"High-altitude winds between 1,640 and 3,281 feet (500 and 10,000 meters) above the ground are stronger and steadier than surface winds. These winds are abundant, widely available, and carbon-free.
"The physics of wind power makes this resource extremely valuable. “When wind speed doubles, the energy it carries increases eightfold, triple the speed, and you have 27 times the energy,” explained Gong Zeqi "
In theory nothing. Wind is just the flow of air from high pressure to low, which itself is caused by heating from sunlight. If uncollected, the kinetic energy of the wind would eventually be lost as heat to friction between air molecules.