Plug-in cars won't be money savers -- yet

Chevrolet Volt

The first generation of plug-in cars probably won't make a lot of economic sense.

Being able to recharge a car's batteries by plugging it in to your home or office's electrical system will be all the rage when the latest models reach showrooms this fall or early in 2011.

That will allow you to drive anywhere from a few miles to as much as 250 miles on electric power alone.

But these electric-powered cars will cost so much more than comparable, conventionally powered models that you won't be able to save enough money at the gas pump to make up the difference.

A study sponsored by the U.S. Department of Energy and the National Research Council of the National Academies found it will be take several decades of further research and development before the up-front cost declines enough to do that.

Even today's crop of hybrids like the Honda Civic Hybrid cost more than you are likely to save in fuel costs while you own one of them.

In fact, it will take almost eight years, driving 12,000 miles a year, with gas averaging $3 a gallon, for the Civic Hybrid's fuel savings to make up the additional cost over a similarly equipped Civic EX.

It will take even longer with plug-ins.

Why is that? There are several reasons, but foremost is that battery technology continues to lag.

The maximum distance an electric vehicle can travel without recharging hasn't increased much in more than a century.

In 1902, the Wood's Phaeton electric car had a range of 18 miles -- just enough to get to work or run a few errands around town.

The 2011 Nissan Leaf electric car will cost $32,780 and have a range of 100 miles -- about what it takes to get to work or run a few errands around today's bigger towns.

The Tesla Roadster, an all-electric plug-in, has a range of almost 250 miles and accelerates from 0-to-60 miles per hour in less than 4 seconds.

Of course, it costs $110,950.

Although you can always go farther by making the batteries bigger, it also means a bigger sticker price.

General Motors will launch the Chevrolet Volt this fall. It will run about 40 miles before its batteries need to be recharged by plugging them in or turning on a small gas engine.

Toyota promises a plug-in version of the Prius about the same time that will be able to run about 12 miles on just its batteries before its gas engine is needed.

Both will retail for about $40,000.

Another plug-in from a new manufacturer, the $89,000 Fisker Karma, will be available for sale this year as well. Its technology is similar to Volt's with a battery range of about 50 miles.

A portion of the purchase price of the plug-ins will be offset by a federal tax credit that could be as much as $7,500. Even so, unless pump prices skyrocket, it will take a very long time to recoup the extra purchase costs over a similarly equipped, similar-size conventional vehicle.

The lack of infrastructure is another issue affecting plug-in practicality.

You'll be able to recharge plug-ins like the Volt, Prius and Karma using any 110-volt electric outlet.

The Volt requires about eight hours to recharge this way, but only about three hours are needed if you use a 240-volt outlet like the one your electric stove needs.

Chevrolet estimates a full charge from your household system will cost about 70 cents.

This is fine when charging at home overnight, but charging when away from home will be a big challenge for at least the next decade.

Some cities like Houston are working on the infrastructure. Public chargers will be available like parking meters around the city.

Realistically, it will be a long time before these public pay-as-you-go chargers are widely available to the public in urban areas and even longer before they will be commonplace along routes between urban areas.

But cost is only one reason to buy a new car -- especially a new car that represents an exciting new technology.

If you want to support a greener future that reduces our dependence on oil-producing countries, why wait?