The tides have great potential for future power and electricity generation. Tidal power is predictable (unlike wind energy and solar power) and renewable, tapping the virtually infinite amount of the earth's rotational energy. The efficiency of tidal power generation largely depends on the amplitude of the tidal swell, which can be up to 10m where the periodic tidal waves funnel into rivers and fiords. Amplitudes of up to 17m occur for example in the Bay of Fundy, where tidal resonance amplifies the tidal waves.
Several smaller tidal power plants have recently started generating electricity in Norway. They all exploit the strong periodic tidal currents in narrow fiords using sub-surface propellers.
