Traditional Uses of Tidal Energy

There are three traditional ways to use the ocean to harness or create energy: using the ocean’s waves, the temperature differences in the ocean water, and leveraging the high and low tides of the ocean. Successful use of tidal energy has normally involved placing a small dam across an open area leading to a tidal basin. There is a small opening or sluice that is moved or opened to let the tidal flow move into the basin and then is closed. Once the tide recedes, the water is let out through specialized turbines modeled off of those used in traditional dams to created electricity. Using tidal energy requires at least a 16 foot difference between low and high tide in order to provide scalable power production. The largest such plant is located in France and produces enough power for more than 230,000 homes. Disadvantages for this type of power generation plant include the start-up cost, and only having approximately 10 hours a day available to produce power.

Other models that make use of direct wave energy include those that use the natural wave action to power a piston which moves a generator. This variant is not as scalable, but can be used for small power needs. This method can also be used on a bit larger of a scale to move turbines as waves move into and out of the facility to make use of the kinetic energy for piston movement. These can be installed cheaply though the use of offshore or vertical-axis turbines, but if you place them in a river can have a significant ecological impact.

Ocean Thermal Energy Conversion is one of the newer alternative energy methods making use of ocean energy to create energy. This method takes advantage of the water temperature differences in the ocean to make energy. This type of energy creation plant requires water temperature differences of more than 38 degrees Fahrenheit. This type of temperature difference is found where there are rapid changes in sea depth such as that found by the Japanese and Hawaiian islands where on-going testing is being conducted.

Tidal energy production systems remain a popular area of research and development since the tidal periods are predictive and regularly occurring on the world’s coasts. With current technology, the use of tidal pools to turn hydroelectric turbines still requires a significant tidal range of 16 feet which is not a common difference found throughout the settled part of the planet, but research continues into developing scalable and affordable means to use tidal energy as a renewable energy resource.