What is it?
Tidal energy is a form of renewable energy. It is powered by the natural rise and fall, or surge, of ocean tides and currents. It is also a type of hydroelectricity. We know this because they both have to do with the movement of water to generate electricity, but what we refer to as hydro energy refers to the use of dams to produce energy from water, whereas tidal energy refers to the use of tides to produce energy from water.
How is it Produced?
Tidal energy systems are used to generate electricity via the tides. However, unlike solar, wind, and hydro energy, there are multiple types of tidal energy systems. Producing tidal energy requires a tidal range of at least 10 feet.
One way is through a system called tidal barrage. This system is similar to a dam. The barrage is installed across an inlet of an ocean bay or lagoon that forms a tidal basin. Sluice gates on the barrage control water levels and flow rates to allow the tidal basin to fill on the incoming high tides and to empty through an electricity turbine system on the outgoing ebb tide. A two-way tidal power system generates electricity from both the incoming and outgoing tides using the movements of the water.
Another type of tidal energy system is using something called tidal turbines. These turbines are very similar to wind turbines. However, because water is much denser (800 times denser) and therefore much more powerful than air, tidal turbines have to be much sturdier and heavier than wind turbines. If you want to learn more about how the tidal turbines work, click here to learn about how wind turbines work. It is the same thing, except the tower is much heavier. Tidal turbines are also a lot more expensive than wind turbines because they have to be stronger and heavier. However, they produce more energy with the same sized blades.
The last type of tidal energy system is tidal fences. Fences are set up similar to that of a barrage, but there are no gates. Instead, vertical tidal turbines are set up. Any water passing through the turbines generates electricity.
The Presence of Tidal Energy in America and the Rest of the World
There is very little amounts of tidal energy in the world. As of the end of 2016, there are no tidal fence systems left in the world. Tidal energy was used 1,000 years ago, but the modern versions discussed are still in their infancy. While there are no tidal power plants in America, it is among other countries that have potential. France, England, Canada, and Russia also have the potential to use tidal power. The potential for tidal energy is best between the latitudes of 30° and 60° in both hemispheres. While America has very few possible locations for tidal power plants, it has great potential. America has 2,100 terawatt-hours of tidal energy washing across its shores each year. Just tapping into one-fourth of the power that tidal energy provides will have the same energy produced as the entire American hydroelectricity energy system, which accounts for 7% of the total energy system.