Water doesn't directly produce electricity. Instead, we harness the energy of moving water to spin turbines, which then drive generators that produce electricity. The most common method is hydropower, where dams create reservoirs of water at high elevation.
The energy conversion process follows a clear chain. Water stored at height has potential energy. When released, it gains kinetic energy as it flows. This moving water spins the turbine, creating mechanical energy. Finally, the generator converts this mechanical rotation into electrical energy through electromagnetic induction.
There are several types of water power systems. Traditional hydropower uses dams to store water at height. Pumped storage acts like a giant battery, pumping water uphill when energy is cheap and releasing it when needed. Tidal power harnesses ocean tides, while wave power captures energy from surface waves.
The key to electricity generation is electromagnetic induction. Inside the generator, magnets spin near copper wire coils. As the magnets rotate, they create a changing magnetic field. According to Faraday's Law, this changing magnetic field induces an electric current in the copper wires, which flows out as electricity.
Water power is a clean and renewable energy source that produces no greenhouse gases. It provides reliable electricity and the infrastructure lasts for decades. Currently, hydropower supplies about 16% of the world's electricity, making it a crucial part of our sustainable energy future.