It’s not just about an alternative source of energy; it’s long been known that solar energy is the way of the future. As the supply of fossil fuels dwindles and comes under scrutiny for pollution, climate change, and health issues, the cost skyrockets. The benefits of clean and abundantly available solar power are widely known: reduces dependence on fast-depleting fossil fuels, reduces carbon footprint, and is environment-friendly. But when I read a recent article on the inauguration of solar powered highways in China I was rather skeptical. “Is it feasible?” I pondered. Because solar power for homes, cars, factories seem practical and time-tested; but for roads?
China’s Solar Powered Highways
In Jinan, the capital of the northeastern Shandong province, traffic is now rolling over a stretch of expressway (1.2 miles) that’s also generating electricity from the sun. Indeed, solar road projects are gaining traction around the world, and some promise to even charge cars wirelessly and digitally assist automated vehicles. The Jinan City solar highway is built in three layers. The top layer is a transparent concrete that has similar structural properties with standard asphalt. The central layer is the solar panels – which are pointed out as being “weight bearing.” The bottom layer is to separate the solar panels from the damp earth underneath. The road will be durable enough to handle vehicles as large as a medium sized truck. This isn’t the first solar road in China. Earlier this year, the Qilu Transportation Development Group — which is also handling the Jinan Expressway solar road - built a 160 meter (0.09 mile) long solar road in the city of Jinan.
The Jinan stretch includes two lanes and an emergency lane and is designed for both electricity generation and public transport. According to a project designer on site, the expressway could handle 10 times more pressure than the normal asphalt variety and in a year generate 1 million kWH of electricity, which will be used to power street lights and a snow-melting system on the road. It’s also designed to supply power to charging stations for electric vehicles in the near future. The initial cost at $458 per sq. meter is rather high, but with the development of solar power in China, costs are expected to reduce. Solar roadways are susceptible to being covered by dirt and other debris, but as their efficiency and applications improve, they’re sure to be a worthwhile investment. And with EVs becoming more popular, the world’s going to need more ways to charge their vehicles.
This project signals China’s solar-power ambitions; it is touted to be the world’s first photovoltaic highway. Last year the country became the world’s top solar-energy producer, boosting its photovoltaic capacity to around 78 gigawatts, and it’s aiming for 105 GW by 2020. China’s eastern city of Huainan operates the world’s biggest floating solar project, which could eventually power 94,000 homes.
Solar Roads in Other Countries
In other parts of the world, solar roads are not new. In 2014, the Netherlands built a bike path fitted with solar panels to generate electricity; a village in the north of France opened a km (0.62 mile) long solar road in 2016. In the U.S. the Missouri Department of Transportation agreed to begin testing solar sidewalks near Route 66. Infrastructure integrated photovoltaics (IIPV) are being found in more and more places; and as solar technology gets cheaper and more efficient, deployment will be more widespread. Some recent projects include:
- China’s solar farm that sits atop a fishery
- Japan is testing growing mushrooms underneath solar farms
- India is covering water canals with solar panels to both minimize evaporation and generate electricity
- A huge 700MW solar farm in China with grapes growing underneath