Hydroelectric plants generate electricity by using the energy of flowing water. They typically involve a dam built on a river, which creates a reservoir. When water is released from the reservoir, it flows through turbines, causing them to spin and generate electricity. This process is renewable and produces no direct emissions. These plants can vary in size, from large facilities that provide power to entire cities to smaller plants serving local communities. The efficiency of hydroelectric plants makes them a significant source of renewable energy, contributing to the reduction of reliance on fossil fuels and helping to combat climate change.