Tidal power is a renewable energy source that converts the energy of tides into electricity. Tidal power is form of hydropower where energy of the water gets extracted from the Earth's oceanic tides.
Tidal power belongs to renewable energy sources because Earth's tides are the result of gravitational interaction with the Moon and Sun and the Earth's rotation which makes tidal power practically inexhaustible source of energy.
Tidal power has very good potential but the entire tidal power industry is still reduced to just a handful of demonstration projects and is yet to receive worldwide attention.
Many areas in the world have strong, constant and predictable tidal resources and tidal power is said to be among the most efficient renewable energy sources, with efficiency up to 80%.
Tidal power doesn't produce harmful greenhouse gas emissions and therefore doesn't contribute to climate change like fossil fuels do.
Tidal power has one major drawback- the high construction costs that significantly prolong the investment return period and drive investors away.
It also has to be said that tidal power is capable to produce electricity only during tidal surges which is in average around 10 hours each day. This means that tidal power is an intermittent energy source (just like solar and wind) and therefore requires adequate energy storage solution.
High construction costs and intermittency are two major setbacks that prevent tidal power from becoming major player on global renewable energy market. Whether science will be able to make the difference and make tidal power cost-competitive with fossil fuels still remains to be seen but the potential is certainly there.