Energy is needed for life to develop on Earth. However, a large part of the energy we use today comes from sources that cannot be renewed once they are used up. Fossil fuels, which took millions of years to form, are the main non-renewable energy source we heavily rely on. So, it's important to use them wisely. To find other energy sources, we know that energy exists in different forms in nature and can be changed from one form to another. Some of these natural energies, like sunlight, wind, waves, and tides, can be converted into usable energy. One such renewable energy source is tidal energy.
What Are Tides?
The sun and the moon have a force called gravity, and when they work together with the earth's rotation, they cause the sea levels to go up and down. In some places, this happens twice in a day, based on the moon's movement.
When the sea level goes up, it's called high tide, and when it goes down, it's called low tide. The moon and the earth's gravitational pull make the water flow towards the shore, creating high tide when they line up in a straight line. When they are at right angles to each other, the gravitational pull is weaker, and the water flows away from the shore, causing low tide.
Sometimes, during a full or new moon, when the moon, earth, and sun are in a straight line, the high tides become even higher, and the low tides become even lower. This is called a spring tide. On the other hand, during the quarter moon phase, the gravitational pull of the moon and sun work against each other, leading to weaker tides with less difference between high and low tide. These weaker tides are known as neap tides.
The sun and the moon have a force called gravity, and when they work together with the earth's rotation, they cause the sea levels to go up and down. In some places, this happens twice in a day, based on the moon's movement.
When the sea level goes up, it's called high tide, and when it goes down, it's called low tide. The moon and the earth's gravitational pull make the water flow towards the shore, creating high tide when they line up in a straight line. When they are at right angles to each other, the gravitational pull is weaker, and the water flows away from the shore, causing low tide.
Sometimes, during a full or new moon, when the moon, earth, and sun are in a straight line, the high tides become even higher, and the low tides become even lower. This is called a spring tide. On the other hand, during the quarter moon phase, the gravitational pull of the moon and sun work against each other, leading to weaker tides with less difference between high and low tide. These weaker tides are known as neap tides.
What Is Tidal Energy?
Tides are a regular happening in the ocean. We can foresee them well ahead of time, even for many months and years. Because of this, we can use the energy generated by the large water movements of tides and turn it into a type of energy that we can use.
Why is tidal energy a limited source of energy
Tidal power leverages the rise and fall of oceanic tides to capture potential or kinetic energy and convert it into other energy forms, often electricity. There are two methods of harnessing tidal power. One method resembles a hydroelectric dam, called tidal barrages, and another relies on underwater turbines that have blades that rotate as water flows by, powering a generator in the process.
Tidal turbines may be installed in water sources ranging from areas with strong ocean currents to tidal streams and estuaries. They may be installed on their own, but larger energy projects commonly install connected rows of turbines, called an array. Tidal barrage systems operate similarly to hydroelectric dams using dam-like structures and submerged gates to control water levels throughout the day and to direct water through turbines.
Michael Howland, Assistant Professor of Civil and Environmental Engineering at MIT, studies the physics of Earth’s atmosphere and renewable energy generation systems. He says that tidal power has one advantage over other renewable energy resources like wind and solar: predictability.
“Variations in wind patterns, weather, and turbulence make it inherently challenging to predict [wind farms’ electricity generation] across different time scales,” he says. Tidal patterns, however, are well-known and well-understood, reducing the need for backup energy sources. “That's a clear incentive for using tidal power,” he adds.
Another benefit of tidal power is its relatively high power output. Because water is roughly 830 times denser than air, tidal or ocean currents can generate more energy per unit area than winds.
Despite these advantages and the skyrocketing demand for clean, renewable energy, tidal power hasn't taken off in the same way that solar and wind energy have. There are only a handful of commercially-operating tidal power plants worldwide, the largest of which is the Sihwa Lake Tidal Power Station in South Korea. The United States doesn't have any large-scale tidal power plants, although a few small-scale projects exist.
Tidal power leverages the rise and fall of oceanic tides to capture potential or kinetic energy and convert it into other energy forms, often electricity. There are two methods of harnessing tidal power. One method resembles a hydroelectric dam, called tidal barrages, and another relies on underwater turbines that have blades that rotate as water flows by, powering a generator in the process.
Tidal turbines may be installed in water sources ranging from areas with strong ocean currents to tidal streams and estuaries. They may be installed on their own, but larger energy projects commonly install connected rows of turbines, called an array. Tidal barrage systems operate similarly to hydroelectric dams using dam-like structures and submerged gates to control water levels throughout the day and to direct water through turbines.
Michael Howland, Assistant Professor of Civil and Environmental Engineering at MIT, studies the physics of Earth’s atmosphere and renewable energy generation systems. He says that tidal power has one advantage over other renewable energy resources like wind and solar: predictability.
“Variations in wind patterns, weather, and turbulence make it inherently challenging to predict [wind farms’ electricity generation] across different time scales,” he says. Tidal patterns, however, are well-known and well-understood, reducing the need for backup energy sources. “That's a clear incentive for using tidal power,” he adds.
Another benefit of tidal power is its relatively high power output. Because water is roughly 830 times denser than air, tidal or ocean currents can generate more energy per unit area than winds.
Despite these advantages and the skyrocketing demand for clean, renewable energy, tidal power hasn't taken off in the same way that solar and wind energy have. There are only a handful of commercially-operating tidal power plants worldwide, the largest of which is the Sihwa Lake Tidal Power Station in South Korea. The United States doesn't have any large-scale tidal power plants, although a few small-scale projects exist.
Advantages and Disadvantages of Tidal Energy
Tidal energy has some benefits:
- It is good for the environment because it doesn't produce pollution.
- It is a predictable source of energy, meaning we can know when it will be available.
- It has a lot of energy packed into it, making it efficient.
- The costs to run and maintain tidal power plants are low.
- It is an unlimited source of energy since tides will always occur.
However, there are also some drawbacks:- Building tidal power plants can be expensive.
- It can harm marine life.
- Tidal power plants can only be constructed in specific locations.
- The strength of the tides can vary, making the energy output inconsistent.
Even though tidal energy is not widely used right now, it has potential for the future. In the past, it has been held back by its high cost and limited places to build. However, with advancements in technology, it is becoming more competitive and environmentally friendly, giving it a promising future for electricity generation.
Tidal energy has some benefits:
- It is good for the environment because it doesn't produce pollution.
- It is a predictable source of energy, meaning we can know when it will be available.
- It has a lot of energy packed into it, making it efficient.
- The costs to run and maintain tidal power plants are low.
- It is an unlimited source of energy since tides will always occur.
However, there are also some drawbacks:
- Building tidal power plants can be expensive.
- It can harm marine life.
- Tidal power plants can only be constructed in specific locations.
- The strength of the tides can vary, making the energy output inconsistent.
Even though tidal energy is not widely used right now, it has potential for the future. In the past, it has been held back by its high cost and limited places to build. However, with advancements in technology, it is becoming more competitive and environmentally friendly, giving it a promising future for electricity generation.
