Solar power station in coal mining subsidence zone built with innovations

China achieved a new milestone in renewable energy by connecting its largest standalone solar power station built in a coal mining subsidence zone to the grid. It started generating electricity on Tuesday.

This photovoltaic power station, nestled in the northern Chinese city of Ordos, has an installed capacity of 3 million kilowatts and spans an area equivalent to 10,000 standard football fields, comprising over 5.9 million solar panels, according to the state-owned CHN Energy, the constructor of the project.

With its annual electricity generation projected to reach 5.7 billion kilowatt-hours, the solar powerhouse is poised to meet the annual residential demands of 2 million households.

The green electricity generated will be transmitted to Shandong, an economically vibrant province in eastern China, which is over 1,200 kilometers away from the station, according to CHN Energy.

The project is the latest example of the country's transition from traditional coal-based electricity to cleaner energy sources. China's installed capacity of renewable energy exceeded the coal-fired power generating capacity by June last year.

Ordos, located in North China's Inner Mongolia, holds about one-sixth of China's proven coal reserves. The city is also shifting towards clean energy. According to the city government, the value added in the city's wind and photovoltaic equipment manufacturing sectors saw a 5.6-fold increase year-on-year in the first half of this year.

The country's total installed power generation capacity reached 3.16 billion kilowatts by the end of September, marking a 14.1 percent increase from a year ago. The installed capacity of solar power generation has reached 770 million kilowatts, growing by 48.4 percent year on year.

INNOVATIVE DESIGNS

The new solar station, built on an abandoned coal mine site, adopted a novel approach of growing plants beneath the panels to facilitate agriculture and animal husbandry.

In areas with abundant native vegetation, edible plants such as alfalfa are grown, while in areas with less native vegetation, more drought-resistant species are cultivated to provide high-quality fodder for livestock.

Additionally, a sand-resistant plant called Chinese sea-buckthorn has been grown in the station to be utilized for co-firing in thermal power plants, thereby reducing the use of fossil fuels and achieving the goals of carbon reduction and pollution control.

To accommodate the challenges of the subsidence area, the power station features an innovative "spring" support system with two distinct components: a subterranean hollow tube pile and an above-ground support column that fits snugly into the pile.

This design incorporates a vertical adjustment range of approximately one meter, enabling the station to accommodate ground subsidence while maintaining its panels at their optimal angles for sunlight exposure, according to the state broadcaster China Central Television.

The solar panels capable of adjusting angles in real-time can increase power generation efficiency by over 7 percent compared to conventional types.

Also, this power station has an intelligent maintenance system featuring 10 drone sheds. These facilities enable drones to autonomously take off and land, as well as recharge, thus reducing the time required for inspections to about 30 minutes -- a task that would otherwise necessitate the labor of 12 personnel over two days using six vehicles.

Smart cleaning robots are also employed in the solar station to remove dust from the panels.