hydrogen filling station

Air Liquide CEO Benoit Potier demonstrates his enthusiasm for the hydrogen economy as he tries out a hydrogen filling station near Paris in 2011. Could solar energy help out with hydrogen production?

Eric Piermont/AFP/Getty Images

What if you could run a car on only yard clippings and expired diet soda?

What if you could capture the energy of the sun in rust and then convert it to hydrogen?

As oil becomes more expensive and the environmental aspects of mining processes like fracking are challenged, the race to find inexpensive and clean energy is on. Sometimes the energy brainstorming gets a little crazy (like that first idea, which you should feel free to try out). The latter idea, however, isn't the dazed thought of a mad scientist. It's actually the very rational process of some extremely intelligent and decidedly sane scientists. Better yet, they did it cheaply.

The idea of creating hydrogen from solar energy has actually been around for a while. Scientists from Ecole polytechnique fédérale de Lausanne (EPFL) in Switzerland originally found a way to produce hydrogen from just water in the 1990s. While it sounds like busting up water molecules and turning them into hydrogen and oxygen would be a mess of scientific jargon, it's actually pretty easy to understand. Essentially, it's just using a semiconductor that creates the reaction to generate oxygen and a solar cell that then frees the hydrogen. And, of course, we can't forget the all-important electrons. Or the light. (Don't worry, we'll go into that more on the next page.)

As we've said, the Swiss contingent had already successfully managed this process two decades ago. But in 2012, they gave themselves the challenge of doing it without extremely expensive equipment. How expensive? One U.S. team managed to make a similar product that produced a 12.4 percent efficiency -- a big number, as it means that they were able to convert 12.4 percent of the solar light into hydrogen. Unfortunately, the product translated to a gasp-inducing $10,000-per-10-square-centimeters surface cost [source: Pousaz]. Not exactly competitive consumer pricing.

So why in the world do the scientists optimistically predict they can create a 10 percent efficiency prototype at a cost of $80 per square meter [source: Pousaz]?