Are plug-ins the next wave of hybrids?

Updated 10:00 AM October 1, 2007

Are plug-ins the next wave of hybrids?

By Nicole Casal Moore
News Service

Is America ready for rechargeable cars? Teams of researchers at U-M and Pacific Northwest National Laboratory (PNNL) will explore this question and others with $2 million from the U.S. Department of Energy offices of Electricity Delivery and Energy Reliability and Energy Efficiency & Renewable Energy.

The Michigan Memorial Phoenix Energy Institute (MMPEI) will coordinate efforts among several University departments, industry partners such as General Motors Corp., Ford Motor Co., DTE Energy and PNNL. The study will explore facets of the future of plug-in hybrid electric vehicles (PHEVs). The research will be conducted over two years, but a preliminary report will be available in January during the North American International Auto Show in Detroit.

"These projects will help provide the perspective and expertise necessary to get plug-in hybrid electric vehicles out of the laboratory and into the showroom, a key part of the president's plan to reduce our reliance on oil by increasing the use of clean energy technologies," says Kevin Kolevar, assistant secretary for electricity delivery and energy reliability at the DOE.

During the study, researchers will explore:

• Americans' willingness to buy PHEVs;

• When, where and how the PHEVs' battery would be recharged with grid power;

• How many PHEVs the current electricity grid could support and how mass adoption of them would influence the way the grid of the future is planned, built and operated;

• The greenhouse gas savings in trading tailpipe for power plant emissions; and

• The optimum design and features of plug-in hybrid vehicles.

"This program provides an outstanding opportunity to address the technical challenges as well as the social issues that will determine the viability of the plug-in hybrid electric vehicle," says Gary Was, director of MMPEI and a nuclear engineering professor. "The interplay between the vehicle, the nation's electric utility grid and consumer attitudes and behaviors is a microcosm of the complexity of the world's energy problem."

"PNNL's original study on this topic revealed that for the nation as a whole, about 70 percent of the energy needed to operate cars, pickup trucks, vans and SUVs could be supported using generating and transmission capacity that's already available," says PNNL energy researcher Rob Pratt. "The new study allows us to take this one step further and say now that we know there's enough electricity, what other challenges, especially at the distribution level, do we need to address to make PHEVs a reality? "

PHEVs are considered by some experts to be the next logical step in cleaner driving. They are similar to gas-powered electric hybrids in that both have a gas engine as well as an electric motor.

In current hybrid electric vehicles, the gas engine does most of the heavy lifting and an electric motor kicks in to assist during acceleration or to move the vehicle during stop-and-go low-speed driving. The battery that provides electric power can only move the car a short distance and is charged by switching the electric motor to act as a generator during braking.

Conversely, in PHEVs a larger battery is charged by plugging the car into a standard household outlet. The electric motor can then propel the car a much longer distance without using any gasoline, until the battery runs low and it reverts to standard hybrid electric vehicles operation.

A consumer survey, conducted by the Institute for Social Research, will monitor the evolving attitudes of the American public toward PHEVs, and provide the first national-level empirical data on how driving behavior differs with these vehicles compared to conventional gasoline, diesel and hybrid vehicles. ISR researchers Richard Curtin and James Jackson, director of the institute, will head the project.

Are plug-ins the next wave of hybrids?

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