Electric cars are the new wave in automobile technology. Many see them as the way to cut greenhouse gas emissions because they plug in rather than fuel up. Nissan’s Leaf and Chevrolet’s Volt are coming to car showrooms, the first in what is expected to be a wide variety of electric vehicles.

To promote the use of electric cars, Congress authorized a $7,500 federal tax credit for the purchase of an electric car, and the state of Washington exempts electric cars and most hybrids from the state’s sales tax.

Our state also received $1.32 million in federal stimulus money to install electric vehicle charging stations along Interstate 5, part of a $100 million program from the Department of Energy. Gov. Chris Gregoire envisions a network of plug-in electric outlets along I-5 from Vancouver, B.C. to Eugene, Ore., where drivers will pull off the interstate, swipe their credit cards for a shot of electricity, and be on their way to the next outlet.

Other states are picking up the electric car initiative as well. In fact, California wants to put a million electric cars on the road by 2020.

But there’s a problem.

Electric cars use electricity – lots of it. In fact, the Edison Electric Institute estimates that driving 10,000 miles in an electric car will use about 2,500 kilowatt-hours, 20 percent more than the average home uses in a year. So, while electric cars reduce greenhouse gas emissions, they increase the need for electricity.

That electricity must come from power plants. As electric cars begin to replace conventional gas and diesel powered engines, electric utilities are scrambling to build new power lines, substations and generating facilities, whether they are wind turbines, biomass boilers, solar panels, dams, natural gas, nuclear or coal-fired power plants.

However, in the Northwest, some of the same activists who promote electric cars are working to constrict the generation of electricity.

For example, they want to shut down the TransAlta coal-fired plant in Centralia that supplies 10 percent of the state’s electricity and provides 600 jobs in Lewis County that pay an average of $88,520 annually. It incidentally supplies enough electricity to heat and light more than 1.1 million homes.

Instead, the activists want electricity produced only by renewable energy. But there’s another problem.

Wind farms are meeting resistance because more and more people don’t want them blocking their panoramic views.

Biomass plants could add to our power production; yet under I-937, our state’s renewable energy requirement, biomass plants that use pulping liquors as part of their biofuels mix do not qualify as renewable energy. Consequently, that energy is being sold outside the state. In addition, restrictive new emissions rules being implemented by EPA will kill many biomass plants in rural northwest communities.

Some of those same activists also shunned hydropower, which supplies 70 percent of our state’s electricity. When they wrote I-937, they excluded hydropower as a renewable energy.

Ironically, the electric car industry is directly benefitting from that very same hydropower.

SGL Group (The Carbon Company) and the German automaker BMW are spending hundreds of millions to build plants in Moses Lake to spin fine carbon fibers to be used in BMW’s new electric Megacity commuter car. BMW came to Moses Lake because of its abundant supply of reliable and affordable hydropower.

There is one other serious glitch. Currently, taxes on gasoline and diesel pay to build and maintain roads and streets. Electric car owners pay nothing. As cars have become more fuel efficient, gas tax revenues have fallen; electric cars will worsen that revenue shortfall.

There is little doubt that electric cars are the wave of the future, particularly in urban areas and in temperate climates. But they are not a panacea and we must carefully evaluate the pros and cons. There are trade-offs that many today either overlook or dismiss.

Failing to deal with those trade-offs will only compound our growing problem of supplying adequate electricity to our factories, hospitals, businesses and homes – and cars.

Don Brunell is the president of the Association of Washington Business.