There have been quite a few solar-road projects launched. We’ve seen them in the United States along a stretch of Route 66 made of hexagonal panels, in the Netherlands with a solar-powered bike lane, or even with paint that charges during the day… and in all of them the result has not lived up to expectations.
But perhaps the most striking case has been France, which in 2016 became the first country in the world to have a solar road. It cost more than five million euros from public coffers, and three years later it was already almost ruined.
A kilometer of solar road to light an entire town
By the end of 2016, Tourouvre-au-Perche, a French commune located in the Normandy region, unveiled the world’s first solar road. The one-kilometer stretch was covered by 2,280 silicon solar panels, capable of powering the village’s streetlights. They consisted of small solar panels adhered to the asphalt and coated with a protective resin that could supply electricity to the grid, and all of this without encroaching on farmland or natural areas.
On paper the projections were very positive: those more than 2,000 solar panels, which had cost five years of research, could produce the equivalent of the public lighting for a town of 5,000 inhabitants.
We’re talking about a 1 km solar road that had cost 5 million euros, and the forecasts pointed to paving 1,000 km of roads with silicon. That would imply an investment of 5,000 million euros, more or less.
But right from the outset there were many doubts: first the outlay (solar roads costed around 17 euros per watt at the time, versus 1.30 euros for rooftop solar panels), second the uncertain energy yield, and third the durability of those panels.
The project’s end: neither energy-wise nor economically profitable
In July 2019, the project was described as a fiasco. The road was reduced to about 100 meters, and it ended up far too damaged to be repaired. “It now presents a lamentable appearance: torn joints, solar panels detached from the surface, and numerous chips that damage the resin protecting the photovoltaic cells,” Le Monde explained.
In addition to premature wear of the slabs due to heavy traffic and the accumulation of dirt from decaying leaves (which prevented the cells from recharging), the surface generated so much noise for local residents that the speed limit had to be reduced to 70 km/h.
And not only that. During its first full year, the road produced 149,459 kWh, barely more than half of what had originally been forecast. For all these reasons we still do not have efficient solar roads.
Images | Pexels
