'Photovoltaic sea' forming in North China desert

An aerial drone photo taken on March 3, 2023 shows a photovoltaic base located in Dalad Banner in the city of Ordos, north China's Inner Mongolia Autonomous Region. (Xinhua/Bei He)

HOHHOT, Aug. 27 (Xinhua) -- In Chaideng Village of Ordos City, 3.46 million blue solar panels stretch across the desert, covering 30 million square meters, transforming the endless sands into a shimmering "photovoltaic sea."

The solar power base is part of an ambitious solar energy desert reclamation project known as the "great photovoltaic wall," spanning along the northern edge of the Kubuqi Desert.

This grand project, though not able to rival the real Great Wall in length, is planned to extend about 400 kilometers with an average width of five kilometers, according to Liu Tianyun, deputy director of the forestry and grassland bureau of Ordos.

It will set a new record in area for photovoltaic farms in China and acquire 100 million kilowatts of installed capacity upon completion, Liu said.

To date, the city has installed 5.42 million kilowatts of solar power on over 200,000 mu (about 13,333 hectares) of sand area.

The Kubuqi Desert has expansive and open land perfect for solar farms. The region enjoys plentiful solar resources, with approximately 3,100 hours of sunshine each year.

In addition to generating power, local solar projects have also proved to be helpful in mitigating the area's frequent and intense sandstorms and desertification.

The project spearheaded an innovative approach, with power generating solar panels placed on the top, allowing plants to grow on the ground and small livestock to graze under the panels.

An aerial drone photo taken on Aug. 24, 2023 shows a photovoltaic base located in Dalad Banner in the city of Ordos, north China's Inner Mongolia Autonomous Region. (Xinhua/He Shuchen)

The solar panels can reduce groundwater evaporation by 20 to 30 percent and in the meanwhile, provides shade and cuts wind speeds, all supporting plant growth.

With plants and poultry thriving in the shade, this approach yields both economic and ecological benefits.

In some arid areas, solar-powered drip irrigation is also adopted to green desert landscapes.

To adapt to the challenging conditions of desert environments, innovations in photovoltaic modules have been introduced.

The photovoltaic modules use bifacial technology and high-efficiency cells that can capture sunlight from both sides, taking advantage of the high reflectivity of sandy surfaces to boost power generation by approximately 8 percent.

The modules' lifespan has also been extended from 25 years to 30 years after the adoption of dual-glass encapsulation materials.

The minimum clearance between the photovoltaic panels and the ground has been adjusted to about 2.5 meters, providing ample space for both people and machinery to move around easily for farm work.

The city of Ordos, also known for its abundant coal resources, has several large coal mines scattered across the Kubuqi Desert. The treated drainage water from the coal mines is channeled from these mines to the solar power base and used to clean the solar panels and water the plants.

Standing under a solar panel array in Chaideng Village, Zhang Xiuling, deputy mayor of Ordos, said that by planting crops in the sand and topping them with solar panels, they are essentially creating a double-layered "shield," keeping the shifting sands firmly in check.