Wattway a solar power road
Photo by Brice Robert via Colas

The Wattway is a 1 kilometer stretch of road built in 2016 in France. It was expected to generate 790 killowatt hours per day (power for 5,000 households). Well, after three years of real world use, the results are in for the $5.5M project.

Wattway, A Failure But We Learned

The road failed miserably in many respects. The resin coating creates a lot of noise at speed and it also does not hold up over time, especially with tractors. To quote Car and Driver:

The noise and poor upkeep aren’t the only problems facing the Wattway. Through shoddy engineering, the Wattway isn’t even generating the electricity it promised to deliver. In 2016, the builders promised it would power 5000 households.

Car and Driver

What is our lesson here? First, solar panels are best when pointed directly at the sun. A flat, stationary application like a road simple is not optimal. Solar panels belong on the roof. Likewise, transportation corridors should use material appropriate to traction and minimize noise levels.

The 1 kilometer stretch could better be suited as a multi-modal transportation corridor. A transportation corridor must be sensitive to alternatives to the car like bicycles and public transportation. So, when innovating, we need to be conscious of the details of the design. Do the materials in the proposal actually work as intended?

But, we also must commend Colas for their courage and determination to try something new. While many hoped to be writing of its success, the attempt at solving a problem gives others the foundation to keep moving forward. Trial and error is a perfectly acceptable method for solving problems as long as the error isn’t making climate change too much worse. Work will continue on cheaply maintained alternative roads, energy production, and solving our climate change issues.

We are on the right journey and we are learning by doing.