Bringing Renewable Energy To China’s Cities

The “world’s largest clean energy corridor” can be found in the southwest of 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 hydrostation by installed capacity – is located at Baihetan, and was built at a cost of US$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 tonnes a year.

Case study electricity distribution cn content

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 football pitches, 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, and they therefore need to be cooled to ensure both safety and reliability. In order to prevent any impurities affecting the valves, ‘ultrapure’ water is used in the cooling system. This is water that has been purified to an extremely high specification, removing every kind of possible 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 customised Güntner Flat VARIO Dry Coolers were installed, designed for maximum cleanliness. 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.

“GÜNTNER CLEARLY UNDERSTOOD THE VERY STRICT REQUIREMENTS FOR THE COOLING SYSTEM AT THE BUTUO CONVERTER STATION AND THEY WERE ABLE TO ADAPT THEIR PRODUCTS PERFECTLY IN ORDER TO MEET THEM.”
TANK JIANG STRATEGIC PURCHASING SUPERVISOR, GUANGZHOU GOALAND ENERGY CONSERVATION COMPANY

Another requirement of the converter valve cooling system was that there should be 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 minimising the loss of cooling medium, allowing the valve to operate reliably.

Once the electricity is converted to direct current, it will pass 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.

“THE BUTUO CONVERTER STATION IS A VITAL LINK IN THE TRANSFER OF RENEWABLE ENERGY TO CHINA’S INDUSTRIAL CITIES, AND GÜNTNER’S DRY COOLERS PLAY A PIVOTAL ROLE IN THE SYSTEM. WE ARE PROUD THAT OUR WORK IS HELPING TO BUILD A GREENER FUTURE.”
WIND CHEN SALES DIRECTOR FOR EPC, GÜNTNER