As early as 2014, energy experts have come up with the idea of replacing tarmac on roads with solar panels, as part of combating climate change. After all, This is entirely a novel idea because till then solar panels were installed only on rooftops or on grounds. Many trials have been done since then to determine whether this technology is safe for normal use. But none of them came up with astounding results.
The solar-powered road is eco-friendly as it would replace petroleum-based asphalt roads. This will reduce the current fossil fuel usage for electricity generation, which in turn reduces greenhouse gas emissions. Less need for fossil fuels would lead to lesser pollution. Solar roads would create cooler roadways and cooler cities. The entire concept got dismissed as it is expensive, unsustainable, and beyond our technological capabilities. It was just contrary to solar panels rooftop installations.
Energy experts are sceptical about solar roadways. Trials have proven that it is very expensive to use solar photovoltaic technology on roads. The installation cost of solar roads is much higher than the rooftop solar panels. Fall in the cost of solar panels, high efficiency, and resilience of solar panels have made many people turn towards residential solar installation.
Some of the solar-powered roads built were:
WattWay, the first solar roadway of the world. European road construction giant Colas built this road in 2016. The construction cost $5.2 million. It is 13 times more expensive than large-scale rooftop solar installations. The expected daily production was about 767 kilowatt-hours, which comes up to an annual supply of 280 megawatt-hours of energy. After a couple of years of usage, news reports say that Wattway is not cost-effective as it generated only half the expected daily output. Wattway Solar Road is 8.5 times more expensive per watt than rooftop solar panel installations.
Solar Roadways (US)
Solar Roadways is developing solar roads in the United States. They came up with solar roads with LED lights and a built-in heating system that melts off the snow. Later it was found that many of the panels were not working and the power generation is nowhere near the expected output. Built-in LEDs and the heating elements consumed most of their power generation. The safety aspect of solar roads was also a matter of concern, as solar roads had less traction than the usual ones.
Solaroad (Krommenie, Netherlands)
SolaRoad is the world’s solar road epecially for bikes, opened in 2014. It is a prototype solar path for cyclists. In a year, this solar road produced 9,600 kilowatts. The fate of this solar road was no different from that of Wattway Road. The pathway broke up in the very first year. Though it could outshine Wattway road in the matter of production, it could produce only half of a normal rooftop solar panel. 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 also attempted solar roads with transparent concrete coating on the solar panels. It claimed to produce a gigawatt of energy per year. This road had the ability to melt snow cover
and power traffic lights. This solar road permanently damaged within 5 days of usage.
In all the above cases, solar road installations began to go downhill quite fast. Main reasons as follows :
- Energy production is much less than expected.
- The roads are very noisy when driving on at high speeds
- Roads are damaging frequently.
- Electricity production declining each year.
- More maintenance charges.
Even though there is no return of investment, there was a high maintenance cost for solar roads. Wattway solar-powered road was 360 times more expensive than a normal road and it could not pay back the amount through energy production. While rooftop solar panel installations are being successful, solar roads done in different countries have all become an example showing the inefficiency of the entire concept.
Solar roads have many disadvantages
Unlike rooftop solar panel installation, solar panels on the road are more challenging. As the solar panels are delicate, it needs to have layers of protection when it is paved on roads. This results in noisy driving as these materials reverberate more than the traditional ones. Unlike the solar panels on the roof, the ones on road have to be even and joiners are used between the panels. This might cause structural weakness.
Solar panels are not very durable
Solar panels are not very stable systems. Excessive force or weight on the panels can hamper the complex electronic systems within the panel and thus fail the entire system. While laying on roads they have to super durable and that will fetch a fortune.
Roads are usually made of rough materials like asphalt and gravel for traction so that wheels can easily grip and propel off. Since solar panels have transparent surfaces they don’t have good traction.
No optimum tilt angle
Solar panels should install at the right angle to receive maximum sunlight.
Consequently, we will get maximum power. As the panels are laid on the road, we cannot lay it at an optimum tilt angle, so they get only limited levels of sunlight during midday. As their position cannot be adjusted, in winter they would receive even lesser amount of sunlight. It affects power production.
Vehicles and people cause shadows, thereby blocking sunlight from reaching the panels and this affects its output. During peak hours of traffic, solar panels will be of no use at all. Dust, dirt, stains, leaves, stones and other pollutants too block light. A shade over just 5 percent of the surface of a panel can reduce power generation by 50 percent.
Solar roads are expensive
To withstand the weight of vehicles, solar panels would need thicker glass which will limit the amount of light they absorb.
Solar roads are very expensive. The installation and upkeep of solar roads are very high that it doesn’t get paid back with the power generation. Solar farms are much cheaper in terms of maintenance and installations. Moreover, solar farms produce more energy.
Installing solar panels on top of buildings and high structures is more viable as its less expensive. Moreover, the panels can be placed in the best possible way to make them function most efficiently. Economic viability is an important aspect of any renewable energy system. Wind energy farms
, traditional solar farms and hydroelectric stations would be a better option. They are much cheaper means of producing clean energy at low cost and have short payback period.
The best solar companies in Perth
would offer the best solar solutions for residential
and commercial purposes. Though there has been a 200% increase in global renewable energy consumption, statistics show that 17,000 terawatt-hours of renewable energy is created globally, of which only 3 % is solar contribution. Due to current limitations, the concept of solar roads doesn’t seem to be viable. As the innovation in the renewable resources sector progress, there are chances that with the latest technological advancements this concept might see a resurgence in the future.