First, it was that China overtook Germany in the solar power sector. Chinese systems are better and cheaper. And now - in the space of 10 years - China has also overtaken Germany and the US in the wind energy sector. It's installed 110 gigawatts of wind capacity - that's almost three times more than Germany, which has 40 gigawatts.

However, the biggest turbine makers in the world are still based in the West. Siemens in Germany, General Electric in the US and Vestas in Denmark were the top three in 2014. The Chinese company Goldwind was number 4 - it even went down a notch since 2013. But China is catching up very fast - half of the top 15 turbine manufacturers in the world are Chinese.

Chinese wind turbines are now so affordable and powerful that they are also being exported - not yet to Germany or the US, but to developing countries. Earlier this month, China signed a deal with Pakistan. China will invest $115 million (105 million euros) in a wind power plant in the south of Pakistan that will produce enough electricity to meet the needs of some 100,000 families living in the region.

The system is supposed to be installed by June of next year and in operation by September. A crucial detail is that China will finance the system - this is its greatest advantage over Western competitors. However, even for Pakistan it's a small investment. At the same time, China is investing $6.5 billion to build new nuclear power plants in Pakistan.

Coal still most important energy source

In China itself the government is realistic when it comes to estimating what role wind energy can play to get away from the dependence on coal that is so damaging to the environment. There is still a lot to be done. Some 70 percent of electricity is still generated from coal, compared to 3 percent from wind. This remains the case despite massive growth.

In the first half of this year, some 100 billion kilowatt hours were fed into the grid. That's over 20 percent more than the year before. Yet, this is precisely the problem. Too many windmills were built too fast. Like in Germany, the bottleneck is being caused at the grid. Thousands of kilometers of power supply lines now cross China to bring electricity from the wind-rich West to the energy-hungry East.

But every year, billions of kilowatt hours are lost in China because the electricity lines are too long and not good enough, or windmills are not turned on or poorly maintained. And because the electricity grid is not efficient enough at peak times. In the first half of this year, the many wind turbines supplied efficiently, but in vain. Some 17.5 billion kilowatt hours were lost. That was a new record - 7 percent more than in 2017. Losses of 15 percent worth $140 million in total.

Although wind energy is growing three times faster than the losses, this is still very annoying. To shorten the lines, it would make sense to build more offshore wind power plants directly off the coasts of the most energy-hungry regions. However, in China little is known about offshore wind energy plants. This is what the Germans can still do better. Siemens is number one in the world when it comes to the offshore market.

DW's Frank Sieren has been living in Beijing for 20 years.