A kilometer-long stretch of highway in China produces electricity, thanks to photovoltaic solar panels installed in place of traditional asphalt. The road section is experimental, but it is giving good results and could soon be enriched with other instruments to connect with the on-board systems of cars and charge the batteries of electric vehicles while they are on the road. The new solution is one of the most concrete examples of the Chinese government's “Made in China 2025” plan, which plans to better differentiate the country's industrial offer by focusing more on technologies related to renewables and automation.
The road that produces electricity is located near Jinan, an industrial city of about 7 million people in Shandong province, of which it is the capital. It was built by Qilu Transportation Development Group, a large road development and construction company that is owned by the state of Shandong. In place of the classic asphalt, solar panels with a transparent protective layer on the surface have been inserted along the experimental kilometer, with characteristics comparable to those of the classic asphalt. The driver notices the difference in the road surface by sight, but does not notice any particular differences while driving along the road. The panels were installed in parallel along two lanes of the road and around 45,000 vehicles pass over them every day. The energy produced is sufficient to power the street lamps along the route and to power 800 homes, according to Qilu technicians.
The experiment is still in its infancy and is only part of Qilu's plans. The idea is in fact to use the road as an infrastructure not only to physically move from one place to another, but also to transfer data and energy. The surface layer is designed for wireless charging of batteries, with a system comparable to that of wireless chargers for smartphones. The problem is that the current stretch of road is too short to test its operation, not to mention that there are not even precise standards and technologies widespread on electric cars on the road to charge in this way.
In the surface layer that covers the solar panels there are also sensors to monitor the temperature of the road, the frequency of passage of vehicles and the load of vehicles in circulation. This information can be used to update traffic information in real time and, in the long run, to plan the possible expansion of roads.
Qilu says the estimated life span of his system is around 15 years, so comparable to that of asphalt on highways. Not being a technology yet widespread and so available, the price is still high and around 7 thousand yuan (900 euros) per square meter; a price of around 3 thousand yuan (390 euros) should make the initiative sustainable, through a mass production of six solar panels and other necessary devices.
It took nearly 10 years of research to develop the system and test it before installing it on the highway. The construction of the experimental kilometer instead took just under two months and the panels have been in operation since last December. An electric heating system is activated in the event of frosts and snow, leaving the road always clear and clean.
China is not the only country to have experimented with similar solutions in recent years. French company Bouygues installed a kilometer of road covered with solar panels in Norway in 2016, with encouraging results. The system, which has been called Wattway, is however dedicated only to the production of electricity and for now there are no programs to extend its functionality, as is happening in China.
