According to AIP, 220 TWh of tidal power was produced in 2021, enough to provide for 21 million households. For those who don’t know, tidal energy is the electricity generated from the movements of the tides using tidal turbines, barrages, or fences. It might seem to be a clean and renewable resource at first, but that’s not the whole story. Keep reading to learn more about the pros and cons of tidal energy.
In this article:
5 Tidal Waves Advantages
Renewable & Predictable Energy Source
Theoretically, tidal power is a renewable source of energy. Unless all oceans are drained (and that’s also the end of our life), tides keep rising and falling. They’re driven by the gravitational pull from the moon and the sun, and this force isn’t going to stop. Such constant movements generate renewable power.
This mechanism also makes it predictable. Tides appear at almost fixed intervals, and if they change, we can forecast them easily. This nature gives tidal power an edge over other renewable energies, like solar (which heavily relies on the weather) or wind energy (which is more variable).
Reduced Carbon Emissions
According to Impactful Ninja, every kWh of tidal energy is estimated to produce only 0.05 pounds of CO2. This number soars to 0.96 pounds and
2.31 pounds for coal and natural gas, respectively [U.S. Energy Information Administration].
Fossil fuel power plants are one of the major contributors to the increasing carbon emissions worldwide. Switching to clean energy, including tidal and wave power, is a strategic move in our efforts to cut down on carbon dioxide emissions and mitigate the greenhouse effect.
High Energy Efficiency
Tides can generate more power than wind, even when water flows much more slowly. Its high power output is credited to the greater density of water, which is over 830 times denser than air. The largest tidal power plant in the world, Sihwa Lake, is based in South Korea and is capable of producing 254 megawatts.
Space Saving
Tidal power, even with its outstanding capacity, doesn’t require extensive power plants. Sihwa Lake, the largest tidal power station to date, only covers 12.7 square kilometers. Meanwhile, the biggest wind farm—Gansu—spans a whopping 39,000 square kilometers with over 7,000 wind turbines.
Solar power plants, though not as massive as wind farms, still take up a significant area of land. In particular, the largest station (Ürumqi Solar Farm) is about 133 square kilometers (nearly 33,000 acres).
Long Lifespan of Equipment
Tidal barrages, thanks to their solid concrete construction, can last up to 120 years. A prime example is the La Rance (France), which has been in service since 1966 and still operates seamlessly.
These stations easily outlast other types of power plants, like solar, nuclear, or wind. In particular, a nuclear station will be past its prime after 40 years, while a wind farm’s lifespan is considerably shorter at 20 years.
4 Disadvantages of Tidal Waves
Hefty Construction & Maintenance Costs
A 2019 study by the U.S. Department of Energy revealed that it costs $280 to produce a megawatt hour of tidal energy, 14 times higher than wind power at only $20. This huge gap stems from the hefty upfront cost of building a tidal power plant.
Not to mention, the equipment is prone to corrosion due to the salty seawater. So, the maintenance cost also skyrockets, adding up the expense significantly.
Limited Locations For Installation
Wind or solar power stations can be constructed anywhere, given the availability of the wind and the sun. This is not the case for tidal electricity, though. These plants must be built near the coastline, meaning landlocked regions can’t access this source of energy.
Another requirement for locations is the significant tidal range. The difference between low and high tides should be great so that it generates enough power to spin the tidal turbines.
Intermittent Energy
While tidal energy efficiency is high, it isn’t always available, which pretty much depends on the tidal cycle. For example, if high tides are around noon, the power station might not produce enough energy during the peak demand periods (mornings and evenings).
EMF Emissions
The electromagnetic emissions from tidal plants can take a toll on aquatic life. A 2015 European Commission study suggested that EMF emissions can interfere with the migratory routes of species like skates, sharks, whales, rays, crustaceans, turtles, bony fish, and dolphins. These creatures sense the natural magnetic fields to navigate the surroundings, so the presence of this emission can mess up their routes.
The Future of Tidal Energy
As more and more countries are embracing renewable resources, we can see a future where tidal energy becomes mainstream. More tidal power stations are on the horizon. Further research on tidal power technologies will also take place, aiming to enhance its efficiency while alleviating its negative impact. Though its environmental impact is still controversial, this transition is poised to reduce carbon emissions and promote a cleaner planet.
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