A ‘photovoltaic sea’ in the desert of northern China

In Chaideng Village in Ordos City, Inner Mongolia Autonomous Region, 3.46 million blue solar panels are spread across the desert, covering 30 square kilometers and transforming the endless sands into a shimmering “photovoltaic sea.”

The solar power base is part of an ambitious solar-powered desert reclamation project known as the “photovoltaic Great Wall,” which stretches along the northern edge of the Kubuqi Desert.

This grand project, while unable to rival the real Great Wall in length, is planned to stretch about 400 kilometers with an average width of five kilometers, according to Liu Tianyun, deputy director of the Ordos forestry and grassland bureau.

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

To date, the city has installed 5.42 gigawatts of solar power on over 133 km2 of sandy land.

The Kubuqi Desert has wide, open land perfect for solar farms. The area enjoys abundant solar resources, with approximately 3,100 hours of sunshine per year.

In addition to generating power, local solar projects have also proven useful in mitigating the area’s frequent and intense sandstorms and desertification.

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

The solar panels can reduce groundwater evaporation by 20% to 30%, while providing shade from the sun and shelter from the wind, which encourages plant growth. Since plants and poultry thrive in the shade, this approach yields economic and ecological benefits.

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

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

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 increase power generation by about 8%.

Workers install solar panels in the Kubuqi Desert in Ordos city, Inner Mongolia autonomous region, last year. DING GENHOU/CHINA DAILY

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

The minimum distance 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 easily for agricultural work.

The city of Ordos, also known for its abundant coal resources, has several large coal mines scattered across the Kubuqi Desert.

Treated drainage water from coal mines is piped 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, Zhang Xiuling, vice mayor of Ordos, said that by planting crops in the sand and covering them with solar panels, they are essentially creating a double-layered “shield,” keeping the quicksand firmly in check.