august.ciell.spring2011.wiki

In today's modern society; fossil fuels are being depleted quicker than new fuels are being made. Fossil Fuels are a non-renewable resource, and we as humans have failed horribly at conserving this source. Most people only see one problem when discussing fossil fuels, and that is the gradual shortage arising from its constant usage by humans. Beyond this problem is a bigger, and in my opinion more severe problem concerning future generations of human civilization. The combustion of fossil fuels produces greenhouse gases that become trapped in the Earth's atmosphere, and greenhouse gases have a direct relationship to the temperature of Earth. The result of the greenhouse gases emitted from burning fossil fuels is Global Warming. Greenhouse gases are the main cause of global warming, and 90% of greenhouse gases are emitted from the burning of fossil fuels. Though everyone has their own opinion on global warming, you cannot hide from the facts. Earth's average air and ocean temperatures are rising at an astronomical rate, global sea level is rising as well, and the North and South pole glacier shelves are retreating faster than ever. The best way to attack the problem is to stop burning fossil fuels, but being realistic this is not possible. Humans are more dependant on fossil fuels than any other resource in the world, with the exception of food and water. So the best reasonable solution is to find cleaner, more efficient alternative energy sources to provide for human energy consumption.

An excellent source of alternative energy is tidal power. Tidal Power is a form of hyropower that takes the energy from running currents of tidal cycles and converts it to useful forms of power. Tidal power has many benefits, it provides a source of energy that has no negative effects on the environment, and it is renewable resource. In addition, tides are caused by the gravitational attraction of the sun and moon; which means tides are predictable, and constant. As long as the sun continues to revolove around the sun, the Earth's Oceans will have tidal flow. On the negative side, tidal energy is restricted to coastal areas, without proper location tidal energy is not possible. Also, comparible to other forms of alternative energy, tidal power is expensive. Logically with problems like global warming and the lowering limit of availible fossil fuels, money should not be a concern.

Tidal steam generators (TSG's) draw energy from ocean currents similar to the way wind turbines draw energy from wind. The current from Tidal flow enters a hydro turbine that is connected to the TSG through the Wicket Gate, the fast flowing water causes the turbine blades inside the turbine to spin at a rapid pace; from there the spinning turbine blades will cause the turbine rotar to rotate via the generator shaft.



As the rotar continues to rotate, the kinetic energy from the moving water is converted into electrical energy by the TSG. The TSG is connected to a transformer which converts the electricity into a usuable voltage which is re-routed to the main electric distribution system (powerplant) via transmission lines. "The technology works like a wind turbine, but instead of win, the turbines are driven by the flow of the tidal currents. It offers a significant advantage over wind because currents are predictable". James Taylor, General Manager of Environmental Planning & Monitoring at Nova Scotia Power.

[]
 * A video of hyrdoturbines being placed in New York City, how they operate, and the energy produced.

In some places, tidal barrages are used to increase the amount of power produced. Tidal barrages are essentially dams across the full length of the tidal area, these barrages capture the potential energy of moving water. Dams allow people to control the water level, and therefore control the flow of the water. During a flood (high) tide, operators can let the water flow in to its highest point, and from there dam the water off. After the tide changes direction, operators have full control of outward water flow, which can me managed for maximum energy efficiency using the TSG's. Above is a depiction of a tidal barrage. The main valve allows water during a flood tide to pass through the damn. During a ebb tide, the valve indicated is opened allowing water to spin the hydroturbines blades at a much faster rate compared to a free flowing tide. Without a doubt tidal power has great advantages in producing energy. Without emitting CO2 in the atmosphere, it will help the fight against global warming. However there is still some negative effects surrounding this idea. Tidal barrages change the natural flow of tides, which disrupts both aquatic and shoreline ecosystems. At this point, it becomes a question of worthiness. The facts are simple, the quantity of fossil fuels are rapidly diminishing, while tidal power, as a renewable resource offers an endless supply of clean energy, a worthy investment in my humble opinion.

Above is a picture of some future hydro turbines based on a computer design. With such great effeciency of producing clean alternative energy, why is tidal power not a main source of alternative. Location is a key problem; beside the obvious need of coastal real estate, the location needs a strong tide to produce a large output of electrical energy. Hydro turbines operate best with a current of 4-6 knot, or roughly the current of the Cape Cod Canal. These qualifications restrict the potential for a large number of tidal power plants. Unfortunately there is no way to change this problem, the only solution is to implement tidal power plants in the areas availible. The most interesting potential future location for tidal power is the Gulf Stream. The Gulf Stream is an offshore current caused by the Coriolis Effect, at some locations off the Coast of Southeastern Florida, the Gulf Stream current is only about 3 miles. The amount of availible future energy is remarkable, the major setback is production cost. []

Protestors of tidal power are not uncommon. The antagonist have their doubts, some of which with good reason. Debates of tidal power are centered around eco-friendliness, cost effieciency, and inconvenience of location. While tidal power produces large scale quantities of clean electrical power, as I mentioned earlier, it can have a negative affect on surrounding ecosystems. Tides keep coastal fisheries and shore life at equilibrium, tidal barrages can disrupt this equilibrium hurting the environment for natural wildlife. Critics also try to argue a point of cost efficiency, however this is where lack of research comes to play. Hydro turbines are said to be 4 times more efficient than a wind turbine of the same size, this is due to the density of water. Water is much more dense the air, which causes water to produce more energy than air. While water turbines are more expensive as an initial investment, the amount of electrical energy produced will far outweigh the initial investment. Lastly is location, because of location restrictions, tidal power plants would have to be constructed in areas people use for sport and leisure, like fishing, surfing, or even hunting. This is only a small group of people of which I am apart, and as much as I myself would love to conserve the land, it is a sacrifice that has to be made.

Companies like Atlantis Resources Corporation are dedicated to innovating, producing, and managing tidal energy. Atlantis as well as numerous other companies know just how valuable this resource is and continue to pioneer to new more exciting fronts in the tidal energy field. I would like to see a enormous increase in the nuber of tidal power plants across the globe. However first, the public need to be educated about this specific field. Which leads me into a touchy subject; media. Media in my opinion controls peoples minds, which is why I feel the need to express the pros and cons of tidal energy and let people decide for themselves if this renewable energy has value. My opinion is not based on politics or money, it is based on facts. The facts are, tidal power can help stop Earth's global warming problem, by lowering greenhouse gas emissions. Also in addition, provide large amounts of clean alternative energy, as long as the moon and sun are in our solar system. Based on this information, I would implement tidal power plants on a large scale world wide, with special reguard to the Gulf Stream. Tidal current is as predictable as a sunrise, it will always be there, and with the availiblity, the real question is not why should we use this resource. The real question is why aren't we using this resource.

Works Cited:

[] [] [] [] [] [] [] [] [] [] []