The market growth of electric vehicles (EV) is poised to take off as governments worldwide implement measures to reduce air pollution and carbon emissions. While EVs are expected to become a trend in the future of transportation, the pace of adoption will depend on the expansion of EV charging stations and the related infrastructure. Being a major EV market, China has also been pursuing innovative projects that will make EV charging more accessible. One of these is a stretch of “solar highway” that is being readied for traffic in Jinan, the capital of China’s Shandong Province. Although there are similar projects of smaller scales in other parts of the world, the solar highway in Jinan is unique in its ambition and application. As a part of the Jinan City Expressway, the solar highway is set to open for traffic at the end of this year. Additionally, EV charging stations are also being installed along the solar highway.
Structurally, Jinan’s solar highway is composed of three layers. The material on the top is a transparent concrete that is stronger than the ordinary asphalt. It protects the solar photovoltaic panels in the middle layer while allowing the sunlight to reach the panels for electricity generation. The very bottom layer beneath the solar panels serves to insulate the panels from the damp soil. The surface of the road is also integrated with an electric thermal system that can be activated when its sensors detect icy road conditions. This system ensures that the solar highway will not be closed due to ice or snow and protects drivers as well.
Zhang Hongchao, a professor at Tongji University’s College of Transportation Engineering, stated that the solar panels used for the solar highway are similar to their conventional counterparts except that they can also withstand enormous pressure and allow greater traction. These additional qualities make them suitable for this particular application. The solar highway is currently connected to the grid, and EV charging stations and smart road signals have also been installed. The project therefore is ready for testing by small EVs as well as medium-size trucks.
The solar highway in Jinan is the largest solar roadway in the world in terms of surface area. The highway’s emergency parking lane, which covers around 26 million square meters, is projected to generate at least 6.217 billion kilowatt-hours of electricity per year with the fitted solar panels. From the aspect of reducing carbon dioxide gases, the emergency parking lane of the solar highway could cut down around 6.2 million tons per year. Based on this estimated emission reduction figure, the monetary benefit of the carbon offset could be worth as much as RMB 1.86 billion (or nearly NT$9 billion) per year.
China has yet to reveal the total length of the solar highway and its construction cost. France’s past experience with building solar bike paths indicates that the cost of building a kilometer of solar road totaled around EUR 5 million (or NT$170 million). Each kilometer of the Jinan solar highway is expected to be a lot more expensive.
A possible way for this project to recoup its cost is the deployment of wireless charging for EVs. Zhang pointed out that wireless charging might be the key link between EVs and solar photovoltaics. If moving EVs could be supplied by electricity generated by sunlight through wireless charging, then the highway network of the entire country could become a humongous source of mobile power with the paving of solar panels.
Wireless charging for EVs has matured technologically in the recent period. This May, major US chipmaker Qualcomm demonstrated its wireless charging solution for EVs travelling at 100 kilometers per hour.
(Credit of the photo at the top of the article goes to the Quilu Transportation Development Group Co. Ltd.)