Hydraulic machinery

There are waterwheels, water mills, turbines, etc. Since the 20th century, hydropower stations using hydro turbines have been increasing, because hydropower stations have the advantages of low operating costs, no pollution, and inexhaustible use. However, the construction of reservoirs and dams has a large initial investment and a long construction period, and it also has an impact on ecological balance and geological force balance. China's hydropower reserves are about 680 megawatts, ranking first in the world, and there is room for development and utilization.