October 6, 2023
By Chuqin Jiang

China wind farm sets high-altitude records, but how do turbines keep up in the thin Himalayan air?
 

China has expanded its highest-altitude wind farm, in the Tibet autonomous region, thousands of metres above sea level. Photo: China Three Gorges Corporation

China’s push for clean energy is testing the limits of high-altitude wind turbines in the same mountain range as Mount Everest, up where the air is rather thin.

In the Tibet autonomous region, phase two of the Zhegu Wind Farm, in the northern foothills of the Himalayas, was put into operation in Comai county on Wednesday, when 15 newly installed wind turbines were connected to local power grids.

The project, funded by the state-owned Three Gorges Corporation, is hailed as China’s highest-altitude wind farm, with parts up to 5,200 metres (17,000 feet) above sea level.

The 15 new turbines, with single-unit capacities of up to 3.6 megawatts (MW) – a record for high-altitude wind farms in China – are expected to generate 200 million kilowatt-hours of clean electricity a year. That’s equivalent to the annual power consumption of 140,000 local households, or more than 10 per cent of all Tibet families, according to a statement by Three Gorges on WeChat.

"We are dispelling the misconception that it is inefficient to develop wind farms on a plateau
Wang Liang, local project overseer"

Its annual power generation, if fully realised, could save more than 60,000 tonnes of coal every year, reducing 173,000 tonnes of carbon dioxide emissions and 20 tonnes of sulphur dioxide emissions, according to state news agency Xinhua.

“[The wind farm] is expected to drive local economic and social development, improve local energy structure, and promote tourism to Zhegu Lake, which will have a positive effect on the country’s rural revitalisation,” China’s State-owned Assets Supervision and Administration Commission said in 2021 upon completion of the project’s first phase.

China, the world’s largest renewable-energy producer, was generating 36.2 per cent of its electricity from non-fossil fuel as of 2022, according to an electric-power report by the China Electricity Council in July. In total, 8.8 per cent of China’s electricity comes from wind.

The nation’s installed windpower capacity reached 365 gigawatts (GW) last year, accounting for 40 per cent of the global total and leading the world for 13 straight years.

“We are dispelling the misconception that it is inefficient to develop wind farms on a plateau,” Wang Liang, one of the local project overseers, was quoted as saying by state broadcaster CCTV.

As the amount of turbine-generated wind energy is correlated with both air density and wind speed, a turbine’s efficiency is lowered by the thin air in high-altitude areas.

This increases the circumference of the rotating blades by nearly 30 per cent.

To function efficiently in the extreme environment, all turbines are equipped with elastic coatings, UV and lightning-protection modules, and thick cables, according to comments in state media by the project’s technical director, Li Chunshan.

The wind-farm expansion in Zhegu adds at least 48MW to China’s total installed capacity, contributing to its full-year target of 430GW while getting the nation a little closer to Beijing’s stated goal of being carbon neutral by 2060.

Tibet has been a pilot region in central leadership’s push for green-energy development. The clean energy generated there will be both used by local residents and sent to other provinces. It is expected to transmit 1.82 billion kilowatt hours to 12 destinations this year, while generating a profit of about 500 million yuan (US$68.5 million).

The Qinghai-Tibet Plateau is one of China’s three major windpower areas, and the potential capacity for wind resources there accounts for about 26 per cent of the country’s total, according to a peer-reviewed report by China’s National Climate Centre last year.

Three Gorges Corp, which also operates the country’s largest hydropower dam, finished another wind farm in Fujian province last month, with installed capacity of 111MW. Its offshore turbines are said to have the world’s largest single-unit capacity: 16MW.