Tidal power, sometimes called tidal energy, is a form of hydropower that converts the energy of tides into electricity or other useful forms of power. The advantages for using tidal and wave energy: it reduces the dependence upon fossil fuels, it is free once the initial costs are recovered, renewable, and clean source of energy, with no production of greenhouse gas or pollution, highly efficient resource, tides are active 24 hours a day, 365 days a year.