What are Solar Roads?
Traditionally, roads are made of concrete, tarmac, asphalt, cement and other materials. However, these items are being redesigned, so that they be replaced with materials that might also provide renewable energy. This is the basic logic behind solar roads. Solar roads are roads that have been built using solar photovoltaic technology.
Basically, the surface of the road is fitted with solar panels or solar photovoltaic cells. The change is in a bid to generate energy from the roads, which cover up to 0.5% of the earth’s surface, as well as make driving better for everyone. The technology is not only being used on public roads, but also on residential streets, driveways and parking lots.
More about solar roads are extensively discussed below, particularly about how they work, their benefits, why they are a bad idea, and if solar roads are the future.
Benefits of Solar Roads
1. Provide Electricity
Solar roads use solar panels that are built to generate electricity from the sun. The electricity can be used by nearby communities, lighting their streets as well as lighting the roads themselves. The amount of electricity generated, however, depends on several factors, including geographic location, the orientation of the driveway and shading.
Also, very busy roads might not generate a lot of electricity because the presence of vehicles ends up blocking the sunlight. However, since most vehicles are not kept at home during the day, the solar driveways would end up generating considerable amounts of electricity. With the increasing popularity of electric cars, solar roads will also be vital in charging these vehicles.
2. Generate Green Energy
Solar panels are very renowned for generating a lot of green and renewable energy. Due to climate change, scientists are advocating for the world to switch to renewable energy instead of relying on fossil fuels that contribute to climate change. For this reason, the addition of solar roads would go a long way in saving the planet and reducing climate change
3. The Roads are Fitted with Other High-tech Features
Solar roads come packed with additional features, which take technology to a higher level. They include the ability to heat the road. Also, they are fitted in a similar way to traditional block pavings, where the blocks are placed together to form an even surface. They are also configured in such a way that they are easy and inexpensive to repair; only the damaged blocks are removed and replaced.
4. The High-tech Features are Very Beneficial
The high-tech features including the ability to heat the road, are very vital, especially in wet and cold areas. The heat generated by the panels can be used to melt ice and snow, ensuring the roads are passable. They also ensure the roads and pathways are not slippery after a heavy snowfall, cold conditions or heavy rains, thereby making them safe for driving.
5. Help With Lighting the Roads
Not all roads in a country, especially in the country-sides, are fitted with lighting. This is because lighting roads is expensive and is not necessary for areas without too much human traffic. However, with solar roads, it is possible to light those areas at much-reduced costs.
It is possible to affix solar lamps on the roads, which are charged by the solar roads, lighting the roads at night. LED lights are also fixed along the edges of the road and they use the stored solar power to mark the road and ensuring the driveway is self-sufficient. Driving at night can never be hectic again, considering the roads are well lit and they are well marked.
6. Can Help Neighboring Communities
These solar roads are also fitted with pressure sensors and detectors, built into the panels themselves, which can help prevent crime. This is possible because those sensors will alert homeowners to the presence of someone on their pathways or drive.
In the same light, the sensors will alert a homeowner to the presence or arrival of guests and other important service providers like postal delivery. It is estimated that one mile of solar road panels can power 428 homes, assuming there are only four hours of sunlight all day.
7. They are Built to Last
Like traditional driveway materials, solar roadways are also built to last a long time. They can withstand any type of weather, they are durable and can also carry a lot of weight. Accordingly, they do not require special treatment or any additional maintenance or cleaning. Removing weeds and re-sealing the driveway with be the same as it has always been with traditional driveways.
8. Diverse Applications
The solar energy generated can be used in more ways than just heating the roads or lighting them. The solar roads can also generate electricity used in areas where access to the energy grid is limited. It can also be used to distill water in areas where access to clean water and supplies is limited. Also, it can power satellites in space. The solar panels can as well be integrated into more than just the roads, as there now exist transparent solar energy windows, which also produce green energy.
9. Low Maintenance Costs
The solar roads require the same, if not less maintenance as compared to traditional roads. What is needed is only to keep them free from dirt by cleaning them a couple of times in a year. When in doubt, one can request the services of a specialist who will not charge a lot. In fact, most solar panel manufacturers offer a warranty that can go over 20 years.
There are no moving parts, meaning there is no wear and tear. The only thing that requires changing every 5-10 years is the inverter, which keeps them back on track. The cables also require some maintenance for them to run at maximum efficiency. But then again, the solar roadways can be a bad idea, and the reasons are explained below.
Why Solar Roads Are a Bad Idea?
1. Safety Concerns
The inventors of solar roads have said that solar tiles can make the roads safer. However, the claims are yet to be tested on actual roads with real automobiles on a real surface. They have so far tested using bikes and with a pendulum rig in an environment. This fails to account for factors like spilled motor oil or rain in the roadway. Even if tests have been done elsewhere, it is unclear if the panels can withstand the weight of traffic.
2. Positioning
A typical solar panel is positioned in a way that it grabs as much sunlight as possible, meaning they are often tilted. Unfortunately for solar roads, the panels will have to be positioned horizontally on the surface of the road, which is not an optimum angle for its productivity. The shading problem means less power will be produced and only a small percentage of the panel will be generating the power required.
3. Reduced Performance
In addition to the panels not generating as much energy because of their positioning, they can also be less effective because of how they are installed. They are fixed on the surface of the road, denying them air circulation.
This means the panels will heat up more than a rooftop solar panel. For each degree Celsius over optimum temperature, about 5% of energy efficiency will be lost. On this account, the performance of the panels drops and this means it fails to produce return on investments.
4. Costs
It is the major drawback of solar roads. Solar roads are a relatively new concept and rely on solar panels which are not so affordable, especially if they are meant to withstand the weight of moving vehicles. Additionally, the panels would be laid one after the other, covering hundreds of thousands of miles.
This means a lot of money is required to kickstart the project, not forgetting the expertise required for the process, as well as other devices like inverters, batteries, and the overall wiring. For instance, the WattWay in France, launched in 2016, covering only 1km, or about 2,880 square meters of solar panels cost around €5 million.
5. They Can Only be Installed in Specific Locations
Some roads pass through natural forests, tunnels or are close to skyscrapers. These structures or habitats cannot allow the proper passage of sunlight onto the road and it translates that the solar roads in such areas would not generate enough energy as required. As such, they can only be fixed in specific locations, especially those that get a lot of direct sunlight.
Are Solar Roads the Future?
Solar roads are the future, considering their increased use and installations in the world over the past five years:
1. France: As mentioned above, in Tourouvre-au-Perche, France, a 1km solar road was built in 2016, making it the world’s first solar road. It used about 2,880 square meters of the solar road is said to generate enough power to power streetlights in the area.
2. Georgia, USA: After the success in France, a test stretch was installed near the Georgia-Alabama border. This pilot test by the Ray C. Anderson Foundation formed part of the foundation’s The Ray project, a 29km living laboratory for testing renewable energies and technologies.
3. China: A 1km expressway was built in 2018 in Jinan, China. It can generate around 1 million kilowatt-hours per year. However, some panels were robbed out soon after the construction, but they have no commercial value and are thought they were taken to be reverse-engineered.
4. Netherlands: In Kilometres, the Netherlands, a 70m bike path has been designed and over one year, the solar cycle path generated between 50 and 70 kWh per square meter, enough to power three houses. Users have commented that they do not even notice the difference with the normal tarmac.
5. The United States: a company from the US state of Idaho is planning to roll out solar-powered roads all over the nation. They intend to use hexagonal solar road tiles that can generate electricity as well as act as digital driving surfaces using LEDs, that are controlled remotely. They will also be reinforced so that the glass can support a truck weighing 113 tonnes.
References:
https://interestingengineering.com/6-examples-of-solar-powered-roads-that-could-be-a-glimpse-of-the-future
https://www.independent.co.uk/environment/solar-panel-roads-energy-bad-idea-renewable-climate-change-environment-a8557076.html
https://science.howstuffworks.com/environmental/energy/solar-roadways.htm
