From the intense heat of the Californian desert to the green hills of Scotland, wind turbines are popping up all over the world.
Humans have been using wind energy for thousands of years. Today, its scope and scale is big and getting bigger. According to the Global Wind Energy Council (GWEC), at the end of 2016 more than 341,000 wind turbines were spinning and generating energy.
CNBC's Sustainable Energy takes a look at the nuts and bolts of wind power – how turbines work, wind energy's impact on the environment, and its role in the planet's energy mix over the coming years.