What Is Tidal Energy And How Does it Work?

Tidal energy is a form of power produced by the natural rise and fall of tides caused by the gravitational interaction between the Earth, the sun, and the moon. The potential or kinetic energy of tide movement is captured and converted into electricity. This energy
is renewable, derived from natural sources that are replenished at a higher rate than consumed, creating far less greenhouse gas emissions than burning fossil fuels. The global potential for tidal energy is huge, estimated to be around 500 gigawatts in 2020, equivalent to about one-fourth of the world's coal capacity at that time.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reference: https://earth.org/what-is-tidal-energy/ Webmaster: Chanepol Suparp M.5/1 No.1

 

Disadvantages of Tidal Energy

High Construction and Maintenance Cost
The average commercial tidal energy project costs as high as US$280 per megawatt hour, while wind energy
only costs roughly US$20 per megawatt hour, according to a 2019 study from the US Department of Energy.
The expensive cost of tidal power comes from the high upfront costs of building plants as well as from expenses associated with maintaining machinery that can survive corrosive seawater and engineering work. What's more,
the generating cost of other more mature renewable energy, including wind and solar power, while the costs of tidal,
being a far less widespread renewable energy source, are still relatively high. Currently, there are no plans to developed supply chains and expand this technology. Hence, costs of tidal energy are expected to remain high.
More technological research is needed to identify new methods that can lower the cost.

Geographical Limitations
Locations that are suitable for tidal systems are limited. Tidal energy power plants can only operate along the coastline. Tidal turbines cannot be installed in shallow water with waves-caused turbulence, nor can they be placed in deep water with a lack of current velocity.
Tidal range technologies will require a large tidal range – preferably about 3.05 meters, while for tidal current technologies, a stream speed of at least 1.5 to 2 meters per second is needed. Australia, Canada, the UK, the USA, France, alongside Easter Africa, are found to have very high tidal ranges. Although only limited studies are conducted on tidal current technologies, it is found that Australia, Spain, Africa, and Norway have the potential to develop tidal current technologies.

 

 

Advantages of Tidal Energy

High Predictability
Unlike wind and solar energy – which are subject to the variability and uncertainty of atmospheric forcing – tidal energy is much more predictable and reliable. Low tide and high tide cycles are easy to forecast and rarely experience unanticipated variation. Long-term and accurate predictions of tidal currents can even be made hundreds of years in advance. In addition, tidal range is hardly influenced by weather conditions.
While tidal currents may be slightly more subjected to the impact of weather, the fluctuations are still low and steady relative to wind and solar energy. The UK had experienced a sharp decrease in wind energy in the past. As a result, wind power generated from UK wind farms fell from more than 6,000 millivolts to less than 500 millivolts within 9 days. "
Variations in wind patterns, weather, and turbulence make it ​​inherently challenging to predict (wind farms' electricity generation) across different time scales," said Michael Howland, Assistant Professor of Civil and Environmental Engineering at MIT, who studies the physics of the Earth's atmosphere and renewable energy generation systems. "Tidal patterns" – he added – "are well-known and well-understood. That's a clear incentive for using [this type of] power".

High Power Output and Space Saving
As water is about 830 times denser than air, tidal devices capture more energy than their wind counterparts. This also implies that tidal energy is able to generate more energy per unit area than winds, taking up far less space than both solar and wind energy.
Sihwa Lake Tidal Power Plant in South Korea – the largest tidal power station in the world – consists of a seawall that spans 12.7 kilometres. Contrarily, wind turbines and solar panels usually require more space. For example, the Roscoe wind farm in Texas takes up 400 square kilometres of land, while Indiana's Fowler Ridge wind project, despite being a smaller wind farm, also takes up about 200 square kilometres. Solar power faces the same issue, with the Bhadla Industrial Solar Park in India spreading across 45 square kilometres.