What are some real life examples of where wind power is being used?

As wind pick speed it will force a blade like a propeller to spin.They spin because of the design whereby differential pressure is applied by the blades wind air flowS. as it spins the rotor is tied to a generator which will be electrically tied to the grid as a source of power. What happens if there is no wind then by design it becomes a motor in other Words take power from the grid to maintain a certain spin waiting for winds to pick. While it is free power it is not quite efficient. It was setup as taxes break to relieve the energy power and as test ground for new energy sources