In this article, we will give a thorough response to the question, “is tidal energy renewable?” and discuss the advantages and disadvantages of tidal energy.
Tidal energy is a hydropower source that depends on changes in sea level. Tidal energy is not typically considered when thinking about the different types of renewable energy sources. Tidal energy, however, is renewable because it doesn’t rely on any finite resources.
Let’s explore the world of tidal energy to better understand how it’s produced, where it comes from, and all of the benefits and drawbacks of this unique energy generation source.
Is Tidal Energy Renewable Or Nonrenewable?
Due to the constant change in tidal movements caused by the moon’s gravitational pull, which takes place twice daily, tidal energy is the most dependable source of renewable energy. 24/7, 7 days a week, 365 days a year, tidal energy is operational.
Additionally, the technology does not require the use of any nonrenewable resources, like oil. It is therefore regarded as a clean and renewable source of energy because it produces no emissions.
What is Tidal Power?
Tidal energy, also referred to as tidal power, is a byproduct of gravity. In particular, it originates from the pull of the moon and, to a lesser extent, the sun, on the planet’s oceans.
All areas of the earth are subject to the gravitational pull of the moon. In contrast, the areas that are most near the moon experience the strongest pull. The sides of the earth that face the moon and those that face away from it bulge outward slightly as a result of this slight deformation.
In these locations, the ocean water rises, resulting in a high tide. Because of this, low tide is created when water is withdrawn from other ocean regions. To demonstrate how it functions, watch this SciJinks animation.
Since ancient times, people have launched boats by harnessing the power of the tides. We first used it to power water wheels for grain grinding more than a thousand years ago. But it’s only in the last 60 years that we’ve learned how to turn it into electricity.
How Does Tidal Energy Work?
We’ve been running electric generators on hydropower, or the movement of water in rivers, for more than 140 years. The water currents produced by the tides rolling in and out are used in tidal energy systems to accomplish the same thing.
The same principles as wind turbines apply to tidal turbines, except that water flow, not airflow, drives them. These generators are powered by turbines, and the electricity is then sent into the grid via underwater cables. Tidal energy can also be used to power ocean-related industries like aquaculture and ocean research.
Where Does Tidal Energy Come From?
The kinetic energy found in the tides of our oceans is where tidal energy originates. Earth’s oceans frequently alternate between low tide and high tide because of the moon’s gravitational pull.
Tidal currents are created by these variations in ocean water levels, and people have learned how to use the kinetic energy of these currents to generate electricity. To put it another way, tidal energy comes from the ocean.
How is Tidal Energy Produced?
Numerous techniques can be used to harvest tidal energy. Ocean surface devices that use wave motion to generate electricity are laid out there. A vertical or horizontal turbine, akin to a wind turbine, is used in underwater devices to generate electricity as the tide passes through it.
Water is stored in reservoirs, and as the water is pumped through turbines out of the reservoir, electricity is generated. When the height, mass, and speed of the water are at their ideal levels, tidal energy is most effective.
How tidal energy is used to generate electricity is demonstrated by the various tidal technology types. Tidal barrages are similar to dams in that once the reservoir is full, the turbines start turning to produce electricity.
Tidal fences are a row of tidal turbines, while tidal turbines themselves are small turbines positioned in areas with strong tidal currents that generate electricity when water flows through them.
How Efficient is Tidal Energy?
Systems that use tidal energy can be very effective. According to engineering firm N-Sci, tidal turbines convert 80% of the energy of the tides into electricity. This is considerably more effective than coal, oil, or natural gas, as well as current wind or solar energy systems.
Only 30% to 45% of the energy contained in these fossil fuels is released by tidal power plants, according to the Energy Information Administration.
You can learn more about other types of power plants, such as Nuclear Power Plants, Hydroelectric Power Plants, Thermal Power Plants, Geothermal Power Plants, Solar Power Plants, Wind Power Plants, and Biomass Power Plants.
Benefits of Tidal Power
As a source of renewable energy, tidal energy has a lot of potentials. Tidal power systems are:
- Efficient: The density of water exceeds that of air by more than 800 times. Accordingly, a stream of water has a much higher energy content than an equally rapid stream of air. A wind turbine of equal size and speed can generate much less power than a water turbine. (However, for the reasons covered in the section below, tidal turbines can’t actually be this large.)
- Emission-free: When a tidal turbine is operating, no pollution is produced. In particular, it doesn’t release greenhouse gases, which fuel climate change.
- Sustainable: A renewable energy source is tidal power. Except for the production, installation, and maintenance of the turbines, it does not require any natural resources.
- Durable: Long-lasting tidal turbines. The British power company SIMEC Atlantis Energy claims that a turbine can operate for 25 years with only five years of maintenance required. As a result, operating expenses are kept low.
- Reliable: Tidal energy is predictable and stable, in contrast to wind energy. It has the capacity to deliver a consistent flow of energy, which is necessary to maintain the grid’s efficiency.
- Hidden: People who believe offshore wind farms ruin the environment frequently complain about them. Tidal turbines don’t contribute to this issue because they are typically submerged and aren’t visible from the shore.
Disadvantages of Tidal Energy
The following list of disadvantages of tidal energy also includes some others.
Limited Installation Sites
The potential installation site must satisfy very specific requirements in order for a tidal power plant to be built. Due to the requirement that they are situated near a coastline, only coastal states can serve as potential station locations.
A potential site must also fulfill additional requirements. For instance, tidal power plants must be built where the height difference between high and low tides is sufficient to drive turbines. This restricts the locations in which the power plants can be built, making it challenging to implement tidal power widely.
Expensive
The high initial expenses are one of the tidal power’s biggest disadvantages. Due to the high density of water, tidal energy turbines must be much more robust than wind turbines. Depending on the technology they employ, tidal power generation plant construction costs can vary.
Tidal barrages, which are essentially low-walled dams, are used to construct most of the tidal power plants that are currently in use. The installation of a complete concrete structure, along with turbines, is required to build a tidal barrage, which is very expensive.
One of the main reasons why tidal power has been slow to catch on is the cost barrier.
Environmental Effects
Tidal energy is not necessarily completely eco-friendly, even though it is renewable. On the local ecosystem, the development of tidal energy power plants may have a significant effect.
Marine life collisions are a problem for tidal turbines just like they are for wind turbines with regard to birds. Fish and other aquatic life may swim into turbine blades as they spin, causing severe harm or even death. Tidal turbines also produce low-level noise below the water’s surface that is harmful to marine mammals like seals.
The environmental effects of tidal barrages are even more severe. In addition to creating the same issues that turbines on their own do, they also have an impact that is comparable to that of dams. Tidal barrages disrupt fish migration and result in flooding that permanently alters the landscape.
Energy Demand
While tidal power does generate energy predictably, it doesn’t do so continuously. Even though we can predict with absolute certainty when the tidal power plant will produce electricity, the amount of energy it produces may not always match the demand for it.
For instance, if high tide occurs at noon, tidal electricity will be generated at or near that time. Typically, the morning and evenings are when energy demand is at its highest, and the middle of the day is when it is at its lowest.
Uses of Tidal Energy
The following are a few uses for tidal energy.
- Tidal Electricity: Tidal energy is primarily used to produce electricity, much like other forms of energy. Sihwa Lake Tidal Power Station in South Korea uses tidal energy to produce 254 MW of tidal electricity at incredibly low prices. Other factories are running in Scotland, the UK, and France as well.
- Grain Mills: Tidal energy has been utilized for hundreds of years. Tidal energy was used in grain mills to crush grains mechanically, much as windmills do. To crush the grains, tidal energy was used to move turbines. However, tidal energy use has significantly decreased since the discovery of fossil fuels.
- Energy Storage: Additionally, tidal energy can be used as a source of energy. Tidal barrages with their reservoirs can be modified to store energy, just like many hydroelectric dams that can be used as significant energy storage. Tidal energy can also be stored with the right adjustments, though this hasn’t been tried out and may be expensive.
- Provide Protection to Coast in High Storms: Tidal barrages are an effective way to move water easily between two arms of a bay or estuary while also protecting the coast from damage during strong storms.
What is Stopping Us from Making the Most of Tidal Energy?
- Due to the significant upfront costs, building tidal power plants is currently expensive.
- issues with the environment, particularly habitat change brought on by tidal barrages.
- Equipment upkeep and repair can be difficult.
- a small need for energy. In order to develop the tidal energy storage capacity, it is necessary to recognize that powerful tides only occur 10 hours out of every day in nature.
- Since the energy generated by the tides is frequently located far from where the electricity will be used inland, it is challenging to supply tidal energy to coastal communities.
The Future of Tidal Energy
Tidal energy is incredibly promising, especially as cutting-edge technologies like dynamic tidal power continue to be created.
There are fewer than ten tidal power plants operating at this time. The two most well-known tidal power facilities, Rance Tidal Power Station and Sihwa Lake Tidal Power Station generate enough tidal energy to supply 94,507 homes in the US for an entire year. That power is not only abundant, but it is also predictable and carbon-free.
However, there are few suitable locations for tidal power plants, and high upfront costs, and they can have a significant impact on the local ecosystem. We should be able to use the energy that the tides store as technology advances.
