Submission + - Three Years Later, the French Solar Road Is a Total Flop (popularmechanics.com)
Three years later, even the most optimistic supporters have deemed the Wattway a failure.
The Wattway consists of 2,800 photovoltaic panels lining one kilometer (0.62 miles) on the way to the small northern town of Tourouvre-au-Perch in Normandy. At the time of its opening its builder, the construction group Colas, part of telecoms group Bouygues, said that the solar panels were covered with a resin containing silicon, strong enough to fend off traffic even from 18-wheelers.
Normandy is not historically known as a sunny area. At the time, the region's capital city of Caen only got 44 days of strong sunshine a year, and not much has changed since. Storms have wrecked havoc with the systems, blowing circuits. But even if the weather was in order, it appears the panels weren't built to capture them efficiently.
Other solar roads across the globe have faced a variety of challenges. In 2018, a week after a solar road opened in China, its solar panels were stolen.