The world's first solar road has opened in France. The Normandy village of Tourouvre-au-Perche now has a 1 kilometer (0.62 mile) stretch of solar pavement, producing enough power to light the village's street lamps.
Judging by the potholed state of may existing plain asphalt roads, it's hard to imagine that its practical to build a road surface that is both hard-wearing and can produce electricity, but the French seem to have managed it. The Tourouvre-au-Perche road, which will be driven over by around 2,000 cars per day, can produce 280 megawatt hours (MWh) of power per year, even in cloudy Normandy. The tiles that make up the road are stuck on top of the existing roadway, which reduces construction costs, the only problem is that the short stretch cost around $5.2 million to build. That is, according to one estimate, is 13 times more expensive than rooftop solar panels.
The Wattway road is made by France's Colas, in collaboration with INES, the French National Institute for Solar Energy. The tiles are made of solar cells embedded in resin, and they're thin enough that they won't peel off the road below during the expansion and contraction caused by heat and cold. Colas, along with France's Environment Minister Ségolène Royal, has some confidence in the practicality of the technology. If the country paved one quarter of its million kilometers (620,000 miles) of roads, it could become energy independent. That independence is important for France, which started its nuclear power program to achieve it, and currently produces three quarters of its energy from nuclear.
Royal has already committed to further trials, but prices will have to come way down to make it practical on a large scale. The solarisation of roads is tempting though. Visually, it makes roads look better, and there's no need to cover up farmland with miles and miles of panels. On the other hand, roads lay on the ground, and can't be angled towards the sun, making them less efficient.
The idea still seems to be a popular one, though, despite the drawbacks. Germany is experimenting with a different method, and in the Netherlands, there are already solar bike paths. But perhaps the most practical solar roadway is in South Korea, where a 20-mile bike highway has been covered with a solar roof, protecting cyclists from sun and rain while powering lights and cars.
We're in a new solar experimental phase right now, as governments assess way to incorporate practical solar energy with existing infrastructure, and without causing a big environmental impact. And that's great, because it means that our governments are finally taking this seriously.
[Photos: © COLAS/Joachim Bertrand]