Renewable energy sources tidal and wave power both rely upon the movement of water and yet they are different. Wave power generates electricity in small, continual amounts through the rising and falling of the waves pushing air in and out of a turbine. Tidal power produces electricity in a much great amount, but only as the tides ebb and flow.
Tidal power is a renewable energy source with a vast potential to harness energy from shifting tides and currents. Tidal turbines work on the same principle as wind turbines, but instead of airflow turning the propeller blades they are rotated by the flow of water as the tide comes in or recedes
There are three main forms of tidal power technology: tidal streams, tidal barrages and tidal fences. The most common form involves tidal turbines placed in tidal streams. Tidal barrages operate like river dams, forming tidal basins with turbines to capture incoming and outgoing tides. Tidal fences are composed of groups of vertical axis turbines assembled in a fence-like structure.
Since water is about 800 times denser than air, tidal power plants can produce substantially more energy than wind turbines and more predicably. Sturdier and heavier they are, also, geographically limited and expensive to construct, and more research needs to be done on the potential environmental impacts to marine life.
While tidal power has a huge potential -- 57% of US electricity demands --there are currently no tidal power plants in the United States and a limited number of sites where tidal energy could be produced at a reasonable price. However, new pilot tests are active, and the Federal Energy Regulatory Commission recently accepted a preliminary permit filing for a controversial $100 million tidal-powered underwater AI data center project in Maine’s Western Passage. Additionally, an Alaska-based tidal energy company is testing a new kind of small, modular turbine in the waters off of Massachusetts. The turbine is being piloted in the strong tidal currents of Cape Cod.
Wave power makes use of the rising and falling of waves in an air chamber to force the trapped air up through a turbine, which produces electricity. Wave power has, like tidal power, huge global potential and can be extremely reliable. It is estimated that harnessing just two one-thousandths of the oceans’ untapped energy could provide power equal to current worldwide demand.
But, like tidal power, building and maintaining wave energy plants will be expensive.
