People really love the idea of cars that run on water, air or solar power. It just sounds so, well, organic. Unfortunately, none of those ideas are actually practical. We’re stuck with the basics: gasoline, electricity, natural gas, ethanol. But get ready for a whole new round of “solar car” stuff, because the World Solar Challenge, held every two years in Australia, is gearing up. Does it feature 100-percent “solar cars”? You bet it does.

From Oct. 6-13, competitors from all over the world will be putting on the sunscreen for the 1,864-mile run from Darwin to Adelaide. Don’t let the fall timing fool you — it’s going to be hot. Drivers motor through the Outback all day, stopping when the sun goes down. Pretty much all the energy they use is solar, all pulled from huge panels that cover the cars.

University of Michigan Generation 2013 solar car team

OK, these solar cars are practical, but only for making vastly uncomfortable endurance tours with indifferent-to-pain college students at the helm. There are no airbags, crumple zones, heated seats and infotainment systems. We’re talking homemade, minimalist solar panels on wheels. When all that stuff is added, cars are just too darned heavy to be powered by the sun. Add a few panels, and the chances are you’ve got a great app for running the cigarette lighter.

Come with me now to the University of Michigan in Ann Arbor, a nice college town that is also home to Road & Track, Car and Driver and Automobile magazines. Just down the road is Dearborn, home of Ford, and beyond that, Detroit. It’s like a regional capital of internal combustion. But the UMich engineering students have come up with something entirely different in their quest for Solar Challenge glory Down Under — a tiny carbon fiber car weighing just 500 pounds (a sixth of a regular subcompact), with room for just the driver.

The Generation, capable of 100 mph, stands just 43 inches tall at the peak of its canopy, and is propelled by a small electric motor in the back. It’s wall-to-wall solar array generates 1,500 watts, and excess power can be stowed in an onboard lithium-ion battery. The Generation has four wheels, in keeping with the Solar Challenge’s new rules, but many competitors have had three for maximum efficiency. The college team (20 male students, two female) are getting ready for Australia with an 1,100-mile shakedown cruise around Michigan.

U of Michigan student works on solar car Generation

Michigan is the top American solar team, and the American Solar Challenge champion (having handily beaten Iowa State in 2012), and came in third in Australia in 2011. It benefits from design help from both Ford and GM (access to Ford’s wind tunnel was a big help), and tires from Michelin. Here's a video so you can get up front and personal with the solar kids:

OK, all this is cool, but it doesn’t say anything about practical solar cars that you or I could drive. That isn’t happening, and Toyota denies rumors that its working on something like that. Instead, the company offers a solar panel as an option on the Prius (see below) — but it’s not asked to do more than run a fan to keep the interior cool while the driver’s away. The now-defunct Fisker Karma also used solar in this way. Solar panels can be useful on cars, but the mobile form is only about 18 percent efficient, so don’t expect miracles.

solar panel on a Prius

I like the approach taken by Solar Electric Vehicles of Westlake Village, Calif. The company came up with a rooftop photovoltaic panel for a Toyota Prius that, the company said, can give it an extra 15 miles of travel per day. The company makes a $3,500 roof-mounted panel for a standard Prius that enables the car to travel up to 15 additional miles a day. Energy created by the panel is stored in an auxiliary battery supplying the electric motor, and supposedly gives you an extended all-electric cruise. And with this setup, if the sun is shining you’re never going to get stranded with a dead battery.

But zero-emission “solar cars” ending the fossil-fuel dead end? Unlikely in our lifetimes. Here’s Forbes on the subject: “An entire Prius rooftop covered in photovoltaic cells could only generate a tiny fraction of the energy needed to propel the car 33.4 miles — the average distance an American drives in a day,” the article said. “There’s a reason why cars that win the World Solar Challenge are built like small, flat spaceships on bicycle wheels. The roomy sedans and SUVs that we love to drive are simply too massive to be powered by the sun.”

Related on MNN:

The opinions expressed by MNN Bloggers and those providing comments are theirs alone, and do not reflect the opinions of MNN.com. While we have reviewed their content to make sure it complies with our Terms and Conditions, MNN is not responsible for the accuracy of any of their information.