Wind turbines, computer artwork. The blades of the turbines (most designs have three blades) are turned by the wind. As the turbine blades rotate, electricity is generated in the structure mounted just behind the blades. A tall support structure (usually over 50 metres tall) allows the blades to take advantage of the wind. Many hundreds or even thousands of wind turbines can be used on a wind farm to generate power for thousands of homes. Wind power is an environmentally-friendly source of energy, as it does not release pollutants and does not rely on a limited resource (such as oil) for fuel.