Bringing Renewable Energy To China’s Cities
The world’s largest clean energy corridor can be found in southwest China. It is a series of huge hydroelectric dams situated on the upper reaches of the mighty Yangtze River and its tributary, the Jinsha River. Fundamental to China’s West-East Electricity Transmission strategy, the dams together generate electricity for the energy-hungry industrial cities in China’s east. Hydropower plays a significant role in China’s energy policy and accounts for nearly a fifth of total electricity production. It will be a significant factor in the country’s aim to reach carbon neutrality by 2060.
The most recent hydropower station to open in the corridor—the world’s second-largest hydropower station by installed capacity—is located at Baihetan and was built at a cost of $34 billion. It became fully operational at the end of 2022, and its 16 turbines have a combined generating capacity of 16,000MW. By replacing traditional coal-burning systems, the station reduces carbon dioxide emissions by an estimated 50M metric tons a year.
In order for the electricity produced by the Baihetan Hydropower Station to be transmitted stably across thousands of miles to the major economic areas of Jiangsu and Zhejiang in the east, it first needs to be converted from alternating current to direct current. For this reason, a special facility was constructed. The Butuo Converter Station covers an area roughly the size of 90 soccer fields, and is the largest station of its kind in the world in terms of both area and transmission capacity.
At the heart of the station is its valve hall, where the conversion process takes place. During operation, the valves generate a large amount of heat, so they need to be cooled to ensure both safety and reliability. “Ultrapure” water is used in the cooling system to prevent any impurities from affecting the valves. This is water that has been purified to an extremely high specification, removing every possible kind of contaminant.
Similarly, high standards need to be applied when it comes to the equipment used in the cooling system, and this is where Güntner enters the story. A total of 16 specially customized Güntner Flat VARIO Dry Coolers, designed for maximum cleanliness, were installed. The units were given a special cleaning treatment, meaning that the coils could be kept clean for a long time, avoiding the need for frequent replacement of the ultrapure water cooling medium.
Another requirement of the converter valve cooling system was sufficient cooling capacity to ensure the operating temperature of the valves remained within the normal range. The closed-loop design of the Güntner Flat VARIO Dry Coolers plays a vital role in minimizing the loss of cooling medium, allowing the valve to operate reliably.
Once the electricity is converted to direct current, it passes through five provinces, 19 cities, and 59 districts and counties. At its final destination, it plays a crucial part not only in China’s economic prosperity but also in its journey to sustainability.