Data released by China's National Energy Administration recently showed that in the first half of the year, wind power generated 97.7 billion kilowatt hours of on-grid electricity, 20.7 percent higher than the same period of last year.

While curtailment reached 17.5 billion kilowatt hours, a year-on-year growth of 10.1 billion kilowatt hours, causing economic losses of nearly 8.7 billion yuan (140 million USD). The average curtailment rate increased 6.8 percentage points to reach 15.2 percent, marking a three-year record high.

The size of China's installed capacity for wind power saw rapid development in recent years and surpassed the United States to become the world's first by the end of 2012.But meanwhile the wind curtailment increased, mainly in western Inner Mongolia, Gansu and Xinjiang with the rate reaching 20 percent, 31 percent and 28.8 percent respectively.

The curtailment rate stood at 15 percent or so in 2012, dropping to 13.5 percent in the first half of 2013, and further declining to 8.5 percent in the first half of 2014.However, the figure sharply increased to 15.2 percent for the first half of 2015, hitting a three-year record high.

Proposals have been put forward to cut the on-grid price in September of 2014, Since then, large wind power enterprises such as China Datang Corporation, State Power Investment Corporation and Longyuan Power Group Corporation have accelerated investment in the construction of wind farms because the reduced price will apply to the wind power projects which put into operation after January 1, 2016.

Experts predicted that install capacity will see surge in a short period of time and exceed the previous planning, which will pose bigger challenges to wind power grid integration and further deepen wind power curtailment.