The analysis noted that the capacity of the U.S. power infrastructure is underutilized. Every evening--and during days of low demand--there is a large amount of spare capacity that could easily be tapped. By charging cars and trucks with electricity at night, American drivers could reduce the nation's dependence on foreign oil while potentially cutting power prices as well. "Since gasoline consumption accounts for 73 percent of imported oil, it is intriguing to think of the trade and national security benefits if our vehicles switched from oil to electrons," notes PNNL energy researcher Rob Pratt. "Plus, since the utilities would be selling more electricity without having to build more plants or power lines, electricity prices could go down for everyone."
The researchers specifically excluded power resources such as nuclear, hydroelectric, wind and solar as each of these already produce electricity at maximum capacity. Yet, plugging in our cars could reduce U.S. greenhouse gas emissions by an average of 18 percent. "Coal plants and gas plants are the marginal units that we considered for charging the plug-in hybrid batteries," says PNNL staff scientist Michael Kintner-Meyer, lead author of the forthcoming report. "Wherever you have a high dominance of natural gas, that is where you improve on the total greenhouse gas emissions."
Such a switch would have other pollution benefits as well, including radically reducing the amount of asthma-inducing particulate matter in the air of urban areas. Basically, the source of pollution is transferred: "It is far less expensive to capture emissions at the smokestack than the tailpipe," Pratt adds. And the report estimates that purchasing a plug-in hybrid--a premium of as much as $10,000--would pay for itself within five to eight years, depending on regional electricity prices.
"Nobody ever asks what's the payback on a sunroof," Calcar's Kramer notes. "People are buying the environmental feature, just like people buy leather seats or sunroofs." But consumers are not likely to get that option on a large scale in the immediate future. "They're still not being made and there's no immediate prospect of them being made," he adds. "Batteries are good enough now to put in cars and they're going to be even better by the time we're in production." Already, initial vehicles--and their outdated nickel batteries--have proven durable beyond 100,000 miles.
Kintner-Meyer predicts a total changeover could take as long as 25 years. In the meantime, technological improvements in things like batteries will likely make the case for such a transition even more persuasive. But the improvements are not only needed on the automotive side; such a switch would probably require smart chargers that would sense the appropriate times to refill the car's electric tank. And the grid would need improvement, too: "Some of the equipment is designed to cool down at night. If you are basically running at maximum capacity for the entire infrastructure, then you are burning the system," Kintner-Meyer says. "There needs to be some smartness in the charger of those plug-in hybrids that will sense emergencies in the grid and briefly interrupt the charging." Not to mention some smartness in deciding to go back to the future (electric cars outsold competitors at the turn of the last century) in short order.