The document discusses hydro-power and provides information about how it works, the pros and cons, and its use and potential around the world. It explains that water flows through penstocks and spins turbines which are connected to generators to produce electricity. While hydro-power is a clean, renewable source of energy, building dams can displace people and disrupt fish migration. Improved turbine technologies may help increase the use of kinetic tide and wave energy in the future.