Tidal/ Wave Power
By Megan Powers
What is Tidal Power?
Tidal Power is a form of hydropower that converts the energy and power of tides into useful forms of power, mainly electricity.
How Does it Work?
Tidal/ Wave Energy can be obtained in many ways, but the three main ways are Tidal Turbines, Tidal Barrages, and Tidal Lagoons.
Tidal Turbines: Works similar to wind turbines, but with shorter and stronger blades. Water currents turn the turbines, which in turn activate a generator that produces electricity. They work the best when in an area with strong tidal zones.
Tidal Barrages: Similar to dams in hydroelectric plants, except are much larger because they are built across an estuary or bay. The tidal range needs to have an excess of five meters for the barrage to work. The tide comes in and water flows through the dam into the basin. When the tide stops, the gate close, which traps the water in the basin. When the tide goes out, the gates contain turbines and when it goes out, energy is generated.
Tidal Lagoons: Similar to barrages but have lower cost and impact to the environment. They are self contained structures cut off from the sea. When the tide rises the lagoon fills and when it falls the water is released escaping through the turbines created energy.
Tidal Turbines: Works similar to wind turbines, but with shorter and stronger blades. Water currents turn the turbines, which in turn activate a generator that produces electricity. They work the best when in an area with strong tidal zones.
Tidal Barrages: Similar to dams in hydroelectric plants, except are much larger because they are built across an estuary or bay. The tidal range needs to have an excess of five meters for the barrage to work. The tide comes in and water flows through the dam into the basin. When the tide stops, the gate close, which traps the water in the basin. When the tide goes out, the gates contain turbines and when it goes out, energy is generated.
Tidal Lagoons: Similar to barrages but have lower cost and impact to the environment. They are self contained structures cut off from the sea. When the tide rises the lagoon fills and when it falls the water is released escaping through the turbines created energy.
Tidal power: how it works
Who Discovered this and When?
Tidal Power can be traced back to 900 A.D. when early people would build a dam across the opening of a basin and allow the basin to fill on rising tide. The water would be impounded as the tide fell and released through a waterwheel, paddle wheel, or similar device that turned it into energy mainly to use for grinding grains into flour. Power was only available two to three hours a day.
However, it was not until the 1960's when the first modern-era tidal power plant was built in France. The paddle wheel and other similar had changed to high efficient bulb type hydroelectric turbine generators. The one in France near St. Malo was installed in 1966 and has been functioning since then after a man in La Rance, River, France discovered the idea of Tidal power by watching the tides and power of waves. The second one of this type was not installed for another 20 years.
However, it was not until the 1960's when the first modern-era tidal power plant was built in France. The paddle wheel and other similar had changed to high efficient bulb type hydroelectric turbine generators. The one in France near St. Malo was installed in 1966 and has been functioning since then after a man in La Rance, River, France discovered the idea of Tidal power by watching the tides and power of waves. The second one of this type was not installed for another 20 years.
How much energy can it produce and how does this compare to traditional forms?
In North America, Tidal power makes up 14% of all power production. Worldwide, tidal power makes up 17% of all production. 40% of worldwide is made of coal production and 23% is the production of gas.
The total world potential for ocean tidal power has been estimated at 64,000 MWe.
The total world potential for ocean tidal power has been estimated at 64,000 MWe.
Countries Leading the World, How Much of Their Electricity is Used
The main energy resources for using tidal power are in England. The Tide moves a huge amount of water in twice a day and it harnesses a great deal of energy, it provides 20% of Britain's needs. There are eight main tidal wave power stations in Britain that are in use. The other countries that use tidal power are Australia, South Korea using 2%, and China it is estimated that by 2020, 20% of China's power will come from tidal power.
Future Outlook
Tidal Energy production is just starting. The amount produced has been small. The future in uncertain because of the environmental and legal concerns especially in the United States. The United States and other countries have concerns of underwater land ownership and the environmental impact. Investors are not interested because they are not guaranteed that money will be made or if it will benefit consumers. Engineers are working to improve the technology behind tidal energy generators to increase the amount of power that is produced providing a brighter future outlook.
The United States, under the Obama Administration, decided to invest 16 million dollars to establish and start 17 projects to help capture the energy from waves, tides, and currents.
The United States, under the Obama Administration, decided to invest 16 million dollars to establish and start 17 projects to help capture the energy from waves, tides, and currents.
How much does it cost to make? How much to continue running?
- The cost of building a Tidal powered electricity station is high and varies from 1.3million USD per MW to 1.8million USD per MW depending on the location and technology used.
- Operating and maintenance cost 2 cents an hour.
How much is it sold for?
5-8 cents per kilowatt hour to be sold.
Where do the raw materials come from?
Raw materials for Tidal/ Wave Power come from the ocean not lakes or ponds. It has to be areas where there are tidal waves.
Benefits and Drawbacks
Benefits:
Drawbacks:
- Tide is predictable- in and out twice a day
- Completely renewable
- Produces no emissions
- Cost Efficient once built
Drawbacks:
- Upfront costs are very high due to massive concrete constructions
- Tidal power stations can only generate electricity when tide is coming and going (10 hours a day)
- Equipment can be damaged by stronger currents and waves
- Can block navigation routes
- Impede fish migration
- Can change the size and location of intertidal zone
Fun Facts
- Tidal Cycles last 12 hours and 25 minutes
- Smaller scale tidal mills were used in the Middle Ages to grind corn and make flour
- Tidal power is used mostly for the production of Electricity.
- The tidal barrage technology has the disadvantage of affecting the surrounding eco-system and wildlife in the area of the barrage.
MLA Citations
"History of Tidal Power." Tidal Electric. Electric. Web. 10 May 2015.
"How Does Tidal Energy Work." OilPrice. CNBC. Web. 10 May 2015.
"Ocean Power." Green24. Green24. Web. 10 May 2015.
"Strangford Lough Tidal Turbine, United Kingdom." Strangford Lough Tidal Turbine. Power- Technology. Web. 10 May 2015.
"Tidal Energy." National Geographic Education. National Geographic. Web. 11 May 2015.
"How Does Tidal Energy Work." OilPrice. CNBC. Web. 10 May 2015.
"Ocean Power." Green24. Green24. Web. 10 May 2015.
"Strangford Lough Tidal Turbine, United Kingdom." Strangford Lough Tidal Turbine. Power- Technology. Web. 10 May 2015.
"Tidal Energy." National Geographic Education. National Geographic. Web. 11 May 2015.