The State Grid Corp. of China has started construction on what it says will be the world's largest capacity power transmission line.

The $3.7 billion, 800-kilovolt power line will be capable of transmitting 37 billion kilowatts on average annually, state-run news agency Xinhua reports.

At 1,373 miles long, it will connect the energy base of the Hami prefecture in eastern Xinjiang with the central city of Zhengzhou, going through the expansive region of Xinjiang, Gansu, Ningxia, Shaanxi, Shanxi and Henan.

"The ultra-high power transmission lines are a way out for the country's imbalanced distribution of energy reserve," said Zhang Guobao, director of the Expert Advisory Committee under the National Energy Administration.

China's State Grid Corp. is also promoting construction of four alternating-current and three direct-current ultra-high voltage power transmission lines across the country, for an investment this year of more than $47 billion.

Under its current five-year plan, China plans to build 19 major UHV lines, including alternating and direct current links. Eleven of the lines are intended to help wind power transmission.

Faced with increased curtailment of wind power by the country's grid operators, China's top wind farm developers lowered expansion targets for this year, Xinhua reports.

China is considering a renewable energy quota system requiring grid companies to transmit up to 15 percent of their power from renewable sources, China Securities Journal reported last week.

Under the proposal, by 2015 Inner Mongolia Power Company's would have a renewable energy quota of 15 percent, while State Grid, China's largest grid operator, would have an energy quota of 5 percent and for smaller China Southern Power Grid, a quota of 3.2 percent.

That compares to the national renewable energy level of about 1.6 percent in 2011.

The proposal is seen as a boost to China's wind power sector. In some areas of the country, up to 30 percent of wind power produced is lost because of limited access to grids.

The most recent quarterly report from the China Electricity Council said that the country is expected to have an electricity shortage of 30 million to 40 million kilowatts this summer, with some regions experiencing severe blackouts.

China's more developed eastern and southern regions will be most affected, followed by north and central China, but areas in the northeast and northwest of the country are expected to seen an electricity surplice, says the report.

CEC said that China's power consumption totaled 1.17 trillion kilowatts in the first quarter of this year. It predicts that annual consumption will reach 5.19 trillion kilowatts.