The cable system has a current-carrying capacity of 4 million kilowatts of electricity over a distance of 1,333 km through five provinces and regions.
China's coal resources are mainly based in the west and the north. The west-east power transmission programme was initiated in 2000.
Cui Jifeng, general manager of Ningxia Power Co. which is a subsidiary of the China Power Grid Co., said the system was built to supply hydropower generated on the upper reaches of the Yellow River as well as thermal power produced in Ningxia to coastal Shandong.
The system was designed, produced, constructed and tested by Chinese companies, he said.