The PhysOrg Web site recently had an article about a $100,000 grant, awarded by the US Department of Transportation to a start-up company called Solar Roadways , to produce a prototype version of its Solar Road Panel™. The Panel is made of solar cells and glass, and is meant to be used as an alternative to other paving materials, such as asphalt, on highways and parking lots.
The 12- x 12-foot panels, which each cost $6,900, are designed to be embedded into roads. When shined upon, each panel generates an estimated 7.6 kilowatt hours of power each day. If this electricity could be pumped into the grid, the company predicts that a four-lane, one-mile stretch of road with panels could generate enough power for 500 homes.
The panels will also include embedded LED lighting for lane markings, and possibly warning indicators. Since this is an engineered surface, it would also be possible to embed sensors that, for example, could detect deer or other wildlife on the roadway, and alert drivers to slow down. It might even be possible to embed inductive charging elements, so that a suitably-equipped electric vehicle might actually recharge itself while proceeding along the road.
Those of us who live in metropolitan areas like Washington DC, with its horrendous traffic, might be pardoned for wondering how on earth enough sunlight could ever reach the road surface to accomplish much of anything. But there are many parts of the country where long-distance roads are not routinely congested (try driving across Kansas or Utah some time); in those areas an idea like this could be of real value. One of the obstacles to widespread adoption of electric vehicles is the requirement to put a recharging infrastructure in place. Being able to generate electricity locally, even in very rural areas, could make this considerably less costly.
Of course, there is a long way to go before this or any prototype is ready for large-scale deployment; and it is entirely possible that some unforeseen problem will end up scuttling the whole idea. I think, though, that if we are ever to wean ourselves from excessive dependency on fossil fuels, we need to be conducting tests of unconventional alternatives like this.