1. Energy Alternatives A Unit of Choices

2. An energy alternative is: any energy resource that is not a fossil fuel. This unit will focus on the following alternatives: Nuclear PowerSolar Energy Hydrogen/Fuel CellWind Energy Geothermal EnergyBiomass Hydroelectric Power

3. Energy Alternatives are Important We depend on fossil fuels for the majority of our energy. Without them we will have no electricity, transportation, or heat. We are polluting the Earth as we continue to depend on them. They are non-renewable and will be gone one day. Alternative sources of energy will have to meet the challenge of the future and they will have to be developed extensively to meet the demands. The current use of alternatives helps us conserve our fossil fuels and future use can help us be independent from countries that sell us oil.

4. Get the Picture?

5. It’s probably a little blurry Now … Let’s start by looking at the most widely used alternative today.

6. Nuclear Power Nuclear fission is what we are talking about. Currently it supplies 8% of our total energy. It involves the splitting of U 235 atoms into cesium and strontium atoms. The heat from this fission reaction can be converted to steam pressure that can be used to heat and drive big turbines to make electricity and power ships through our oceans. Like fossil fuels, nuclear energy is non- renewable, but it is an alternative to fossil fuels. It’s a chain reaction!!!

7. A Chain Reaction?

8. A Chain Reaction Controlled in a nuclear reactor Uncontrolled in an atomic bomb.

9. The Fission Reaction and it’s Uses Uses include making electricity…..check this out

10. We use nuclear power to generate 16% of the world’s electricity

11. How about a closer look around the world…

12. Other uses of nuclear fission include: Propelling military vessels like nuclear subs, aircraft carriers, and others. Providing electricity to space probes and one day propelling space craft. Propelling air craft and more and more privately owned vehicles. Providing electrical power in medical science….like in pace makers, and bionic limbs.

13. Now lets see how it works!

14. KABOOM!!! Uncontrolled Chain Reaction Ended World War II

15. Here’s a look at the basic process!

16. Nuclear Reactor Core at full power

18. Here’s how a typical boiler reactor makes electricity.

19. The North Anna Plant, Lake Anna, VA

21. Surry Power Plant, James River, across from the Jamestown settlement

23. Now that we know what it is… and how it works… Let’s think about what makes nuclear power good or bad as a choice for the future?

24. The advantages are… It is based a working technology and it has been used for over 50 years to meet our needs. It does not pollute the air like fossil fuels. It will last much longer into the future than fossil fuels. It can be used for transportation, heating, and to make electricity. The United States has access to a lot of Uranium fuel.

25. The disadvantages are… The danger of exposure to radiation is great if an accident occurs or if radioactive waste leaks into our environment. Because of risks and insurance it is currently cheaper to build a new fossil fuel power plant than it is to build a new nuclear power plant. High and medium level nuclear waste is already filling present storage sites and presents a large threat for safe storage for thousands of years. Lets look closer at the radiation risks and storage problems.

26. Radiation exposure can come from an accident at a nuclear power plant, an explosion of a conventional or unconventional nuclear bomb, or from contamination of your environment from a radioactive substance like nuclear waste. What can exposure do to you? WARNING!WARNING!

27. Not feeling so good? Radiation sickness may be fairly mild and transitory, consisting of weakness, loss of appetite, vomiting, and diarrhea. Since even in a mild dose of radiation the blood-forming tissue is destroyed to some extent, there is a reduction in the supply of blood cells and platelets. This increases the tendency to bleed and reduces the body's defense against infection. After a massive dose of radiation the reaction may be so severe that death quickly ensues. This is usually due to severe anemia or hemorrhage, to infection, or to dehydration. Extremely high doses damage the tissues of the brain, and death usually follows within 48 hr, as was demonstrated at Chernobyl. Chernobyl There is no treatment for radiation sickness, although it is sometimes possible for persons to survive otherwise lethal doses of radiation if bone marrow transplants are performed.

28. Radiation Causes Cancer? Potassium iodide is to protect against thyroid cancer from radiation exposure, but the drug should ideally be taken four hours prior to the exposure. Exposure to radiation can cause genetic mutation; the progeny of those subjected to excessive radiation tend to show deleterious genetic changes. The genetic damage from the atomic bombs dropped on Japan is still evident and such damage will continue to surface in people directly affected by the nuclear disaster at Chernobyl.

29. Nuclear Waste is another problem! Spent fuel is hot and very radioactive. It has to be cooled and stored where any leaking can be closely monitored. There are currently 136,000 metric tons of spent fuel stored in the US and only 5000 are stored in proper facilities, the other 131,000 metric tons are being stored at the reactor sites and will eventually need to be transported. Other wastes can be safely buried or dropped into the ocean. Store for how long? About 10 half-lives A half-life is the time it takes for half of the radioactive material to decay to a stable safe material. If the half-life was 10 years, it would take 100 years before the material was considered safe for the environment. Check out these half-lives Although its half-life is 29 years, a quantity of Sr 90 (Strontium) is not considered safe for 290 years. 239Pu (plutonium) is also radioactive, and has a half-life of approximately 24,000 years How long would it take for that to become safe?

30. Here’s a picture of full storage on-site In 1994, Minnesota's largest utility, then known as Northern States Power, went to the state Legislature with a controversial request. The cooling pool where NSP stored spent nuclear fuel inside its Prairie Island plant was nearly full. The company wanted to store additional waste outside, in steel casks. After months of bitter debate, lawmakers granted permission for 17 casks. Nine years later, the casks are full and the company --- now Xcel Energy -- is back at the Capitol asking for more.

31. Well… Now that you are informed… How many of you would vote to build another nuclear reactor in Virginia? Lets find another alternative?

33. How About a Renewable Alternative like Hydroelectric Power? Hydropower (also called hydroelectric power) facilities in the United States can generate enough power to supply 28 million households with electricity, the equivalent of nearly 500 million barrels of oil. The total U.S. hydropower capacity—including pumped storage facilities— is about 95,000 megawatts. That represents 45% of renewable energy resources used in 2002. How does it work?

34. There are conventional plants like the Hoover Dam. These types of dams are called impoundment plants. They basically involve damming up a river or stream into a big lake. The following picture explains how a typical impoundment plant works.

36. Another type of hydropower is called a diversion plant. In this type of plant no dam is required, but nature has provided a drop in the form of a waterfall. The water is then diverted through a turbine on the side of the river. Check it out!

38. Another type of hydropower is called a pumped storage facility. In this type of plant a dam is required and water is pumped into the reservoir using electricity when there is extra electricity available. The water can be stored until a peak amount of electricity is needed and then the water is let back out of the dam to make the needed electricity. Smith Mountain Lake Dam is a pumped storage facility.

39. Bath County Pump Storage Facility The Bath County Pumped Storage Station, which went into operation in 1985. This mammoth station was cited as one of the nation's most outstanding 1985 engineering achievements. The earth and rock fill moved to construct the dams and other project facilities, if piled up, would create a mountain 1,000 feet (305 meters) high. Enough concrete was poured to build 200 miles (322 kilometers) of interstate highway. The station consists of two large reservoirs — one 1,262 feet (385 meters) higher than the other, a massive power house and the huge tunnels that connect them. When demand is low, water is pumped from the lower reservoir to the upper one. When demand is high, valves permit water to run through the tunnels to the lower reservoir at a rate as high as 14.5 million gallons (915 cubic meters/second) per minute, turning six 350-megawatt turbine generators. The water level in the 265-acre upper reservoir can fluctuate as much as 60 feet when the unit is operated.

40. Hydropower plants can be large – more than 30 megawatts They can be small – 100 kilowatts to 30 megawatts. They can be micro – less than 100 kilowatts, but enough to give electricity to a farm or home. Check out a micro-power plant…..

42. Still more hydropower? Tidal Energy – uses the ebb and flow of the tide, narrow inlets, to turn turbines in dams or fences to make electricity. Wave Energy – uses the motion of the waves to spin wheels and produce electricity. Ocean Thermal Energy Conversion (OTEC)– uses warm and cold ocean currents to contract and expand materials to spin turbines and make electricity. These are experimental…what about the pros and cons?

43. Advantages to Hydroelectric Power Fuel is not burned so there is minimal pollution Water to run the power plant is provided free by nature It's renewable - rainfall renews the water in the reservoir, so the fuel is almost always there. It is a proven technology.

44. Disadvantages of Hydroelectric Power Needs fast-flowing rivers or dams (very costly and flood farmland/villages). Damming meets opposition from environmental groups and salmon fisheries because of ecosystem destruction. It can never contribute more than a tiny percentage to the National Grid. Already developed to 60% or more in this country.

45. So how about hydropower as an alternative? What’s your vote? What else is there?

46. Well there’s Biomass…What’s that? Biomass is the energy resource related to things that were once alive. We can burn the actual remnants of the living things themselves, (i.e. burning firewood) or burn natural products from their decay. (methane from plants on farms, or ethanol) This resource currently provides 47% of all renewable energy used in the world.

47. That’s the basic process. For example: sugar cane is harvested and taken to a mill, where it is crushed to extract the juice. The juice is used to make sugar, while the left-over pulp, called "bagasse" can be burned in a power station. The station usually provides power for the sugar mill, as well as selling electricity to the surrounding area. There are other available fuels….Check ‘em out!

48. Other Fuels….. from where? "Bioconversion" uses plant and animal wastes to produce fuels such as methanol, ethanol, natural gas, and oil. We can use rubbish, animal manure, woodchips, seaweed, corn stalks and other wastes. What are the pros and cons of using this energy resource?

49. Advantages In addition to the many environmental benefits, biomass offers many economic and energy security benefits. By growing our fuels at home, we reduce the need to import oil and reduce our exposure to disruptions in that supply. Farmers and rural areas gain a valuable new outlet for their products. Biomass already supports 60,000 jobs in the United States; if the Department of Energy's goal is realized, the industry would support three times as many jobs.

50. Disadvantages for Biomass Collecting the waste in sufficient quantities can be difficult. Using acres of land that can produce food to make fuel is an impossible trade-off considering world starvation. We burn the fuel, so it makes greenhouse gases and other air pollutants. Some waste materials are not available all year round.

51. Biomass! That’s not just another load of manure is it? You’re already using it…. What other choices do we have besides, nuclear, biomass, and hydroelectric energies? Let’s look at the sunny side!!

52. How about Solar energy It is very popular even though it only provides 1% of the renewable energy that we use right now. The technology is very expensive and complicated. You can divide the technologies into two basic types. Passive, and Active Solar Technologies

53. Passive technologies take advantage of the suns light and heat energy, but do not involve actively collecting, concentrating and storing the energy with special devices. Placing large windows on the south side of your house to take advantage of the warming sunlight in the winter time is an example of passive solar use.

54. Kind of like a greenhouse. You can also use shading and insulation when building to increase the efficiency of your use of energy. What about active solar design?

55. Active Solar Design One example would be a solar collector. This collector traps heat in water on the roof and stores it for use as hot water in the insulated tank in the basement. Even in Salem, this could lower your hot water bills. What other active technologies are available?

56. Active Solar Design Solar cells convert photons into moving currents of electrons using two different kinds of silicon semiconductors. That electric current can be used to…check it out…

57. These solar cells are producing electricity that is being used to make hydrogen gas.

58. Large scale solar furnaces can be used to make steam and electricity or to melt metals in industry. They use mirrors to concentrate the suns energy on a single point. Check out the plant in the Mojave Desert….

59. This is the Solar 2 project, in the Mojave Desert…The mirrors concentrate light on the tower and turn water to steam to drive turbines and make electricity below the ground…

60. But what about night time? Lets take a look at the pros and cons of solar energy…

61. Advantages of Solar Power Its clean! Its renewable! Its available to anyone that has a lot of sunshine every year! The technologies are affordable on a small scale.

62. Disadvantages of Solar Energy The sun doesn’t shine 24 hours a day. Therefore one always has to have a back-up. Sunlight has to be collected, concentrated, and stored to be useful. Solar Energy only accounts for about 1% of all renewable energy resources used today. Most of the United States, including Salem, does not get enough sunshine throughout the year to make this a worthwhile investment.

63. Talk about clouds on a sunshiny day… What other alternatives are there?

64. How about Hydrogen? Hydrogen is the same fuel used to launch the space shuttle. It can be made lots of different ways. Fuel cells can be used to convert hydrogen to electrical and mechanical energy. Just how does this stuff work?

65. Hydrogen Technologies There are many different types of fuel cell technologies, but most use pure hydrogen gas and use an electrolyte, and a positive and negative electrodes to separate the electrons from the hydrogen atoms, and then allow the hydrogen ions to react with oxygen in the air to make water. The electricity caused can be used to run electric motors in cars and other devices. The heat given off can also be used.

66. Hydrogen Energy on the go…. These vehicle all use fuel cell technology to hit the highway

67. Advantages of Hydrogen Power Fuel cells are significantly more energy efficient than combustion-based power generation technologies. A conventional combustion-based power plant typically generates electricity at efficiencies of 33 to 35 percent, while fuel cell plants can generate electricity at efficiencies of up to 60 percent. By recovering heat they can be up to 80% efficient. Fuel cells powered by pure hydrogen emit no harmful pollutants. Hydrogen can be derived from a variety of domestically available primary sources, including fossil fuels, renewable resources, and nuclear power.

68. Disadvantages to Hydrogen Power Cost is the greatest challenge to fuel cell development. High-temperature fuel cells, in particular, are prone to material breakdown and shortened operating lifetimes. Hydrogen is currently more expensive to produce than conventional fuels. Hydrogen, like gasoline or any other fuel, has safety risks and must be handled with due caution. While we are quite familiar with gasoline, handling hydrogen will be new to most of us.

69. We’ve talked about nuclear, hydroelectric power, biomass, solar energy, and hydrogen power. What’s left as an alternative to fossil fuels? There are just two alternatives left Geothermal and Wind Energy

70. Lets talk about Geothermal first This energy resource uses heat from the heated layers of the earth to make electricity and heat. Places rich in this resource are close to earthquake and volcanic activity. Let’s see how it works.

71. Geo- earth….thermal…heat First, find a place where the ground water is hot… Above 90 degrees Celsius. See the darkest regions on the west coast.

72. It’s pretty simple…really

73. This is the Geysers Power Plant 20 in California….That’s a pretty hot place

74. Advantages of Geothermal Geothermal energy does not produce any air pollution, and does not contribute to the greenhouse effect. The power stations do not take up much room, so there is not much impact on the environment. No fuel is needed. Once you've built a geothermal power station, the energy is almost free. It may need a little energy to run a pump, but this can be taken from the energy being generated.

75. Disadvantages of Geothermal Power The big problem is that there are not many places where you can build a geothermal power station. You need hot rocks of a suitable type, at a depth where we can drill down to them. The type of rock above is also important, it must be of a type that we can easily drill through. Sometimes a geothermal site may "run out of steam", perhaps for decades. Hazardous gases and minerals may come up from underground, and can be difficult to safely dispose of.

76. Are you blown away yet? Let’s try one more alternative

77. Wind Energy – How can we use it? We’ve been using it for centuries to sail, and pump water, and grind grain. Today, we are most interested in it’s ability to turn generators and make electricity. Devices that do this are called wind turbines. Let’s make like the wind and blow to the next slide….

78. What a pretty scene! This wind field in Trent Mesa uses a collection of turbines to make large amounts of electricity. It makes 150 megawatts for Texas. Look at the map on the next slide to see where other places can make use of wind energy.

79. Check this out TOTAL INSTALLED U.S. WIND ENERGY CAPACITY: 6,374 MW as of Jan 22, 2004

82. The advantages of wind power Wind energy is fueled by the sun, so it's a clean and renewable fuel source. Wind energy doesn't pollute the air like power plants that rely on combustion of fossil fuels, such as coal or natural gas. Wind turbines don't produce atmospheric emissions that cause acid rain or greenhouse gasses. Wind energy is a domestic source of energy, produced in the United States. The nation's wind supply is abundant.

83. The disadvantages of wind energy Wind power must compete with conventional generation sources on a cost basis. Depending on how energetic a wind site is, the wind farm may or may not be cost competitive. Even though the cost of wind power has decreased dramatically in the past 10 years, the technology requires a higher initial investment than fossil-fueled generators. The major challenge to using wind as a source of power is that the wind is intermittent and it does not always blow when electricity is needed. Wind energy cannot be stored (unless batteries are used); and not all winds can be harnessed to meet the timing of electricity demands. Good wind sites are often located in remote locations, far from cities where the electricity is needed. Although wind power plants have relatively little impact on the environment compared to other conventional power plants, there is some concern over the noise produced by the rotor blades, aesthetic (visual) impacts, and sometimes birds have been killed by flying into the rotors. Most of these problems have been resolved.

84. Are you really blown away yet? We have covered a lot of information. Whether we choose hydroelectric or the radioactive risks of nuclear energy, we have to make some choices about energy alternatives right now and in the future. Biomass is a great resource, but it has it limits.

85. The future may show a United States that relies less on oil, and more on Wind, Solar, Geothermal, Hydrogen, Biomass, Hydroelectric and Nuclear energies. How do you see it? I’ll bet you have a prediction…but… Only our children will know for sure what the future holds.