China is beating winter storm power blackouts as Western countries warn to get supplies

After major grid collapse in 2008, valuable lessons now keep the lights on during major storms
Real-time hi-tech platform warns power providers when it’s time to burn off ice build up on power lines

Science

Zhang Tongin Beijing

Published: 4:37pm, 26 Feb 2024

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In early 2008, a severe ice storm swept across large parts of central and southern China, leaving so much ice build-up on power lines that transmission towers collapsed like dominoes.

In the biting cold, more than a hundred million people soon found themselves without electricity. The chaos made global headlines.

This month, it happened again, but this time there were no reports of widespread blackouts, damage or chaos, even as such storms menace power grids in other parts of the world, even in the most advanced nations.

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Last April, an ice storm devastated the Canadian provinces of Quebec and Ontario, knocking out electricity for more than a million people. And last month, a massive winter storm in the eastern United States knocked out power to 811,000 homes and businesses across 12 states.

In parts of the US, the Federal Emergency Management Agency has warned that winter storms are treacherous killers. Power companies urge residents to stock up on supplies for survival.

In China, scientists and engineers have learned valuable lessons from the weather disaster 18 years ago, and have since developed an innovative monitoring system to prevent ice build-up on power lines during cold, snowy and icy weather, according to reports in state media.

For instance, at the end of 2022, State Grid Hubei Electric Power Company launched an online ice monitoring platform to help protect its transmission lines.

“Using cameras and sensors, the system enables real-time monitoring and prediction of ice accumulation on transmission lines in Hubei from far away, as well as managing ice melting and removal,” Science and Technology Daily reported on Thursday.

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Wire icing happens when could or fog vapour lands and then freezes on the surface of transmission lines at temperature of 0 degrees Celsius (32 Fahrenheit) or lower.

Each winter and early spring in China’s northeastern and central regions, cold dry northwestern air mixes with warm moist southeastern air, forming an “ice belt” stretching from the provinces of Hunan and Guizhou in the south to Liaoning and Jilin in the north. The vast areas threatened by such storms have made it essential to develop weather surveillance systems in the regions.

“For precise control over ice accumulation on the grid, we installed 395 items of intelligent ice monitoring equipment, including simulated conductors and microwave sensors, along transmission lines based on local topography and climate,” said Huang Junjie, a senior engineer at the Equipment Technology Centre at the State Grid Hubei Electric Power Research Institute.

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This method involves suspending a 1-metre (39-inch) section of simulated conductor line from a tower. Intelligent devices are able to calculate the thickness of the ice accumulated on the simulated conductor based on changes in its weight.

Meanwhile, microwave sensors attached to simulated conductors provide real-time information about the thickness of the ice by analysing differences in microwave signal feedback from the ice, water and air.

Ice formation can also be affected by regional topography and wind direction. Areas with favourable wind conditions, such as mountain peaks, passes, windward slopes and locations near sources of moisture like rivers and reservoirs are prone to freezing.

“Hubei’s power grid has more than 180 areas that are prone to icing. The platform’s predictive capabilities utilise meteorological data and modelling to assess ice risks in these areas, displaying four risk levels in different colours,” Huang said, according to the report.

The platform’s prediction module displays a map of Hubei dotted with blue, yellow, orange, and red patches, allowing real-time visualisation of ice risks on transmission lines.

With the help of real-time data and visual monitoring of ice, personnel can implement de-icing measures when necessary.

The most effective way to de-ice transmission lines is by running a short-circuit across the line using a large battery, which then heats the wire and melts the ice.

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Last Wednesday, the platform detected an ice build-up on a major transmission line in the city of Jingmen in Hubei that was 8.71mm (0.34 inches) thick – enough to pose a serious risk to the power supply. The platform immediately notified a power company in the city, which then began de-icing measures to reduce the hazard.

After the ice disaster of 2008, other ice prevention and removal techniques have also been developed. State Grid Hubei Electric Power has begun using drone-assisted mechanical de-icing, and a power grid company in Guangdong has begun experimenting with flame-throwing drones and even de-icing devices that use lasers.