Rick Ehrlich lets me take the wheel of the small truck outside his electric car business.
It's a no-frills Zap pickup. It has three wheels and weighs about 1800 pounds. It's doesn't look a lot different from the other vehicles at the Houston Electric Car Corporation, but what makes this one different is that you don't have to plug it in to a charging station. It gets all its power from the sun.
"They're for people who drive 30 miles or less in a day. It's a fantastic little car for things around where you live. If you work close to where you live, many people get, like, 99 percent of their use of an automobile in those cars."
The truck is powered by a lightweight 180-watt solar panel that's mounted over the bed. It feeds a battery that powers a small electric motor. The truck only has a top speed of around 35 MPH. You can't drive it on the freeway, but it's legal everywhere else. Ehrlich says on a clear day you can go eight to ten miles just on the power of the sun, a bit further if you use the power stored in the battery.
"I think if you go out and buy gasoline every week for your heavy vehicle, you're crazy."
But that's what most Houston drivers are still doing. Large SUVs and heavy-duty pickups remain the predominant vehicles on local freeways.
So what would it take to get solar-powered vehicles into a wider market?
University of Houston architecture professor Patrick Peters works extensively in solar design.
"The efficiency of the solar cells and the efficiency of the electric motors that drive the vehicles has been proven. So, what is only soon to take place is the migration of that technology into consumer vehicles."
Peters points out that solar technology is already being used in the auto industry. Mercedes, for instance, uses a solar-powered ventilation system. The Toyota Prius also has a solar-powered sunroof.
But to make commercial vehicles that run solely on the power of the sun, Peters says car makers will have to find ways to integrate the solar panels into the body of the vehicle.
"Thin film solar is happening in lots of industries, including the building industry, as an integrated surface, power-producing surface. And those thin films can take the geometry of the vehicles that's required to maximize its aerodynamic qualities."
And if gas prices continue to rise as some analysts predict, Peters expects more Houston drivers will take an interest in that funny little truck in their neighbor's driveway.
"When fuel costs go up, people get very interested in energy-efficient vehicles of every kind."