The electric power industry in China has progressed at an unprecedented pace since 1980 and this is best illustrated by two graphs that show the growth in annual generation as well as in total length of overhead transmission lines.

The recent rapid expansion of Chinese overhead network, combined with ever increasing voltage levels, led to a huge local demand for insulators. At the same time, it placed upon them more stringent electrical and mechanical requirements.

Silicone rubber composite insulators quickly came to be viewed as offering several unique advantages, including superior wet and pollution flashover performance, light weight, high strength to weight ratio, easier transport and installation and resistance to vandalism.

The rate of application of composite insulator in China therefore experienced tremendous growth to the point where, by 2014, an estimated 7.1 million units were operating on transmission lines of 110kV or higher. Moreover, by mid 2015 about 153,000 such insulators were in service on 9 key UHVAC and UHVDC lines. Indeed, China became the first country where silicone rubber composite insulators dominate all EHV and UHV lines.