The world has come around to see we need to produce energy as responsibly as possible however, there is one major hurdle that we face when it comes to producing energy through renewable sources intermittently.
Can renewable energy be produced anytime energy is needed? that is a question wind and solar power cannot answer yes to, there is however a breakthrough method of generating energy that neatly solves the intermittency problem that invades wind and solar energy. This game-changing tech is Tidal Energy and is getting many players in the energy industry excited.
Why Tidal energy is 10 times better than wind and solar energy?
Wind and solar energy are great ways to generate the energy they're relatively cheap and do not cause pollution unlike fossil fuel-based generating stations that produce carbon emissions moreover we can't run out of solar or wind power at least not in a billion years. However as great as wind and solar energy is they have a serious drawback, they can be affected by environmental seasonal and daily cycles that can limit their use or efficiency as such renewable energy cannot always consistently produce energy at all hours of the day, for example, you can't produce solar energy when the sun has set, this is called intermittency.
Intermittency is a big headache for energy professionals for example solar and wind farms' energy production in Europe has been known to vary between 0 to 23 and 24 gigawatts of energy respectively, during peak times. So these peak production periods provide a large share of energy however sometimes unpredictable lows are the bane of renewables compare this intermittency with the constant power output that can be generated by fossil fuel-based power plants using coal or natural gas and you will see renewable energy's Achilles heal energy production companies try to mitigate this inherent flaw with battery solutions. But this only introduces a different set of problems as you shall soon see. This is where tidal energy comes in it is renewable energy that means no damage to the environment and at the same time, it can be available all day and at any time solving the intermittency problem of wind and solar energy.
What is Tidal Energy?
Simply tidal energy is produced by the surge of ocean waters during the rise and fall of tights when the water has risen to its highest level covering much of the shore it's at high tide. When the water falls to its lowest level it's a low tide. Some lakes and rivers can also have types you can thank the sun and the moon because the two celestial bodies responsible for the rise and fall of times how the forces that cause tides are known as tidal constituents, for example, the earth's rotation is a tidal constituent but the major tidal constituent is the moon's gravitational force acting on the earth. The closer objects are the greater the gravitational forces between them and this is why the moon exerts more pull on the planet than the sun does despite being significantly smaller.
So basically the moon is constantly pulling on the earth including on land surfaces. However, land surfaces do not move that much because they are not very flexible they move not more than 55 centimeters a day. But when it comes to the ocean the pull is more dramatic because water is liquid and can respond to gravity more the moon pulls on both the side of the earth facing it and the opposite side. But the greatest force is felt on the side closest to the moon, at the center of the earth the gravitational force is zero. High and low tides come with a degree of accuracy as the earth continues to spin and tidal energy engineers simply take advantage of this phenomenon.
How does Tidal energy work?
The main maneuver is to harness the kinetic energy created from the rise and fall of ocean tides and currents or tidal flows and turn it into electricity. The larger the tidal range or the height difference between sea level at high and low tide the more power can be produced. When you want to build a tidal project there are three types that you can choose from.
Tidal Turbine
The first is the tidal turbine which is fairly straightforward it is very similar to wind turbines except that you place them below the water's surface instead of above or on land. So the water's current pushes the blades of the turbine which is connected to a generator bam you have produced electricity. Tidal turbines can produce much more electricity than wind power plants and this is because water is much denser than air meaning it will move the blades faster. However, the same water's high density also means the tidal turbines need to be much stronger than wind turbines making them more expensive to manufacture. Tidal turbines are large but they have the advantage of causing relatively little disruption to the ecosystem around them. They could cause collision damage like wind turbines however with marine life but the slow speeds of the blades mean it isn't that much of a concern.
Tidal Barrage
The second type of tidal power project is the tidal barrage here the tidal barrages are actually low-walled dams they're constructed at tidal inlets or estuaries. They're similar to your standard hydroelectric dams because you use sluice gates to form a reservoir on one side of the barrage the barrages attach the sea floor with the top of the barrage just slightly above where the water level hits, during the highest tide you then place your tidal turbines towards the bottom of the barrage inside a tunnel, which lets water pass through the turbines are turned with the incoming and outgoing tides. during an incoming high tide, water flows over the turbines as the water rises then the water flows back through the turbines as it becomes low tide. The turbines are connected to a generator which generates electricity. While tidal barrages are the most efficient way to harvest tidal energy they're also the most costly. Engineers have to construct an entire concrete struct, which adds to the development costs. Also, the barrages have a more serious environmental impact on the surrounding ecosystem than tidal fences or turbines. You are basically building an underwater wall so fish and other sea creatures can't pass through causing a myriad of effects on the local ecosystem.
Tidal Fence
The last type of tidal energy project is the tidal fence which is like a cross between tidal barrages and tidal turbines. Here the vertical tidal fence turn styles are positioned together in what looks like a fence which is why it's called a tidal fence, instead of spinning like a propeller tidal fences spin like a turnstile. You produce electricity by using the energy from tidal currents to spin the turn-style blades which are connected to a generator. Tidal fences have vertical blades that are pushed by moving water these vertical turbines are installed together like a fence, but they don't require the large concrete structure that tidal barrages do. Usually, they'll be installed in between land masses in things like inlets and fast-moving streams they are submerged entirely underwater and have little impact on the surrounding ecosystem.
How do engineers decide if a site is suitable for locating a Tidal energy project?
The fact is that even though water covers two-thirds of the earth's surface not all the nations or regions on the earth are suitable for tidal power projects due to the specific requirements for example the difference between flood tide and herbicide must be minimum of the order of 4.6 meters or above that or the project would not be viable. The volume of water moving around during the tide or the cubature of the tidal flow also matters.
Let's say your preferred site is a place where the tide may go up and down by say around 10 meters but with a minuscule volume of water associated with it. It makes no engineering sense because there is not even energy to spin the blades you must also account for wave actions and storms because these two can be destructive so you must find a way to protect your tidal plant or find another site or you could be spending much of your budget on constructing an embankment your site must not interrupt the flow of normal shipping traffic which passes through the estuary, otherwise it will interrupt the economic cycle of the region. there's also the silt index of water in the factory. However, it is very possible to find suitable sites for tidal energy projects it's worth noting here that the first title projects did not involve electricity production but were used by our ancestors to grind grain. They came to be known as tide mills.
Where was the first Tidal Plant built?
The first modern tidal plant used for generating electricity was built in 1965 in the branch estuary in France, It was on a commercial scale and used 24 turbo generators the plant still produces electricity today from the difference between high and low tides up to 600-gigawatt hours per year evidence that tidal power projects can withstand the test of time. The power from this station is enough to power more than 50000 American homes for a year.
The second commercial-scale tidal barrage was installed in Nova Scotia in 1982 to highlight the working of the Straflo turbine an invention by Escher Wyss of Switzerland. Despite its initial problems the plant now generates electricity with no issues the largest tidal power project in operation is located on Shiwa lake in South Korea. It has an installed capacity of 254 megawatts. However, it was more than just a power generating plant, it was created to provide reclaimed land for the nearby metropolitan area flood mitigation and secure irrigation water by converting the coastal reservoir to fresh water using a 12.7-kilometer long sea wall at Jongi bay. Let's hear what you think of tidal energy in the comments section below.
