Features Of Wave Energy, Technology And Possibilities
Nowadays, policies are being developed in many countries in order to decrease their greenhouse gases emissions. While in here some technologies are widely installed, like the sea energy, could get an important role in the medium and long term. That is why the most relevant technologies associated to the sea energy conversion are here. Tidal energy, wave energy and ocean thermal energy conversion. However, the sea energy conversion is not completely developed yet due to some unsolved technical problems, apart from their high cost. Therefore, technological development government policies and the possibility of setting up a related industrial field will be the key actions to make possible the future of the sea energy. Solving the economical and technical problems, it will be possible to make good use of this alternative source of energy, with high energy density. The available sea energy is enormous. If only a 10% were used to generate electricity, it would be a significant amount of energy regarding to the total world energy.
Oceans cover 70 percent of the earth’s surface and represent an enormous amount of energy in the form of wave, tidal, marine current and thermal gradient. In fact, the possible sea energy sources and consequently the conversion systems are divided in three main groups,
• Tidal Energy: Making use of the potential energy of the different sea levels created by the tidal effect or by using directly the energy of the tidal streams
• Wave Energy: It is mainly caused by the wind effect on the sea.
• Ocean Thermal Energy: This energy is harnessed by using a thermodynamic cycle between the different temperatures of the ocean deep and surface water. The energy potential of our seas and oceans well exceeds our present energy needs. India has a long coastline with the estuaries and gulfs where tides are strong enough to move turbines for electrical power generation. A variety of different technologies are currently under development throughout the world to harness this energy in all its forms including waves, tides and thermal gradients.During the last decades, several devices and equipments have been developed to convert the sea energy. But only a few ones have become real scale prototypes to be tested on the sea. Tidal energy, the other kinds of sea energies are also being tested obtaining different results. Besides their technical problems, economical ones should be taken into account. Nowadays, the cost of the produced sea energy can not compete with other renewable energies or with the traditional ones.
Although currently under-utilised, Ocean energy is mostly exploited by just a few technologies: Wave, Tidal, Current Energy and Ocean Thermal Energy. Wave energy is generated by the movement of a device either floating on the surface of the ocean or moored to the ocean floor. Many different techniques for converting wave energy to electric power have been studied. Wave conversion devices that float on the surface have joints hinged together that bend with the waves. This kinetic energy pumps fluid through turbines and creates electric power. Stationary wave energy conversion devices use pressure fluctuations produced in long tubes from the waves swelling up and down. This bobbing motion drives a turbine when critical pressure is reached. Other stationary platforms capture water from waves on their platforms. This water is allowed to run off through narrow pipes that flow through a typical hydraulic turbine. Wave energy is proving to be the most commercially advanced of the ocean energy technologies with a number of companies competing for the lead.
Tidal energy does not seem to be a big sustainable resource as compared to other renewable energies such as wind energy, yet it is doing a fast rate progress in recent decades. We can see a sustainable future of the tidal power energy, after solving several problems. First we need to lower the cost, so that it can be built on a large scale. Hopefully, within six years of operation, the Blue Energy system will generate electricity. Secondly, the turbine needs to be more efficient and the technology related to its working process should be fully developed. We should never neglect the impacts of tidal power on our environment and need to find a way to solve the problems related to it. As per the high capital costs for tidal energy project, the cost concerning electricity has proved to be sensitive to discount rate. Therefore, we need to prove that the tidal energy is not a waste of money. Public opinion plays a very important role. In countries, some renewable yet costly energy are being used because of public support at large. A bright future can be obtained if we have public knowledge and support and possible threats are researched well.