Julian Spector is a former editorial fellow at CityLab, where he covers climate change, energy, and clean tech.
Thin panels installed on existing roads could be used to power streetlights and homes within five years.
Sooner or later the lamps glowing softly over the Champs-Élysées could be powered by the road itself.
France plans to install 1,000 kilometers of solar panel roadways in the next five years, Global Construction Review reports. That’s an ambitious goal, but not at all out of reach, because the technology is ready to go: the 7-millimeter-thick photovoltaic panel called Wattway, produced by French transportation infrastructure firm Colas. These panels can glue onto existing road surfaces to draw power from the sun, while providing enough grip for cars and trucks to drive over them. Colas says one kilometer is enough to power public lighting for a city of 5,000 people and 20 square meters of Wattway can power a single French home.
This project joins a growing trend in urban innovation. A couple in Idaho raised more than $2 million to develop their own version of smart, solar panel road surfaces (their panels incorporate programmable LED lights and heating elements for melting snow). The Dutch SolaRoad project in Krommenie, which is actually a solar-paneled bike path, generated more electricity than expected in its pilot phase. The U.K., taking the inverse approach, is looking into roads that can transmit electricity to charge electric cars on the move.
The French effort offers a possible advantage over other approaches: It can be installed easily on top of existing roads, sidestepping the costly need to build new ones. And even though this technology probably won’t produce electricity more cheaply than conventional solar, it is a more efficient use of land.
France’s investment in this improvement will show the world how it works at a larger scale than previous endeavors, and how the wear and tear of real-world driving affects the panels. If the road underneath a Wattway installation needs repairs, will the panels need to be torn up? With several different versions of a similar technology now working their way into use, sustainably minded cities stand to benefit from the friendly competition driving down costs and differentiating the strengths and weaknesses of each approach. Who needs a Sun King when you can have Sun Roads?