A spokesperson from the International Energy Agency said that China is rapidly building wind turbines, but the turbines are shut down by smoke coming from coal burning plants.
The country is building turbines twice the amount produced by the U.S.
He said, "The rather rosy statement on wind energy hides the issue that 2015 and the first half of 2016 also saw record new installations of coal. China has now a clear over-supply."
According to the expert, 39 percent of wind energy had to be curtailed. The turbines had to be turned off because there is not enough capacity on the grid.
"China's position is clearly unsustainable. It will need strong policy decisions, including the construction of many more grid lines and a phase-out policy for older, more inefficient coal power plants," he added.
The government has imposed a moratorium to coal plants to curtail production until 2018 while increasing energy production from wind turbines to 30,000 megawatts.
Steve Sawyer, an expert from the Global Wind Energy Council, said, "China's buildup of its capacity in wind--and now solar--is truly without parallel. It is no surprise that the Chinese grid's capability to integrate this variable renewable energy has not progressed at the same rate, but to change this situation China needs to rapidly progress with electricity market reform."
The government was observed to have overestimated electricity consumption, as there was only a rise of 0.5 percent due to the country's efforts to be more energy efficient.
IEA Executive Director Fatih Birol said, "We see a broad shift of spending toward cleaner energy, often as a result of government policies."
The IEA released a report that China is the biggest investor in clean energy. The government's investment has totaled to $315 billion.