Pumped hydro is a method of storing energy by using water. It works by pumping water from a lower reservoir to an upper reservoir during times of low electricity demand. When energy is needed, the stored water is released back down, turning turbines to generate electricity. This technology is often used in conjunction with renewable energy sources like solar and wind power. By balancing supply and demand, pumped hydro helps stabilize the electrical grid and ensures a reliable energy supply, making it an important component of modern energy systems.