State Grid Corporation of China (SGCC) said Thursday it will invest 500 billion yuan (75.4 billion U.S. dollars) over the coming 5 years to extend its ultra-high voltage (UHV) electricity transmission system.

The length of the UHV electricity transmission network will reach 40,000 kilometers by the end of 2015, SGCC general manager Liu Zhenya said in a statement posted on the company's website.

Liu forecast China's total electricity consumption to top 6.1 trillion kilowatt-hours by the end of 2015.

By 2020, the country's electricity consumption may double the 2009 figure to hit 7.8 trillion kilowatt-hours, giving rise to significant opportunities for UHV electricity transmission system development, he said.

He expects UHV transmission systems to play a big role in helping China's cross-regional power transmission capacity top 400 million kilowatts by the end of 2020, about one third of the country's total electricity power installed capacity.

Defined as voltage of 1,000kV or above of alternating current or 800kV or above of direct current, UHV is designed to transmit large currents of power over long distances efficiently.