Chongqing - As a prolonged heatwave pushed electricity demand to record levels, southwest China's Chongqing municipality kept its power grid operating steadily by combining long-distance electricity from Xinjiang with expanded local generation capacity.
From July 14 to 16, Chongqing issued three consecutive red alerts for high temperatures. As temperatures climbed, the city's power demand reached a new record for three straight days.
At 1:49 p.m. on July 16, the maximum load on the Chongqing power grid reached 31.4 million kilowatts, surpassing last year's peak of 30.28 million kilowatts by 1.12 million kilowatts, according to State Grid Chongqing Electric Power Company.
Employees of State Grid Chongqing Wushan Power Supply Company install a disconnect switch on a 10-kilovolt line. (Photo/State Grid Chongqing Electric Power Company)
Company officials said the municipality's strongest support during the summer peak has come from the "Xinjiang-to-Chongqing" ultra-high-voltage (UHV) transmission project, which delivers electricity from China's far western Xinjiang Uygur Autonomous Region to Chongqing.
Since the start of summer, the project has supplied up to 6 million kilowatts of electricity, accounting for roughly one-fifth of Chongqing's peak demand. By July 19, cumulative electricity transmitted through the project had exceeded 30 billion kilowatt-hours.
The imported electricity, much of it generated from clean energy sources in Xinjiang, enters Chongqing through the Yubei Converter Station, a key hub in the UHV direct-current transmission network.
Maintaining stable operations at such scale depends on continuous monitoring.
Employees of State Grid Chongqing Pengshui Power Supply Company use a drone to inspect a 110-kilovolt transmission line. (Photo/State Grid Chongqing Electric Power Company)
At the ±800-kilovolt Yubei Converter Station, operators use an intelligent inspection system to monitor more than 200,000 data points linked to the safety and performance of critical equipment.
The system conducts automated inspections and temperature monitoring of core components, including converter transformers and converter valves. At the same time, technicians perform manual inspections using infrared thermal imaging equipment to verify operating conditions.
While imported electricity has eased pressure on the grid, local generation has also played a critical role during periods of peak demand.
At the Huaneng Chongqing Liangjiang Gas Power Plant, operators monitor real-time indicators including load, frequency, temperature and pressure as four generating units run at high output.
According to the plant, the facility can reach full power generation within one hour after a hot start, allowing it to respond quickly to sudden increases in electricity demand.
Plant officials said all generating units completed comprehensive maintenance before the summer season. Daily electricity generation has now exceeded 45 million kilowatt-hours, up 7.4% from a year earlier.
Another major supplier, Datang Chongqing Jiangjin Gas Power, has increased equipment inspection frequency while optimizing unit efficiency and strengthening emergency response capabilities to support summer electricity supply.
In recent years, Chongqing has expanded its flexible power generation capacity alongside long-distance transmission infrastructure. Local projects, including the second phase of the Huaneng Liangjiang Gas Power Plant, Datang Jiangjin Gas Power Plant and Huadian Tongnan Gas Power Plant, have all entered operation.
State Grid estimates Chongqing's peak electricity load could reach 32 million kilowatts in August.
Ahead of the summer peak, more than 6,000 grid maintenance projects were completed across the municipality. Authorities also addressed 3,505 major equipment risks and defects and commissioned 11 key grid reinforcement projects to improve the grid's ability to withstand sustained high electricity demand.