM car that Tazewell and her staff at the N.C. Solar Center use around campus is a brand-name in the NEV category. It's made by Global Electric Motorcars (owned by Chrysler), based in North Dakota. (Sen. Byron Dorgan, D-N.D., is chief sponsor of a bill called the Electric Vehicle Deployment Act of 2010, which would fund government purchases of NEVs and other EVs.) NEVs are limited to roads with speed limits of 35 mph or less. Sometimes called "golf carts on steroids," they're good to go at speeds of 25–30 mph and, like all EVs, are charged by plugging them into a household outlet.