Tides are more predictable than wind energy and solar power. Historically, tide mills have been used, both in Europe and on the Atlantic coast of the USA. As with wind power, selection of location is critical for the tidal turbine. Tidal stream systems need to be located in areas with fast currents where natural flows are concentrated between obstructions, for example at the entrances to bays and rivers, around rocky points, headlands, or between islands or other land masses.
Tidal Energy is another type of renewable energy resource that utilises large amounts of energy within the oceans tides to generate electricity. As we all know from our science lessons, tides are caused by the gravitational forces upon the earth of the sun and the moon, which varies due to their elliptical orbits around the earth. These gravitational forces cause our seas and oceans to rise and fall in a continuous and predictable cycle as vast quantities of water circulate around the earth. The result is that coastal areas have two high tides and two low tides within slightly more than a 24 hours cycle.
Electricity is generated by the force of the sea water flowing both into and out of a tidal bay through a water turbine, turning an electric generator to produce electricity. Because there are two high and two low tides each day, electrical generation from tidal power plants can be predicted years in advance, unlike wind energy, and is characterized by periods of maximum generation every twelve hours, with no electricity generation at the six-hour mark in between the high tides.
Another tidal energy design that uses the currents created by the ebb and flow of the tides is Tidal Stream Generation. Tidal stream generation is very similar in principle to wind power generation except this time water currents flow across a turbines rotor blades which rotates the turbine, much like how wind currents turn the blades for wind power turbines. In fact, tidal stream generation areas on the sea bed can look just like underwater wind farms and in areas where the coastal currents are strong, a suitable tidal stream turbine can generate as much free tidal energy as a wind turbine at the same speed and almost four times the size.
Tidal energy has many advantages compared to other forms of renewable energy with its main advantage being that it is predictable, which means power generation is predictable too, unlike wind or solar energy and being located underwater, tidal turbines produce no emissions or noise.
Tidal energy is a renewable source of electricity that does not result in the emission of gases responsible for global warming or acid rain, which are associated with fossil fuel-generated electricity. Use of tidal energy could also decrease the need for nuclear power.
Tidal energy requires a large capital investment in dams, turbines and support ships, but once a “tidal energy” plant is built the energy it generates is essentially free with the system being relatively inexpensive to run.
There are several drawbacks though. Because of the sometimes violent and unpredictable nature of the ocean, they can not be constructed in many places. So far only about 30 places have been identified to build this kind of power plants. And these power plants can have a negative impact on migratory birds and also fisheries.
Inflexible generation times dependent upon the tides and the fact that it operates in the hostile conditions of the open oceans and seas which can be a stormy and violent environment, resulting in the tidal turbines being destroyed by the very energy they were designed to capture.
Changing tidal flows by damming a bay or an estuary or locating large turbine generators onto the seabed could, however, result in negative impacts on aquatic and shoreline ecosystems, as well as on navigation and recreation.
The most important advantage of using tidal power is that it will not cost you a penny to produce it. As long as there is gravitational pull from the moon, this energy will continue to be released. It does not also possess any adverse effect on the environment. Creation and using this type of energy do not result to the emission of unhealthy greenhouse effect. There aren’t any hazardous wastes created when it is generated. It can also be a good source of electricity and doing so does not require much money. The drawback in using this type of energy is that that it can solely be effective generated in areas where water level is liberal. This limitation has led to further studies that concerns about increasing the potential energy generation in an area.
Tidal Energy Pty Ltd