BEIJING -- China's top electricity company State Grid announced a record investment plan for 2015 on Friday to fund its large-scale grid construction.

State Grid plans to spend 420.2 billion yuan ($68.7 billion) on grid infrastructure in 2015, up 24 percent year on year.

The growth is much faster than a 14.1 percent increase in 2014.

The company will start to construct 64,000 km of alternating current (AC) power transmission lines and 13,000 km of direct current lines in 2015.

AC lines, over 46,000 km in total, will be put into operation this year.

State Grid will also build ultra-high voltage (UHV) and "smart" transmission lines. It will start pre-project work for four power links connecting China with Kazakhstan, Russia, Mongolia and Pakistan.