With the success of existing tidal power plants such as La Rance, scientists have been eagerly looking for favorable sites to build additional plants. One proposed site is that of the Severn River in England. In recent years, however, the proposal to build at this site has provided quite a controversy. Many people believe that the conditions found at Severn River will yield a highly productive tidal power plant. Others claim that the costs outweigh the benefits. As a concerned citizen, you decide to learn more about the details of the Severn River site. Consider the proposed site for the Severn River Tidal Plant, the aspects of the build listed below and what you learned using tidal energy for generating electricity; then answer the questions in the space provided.

Expected Power Contribution
It is anticipated that the tidal power plant will provide 10 percent of the country’s electricity needs.
Tide Amplitude
During spring tides, the tide amplitude can reach 11 meters (36 feet).
Inlet Data
The inlet is a narrow 15 kilometers (9 miles) across at the location proposed.
Emissions Reduction
The site could reduce coal emissions in the area by 3 percent by replacing fossil fuel power.
Marine Environment
The disruption of the tide cycle will alter the feeding grounds of local birds. It is unknown how these birds would adapt. Fish in the inlet are able to pass through the turbines. Occasionally, however, they can get trapped and die.
Costs
It is unknown exactly how costly the project would be; however, it is estimated at around $16 billion. It is projected that the project will take 9 years to build.
Requirements to Build
Tidal power plants need to be built in areas that cause channeling of tidal water. The narrow opening to a bay, for example, will force the tidal waters to rise and fall rapidly. This will cause the waters to stream through at a great speed. An appropriate area must also have a large fluctuation between high and low tides. At a minimum, there should be a difference of 5 meters. A tidal power plant built in such an area will be highly efficient at generating electricity.
Efficiency
Using tide for power is efficient because a lot of electrical power is generated. Tidal power plants are capable of converting the movement of water into usable electricity.
Energy Input
Tides provide one of the most stable sources of energy. Recall that tides are caused by the gravitational forces of the sun and the moon. Unlike fossil or nuclear fuels, tidal power uses an inexhaustible source of energy as its input. It can be very expensive to build the tidal power plant structure initially. However, once the initial structure is built the fuel is constant and predictable.
Environmental Impact
Tidal power plants do not completely restrict the movement of tides. Therefore, tidal power plants may not have a major effect on marine life that depends on tides. However, tidal power plants may restrict the movement of marine organisms. The environmental impact of tidal power plants should be watched closely. On the flip side, tidal power does not pollute the environment. Unlike fossil fuels, tides provide an entirely clean form of energy.

Questions
1) Now that you have studied the facts about the Severn River, you are ready to make a decision. What questions would you want answered if you were to determine whether to build a tidal power plant at the Severn River?
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Using the information you have learned in this lesson and the facts you can gather from the Severn River Fact Shee (above), answer the prompts in items 2-6.
2) What are two costs of using tides for energy?
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3) What are two benefits of using tides for energy?
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4) How do tides generate electricity?
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5) Why is the Severn River a good location for generating hydroelectricity?
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6) Give me examples from the facts in thise assignment or yourreseacher that explain why you feel the power plant should or should not be build.
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