The first domestic-made 500-kilovolt submarine cable loads into a ship at a port along the Yangtze River in Jiangsu province on Oct 23. [Photo/ zhoushan.cn] 

The first domestic-made 500-kilovolt submarine cable set off for Zhoushan on Oct 23, and was expected to reach the city in three days. 

The cable, developed by the State Grid Zhejiang Electric Power Co and related national research institutes and cable manufacturers, is also the world's first 500-kilovolt cross-linked polyethylene insulated submarine cable. 

It marked a great advancement in the country's submarine power transmission technologies, before which China could only rely on imports from other countries for 500kv submarine cables due to the lack of related technologies and production capacity.

Stretching 18.15 kilometers long and weighing 1,540 metric tons, the cable will be laid in Zhoushan as part of its 500-kilovolt power transmission project, which was started on Dec 28, 2016, and is projected to enter operation by the end of this year. 

The project, worth 4.62 billion yuan ($665.5 million), aims to build a 500kv power transmission channel between the city and Ningbo, so to strengthen the power supply for the development of Zhoushan Archipelago New Area and contribute to the construction of the Belt and Road Initiative. 

The project also included the building of two 380-meter-high power transmission towers in Zhoushan, the highest of its kind in the world, with the one at Cezi Island, Dinghai district, recently having finished its head installation.

The first domestic-made 500-kilovolt submarine cable loads into a ship at a port along the Yangtze River in Jiangsu province on Oct 23. [Photo/ zj.zjol.com]