水能, or hydropower, is a renewable energy source that harnesses the energy of flowing or falling water to generate electricity. It is one of the most widely used forms of renewable energy worldwide, utilizing rivers, dams, and waterfalls to produce power. The process typically involves a dam that creates a reservoir, where water is released to turn turbines connected to generators. This method is efficient and can provide a stable energy supply, making it an important component of many countries' energy strategies, including those of 中国 and 美国.