Plug-in vehicles not yet straining U.S. grid

Jan. 24 (UPI) -- Plug-in electric vehicles aren't yet putting a strain on the national grid, but may require upgrades to infrastructure as demand increases, a U.S. report found.

The U.S. Department of Energy's National Renewable Energy Laboratory looked at how plug-in electrical vehicles impact the grid, particular as more owners charge their vehicles at home.

"Previous research into the amount of energy required by homes hasn't taken into account plug-in electric vehicles," Matteo Muratori, a transportation and energy systems engineer at NREL and author of the agency's report, said in a statement. "Given that more people are choosing to drive these types of vehicles and charging them at home, this additional demand should not be overlooked."

The Energy Department said it estimated there were more than a half million plug-ins on the road by the end of 2016, which included 150,000 that were sold that year. Its study found that a market share for plug-ins of 3 percent, or about 7.5 million vehicles, doesn't do much to impact net residential power demand.

However, if sales were to be concentrated in one particular geographical area, the grid could be strained when the owners return home and charge their vehicles at similar times. Muratori's study found that this "clustering effect" could strain the system during peak demand and require upgrades to grid infrastructure.

Alternative vehicles have yet to reach parity with their conventional counterparts. A study from the University of Michigan's Transportation Research Institute found the annual cost to drive a gasoline-powered vehicles last year was around $1,100, compared with a cost of $485 for a typical battery-electric.

On sticker price, however, the Honda Civic, one of the Top 10 sellers in the United States, sells for around $20,000 and boasts 40 miles per gallon on the highway. By comparison, Car & Driver lists the electric model of the Ford Focus with a sticker price of around $30,000 and boasts 99 mpg on the highway.

Meanwhile, President Donald Trump vowed last year to review, or possibly revoke, the guidelines submitted by his predecessor that were aimed at putting more clean vehicles on the road. Nevertheless, more consumers are buying alternatives.

Colorado Gov. John Hickenlooper on Wednesday spelled out his vision for a state electric vehicle plan that will "electrify" the state's transportation corridors. In October, the governor led a bipartisan coalition of Western states in announcing plans for an electric vehicle corridor that would affect more than 5,000 miles of highway.

More than 90 percent of all transportation-related energy consumption in the United States comes from petroleum-based products, with electric vehicles accounting only for a small fraction of total consumer use.