Electric cars will need juice

To gain wide acceptance, electric cars will need access to electricity, and plenty of it.

So N.C. utilities are working with N.C. State University's newly created Advanced Transportation Energy Center to avert an energy crisis that potentially looms in the plug-in hybrid bonanza.

“You don't want to build more power plants to accommodate all these electric vehicles coming online,” said Alex Huang, director of N.C. State's new electric car research project. “If (electric cars) … cause blackouts, either you have to build new power plants, or you have to shut down somebody.”

For decades, electric cars had been hobbled by a major drawback that made them impractical: a short driving range rarely exceeding 50 miles. Hybrid technology, combining an electric motor with a gasoline engine, gave the cars unlimited range.

Now a new generation of electric cars – plug-in hybrids – are about to hit the market. They boost power storage to deliver more than 100 miles a gallon.

Electric cars have another plus: By drawing their energy from power plants, electric cars reduce overall pollution and cut greenhouse gas emissions.

Major automakers expect to introduce the first commercial plug-in electric models in two years. Some predict that half of all new cars sold in about a quarter-century could be plug-in electric vehicles.

Some will recharge from a standard 110- volt outlet, draining as much power as about 11/2 refrigerators. But electric cars that require 220-volt outlets, the kind used by electric stoves and clothes dryers, will drain as much power as a central air conditioner.

That won't be a problem as long as the cars recharge at night, when energy demand is low and utilities have cheap power to spare.

The U.S. Department of Energy has said that even if all the nation's cars switched from gas to electricity, power plants could fuel 84 percent of the cars during off-peak hours, mostly at night.

But if plug-in hybrids catch on, they are expected to trigger an appetite for power on demand, and businesses are likely to oblige by providing power outlets for convenient recharging.

A study by the Department of Energy's Oak Ridge National Laboratory said in March that the worst-case scenario would require building 160 power plants nationwide. That's if all plug-in hybrids recharged in the daytime in 2030, when the plug-ins are expected to be ubiquitous.

“You've got to have incentives in place to delay charging until nighttime,” said Stan Hadley, a senior researcher at the Oak Ridge laboratory. “Otherwise people will charge whenever they have the opportunity.”

Selling more power

Electric cars represent a lucrative business opportunity that would boost utilities' revenue. To maximize those sales, utilities would want customers to recharge at night, when the most efficient power plants are generating the cheapest energy.

This year, Progress Energy and Duke Energy agreed to fund research and testing by NCSU's electric-auto research project. The Advanced Transportation Energy Center is budgeted for $5 million over five years, with half coming from the state and the other half from the two utilities.

N.C. State has already done some electric-vehicle research, mainly testing the durability and longevity of batteries. The transportation research center will join the race to develop lightweight battery packs with a driving capacity of 100 miles on one charge.

But preventing power grid jams will require restricting customer access to recharging during times of peak demand.

The simplest solution is a timer that won't let people recharge cars until sometime after 9 p.m. in the summer, when air conditioners aren't working as hard.

A more advanced alternative would be discounted rates for off-peak use and premium prices for on-peak charging.

Utilities in California have offered such discounts for more than a decade.

More advanced options include “smart meters” that communicate with the vehicle, remotely activating the recharging function when the utility has spare power.

Future concepts include electric cars that store power in batteries, then allow reselling the power back to the utilities in times of extreme peak demand.

“This will be a concentrated effort that will focus on grid management,” Huang said of the state project.