China builds world's longest 220kV AC submarine power cable - Jiapu Cable

China builds world's longest 220kV AC submarine power cable


Electrical power systems are the backbone of modern life. But how does one "empower" remote islands? 

One obvious answer remains "submarine power cables" also known as "sea power cables." These are transmission cables that carry electric power below the surface of the water.

However, developing a long-distance submarine power cable system could be extremely tricky. 


China, which is home to some of the most exotic islands in the world, is making significant progress in electrifying its nature-rich islands. 

Chinese engineers have recently built a 27-kilometer-long 200kV AC undersea power cable to connect the Chinese mainland to an offshore wind farm in Dalian City, northeast China's Liaoning Province.

The cable has no joints between terminations and can work problem-free even after lying on the seabed for decades.

"In a factory, we have to monitor the cable output for 25 days non-stop," said Li Ziwei, the manager the cable's production unit.

If anything goes wrong during the 25-day process, the engineers need to start all over again from the beginning. So, this work requires extreme caution.


"We achieved this after years of progress in technology," Li told CCTV.

It's the world's longest cable of its kind and has passed several levels of examination. Now, it's waiting to be put into actual use.

In December 2018, a 17-kilometer-long 500kV submarine cable was laid to electrify an island in Zhoushan City, east China's Zhejiang Province.