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Do Solar Roadways Have a Future?

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Jane Marsh's picture

Jane Marsh is the Editor-in-Chief of She covers topics related to climate policy, sustainability, renewable energy and more.

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  • Feb 22, 2022

Solar roadways were introduced years ago with the promise of making the world more eco-friendly. Despite their benevolent purpose, solar roadways still aren't well-known. There could be a reason why only those in the field or those particularly enthusiastic about renewable energy know of solar roadways: Society has yet to see a demonstration of a solar roadway that works effectively on a large scale.

What Are Solar Roadways?

Solar roadways are a type of road fashioned from glass that, in theory, would harness energy from the sun and redistribute that energy throughout the area. While it is a noble effort to encourage renewable energy generation, implementation isn't often so easy.

Theoretically, a solar roadway would support the weight of cars without suffering any drawbacks. It would also be able to sense if an animal or some other obstruction is on the road due to a certain weight the glass could detect. It could also provide a beneficial charge for electric cars driving on the road, thus making the roadway more eco-friendly and encouraging electricity-powered cars.

On paper, it sounds like a great idea toward a more environmentally conscious future.

Famous Solar Roadways

Only a few solar roadways exist currently, and they aren't the best examples of what these types of roads could be like in the future. Still, they should be viewed as cautionary tales that can show you what the future could be like, even if roads like these can't be implemented currently.

1. Wattway

Wattway is a solar roadway in France. It took around $5.2 million to build, but it was not worth the price. Aside from being noisy to drive on, this roadway presented hazards to motorists. With damage from thunderstorms, leaves, and debris, the Wattway seemed to be a failure – but it was an excellent opportunity to learn what could and could not work in today's society.

2. Solar Roadways Sandpoint

In Sandpoint, Idaho, around 150 square feet of solar panels were installed to create the world's first solar area. While this space can't support cars, people can bike or walk on it without fear.

The state of Idaho funds this project, and it's already made waves as a popular gathering area. It isn't a road, but the small-scale implementation of solar-activated glass surface panels shouldn't be ignored.

3. Georgia Solar Roadway

In 2020, another solar roadway was built in the United States. This roadway is in Peachtree, Georgia, and expands over 18 miles of road, making it a small-scale test of a roadway that could be plausible in the future. Because it is so new, no one has any insight into its durability. Only time will tell how strong this roadway will prove to be.

Roadblocks to Solar Roadways

Several things stand in the way of the widespread implementation of solar roadways. These obstacles range from the integrity of glass roads to concerns for the safety of drivers and passengers. Until these obstacles are resolved, solar roadways likely won't be seen as commonplace in any city or country.

1. Trickiness of Glass

Cars are meant to drive on asphalt, as current tires are optimized for. Driving on glass for an extended time is entirely different, and there may be less traction for tires, which means the ride might be too smooth.

Friction is necessary on roads – without it, cars wouldn't be able to handle curves and ramps, and roads would see many more crashes. Furthermore, the smooth glass could be hazardous on icy or wet roads.

2. Inefficient Angles

Roads are on the surface of the earth, so, understandably, they're not going to absorb as much sunlight as a skyscraper or even a house that reaches up a little farther into the sky. With the inefficient angle a solar-powered road provides, even less than the standard 20% of the sun's rays get converted into usable energy.

3. Maintenance Costs

Maintaining, repairing, and manufacturing solar roadways to a widespread degree requires vast sums of money and expertise. Not to mention, fixing an issue with glass is much more intensive and challenging than patching over a spot in asphalt.

Cities and state governments may be looking at an almost $10,000 cost to replace just one solar panel. Many governments may find it challenging to contribute money to a solar roadway at this time.

The Future of Solar Roadways

While it seems like solar roadways aren't a possibility right now, they could be a significant factor in the future. Once society figures out how to solve some of the basic problems that stand in the way of the full adoption of solar roadways, you might see more of them starting to pop up in different forms.

One such form is a solar driveway – a much smaller form of a solar roadway that can charge an electric car at home and provide solar power to the family who lives there. Whatever the case, solar power definitely is the power of the future, just not at the moment in the form of a solar roadway.

Matt Chester's picture
Matt Chester on Feb 22, 2022

Solar roadways come up a lot, but they really seem like a shiny toy at best, and an unfortunate distraction at worst. There's lower hanging fruit and more immediate needs to get to vehicle electrification, but focusing resources towards these projects won't get us there any faster. 

Donald Osborn's picture
Donald Osborn on Feb 25, 2022

That you would give any credence to this very misguided approach reflects poorly on you as an “editor” and on Energy Central. Yes you do bring up some key problems but neglect a very major one , horizontal surfaces get very dirty and are hard to clean, especially at road level. Solar Roads is nothing more than a scam and a distraction from real solar opportunities. As a more than 40 year solar professional, I ask please STOP!

Jane Marsh's picture
Thank Jane for the Post!
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