I’m not much of a car guy. I drive a 1994 Volvo with 130,000 miles on it, and can barely change a tire. But I couldn’t resist the opportunity to test drive the new BMW Hydrogen 7, the world’s first hydrogen-powered luxury car, which has just begun a tour of America as part of BMW’s longstanding support for the Susan G. Komen Breast Cancer Foundation. I was curious in part because I’d never driven a Beemer but more so because the future of “sustainable personal mobility,” as the company calls it, may well depend on hydrogen.

BMW calls hydrogen the energy source of the future:

The tiniest molecule in the universe could solve Earth’s great problems: dependence on fossil fuels, coupled with global warming from steadily rising carbon dioxide emissions. The fact is that fossil reserves, such as oil, natural gas and coal, are in decline. Nobody knows precisely when but one day these resources will have ebbed away. At the same time, mankind’s energy requirements are growing. It seems only sensible to look around for alternatives before it is too late.

Hydrogen..is the simplest, oldest and most common element in the universe. The Earth harbors a virtually endless store of hydrogen in the form of water. One way of extracting pure hydrogen from water is through electrolysis. This requires electricity, which can be derived from such renewable sources as the sun, wind or water power, among others. The hydrogen could then be transported anywhere for conversion into energy by engines or fuel cells.

Interesting, no? It’s an appealing vision–running an entire transportation system off energy from the sun, wind or water, stored in hydrogen. What makes the hydrogen-powered greener and cleaner than anything on the road right now a car burning hydrogen emits water vapor, and almost nothing more.

Of course, if making and selling them were easy, we’d be all be driving hydrogen powered cars (if not BMWs). Among the many, many, many daunting problems are distribution issues surrounding hydrogen, which is stored as a liquid at temperatures colder than -418 degrees F. Right now, there are only two hydrogen fueling stations in the U.S., one in Oxnard, Ca., and one in Washington, D.C. I rode the metro to Passport BMW in Marlow Heights, Md., for my test drive.

The Hydrogen 7 is a cool-looking vehicle, not all that different from the outside from BMW’s 7 series:

Those are windmills in the background, by the way.

And what was it like to drive the car? Well, I can’t tell you because I opted not to get behind the wheel. Call me cautious, but I hadn’t checked my insurance policy and I didn’t want to take a car worth nearly as much as my house onto the Capital Beltway. You can’t buy one of these babies, by the way. BMW made 100 in Germany, and shipped 25 to the U.S. “where they will be made available to influential public figures” — gee, thanks! — “who by driving these near-zero emission BMWs will demonstrate the start of an exciting new era of clean energy.”

In any case, I did enjoy a spin on the beltway in the passenger seat. The car goes from 0 to 60 in 9.5 seconds, and has a 260hp 12-cylinder engine. More pickup than my Volvo, for sure.

Here are a few more things I learned about the car, and about the road to a hydrogen future:

1. The Hydrogen 7 runs on gasoline as well as hydrogen. The gas tank holds 16.3 gallons and the hydrogen tank holds 17.6 lbs of liquid hydrogen. You can switch seamlessly from one to the other by pressing a little “H2″ button on the steering wheel. Total range of the car is more than 400 miles.

2. The hydrogen tank is an amazing engineering feat. An inner tank is encased in 40 thin layers of aluminum foil, which provides insulation equivalent to a Styrofoam jacket 56 feet wide! Remember, the hydrogen is cooled to below -418F. The tank sits behind the back seat and takes up valuable trunk space, for now.

3. About 3,000 hydrogen-powered passenger cars will be used to shuttle people around during the 2008 Olympics in Beijing, which is a very good thing given the smog they usually have over there.

4. California’s planning a “Hydrogen Highway,” using state, federal and industry money to build 150 to 200 hydrogen fueling stations on major highways, by 2010.

5. Best guess is that getting from here (meaning our gas-guzzling, energy-wasting, Middle East-oil supporting cars) to there (clean, green hydrogen) will probably take 20 years, minimum. BMW’s been working on hydrogen cars since the 1980s. What’s new about this car, which was introduced last fall, is that it was made on a production line, albeit a small one, and not as a concept car.

There’s lots more info at www.bmw.com/cleanenergy.