Solar Roads: Will They Ever Come?

If you’ve ever been interested in renewable energy, chances are high that you’ve heard of the ‘solar road’ concept. The idea is based on a relatively simple concept. j

Roads are constructed with solar panels that create a drivable surface. A few years ago, people had dismissed the idea as unsustainable and beyond our current technological capabilities.

However, recent conversations among eco-friendly outlets have caused a resurgence of interest in this fad idea. With our latest advances in technology, is the idea really more feasible? And with all the associated hype, why haven’t we seen more of them installed around the world?

Read on to see our analysis and future projections for the always popular “solar road” concept.

The Factors at Play

Solar roads not being used in practice may be a result of different limiting factors. Many of them are derived from issues associated with the traditional purpose of a road.

A road’s main function is to provide a surface that is…

    • Flat
    • Even
    • Stable
    • Good for traction
    • Durable
    • Unobstructed
    • Used for vehicles or people to travel on

The Benefits of Using Solar Panels

Solar panels do hit the mark when it comes to a few roadway functions. However, it’s ultimately all a balancing act.

They Are Flat

Solar panels, by their very nature, are flat. This is beneficial for road construction as the surface has to be flat and unobstructed.

However, you must apply layers of protection to solar panels. People must do that if they are to be used in roadways as the panels are delicate.

This often results in noisy driving. That’s because the materials reverberate more than traditional mixtures of asphalt and concrete.

They Are Even

Solar panels are ordinarily quiet when you line them up. This isn’t as much of a necessity when the panels are used on rooftops.

However, on roads, it is absolutely essential. In order to make these panels as even as possible, joiners need to be placed between them. Unfortunately, this can cause structural weakness.

The Challenges of Using Solar Panels

Most of the time, solar panels fall flat when it comes to functionality beyond their traditional purpose: converting energy. If they are to be implemented in a roadway, even more challenges arise.

They Aren’t Stable

Solar panels by nature are not the most stable systems. This is partly due to the complex electronic systems within their construction. It does the real work of converting solar energy into electricity.

Applying excessive force to anything that has complex electronics built-in is usually not advisable. That’s because the potential for things to break or become dislodged is high. Once the delicate components are broken, the entire system can fail.

They Aren’t Durable

Solar panels require a transparent surface that allows sunlight in. Transparent materials are often not the most durable materials.

They can be quite strong, like bulletproof glass or polycarbonate sheets. However, other materials still outperform them. If companies make these transparent materials into super-durable items, they usually do so at considerable cost.

They Don’t Have Good Traction

In order to create a surface which has good traction, the most suitable method is to use irregularity. Roads generally consist of rough materials. Those include asphalt, gravel pieces and other coarse textures that create a surface wheels can easily grip and propel off.

Solar panels need as much direct sunlight as possible to produce energy and be cost-effective. A transparent surface that has a rough texture results in the refraction of light. The redirection of precious sunlight away from the solar panels’ voltaic cells means they are less effective and will produce far less energy.

They Can’t be Obstructed by Shadows

Roads are ultimately specifically for vehicle and foot traffic. While people are walking or driving on the road, it’s very likely that they are blocking sunlight from reaching any potential solar panels.

The more cars and people use the road, the more shadows there are. During peak-hour traffic, while thousands of cars cover the roadway, the solar panels would be absolutely useless.

Other foreign objects can also obstruct the surface of the solar panels. Tires can scratch and dirty the transparent layer of the panels.

Dust, leaves, stones and other various pollutants will find their way onto roads and further block the light. The higher the speed of traveling cars, the worse these effects are for the solar panels. Something as simple as a small stone caught within the tread of a tire can cause major damage.

Back to Top

Real Solar Roads

At first glance, the idea doesn’t appear to be viable. Regardless, several countries have executed the idea despite its untenability. Unfortunately, they all followed a similar trend: failure.

Wattway Solar Road (Normandy, France)

This solar road opened in 2016 and had high hopes for being a revolutionary development in sustainable energies. There was a lot of media coverage surrounding the road and its potential to provide clean energy while also offsetting its cost.

The following years showed a vastly different reality and things began to go downhill quite quickly.

This road only managed to produce half of the energy officials expected it to, as engineers hadn’t factored in the effect of fallen rotting leaves. Even without this inconvenience, the solar road encountered several other issues. The roads were very noisy when driven on at high speeds, and they had to lower the maximum speed on the road to a measly 70km/h or 43mph.

Eventually, the road began to break apart in 2018, just two years after its initial installation. They demolished a large chunk of the road midway through 2018 as it was unsalvageable due to the severity of damage. As of 2019, more of the road has begun to fall apart.

With each year of use, the Wattway Solar Road’s ability to produce electricity has declined rapidly, and at current standing, the road is only producing an approximate 38,000 kilowatts. This is a quarter of what they projected it to produce (150,000 kilowatts). The Wattway Road was a painfully expensive mistake for the French government as it cost them 5.2 million euros of tax money to create.

The stinging truth is that the Wattway Solar Road was 360 times more expensive than normal asphalt per square meter and had no hope of paying for itself through energy production. As the most well-known and revered solar road created thus far, it paradoxically showed the world the inefficiency of the entire concept.

Solaroad (Krommenie, Netherlands)

The Solaroad in Krommenie, Netherlands, first opened in 2014 and was to be a path for cyclists. The added benefit was the ability for the path to produce clean energy for surrounding homes and businesses. It was 236 feet long and the creators made it for the sole purpose of testing the feasibility of such a system.

Unfortunately, the Solaroad faced problems similar to that of the Wattway Road. Pieces of the pathway broke up in its first year and they had to replace the top layer of coating within its second year of use.

The pathway had managed to produce a total of 9,600 kilowatts in a year when they assessed in 2015, which is enough to power 3 average homes in the Netherlands.

Although the pathway had managed to outperform the Wattway Road in France, it still only managed to produce half of what normal rooftop solar panel systems can in a similar location. While this doesn’t look too bad on paper, it was still a colossal cost for the Netherlands, ringing in with a final price tag of $3.7 million.

The uncomfortable truth is that each kilowatt produced by the pathway is 173 times more expensive than the cost of the average kilowatt of power in the Netherlands.

Jinan solar highway (China)

China has also attempted to create a working solar road that has a two-kilometer stretch of solar panels with “transparent concrete” coating it. The designers of this project have made bold claims that the solar road will be able to produce a gigawatt of energy per year and power as many as 800 homes. The road goes one step further by having the ability to melt snow cover and power the traffic lights above.

However, just five days after the solar highway opened, parts of it had damage beyond repair. At first, people believed the culprit was thieves or vandals who were attempting to steal pieces of the solar road, but they found this to be inaccurate.

Vehicles driving over its surface have damaged the road, just like the Wattway Solar Road in France. There have not been any reports stating how much real energy the road has produced as of yet. However, realistically, it is unlikely that they will openly publicize news of the road’s underperformance.

Back to Top

Solar Roads in 2020

While innovation in the renewable resources sector has been rocketing ahead, solar roads have become an unrealistic side project in the industry. After several failed attempts worldwide, researchers agree that solar panels in their current form are not well-suited for usable roadways.

Why We Won’t be Seeing Much Development

There Are Better Places to Put Solar Panels

Solar panels work best when installers angle them to receive as much sunlight as possible. When they place them flat on the ground, solar panels only have access to adequate levels of sunlight during midday.

In winter months, when the sun moves south, they will receive even less as people can’t adjust them. Other obstructions to sunlight, like vehicles, trees, leaves, and dirt, are also common on or above roads, which further restricts the solar panels’ efficiency.

Taking delicate, advanced technology and placing it on surfaces to be driven over is usually not something people advocate for, and it’s surprising that many people found this idea to be so alluring. Fast-moving vehicles have the potential to cause serious damage to roads of resilient materials such as concrete, asphalt and stone, so it doesn’t make sense to expose expensive equipment to these conditions unnecessarily.

Instead of installing solar panels on the surface of a road, it would be much more effective to cover the roofs of available buildings. On top of high structures, there’s no need for super strong, expensive, and uneven surfaces. We can also angle them to face the sun, making them much more efficient.

In a world where we have used all available space up, putting solar panels on road surfaces might make sense. However, in our modern cities, there is more available space up above than down below.

Solar Roads are Very Expensive

The cost of solar roads per square meter is astronomically more expensive than normal solar panels. As a fantastic example, the Wattway Solar Road in France is 8.5 times more expensive per watt than a traditional solar panel farm. A solar farm located in the open space just next to the road would be significantly cheaper and would produce far more energy at the same time.

One of the big issues with the monetary costs of these roads is that the solar panels must to be able to pay for themselves in energy production when weighed up against the price of their initial installation and upkeep.

If it would take 50 years for a solar panel to pay for itself in electricity, and the lifespan of the solar panel is only 20 years, it is not economically viable. When the numbers are crunched and we take a look at the Solaroad in the Netherlands, which is still more efficient than the Wattway Road, we find that the return on investment would take an insane 1,545 years to pay back.

With so many renewable energy systems currently available to us as humans, it seems nonsensical to be pouring money into a something as inefficient as solar roads. Wind energy farms, traditional solar farms and hydroelectric stations all provide huge amounts of clean energy at low cost and pay for themselves relatively quickly.

No matter how alluring a renewable energy system may be, it is not practical until it is economically viable.

Plans to Implement Solar Roads in America

Despite the failings of solar roads in several other countries, some states in the U.S. have decided to implement plans to install solar roads.

Missouri has put forward plans to install solar panels on Route 66, using Solar Roadways’ solar pavers. Georgia has also decided to create a solar road alongside one of its highways and has dubbed the project “The Ray”.

These states have gone ahead with their projects, weathering heavy criticism from government officials and taxpayers alike. The allure of solar roads has been too much for these shot-callers to ignore, even though these investments have proven to be fruitless in several other communities.

While prioritizing green initiatives is always beneficial for society at large, some projects may not be the most logical of solutions to our problems.

As tax-paying citizens, the average American has a voice and the ability to help steer government bodies in a more productive trajectory. The funding that is poured into these projects could instead be used to create technologies that are more viable and stand a real chance of making a difference in our communities.

If you are currently living in one of these states, you have the right to speak up and join the conversation. You can suggest better technologies that would be more productive and efficient additions to our public infrastructure.

Back to Top

Better solar technologies are on their way

While solar roads may be too much of a stretch of the imagination, there are still brighter options ahead. Innovation in the solar industry has shed light on several different options that could help to shape our future.

Solar Windows

Solar windows are a much more viable and exciting technology that we will likely see in the near future. These new windows will be cheaper and more efficient than solar roads could hope to be.

Due to the positioning of windows, built-in solar panels can receive plenty of unobstructed light. At the same time, these solar windows can provide shade for buildings, lowering electricity costs for tenants.

Floating Solar Farms

Floating solar farms are another great alternative to solar roads. Installers could place these solar farms on calm stretches of ocean or any other flat body of water.

In peak season, they could produce more electricity at a fraction of the cost of solar roads. The cooling effect of water also makes these floating solar farms up to 10% more efficient than solar farms on land.

Solar Skins

Solar skin is a new type of technology that has the power to revolutionize the entire industry. In essence, solar skins are a thin film of solar cells that people can attach to any surface.

People can print the skins in a variety of different colors or patterns, allowing them to blend in seamlessly on roofs, walls or even cars. Surfaces all over the city could produce energy, invisibly.

Back to Top