Solar panels we be installed underneath the surface of some roads in Tokyo, according to the Independent. The metropolitan government announced their plans for "solar roads" as part of a campaign to make Tokyo a more eco-friendly city.

Solar power capacity is growing across the world. Image: IEA

The change is in part motivated by the fact that the city will imminently be hosting both the 2020 Olympics and Paralympics.

Some solar panelling has already been installed on a trial basis in the Sagamihara, Kanagawa Prefecture by a Seven-Eleven. The technology was only introduced in May, but a manager at the Seven-Eleven store told the Business Times that it's starting to pay off.

"(The solar road system) can generate 16,145 kilowatt-hours of electricity annually, covering about 9 per cent of the entire electricity the store consumes."

It's important that the roads begin generating power more quickly, because they are currently quite expensive to install. Both France and the Netherlands have been experimenting with solar roads, and in France, it costs about 5 million euros for every kilometer of road.

Japan has decided to continue the introduction of solar roads on government owned property, and will more likely focus on parking lots. The wider surface area can generate more electricity and justify the cost of installation.

Installation is supposed to begin during the 2019 fiscal year, and the process is intensive.

The road is made of solar panels that are installed in the ground, then covered in a special resin that makes them durable under the weight of traffic.

If this technology were more widely used, it would greatly reduce the cost of installation, as the components could be more affordably mass produced. So implementing any usage is increasing the likelihood of solar roads everywhere.

The Japanese government is hoping the coverage of the process leading up to and around the games will make it more popular, and lead the way to expansion across the country.

But it's just one step in Tokyo's plan.

They're also considering introducing power-generating floors, which are made with special ceramics that respond to pressure, turning footsteps into voltage. The company who developed it, Soundpower Corp, claims an average walker can generate a current of about 2 milliwatts of electricity. One step can light up 300 to 400 LEDs.