Tidal energy resource

Tidal energy refers to water potential energy formed by the flood tide and ebb tide of seawater. Its utilization principle is similar to that of hydropower. The amount of tidal energy is direct proportion to the amount of tidal and the difference of tidal. Or the square of the difference of tidal is direct proportion to the area of the reservoir. Comparing with hydropower, the amount of tidal energy is lower in the density equaling to the electricity powered by mini water head. The difference of tidal can be larger to 13-15m in the world, while in China are 8.9m. In a general way, it is be of practical value with the average difference in tidal of more than 3m.

It is theoretically estimated that the potential of tidal energy is in the scale of 10⁹kW in the world and 10⁸ kW in China, which the actual value available for utilization is still far less. According to the results investigated on the distribution of ocean energy resources in China, sites ideal for the development of tidal power station have 424 places with the installed capacity of 2.2 x 10⁷kW. The coastal area along Zhejiang and Fujian provinces are rich in tidal energy.