On december 22nd, 2016, france reached new heights in solar power advancement by paving the streets of tourouvre-au-perche with enough solar panels to provide continuous energy to 5,000 residents. The ‘solar highway’ is part of 641 miles (1000 kilometers) of road that france plans on installing solar panels.

Dubbed the “Wattway”, roughly 30,000 square feet of solar paneling was connected to the town’s power grid in an effort to utilize the large amount of highway already in use. The resin-coated paneling is being piloted in only a small area to gauge how much sunlight these panels may attract. With an estimated 80% daily downtime, roads should be cleared enough to allow consistent charging, according to Environment Minister Segolene Royal.

So far, the panels are able to power street lighting and several dwellings without interruption.

The town receives a reported 44 days of sunshine yearly, which could make constant charging, a challenge. Marseilles, which receives 170 good days of sunlight yearly, hasn’t planned on solar power use but would have been a much stronger candidate for the RD5 project.


The Dutch beat France by two years in constructing solar roadways, introducing an all-solar bike path spearheaded by SolaRoad. The pathway can generate 3000 kWh of power, yet cost 520,000 kWh worth of regular electric energy to construct. So far, roughly 150,000 cyclists and a few thousand walkers have traversed the solar bike path.

Solar panels are designed to collect solar rays at specific angles. Without tilting the Wattway to be able to collect sunlight, intermittent power outages could arise. Panels were first tested in four French auto parks before being installed in a town which sees around 2,000 vehicles commuting daily.

One kilowatt-peak being generated by Wattway currently costs 17 euros, whereas rooftop solar panels generate slightly better solar power yet only cost 1.3 euros per kWp.

Costs associated with using photovoltaic glass versus asphalt could be one roadblock to widespread use. Adverse roadway conditions could thwart progress, too, as many vehicular accidents that spread debris could cost money to replace panels, which already cost heftily.  With Royal planning to provide sustainable energy to five million French residents using solar roadways over 10 years, funding will eventually become an issue.


Royal envisions 1km of panels per 1000 km of roadway. France, which boasts roughly 1 million kilometers of roadway, could burgeon with solar panels within a few short years under that vision, provided costs are there. Just 215 square feet of panel can power an entire home, according to early estimates. This would mean millions of square feet would be needed to power cities like Paris.

One Idaho couple raised enough money through Kickstarter to fund a small solar highway project which netted them a 2-year, $750,000 contract with the Federal Highway Administration, although that project hasn’t come to fruition yet. The French city’s solar panel project is the first successful use of roadway solar powering, with several more countries looking closer at financial investment needed.

MDOT (Missouri Department of Transportation) and a private project in Baltimore are in initial stages. Germany, too, is looking to leverage areas with vast sunshine to pilot their own solar projects. The technology is coming around, but one issue could hinder mass development: infrastructure.


A country like the United States, synonymous with mass windmill farms and hydroelectric powering, could face cynicism due to infrastructural challenges. Whereas windmills need little space and generate wind power much quicker than solar panels, the land space required to install mass solar substations to process stored power could prove problematic. That is, of course, unless solar panels in roadways could self-contain power generated through underground power stations.

Installing ‘Wattway’ in New York City wouldn’t be feasible, either. Traffic is far too heavy with limited sunlight opportunities. So, any solar projects atop roadways would need smaller community testing before implemented in cities over 25,000 or those near interstates. To date, the Idaho project hasn’t succeeded due to numerous broken panels, it also hasn’t produced power and cannot be driven on.

Apart from cracking and road conditions hindering progress, consider this: vehicle shading decreases solar panel effectiveness by roughly 10%. Couple that with its flat surface, collecting enough rays to power buildings or homes would take much longer than tilted rooftop panels, which have 20-25 year life spans. Nonetheless, progress is being noticed in larger increments than initially expected in Netherlands and France project.

Standard roadway maintenance versus photovoltaic panel replacement draw heavy criticism as glass shards could fly off into tires or hit joggers. When Missouri tests their solar roadway at rest areas, more information regarding dangers, maintenance and short-term costs will help determine future feasibility.

With only 1% of United States power being generated via solar, any improvements in solar usage starkly contrasts with what economists believe is plausible given the limited amount of data made available. With Trump beginning a new administration based on the premise of coal revival, it’s difficult to discern what facts will be presented to Trump: failing solar roadways in America, or successful ones in smaller cities abroad.


When France completes all 641 miles of Wattway, it’ll only supply 8% of France’s power demands. That’s roughly 92% of power still being drawn from water, power plants that use coal and fossil fuels, and other sources. The solar panels will electrify homes, but costs to construct could amass a small fortune. The SolaRoad sidewalk project, however, could provide a more useful pilot program given the smaller test area.

France’s controversial nuclear shutdown program, pioneered by The Greens and backed by French President Hollande, will see 19 of 58 reactors closed down by 2025, paving the way for more solar projects like this.

For now, Tourouvre-au-Perche will enjoy being the first town successfully semi-powered by 420kW photovoltaic array panels installed in roadways seldom driven or sunlit.