Wind turbines stand tall and scatter on the hill in Zhangbei county, Hebei province. (PHOTO: VCG)

By CHEN Chunyou &WEI Yichen

During the Olympic Winter Games Beijing 2022, the use of Zhangbei's wind energy resources provides a solid power supply for the Olympic stadium.

Zhangbei, a county in Hebei's Zhangjiakou city, is 45 kilometers away from other urban areas. The landscape in Zhangbei is very rugged, and the huge temperature differences produce strong air convection, making it the main airflow channel for cold air from the Mongolian Plateau to the North Plain. The wind resources are very rich, with a reserve reaching more than 20 million kW.

A wind turbine with a 146-meter-diameter blade in Zhangbei county can generate about 24,500 kWh of electricity a day, which can satisfy all the needs for snow-making at the Shougang Big Air, a sports venue in Beijing's Shijingshan district.

In Zhangbei, it takes about three seconds to drive a two MW wind turbine to rotate at a rated speed, which can generate about two kWh electricity, with almost zero carbon dioxide emissions.

One kWh of green electricity can light up the main stage of the award plaza for 22 seconds, and allow a chef to make two dishes in an all-electric kitchen at the Winter Olympic Village.

It is estimated that by the end of Beijing 2022, which will end on March 13, the Olympic stadium will have consumed about 400 million kWh of green electricity, which is equivalent to reducing standard coal burning by 128,000 tons and carbon dioxide emissions by 320,000 tons.

Wind power is prone to be affected by the natural wind, and the wind speed is not subject to human control. However, the normal use of wind power needs high stability，as unsteady electric current is likely to cause a breakdown to the power system.

In order to reduce the instability of wind power use and ensure a safe transmission of energy to Beijing, the Zhangbei flexible direct current (DC) power grid project was constructed with the support of the State Grid Corporation of China.

With a total investment of up to 12.5 billion RMB, the transmission line is the world's first renewable energy-based flexible DC power transmission system, with pioneering core technologies and key equipment created by China.

The project is significant for improving clean energy delivery ability, such as supporting the green Olympics. The wind resource in Zhangbei has been turned into efficient and clean energy, which offers a solid guarantee for the power demand of the competition events, and adds a new dimension to Beijing 2022.