Last September, we told you about the idea for a solar road that would generate power, even when used as normal. Vehicles would drive on the road, but a translucent glass surface backed by photovoltaic solar collectors would suck up the sun's energy into super- and ultracapacitors throughout the day. In some areas at some times, the energy would be used to heat the road and melt snow and ice, but the real holy grail here, IMHO, is to plug the road into the grid. Apparently, by using this three-layer solar road on all of the highways in the U.S., we could generate enough electricity to power the world. Seriously.

The brains behind this idea is Scott Brusaw, and the good news for all of us is that the solar roads idea is moving forward. An Idaho-based company called Solar Roadways has been attempting to get universities and research labs on board and is also working on a 45-mile prototype between Coeur D'Alene and Sandpoint, Idaho. Investors - because this will not be a cheap project - will be approached once Solar Roadways has cost estimates although Brusaw said four companies have expressed interest.

This project shouldn't be confused with the solar energy stored in asphalt idea that Dutch company Ooms Avenhorn is working on or the new solar road studs developed by Astucia in the UK. These are all very cool ideas, but Brusaw's has the most potential, should it be implemented. There's a video interview with Brusaw after the break.

Some people have said that the U.S. highway system is "the silliest thing that any people ever did to themselves." Well, if we replaced at least some of the endless roads in this country with the solar-heat-storing asphalt developed by Ooms Avenhorn Holding BV, I think that would go a long way to making the highways a lot less silly.

The AP had a story a few days ago on Ooms Avenhorn, a Dutch company that has found a way to use some of the heat that road naturally suck up to heat office buildings. The system (first imagined ten years ago) certainly seems efficient: one test patch - made up of 200 yards of road and a small parking lot - generated enough heat for 70 apartments in a four-story building. As the AP writes, this happened "under normally cloudy Dutch skies, with only a few days a year of truly sweltering temperatures."

How does it work? I'm glad you asked. Water is run through pipes under the asphalt and heated from the warmth of the road. This heated water is then pumped underground and stays warmish at 68 degrees F. The water can be sent to nearby houses (where it must be heated a bit more) and, during winter months, this water can be pulled up to prevent ice from building up on the road. The pump can also call on the water to cool the buildings on hot summer days. The problem? The pipes and the rest of the system double the cost of building the road.

Check out the AP story for details, and you can also download a PDF from Ooms Avenhorn describing the technology.

Related:

• Astucia's SolarLite "road studs" offer 10x road visibility through solar power
• Greening your architecture with solar parking lots and solar trees

[Source: AP via CNET and Jalopnik]