Tidal Energy
Wave of the Future
Works
Through the rotation of earth and the gravitational pull of the moon and sun, tides are created. Tides provide energy for turbines on the seafloor. The change in sea levels also help provide energy.
Change in Sea Level
The mechanism used runs like a dam and is called a barrage.
When the tide falls and gets low enough, water flows through the higher, upstream side to the downstream side. During this process, a turbine is turned, located inside the barrage. This vast water movement rotates the turbine and produces energy. This specific design can also be reversed (downstream to upstream).
Turbine
These turbines are almost like a wind turbine, just under water. Currents at the bottom of the ocean turn the blades on the generator and produce energy.
Environmental Impacts
Decreases greenhouse gas emissions (carbon free)
No pollution involved
Impacts shoreline and aquatic ecosystems in a negative way
Older models-devastate fish population
Cost
Determined by size of barrage and difference between high and low tide. (no specific cost) Generally very expensive to construct
Benefits
Reliable
Predictable pattern (more than wind and sunlight)
Renewable
- Continuously available
- Electricity
- Grain mills
- Store energy
- Protect the coast in high storms
Disclaimers
Ease of use in Eastern South Dakota
This type of energy requires some sort of coast line, and South Dakota is not near an ocean. Therefore, due to it's location, a tidal energy source wouldn’t necessarily work here.
Challenges
Installation and running a station can disturb the local ecosystem balance
- Best tidal currents could be located too far away or in shipping channels
Aesthetics
This can be an eye-sore from the beautiful beach. Even though most of the machinery is under water, some parts are still visible from the coast. Depending on which machine is built, there may be pole-like structures popping out or a bridge-like design stretched wide.
More Information
Material Required
Cement
Steel
Turbines
- Barrages
Maintenance
Periodic marine growth removal on submerged sections
Full cable inspections
Annual maintenance of substations- part of an electrical generation, transmission, and distribution system
Possibility of replacing parts
Component design duty
Fluid pumping systems
Longevity
New Barrage-100 years
Sources
http://www.ei.lehigh.edu/learners/energy/tidal/tidal8.html
http://www.energybc.ca/profiles/tidal.html
http://www.oceanenergycouncil.com/ocean-energy/tidal-energy/
http://www.greenworldinvestor.com/2011/03/15/uses-of-tidal-energy-tidal-electricity-the-biggest-one/
https://www.wbdg.org/resources/oceanenergy.php
http://www.ei.lehigh.edu/learners/energy/tidal/tidal5.html
http://www.thegreenage.co.uk/cos/rance-tidal-power/
https://sites.psu.edu/lucasrcl05/2014/04/22/the-power-of-the-tides/