Ess 116 Group Teaching Project Chapt 14


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Very, VERY dry material, I'm afraid. We were asked to teach a chapter of the text book. I did this presentation, and found it difficult even using PowerPoint to keep in interesting and streamlined enough to keep people awake. But the pictures are pretty, and I made the design template myself using modified clipart. :o)

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Ess 116 Group Teaching Project Chapt 14

  1. 1. Chap. 14: Renewable Energy By: Beth Theve Reggie McMillian Kim Curry Letta Johnson Eugene Mackey
  2. 2. Key Topics <ul><li>Putting Solar Energy to Work </li></ul><ul><ul><li>How do you harness the sun? </li></ul></ul><ul><li>Indirect Solar Energy </li></ul><ul><ul><li>Putting the wind in your sails. </li></ul></ul><ul><li>Renewable Energy for Transportation </li></ul><ul><ul><li>What will we do when the oil runs out? </li></ul></ul><ul><li>Additional Renewable Energy Options </li></ul><ul><ul><li>Ride a wave, anyone? </li></ul></ul><ul><li>Policy for a Sustainable Energy Future </li></ul><ul><ul><li>Key Recommendations of the National Energy Policy </li></ul></ul>
  3. 3. What should you walk away with? <ul><li>A greater understanding of the potential for sustainable energy from sunlight, wind, biomass, and other sources. </li></ul><ul><ul><li>Sun and wind are rapidly becoming cost effective, reliable energy solutions that don’t pollute the air or depend on limited fossil fuel supplies. </li></ul></ul><ul><ul><li>6% of US energy use in 2002 were from renewable resources – we can use it, and we should! </li></ul></ul>
  4. 4. 14.1: Putting Solar Energy to Work <ul><li>Some general solar energy concepts: </li></ul><ul><ul><li>Solar energy originates from the sun. </li></ul></ul><ul><ul><ul><li>Fantastic! All the chemical and radioactive wastes stay there, light years away from us! </li></ul></ul></ul><ul><ul><li>Solar energy reaching the earth is radiant energy called the solar constant. </li></ul></ul><ul><ul><ul><li>1,370 watts per square meter – that’s a lot of power! </li></ul></ul></ul><ul><ul><li>Only about half of the energy that reaches the top of the Earth’s atmosphere actually gets to the surface. </li></ul></ul><ul><ul><ul><li>30% is reflected, 20% is absorbed. </li></ul></ul></ul><ul><ul><li>At full sunlight, we can get about 700 watts per square meter with the sun directly overhead. </li></ul></ul><ul><ul><ul><li>That’s the same output as a large power plant! </li></ul></ul></ul>
  5. 5. General Concepts continued <ul><li>40 minutes of solar energy striking the land surface of the United States yields the equivalent of a years’ expenditure of fossil fuel. </li></ul><ul><li>The Sun delivers 10,000 times the energy actually used by humans today. </li></ul><ul><li>Using solar energy does not hurt the energy balance of the biosphere. </li></ul><ul><ul><li>Solar energy is eventually converted into heat and is lost into outer space. </li></ul></ul>
  6. 6. So why not use it for everything??? <ul><li>Solar energy is a diffuse source, meaning it’s widely scattered. </li></ul><ul><ul><li>How do you collect it and turn it into readily accessible, constant fuel sources for cars, computers, machinery, homes and offices? </li></ul></ul><ul><ul><li>What if it’s cloudy one day? Or for a week? Or a month? </li></ul></ul><ul><li>The problems of utilizing solar energy involve collection, conversion, and storage. </li></ul>
  7. 7. Solar Heating of Water <ul><li>Flat-plate collectors </li></ul><ul><ul><li>Faced toward the sun, the black bottom gets hot and the clear cover prevents heat from escaping. </li></ul></ul><ul><li>Active system </li></ul><ul><ul><li>Uses pumps to move heated water. </li></ul></ul><ul><li>Passive system </li></ul><ul><ul><li>Relies on natural convection currents. </li></ul></ul><ul><li>In climates where water might freeze, a heat exchange coil is placed in the hot water tank. </li></ul><ul><ul><li>Antifreeze is circulated in the coil to keep the water from freezing when not heated. </li></ul></ul><ul><li>Only a small portion of the US uses solar water heaters. </li></ul><ul><ul><li>Cheaper to use, but more expensive to buy. </li></ul></ul><ul><ul><li>Mostly used to heat pools. </li></ul></ul>
  8. 8. Solar Space Heating <ul><li>Can use flat plate collectors just like with water, but the greatest efficiency is achieved when the building acts as its’ own collector! </li></ul><ul><ul><li>Windows facing the sun. </li></ul></ul><ul><ul><ul><li>In the winter, the sunlight can come in and heat the building. </li></ul></ul></ul><ul><ul><ul><li>At night, insulated window coverings keep heat from escaping. </li></ul></ul></ul><ul><ul><ul><li>Awnings can be used in summer to shield the windows to keep heat from entering. </li></ul></ul></ul>
  9. 9. Landscaping <ul><li>Along with design, positioning and good insulation, landscaping can contribute to heating and cooling efficiency. </li></ul><ul><ul><li>Deciduous trees or vines on the sunny side of a house block excessive summer heat while letting winter sunlight pass through. </li></ul></ul>
  10. 10. Earth Sheltered Houses <ul><li>Uses earth as a form of insulation. </li></ul><ul><ul><li>Earth has a high capacity for heat storage. </li></ul></ul><ul><ul><li>Walls are built with concrete or masonry so at night, they radiate stored heat. </li></ul></ul><ul><ul><li>In the summer, being “underground” helps keep the building cool. </li></ul></ul><ul><ul><ul><li>Humidity can be a problem. </li></ul></ul></ul><ul><li>Faces the house toward sunlight for passive solar energy collection. </li></ul><ul><ul><li>Large south-facing windows expose the interior to heat that can be stored in the earth and bricks. </li></ul></ul>
  11. 11. But don’t you still need a backup? <ul><li>What if it’s cloudy and cold for a week? Won’t my house freeze? How will I get warm water??? </li></ul><ul><ul><li>Good insulation works wonders. When good insulation is used, little more than a small wood stove or gas heater is needed. </li></ul></ul><ul><li>But this question misses the point completely. </li></ul><ul><ul><li>The point is to reduce our dependency on limited fossil fuels. Even if it doesn’t replace the usage of these fuels completely, utilizing solar power still reduces the dependency greatly – and all the pollution fossil fuels cause. </li></ul></ul>
  12. 12. Energy Stars <ul><li>Created by the EPA in 2001 </li></ul><ul><ul><li>The Energy Star label is awarded to public and corporate buildings that use at least 40% less energy than others in their class. </li></ul></ul><ul><ul><ul><li>In 2 years, 1,000 buildings earned the label, saving $130 million and reducing carbon dioxide emissions by 2.6 billion pounds. </li></ul></ul></ul>
  13. 13. Some folks don’t like solar energy… <ul><li>Especially the ones making money off of fossil fuels. </li></ul><ul><ul><li>In the 1980’s, utility and oil companies ran massive anti-solar energy campaigns saying solar energy was expensive and impractical. </li></ul></ul><ul><ul><li>They also lobbied to end incentive programs encouraging renewable energy usage. </li></ul></ul><ul><ul><ul><li>A solar tax credit program was ended that had increased solar powered water heater usage. </li></ul></ul></ul><ul><ul><li>In the 1990’s, fuel costs were low and the public had no reason to look for renewable fuel sources. </li></ul></ul><ul><ul><li>In 2002, the World Summit gave in to pressure from fossil-fuel industries, and ended with a weak, watered down call to increase renewable energy. </li></ul></ul>
  14. 14. Solar Power is Electric! <ul><li>Solar power can be used to create electricity, providing a safer, healthier alternative to coal and nuclear power. </li></ul>
  15. 15. Photovoltaic Cells <ul><li>No moving parts, solar cells convert light energy directly to power with an efficiency of about 20%. </li></ul><ul><li>Life span of around 20 years. </li></ul><ul><li>Made with silicon, one of the most abundant resources on earth. </li></ul><ul><li>Cost lies in intricate design and construction. </li></ul>
  16. 16. How are PV Cells used? <ul><li>Today they are commonly used in calculators, watches, and some toys. </li></ul><ul><li>Panels of PV cells provide power for rural homes, irrigation pumps, offshore oil-drilling platforms (ironic!) and more. </li></ul><ul><li>Arrays placed in roof shingles provide power for some homes in the US. </li></ul><ul><ul><li>Rooftop electrical output is subtracted from customer’s use of power from the power grid, reducing energy costs. </li></ul></ul>
  17. 17. Putting consumers to work to harness more power <ul><li>PV Pioneers in California </li></ul><ul><ul><li>A local utility company pays homeowners $4 a month to maintain a 2 to 4-kw PV system on their roof. These systems feed 3,600 kwhr/year back to the grid. </li></ul></ul><ul><ul><li>Similar programs have begun in Japan. </li></ul></ul><ul><li>Million Solar Roofs campaign </li></ul><ul><ul><li>A Federal initiative encourages installation of solar energy units on residential and commercial rooftops. </li></ul></ul><ul><ul><li>The goal is one million rooftops by 2010. </li></ul></ul><ul><ul><ul><li>Few financial incentives, but hopes to encourage grassroots efforts. </li></ul></ul></ul><ul><li>The cost of PV Power is still more expensive than traditional electric harnessing methods. </li></ul><ul><ul><li>In order for solar power to become routinely used, the government needs to institute tax incentives and the price of PV power needs to drop. </li></ul></ul>
  18. 18. Concentrating Solar Power <ul><li>Government funding has developed several technologies for converting solar power into electricity using reflectors such as mirrors to focus concentrated sunlight into receivers that transfer heat to a turbogenerator. </li></ul><ul><ul><li>Works well only where there is abundant sunlight. </li></ul></ul>
  19. 19. Methods of Collecting <ul><li>Solar Trough </li></ul><ul><ul><li>Trough shaped reflectors tilted toward the sun with a pipe in the center. A heat absorbing fluid is run through the pipe, heated to high temperatures, passed through a heat exchanger that creates boiling water which creates steam which feeds a turbogenerator. </li></ul></ul><ul><li>Power Tower </li></ul><ul><ul><li>An array of sun-tracking mirrors that focus sunlight from several acres of land into a receiver tower. The tower transfers heat to a molten salt liquid, which flows to either a turbogenerator or a tank for usage later. </li></ul></ul><ul><li>Dish Engine </li></ul><ul><ul><li>A parabolic concentrator dish that focuses sunlight onto a receiver. Fluid in the receiver is transferred to an engine that generates electricity directly. </li></ul></ul>
  20. 20. The Promise of Solar Energy Vs. Its Disadvantages <ul><li>Available solar technologies are still more expensive than conventional energy sources. </li></ul><ul><li>However, the Available technologies: </li></ul><ul><ul><li>Create air pollution </li></ul></ul><ul><ul><li>Destroy the earth through strip mining </li></ul></ul><ul><ul><li>Create greenhouse emissions </li></ul></ul><ul><ul><li>Create nuclear waste </li></ul></ul><ul><ul><ul><li>Is expensive to dispose of and has, in the past, been disposed of unethically in order to save money. </li></ul></ul></ul><ul><ul><ul><li>Poisons our water, our land, and creates fatal and devastating illness in people, vegetation and wildlife. </li></ul></ul></ul>
  21. 21. The Promise of Solar Energy Vs. Its Disadvantages <ul><li>Solar power only works in the daytime, and requires a backup energy source or storage battery for evening use. </li></ul><ul><li>70% of electrical demand occurs during daytime hours, when offices, industries and stores are open. </li></ul><ul><ul><li>Using solar panels only for daytime energy would drastically reduce our need for fossil fuels. </li></ul></ul><ul><ul><li>Nighttime needs could be addressed by indirect solar energy, like wind or hydropower. </li></ul></ul>
  22. 22. 14.2: Indirect Solar Energy <ul><li>Indirect solar energies are: </li></ul><ul><ul><li>Dams </li></ul></ul><ul><ul><li>Firewood </li></ul></ul><ul><ul><li>Windmills </li></ul></ul><ul><ul><li>Sails </li></ul></ul><ul><li>Why are these considered solar energies? </li></ul><ul><ul><li>The sun is the driving force behind all of these energy sources. </li></ul></ul>
  23. 23. What is Hydropower? <ul><li>Hydropower is created by huge hydroelectric dams, where water under high pressure flows through channels, driving turbogenerators. </li></ul><ul><ul><li>The amount of power generated depends on the height of the water behind the dam. The water behind the dam provides pressure and controls the volume of water flowing through. </li></ul></ul>
  24. 24. Hydropower Facts <ul><li>About 6.7% of electric power that is generated in the U.S. comes from hydroelectric dams. </li></ul><ul><li>Most of the hydro power comes from 300 large dams in the northwest and southwest of the country. </li></ul><ul><li>Hydroelectric dams have a generating capacity of 780,000 m.w. </li></ul><ul><li>Hydropower generates 17% of electric power worldwide. </li></ul>The Hoover Dam in Westerville, Ohio.
  25. 25. The Advantages vs. The Disadvantages of Hydropower <ul><li>Eliminates the cost and environmental effects of fossil fuels and nuclear power. </li></ul><ul><ul><li>Non-polluting renewable resource. </li></ul></ul><ul><li>Equipment life expectancy is longer than traditional fuel-fired generators. </li></ul><ul><li>Provides flood control on rivers in addition to supplying power. </li></ul><ul><li>Provides irrigation water for agriculture. </li></ul><ul><li>Reservoirs behind the dams provide recreational and tourist opportunities. </li></ul><ul><li>Reservoirs behind dams can drown farmland, wildlife habitats and can destroy towns of historical, archaeological or cultural value. </li></ul><ul><ul><li>Glen Canyon Dams (located on the border of Arizona and Utah) drowned one of the worlds’ most spectacular canyons. </li></ul></ul><ul><li>Dams and large reservoirs often displace rural population. </li></ul><ul><ul><li>40 to 50 million people have been displaced by dams in the last 50 years. </li></ul></ul><ul><li>Dams prevent the migration of fish according to Federal surveys. </li></ul><ul><li>Because the flow of water is regulated according to the need for power, dams create ecological problems downstream. </li></ul><ul><ul><li>Water may go from flood levels to complete dryness in a single day. </li></ul></ul><ul><li>Dams cannot be increased due to a lack of space. </li></ul><ul><ul><li>U.S. has 75,000 dams 6’ high and 2 million smaller ones. </li></ul></ul>
  26. 26. Where else are dams being built? <ul><li>Laos built a dam 50 meters high. </li></ul><ul><ul><li>Nam Theun Dam – 1,060 MW </li></ul></ul><ul><ul><li>Project on a tributary of the Mekong River </li></ul></ul><ul><li>China is building a dam 185 meters high. </li></ul><ul><ul><li>Three Gorges Dam – 18,200 MW </li></ul></ul><ul><ul><li>Built on the Yangtze River, will be the largest hydroelectric dam in the world. </li></ul></ul><ul><ul><li>The dam itself was completed in May, 2006. Scheduled for completion in 2009. </li></ul></ul>
  27. 27. What is Wind Power? <ul><li>Wind power is the kinetic energy of wind, or the extraction and use of this energy. </li></ul><ul><ul><li>The most popular design for harnessing wind is the wind turbine. The propeller shaft is geared directly by a generator. </li></ul></ul><ul><li>Wind power usage has increased 28% per year in the last five years to 59,000MW in 2006. </li></ul><ul><ul><li>Supplies 1.3% of global electricity. </li></ul></ul><ul><ul><li>Will be supplying 12% of the world’s electricity by 2020. </li></ul></ul><ul><ul><li>It already supplies 20% of the electricity in Denmark. </li></ul></ul><ul><li>Wind is the second fastest growing energy source in the world (behind solar PV cells). </li></ul>
  28. 28. The Advantages vs. Disadvantages of Wind Power <ul><li>Pollution free, sustainable power. </li></ul><ul><li>Inexpensive at 5 cents per kilo-watt hour. </li></ul><ul><li>Amount of wind that could be tapped is immense. </li></ul><ul><ul><li>American Wind Energy Association says wind farms located throughout the Midwest could meet the electrical needs for the entire country, with land below still used for farming. </li></ul></ul><ul><li>Farmers paid handsome royalties to install wind turbines on their farmland – $2-3,000 per turbine per year. </li></ul><ul><li>Wind is an intermittent power source. </li></ul><ul><ul><li>Storage or backup could become an issue. </li></ul></ul><ul><li>Wind turbines are not very attractive. </li></ul><ul><ul><li>Creates a gaudy, unpleasant landscape. </li></ul></ul><ul><li>Windmills are a hazard to birdlife. </li></ul><ul><ul><li>Windmills located on migratory routes or near endangered species could cause serious problems. </li></ul></ul>
  29. 29. An example: Offshore Wind <ul><li>The Nantucket Sound is located south of Cap Cod. </li></ul><ul><ul><li>It is a body of water which has continuous windy days. </li></ul></ul><ul><li>Cape Wind Associates purposed an offshore wind farm in that location. </li></ul><ul><ul><li>130 turbines each 417 feet tall would spread over 24 square miles. </li></ul></ul><ul><ul><li>Would be able to provide 75% of electricity to Cape Cod. </li></ul></ul><ul><li>But the people objected! </li></ul><ul><ul><li>The turbines would threaten tourism, navigation, fishing industry and migrating birds. </li></ul></ul><ul><li>Proponents for the project claim this is a classic case of “NIMBY”… </li></ul><ul><ul><li>“ Sure, I want clean energy from renewable resources, but not in MY backyard!” </li></ul></ul><ul><li>The project has passed numerous reviews, and now awaits license from the U.S. government. </li></ul>
  30. 30. Biomass Energy <ul><li>Definition: Energy derived from present-day photo synthesis. </li></ul><ul><ul><li>Burning wood in a stove </li></ul></ul><ul><ul><li>Burning municipal wastepaper and other organic waste </li></ul></ul><ul><ul><li>Generating methane from the anaerobic digestion of manure and sewage sludge </li></ul></ul><ul><ul><li>Producing alcohol from fermenting grains and other starchy materials. </li></ul></ul>Sounds Yummy, right?!?!
  31. 31. Firewood as an Energy Source <ul><li>Firewood is a primary source of energy for 2.6 billion people. </li></ul><ul><ul><li>It accounts for 7% of total energy used worldwide. </li></ul></ul><ul><li>5 million homes rely entirely on wood for heating. </li></ul><ul><li>20 million people use wood for some heating. </li></ul><ul><ul><li>Extra winter heat. </li></ul></ul><ul><ul><li>Nighttime heat. </li></ul></ul><ul><li>A Pellet Stove is a device that burns compressed wood pellets made from wood waste. </li></ul><ul><li>Fuelwood Crisis </li></ul><ul><ul><li>Two ways forest resources will be exploited: </li></ul></ul><ul><ul><ul><li>Consumptive use– in developing countries people gather wood for daily needs, destroying forests. </li></ul></ul></ul><ul><ul><ul><li>Productive– People gather wood converting it into charcoal and selling the wood products. </li></ul></ul></ul><ul><ul><li>Both have potential to degrade local forest and woodlands. </li></ul></ul>
  32. 32. 14.3: Renewable Energy for Transportation <ul><li>Due to the decline in the oil reserves in our economy and global climate, there is a critical need for sustainable energy to fuel our vehicles. </li></ul><ul><li>Two types of renewable energy are being used for transportation: </li></ul><ul><ul><li>Bio-fuels </li></ul></ul><ul><ul><li>Hydrogen fuel cells </li></ul></ul>
  33. 33. Bio-Fuels <ul><li>A bio-fuel is an organic matter that can be processed to make fuels for vehicles. </li></ul><ul><ul><li>These fuels are primarily made of plants, but some also use animal wastes. </li></ul></ul>
  34. 34. Bio-Fuels <ul><li>Ethanol Fuel </li></ul><ul><li>Produced by fermentation of starches and sugars </li></ul><ul><li>Suitable substance for MTBE </li></ul><ul><ul><li>A petroleum derivative used as a fuel additive to make burning of gasoline cleaner. </li></ul></ul><ul><ul><li>M ethyl, T eriary, B itul, E ther </li></ul></ul><ul><li>Bio Diesel Fuel </li></ul><ul><li>Made from vegetables. </li></ul><ul><ul><li>Usually made with 20% soybean oil, 80% normal diesel fuel </li></ul></ul><ul><ul><li>Can be made from any natural oil or fat </li></ul></ul><ul><li>Truck exhaust that smells like french fries! </li></ul><ul><ul><li>Sometimes made with recycled restaurant frying oil </li></ul></ul>Two types of fuel are currently providing for 2% of transportation fuel needs globally:
  35. 35. Hydrogen <ul><li>Another alternative fuel source for conventional cars. </li></ul><ul><li>Hydrogen is not a fuel, but carries energy like electricity generated with some other types of energy source. </li></ul><ul><ul><li>Produces neither carbon dioxide nor hydrocarbon pollutants. </li></ul></ul><ul><li>Sounds great, right?? BUT… </li></ul>… there is virtually NO pure Hydrogen gas available on Earth.
  36. 36. So How Can We Get It?? <ul><li>Electrolysis </li></ul><ul><ul><li>Pass electricity through water to release water molecules and collect hydrogen at the negative electrode. </li></ul></ul><ul><li>Plants do it! </li></ul><ul><ul><li>Photosynthesis </li></ul></ul><ul><ul><li>Research being done to mimic the action of the plants. </li></ul></ul><ul><li>Solar Energy </li></ul><ul><ul><li>Generate large solar trough or PV cells </li></ul></ul><ul><ul><li>Use this electricity to produce hydrogen by electrolysis </li></ul></ul><ul><ul><li>Move hydrogen via underground pipelines </li></ul></ul><ul><li>Need Hydrogen burning cars! </li></ul><ul><ul><li>Model U by Ford. </li></ul></ul>
  37. 37. Fuel Cells <ul><li>An alternative to burning hydrogen in conventional internal combustion engines. </li></ul><ul><ul><li>Hydrogen is chemically recombined with oxygen that creates electricity rather than burning. </li></ul></ul><ul><ul><li>The only emissions are water and heat! </li></ul></ul><ul><li>Fuel cells now power buses in Vancouver, Chicago and 10 European Cities </li></ul><ul><li>Versions being made by DaimlerChrysler, GM, </li></ul>
  38. 38. FreedomCAR <ul><li>“ C ooperative A utomotive R esearch” </li></ul><ul><ul><li>Launched by President Bush in 2003 </li></ul></ul><ul><li>Government partnered with automobile companies to move toward fuel-cell-powered vehicles. </li></ul><ul><li>$1.7 million dollar budget over five years. </li></ul><ul><li>Make fuel-cell cars competitive in automotive market by 2010. </li></ul>
  39. 39. 14.4: Additional Renewable Energy Options <ul><li>Geothermal Energy </li></ul><ul><li>What is Geothermal energy? </li></ul><ul><ul><li>The word geothermal comes from the Greek words geo (earth) and therme (heat). </li></ul></ul><ul><ul><li>It is useful energy derived from water heated by the natural hot interior of the Earth. </li></ul></ul>
  40. 40. What is Geothermal Energy Derived from? <ul><li>Volcanic energy cannot be harnessed (controlled and collected), but in a few places heat from the earth, called geothermal energy, can be collected. </li></ul><ul><ul><li>Engineers try to collect this heat in the rare places where the Earth's crust has trapped steam and hot water. </li></ul></ul><ul><ul><li>They drill into the crust and allow the heat to escape, either as steam, or as very hot water. Pipes carry the hot water to a plant, where some of the steam is allowed to &quot;flash,&quot; or separate from the water.   That steam then turns a turbine - generator to make electricity. </li></ul></ul>
  41. 41. Is Geothermal Energy Widely Used? <ul><li>Geothermal energy was first used to produce electricity in Italy in 1903.  </li></ul><ul><li>At the end of 2004, there were 43 power plants producing electricity from geothermal energy in the USA.  </li></ul><ul><ul><li>Most of these are located in California and Nevada; Utah has two geothermal plants and Hawaii, formed by volcanic eruptions, has one.  </li></ul></ul><ul><li>Generating power from geothermal sources is &quot;site specific,&quot; meaning it's only possible in a few places under unique geologic conditions.  </li></ul><ul><ul><li>The Geysers in California, can produce almost as much electricity as all the other geothermal sites combined. </li></ul></ul>
  42. 42. Ecosystem Capital Derived from Geothermal Energy <ul><li>Geothermal Energy can be used to heat homes and businesses, or to generate electricity via turbogenerators. </li></ul><ul><ul><li>In the year 2000, geothermal energy provided over 8,000 MW of electrical power </li></ul></ul><ul><ul><li>That’s equivalent to the output of eight large nuclear or coal powered plants! </li></ul></ul>
  43. 43. The Science Behind Geothermal Energy <ul><li>Some Scientist feels that the potential for geothermal energy has barely been tapped. </li></ul><ul><li>They predict that with today’s technology, an additional 80,000 MW of electricity could be generated. </li></ul><ul><li>Utilizing this natural energy would heat more homes and save thousand of dollars to consumers. </li></ul><ul><li>It would also help eliminate dangerous pollutants. </li></ul>Castle Geyser, Yellowstone Park
  44. 44. Tidal Power <ul><li>Tidal Power - Power achieved by capturing the energy contained in moving water in tides and ocean currents. </li></ul><ul><li>There are two types of energy systems that can be used to extract energy: </li></ul><ul><ul><li>Kinetic energy - the moving water of rivers, tides as face ocean currents </li></ul></ul><ul><ul><li>Potential energy – aquired from the difference in height (or head ) between high and low tides. </li></ul></ul><ul><li>Kinetic Energy uses turbines. It is gaining popularity because of the lower ecological impact compared to potential systems that are similar to dams sometimes called barrages or tidal fences. </li></ul><ul><li>Many coastal sites worldwide are being examined for the suitability to produce kinetic energy. </li></ul><ul><ul><li>Suitable Sites exhibit high water speeds which typically occur in channels such as the entrances to bays, rivers or between islands where water currents are concentrated </li></ul></ul>Kinetic Energy Turbines
  45. 45. The Global Impact of Tidal Power <ul><li>A tidal power scheme is a long-term source of electricity. </li></ul><ul><ul><li>A proposal for the Severn Barrage, if built, has been projected to save 18 million tons of coal per year of operation. </li></ul></ul><ul><ul><ul><li>Decreases the output of greenhouse gases into the atmosphere. </li></ul></ul></ul><ul><ul><ul><li>Will help replace fossil fuel usage by the end of the 21 st century. </li></ul></ul></ul>
  46. 46. Ocean Thermal Energy Conversion (OTEC) <ul><li>OTEC harnesses the difference in temperature between surface waters to produce power. </li></ul><ul><li>OTEC utilizes the temperature difference that exists between deep and shallow waters to run a heat engine. </li></ul><ul><ul><li>Done within 20° of the equator in the tropics. </li></ul></ul><ul><li>The oceans are continually heated by the sun and cover nearly 70% of the Earth's surface, so this temperature difference contains a vast amount of solar energy which could potentially be tapped for human use. </li></ul><ul><li>If this extraction could be done profitably on a large scale, it could be a solution to some of the human population's energy problems. </li></ul><ul><ul><li>The total energy available is one or two orders of magnitude higher than other ocean energy options such as wave power. </li></ul></ul><ul><ul><li>The small size of the temperature difference makes energy extraction difficult and expensive. Hence, existing OTEC systems have an overall efficiency of only 1 to 3%. </li></ul></ul>View of a land based OTEC facility at Keahole Point on the Kona coast of Hawaii
  47. 47. How Does That Work?!? <ul><li>The concept of a heat engine is very common in engineering, and nearly all energy utilized by humans uses it in some form. </li></ul><ul><li>A heat engine involves a device placed between a high temperature reservoir (such as a container) and a low temperature reservoir. As heat flows from one to the other, the engine extracts some of the heat in the form of work. </li></ul><ul><ul><li>This same general principle is used in steam turbines and internal combustion engines, while refrigerators reverse the natural flow of heat by &quot;spending&quot; energy. </li></ul></ul><ul><li>Rather than using heat energy from the burning of fuel, OTEC power draws on temperature differences caused by the sun's warming of the ocean surface. </li></ul>
  48. 48. 14.5: Policy for a Sustainable Energy Future <ul><li>Global issues are social, political, economic and environmental issues that affect us all! </li></ul><ul><ul><li>Fossil fuels, oil and natural gases are being used at such a rapid rate that it will soon hinder production. </li></ul></ul><ul><ul><li>An unhealthy daily dependence has been created that is increasing the atmospheric burden of carbon dioxide…the dreaded Greenhouse gasses. </li></ul></ul>
  49. 49. Renewable Energy <ul><li>Renewable energy means sustainable energy. </li></ul><ul><li>A sustainable energy future does NOT include significant fossil fuel usage. </li></ul><ul><li>Globally, we should aim for: </li></ul><ul><ul><li>Stable atmospheric levels of greenhouse gasses, especially carbon dioxide </li></ul></ul><ul><ul><li>An energy development and consumption pattern based on fuels that are renewable and safe to use. </li></ul></ul>
  50. 50. National Energy Policy <ul><li>The U.S. depends on importing over half of our oil, all of which is used for transportation. </li></ul><ul><li>$200,000 leaves the U.S. every minute to pay for imported oil. </li></ul><ul><ul><li>Enormous drag on our economy. </li></ul></ul><ul><li>Natural gas resources are being stretched thin to create electrical power. </li></ul><ul><ul><li>Electricity prices tripled in 2002! </li></ul></ul><ul><li>Energy Security Problems </li></ul><ul><ul><li>We are completely at the whim of OPEC and other oil producers </li></ul></ul><ul><ul><li>Also vulnerable to terrorist attacks on various aspects of our energy infrastructure. </li></ul></ul>
  51. 51. Energy Policy Act <ul><li>“ America must have an energy policy that plans for the future but meets the needs of today. I believe we can develop our natural resources and protect our environment”. </li></ul><ul><li>~ President George W. Bush </li></ul>
  52. 52. Renewable Energy & Efficiency Hits and Misses of the Energy Policy Act <ul><li>Does: </li></ul><ul><li>Attempt to combat growing energy problems </li></ul><ul><li>Provide tax incentives </li></ul><ul><li>Provides loan guarantees for energy production of various types. </li></ul><ul><li>Does Not: </li></ul><ul><li>Include a Federal Requirement that </li></ul><ul><ul><li>That utilities purchase a certain percentage of electricity from renewable sources. </li></ul></ul><ul><ul><ul><li>Wind, solar, bio-mass </li></ul></ul></ul><ul><li>Address Global Warming </li></ul><ul><ul><li>Greater energy efficiency and the use of renewable energy sources would reduce greenhouse gas emission in the U.S. </li></ul></ul>
  53. 53. Questions?