Renewable energy sources like wind and solar are increasingly popular in the world today but there is one alternative energy source that might soon join the trend. This is tidal energy. According to reports, the potential of tidal power on a global scale is approximately 700 terawatt hours in a year. Although fossil fuels in the form of natural gas, petroleum and coal have supplied 80% of the world’s energy for a century, tidal energy is being considered as an additional source.
What Is Tidal Energy?
Tidal energy, also referred to as tidal power, transforms the energy from tides as a result of the rise and fall of sea levels. These tides are brought by the gravitational forces that come for the Earth rotation and the Moon and the Sun. The energy from tides is converted into power, such as electricity people from the coastal areas can use. The good thing is, the harnessed energy can come in two forms: the tidal range and the tidal stream.
The former is equivalent to the vertical difference in terms of height between high tide and low tide, which happen in succession while the latter is equivalent to the flow of water during the ebbing and flooding of the tides. For the tidal range to take place, construction of tidal lagoons are needed to store the tide and as the tide flows, water is then released through turbines to generate electricity. Conversely, tidal stream works by the extraction of energy with the kinetic movement of water. This is similar in theory with the way wind turbines run with the aid of air.
However, despite the existence of tidal energy for years and with countries in Europe and other parts of the world believing in its potential as an alternative energy source, supporters and critics are divided. Here are some of the views of the two groups.
List of Pros of Tidal Energy
1. Renewable Energy Source
Supporters of this energy source posit are confident that people can expect tidal power to continuously provide electricity because of what produces it. Like solar energy, tidal energy is renewable because of the numerous oceans and bodies of water scattered all over the world and its abundance. Since it is a result of the gravitational pull of the Moon and the Sun as well as the rotation of the Earth, its supply can be replaced. This is because these activities have been happening for billions of years and it will take, perhaps, that long for the Sun, Moon and the Earth to stop existing.
Advocates for tidal energy claim that unlike solar energy that relies on the Sun, which can sometimes be unreliable at times of rain and when covered with clouds, changing of the tides are predictable in the sense that high tide and low tide are parts of a cycle that with the application of the right dimensions, it will be easier to construct with the knowledge of the kind of power that is present.
People who are for the use of tidal power claim the use of tides to generate electricity or power does not result to the emission of green house gases that affects the temperature levels of the Earth’s layers. With that being the case, it does not add to pollution and does not aggravate global warming. Moreover, it does not eat up a lot of space, unlike solar panels which require a large area for installation.
Proponents of this renewable energy source say that there have no reports yet of tidal power plants having shorter life spans. Tidal barrage power plants like the La Rance has been in existing for almost 50 years and it still is a great source of electrical power.
Supporters of tidal power say that this is an effective energy source because it depends on water which has a density of at least 1000 times as opposed to air. Because of this characteristic, it can still generate power even at low speeds.
List of Cons of Tidal Energy
1. Benefits Limited Areas
Critics of the use of tidal energy to produce electricity argue that although this form of energy is renewable, it can be used in coastal areas and the people who are not living in these areas might not necessarily benefit from it. Moreover, with the results of climate change and global warming, bodies of water are also subsiding and reduced because of drought. In some parts of the world, shorelines are becoming bigger as if the water is diminishing. This year, CNN has reported about the drying up of eight bodies of water. Another case is that of the Aral Sea that used to be the size of half of England which almost dried up.
Opponents of tidal energy are concerned about costs of putting up tidal energy plants. Even if it has been used years ago, this form of energy and its application is relatively new as it is still in its early developmental stages. Consequently, new technologies have to be used and this requires subsidy from the government. Moreover, salt water can lead to the corrosion of equipment which also entails expenses. Maintenance can also be costly.
3. Negative Impact of Marine Life
Environmentalists posit that the open blades and turbines used to generate power can destroy marine life. Also, the construction of the bases of these turbines on the ocean floor can destroy the habitat of the water species in the ocean. Fish migration can also be affected by wave and tidal energy construction.
4. Effect on Livelihood and Recreation
With the creation of tidal energy power plants, there will be a reduction of available body of water for fishermen to fish and for people to enjoy recreational activities. Say, part of the coastal area will be off limits to the people once a tidal energy plant operates there.
Although conversion of electrical power with the use of tidal energy does not result to green house gases emissions, critics say that the acoustic noise and vibration from tidal energy plants can cause noise pollution. Aside from this, oil and sewer spillage from the vessels used in the construction of turbines can happen if workers are not careful and this can risk their lives as well as that of the people in the community.
It is true that tidal energy as an alternative source of electricity is promising. However, there should be enough research and analysis when it comes to its application. There should be a study on its effects on the environment, marine life and the people.