Now, such roads are finally becoming viable. Prices have fallen drastically in recent years — thanks in large part to soaring Chinese production, a solar panel costs a tenth of what it did a decade ago. Road builders in China even want to design solar roads that can wirelessly recharge electric cars running on them, emulating a recent American experiment.
China’s leaders in solar road development are Pavenergy and Qilu Transportation. The two companies are working together here in Jinan, in Shandong Province, with Pavenergy making panels for Qilu, a large, state-owned highway construction and management company that operates the highway.
The surface of these panels, made of a complex polymer that resembles plastic, has slightly more friction than a conventional road surface, according to Zhang Hongchao, an engineering professor at Tongji University in Shanghai. Professor Zhang, who helped develop Pavenergy’s road surface, said that the friction could be adjusted as needed during the manufacturing process to ensure a level of tire grip equal to that of asphalt.
The location of the solar road here, on a long curve at the bottom of a hill, was not Pavenergy’s first choice. The site was chosen because of its proximity to an electricity substation, ensuring that it would be connected to the grid. China is adding solar and wind energy sites so fast across the country that power generation projects farther from substations sometimes face delays of years in getting connected.