Public facilities in cities usually consume a massive amount of electricity. A growing number of such facilities across China have installed solar panels to provide renewable energy and help the country achieve the carbon neutrality goal by 2060.
The subway in east China's Shanghai Municipality, the longest globally, comprises 20 lines covering 831 kilometers and has 508 stations.
It is also one of the busiest city transit systems, carrying over 10 million passengers per day. The system guzzles over 2.5 billion kWh of electricity annually.
Solar panels have been installed on the rooftops of 13 metro stations in Shanghai. They generate about 36 million kWh of electricity a year, contributing to 1.5 percent of the total energy used by the subway system per year.
"There is plenty of rooftop space to install solar panels in the rail transit system. The panels generate power while the metro system operates, so a high proportion of solar power generated can be used directly," said Mu Zhenying, Chairwoman of the Shanghai Metro New Energy Co., Ltd.
The project has brought significant environmental benefits. It saves 10,368 tonnes of standard coal and reduces 28,368 tonnes of carbon dioxide emission per year.
More solar panels will be installed on the rooftops of existing subway stations and new stations under construction in Shanghai.
In addition, an energy monitoring and management platform have been introduced to keep a close eye on real-time energy consumption.
"The system can monitor the fluctuation of energy usage to trace abnormal situations and analyze problems. And we can use the information to take action," said Zhu Dahuan, a senior engineer of the Technical Center of the Shanghai Shentong Metro Group.
A growing number of solar panels have been installed on rooftops of public facilities to provide clean energy across China, including the Beijing Daxing International Airport and the Xiong'an high-speed railway station in Hebei Province.
And major cities, including Beijing and Guangzhou, have also been promoting rooftop solar panels in recent years. A number of city metro operators have visited and learned the experience from Shanghai Metro.
"Public facilities like the metro system provide public service to people. China's target of carbon neutrality by 2060 has become a national strategy, and the public facilities need to undertake their social responsibility and play a bigger role in this process," said Professor Bao Cunkuan from the Department of Environmental Science and Engineering of Fudan University.
He said public facilities and infrastructure will be more willing to install solar panels as the technology further develops and brings more economic benefits.