How does a windmill work?

A windmill is a power machine that converts wind energy into mechanical work, also known as a wind turbine. It is a thermal energy utilization engine that uses the sun as the heat source and the atmosphere as the working fluid. It depends largely on the wind conditions of the installation site. Through meteorological measurements, a continuous curve of wind speed at the installation site can be obtained. The output power gradually increases with the increase of wind speed. When the wind speed continues to increase, the power output can be stabilized at the rated value by adjusting the blade pitch or other methods. There are thousands of wind turbines in operation around the world, and they play a huge role as auxiliary energy. However, wind turbines still have some disadvantages. First, energy output is unstable, especially large wind turbines with low utilization rates and lack of independent energy supply. Secondly, the safety and reliability of wind turbines are not fully guaranteed; in addition, the cost of wind turbines is not sufficient to compete with fossil fuels in the short term.