polar, grizzly, and black bear; wolf, wolverine, Dall sheep, moose, muskox, and the free-roaming caribou. 180 species of birds have been observed on the refuge. ...
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1. Announcements – Nov. 3, 2006Seafood faces collapse by 2048 November 2, 2006 Clambakes, crabcakes, swordfish steaks and even humble fish sticks could be little more than a fond memory in a few decades. If current trends of overfishing and pollution continue, the populations of just about all seafood face collapse by 2048, a team of ecologists and economists warns in a report in Friday's issue of the journal Science.
3. ANWR – To drill or not to drill?
Arctic National Wildlife Refugepolar, grizzly, and black bear; wolf, wolverine, Dall sheep, moose, muskox, and the free-roaming caribou. 180 species of birds have been observed on the refuge. 45 species of land and marine mammals 36 species of fish occur in Arctic Refuge waters But it is also has oil and natural gas Current political debate over whether or not to allow drilling The total quantity of recoverable oil within the entire assessment area is estimated to be between 5.7 and 16 billion barrels (numbers vary depending on who is reporting them) Anywhere from 30 to 70 percent of oil, and 10 to 20 percent of natural gas, is not recovered Peak production from ANWR could to be between 1 and 1.3 million barrels a day “ANWR production could equal 46 years of current oil imports from Iraq.” D.Cheney But what does that statistic really mean given that we don’t get much oil from Iraq? So, if the US were to get all of its oil from ANWR, it would last a little longer than 6 months (exact number depends on which estimates of supply and use are used). Some opposed to drilling have claimed that ANWR only has 6 months worth of oil 4.5 billion barrels recovered from ANWR / 24 million barrels per day used in US = 187.5 days But, it can’t be pumped that fast, and we will never get all of our oil from ANWR 1/24 = about 4% of our oil needs Better calculation: Peak production from ANWR could to be between 1 and 1.3 million barrels a day But it will take at least 10 years to reach the market By that time, it is predicted we will be using ~ 24 million barrels/ day How much oil will be pumped depends not only on how much is there, but on current crude oil prices Profits for oil industry have to exceed their costs USGS estimate: 95% chance of producing 2 billion barrels 50% chance of producing 4.5 billion barrels 5% chance of producing 9 billion barrels But, will ANWR reach maximum production? Environmental Impacts Roads will be constructed of ice, which can alter availability of freshwater for animals Noise, pollution and construction will impact wildlife At other Arctic drilling sites, crews have dumped garbage, sewage and toxic waste Oil spills Construction will alter habitat If the average fuel efficiency of cars and light trucks were improved by ONE mile per gallon it would save more oil than is likely ever to be recovered from ANWR Ford Model T in 1908 – 20-25 mpg Current Corporate Average Fuel Economy (CAFE) standards: Cars - 27.5 mpg Light trucks (includes vans and most SUVs) – 20.7mpg Another suggestion…
13. What do you think?
Should we allow oil drilling in ANWR? Why (explain your answer)?
14. Energy Sources II
Lecture Objectives: Understand the breakdown of fossil fuel usage in the U.S. Learn about pros and cons of alternative energy sources Understand the benefits and risks of nuclear energy Learn easy ways to conserve fossil fuel use
15. How do we consume fossil fuels in the U.S.?
85.7% of total energy Petroleum (39.2%) Transportation 67% Electrical Power 3% Industrial 24% Residential/Commercial 6% Natural Gas (23.7%) Total by Area Transportation 0.1% Transportation 26.3% Electrical Power 35% Electrical Power 30.1% Industrial 43.6% Industrial 21.8% Residential/Commercial 21.2% Residential/commercial 7.5% Coal (22.8%) Transportation NA Electrical Power 90.5% Industrial 9% Residential/Commercial 0.5% Source: www.eia.doe.gov
16. One Problem with fossil fuels ~86% of energy in U.S. currently supplied by non-renewable resources, which will run out at some point in the future!!! Solution? Develop alternative sources of energy, preferably from renewable resources.
17. Hydroelectric Power
2.5% of world’s commercial energy (2.7% U.S.) River water is held behind a dam Falling water is used to spin the turbine to generate electricity
18. Environmental Impacts of Hydroelectric Power
Reservoir construction causes significant environmental and social damage. Loss of farmland Community relocation Reduction of nutrient-rich silt leading to loss of wetlands. Changes to the hydrology of the river Impacts aquatic animalsCNN Dam removal presents costly challenge October 29, 2004 Removal of the Matilija Dam carries an estimated price tag of $130 million. California (AP) -- The Matilija Dam isn't much of a dam anymore -- on rainy days, it looks more like a waterfall. A pile of sediment has built up so high behind the dam that when just an inch of rain falls, water spills over in glistening cascades. The dam's aging concrete also chokes off sediment and nutrients that could nurture the riverbanks and restore Ventura County beaches downstream. So, it's got to go. But, tearing down the Southern California structure presents a costly challenge. Officials add that demolishing the 198-foot-high dam would ultimately improve the area's ecosystem -- helping restore endangered steelhead trout by allowing them to swim upstream and spawn, and allowing sand to flow downstream and restore eroded beaches.
20. The Three Gorges Dam
Started in 1997 Will stretch 1.3 miles across the Yangtze River
21. The Three Gorges Dam
Reasons for constructing: Power Generation Increased ability for navigation Flood control Environmental and Social Impacts: Endanger Wildlife (Chinese alligator, river dolphin) Massive relocation of people Will flood archeological sites and scenic canyons
U.S. Dept. of Energy rated wind power the world’s fastest growing energy source in the 1990s. (but currently supplies <0.1% of U.S. energy needs Cost for electricity generation becoming competitive with fossil fuel sources. Steady, dependable wind source is critical
23. Environmental Impacts of Wind Power
Can be hazardous to birds Produce noise Considered “visual pollution” by some
24. Solar Energy
Daily energy from the sun is 600X greater than energy produced by all other energy sources combined. Major problem as an energy source is its intermittent nature. Beverly, Massachusetts photovoltaic (PV) array
25. Three Major Use Categories
Passive Heating — Sun’s energy is converted directly to heat and used at collection site. Active Heating — Sun’s energy is converted into heat, but transported elsewhere to be used. Electrical Generation — Solar energy is transformed into electrical energy.
26. Photovoltaic Cells
Unit that allows direct conversion of sunlight to electricity. Developed in 1954 by Bell Laboratories essentially as a novelty. By mid 1980s, more than 60 million solar calculators produced annually.
27. Limitations of Solar Energy
Currently provides less than 1% of world’s energy Works only during the day Inadequate in many colder climates as sole heating source (need conventional back-up) Inadequate in cloudy climates.
28. Environmental Impacts of Solar Energy
Large PV arrays require space
In less-developed countries, fuelwood has been major energy source for centuries. Fuelwood is primary energy source for nearly half world’s population. Estimated 1.3 billion people cannot get enough fuelwood, or are using it faster than rate of regeneration. Source of air pollution and fly ash Not really a viable alternative energy source for USLess common sources: Tidal Power – tides can be used to spin an electricity-generating turbine limited applicability La Rance Tidal Power Station Tidal Power Generation. The Annapolis Tidal Generating Station is a pilot project to explore the potential of harnessing energy from the sea. Annapolis Tidal utilizes the sea water of the Bay of Fundy. Tides, which can sometimes reach 21 feet in height, rise and fall every 12 hours and 25 minutes in harmony with the gravitational forces of the Sun, the Earth, and the Moon. Less common sources: Geothermal - molten material is close enough to surface to heat underground water and form steam limited applicability Steam is captured and used to spin a turbine to produce electricity Lake Source Cooling http://www.utilities.cornell.edu/LSC/default.htm Cornell University Ithaca, NY Uses cold water from Cayuga Lake to cool University Buildings 80% energy savings over conventional chillers Lake Source Cooling http://www.utilities.cornell.edu/LSC/default.htm
35. History of Nuclear Development
First controlled fission—Germany 1938. 1945—U.S. dropped atomic bombs on Hiroshima and Nagasaki. U.S. built world’s first nuclear power plant in 1951 Currently, 8.4% of U.S. energy from nuclear power
36. The Nature of Nuclear Energy
Nuclear Chain Reaction — Splitting nuclei release neutrons, which strike more nuclei, releasing even more neutrons…. Nuclear Fission — Occurs when neutrons impact and split the nuclei of certain atoms.
37. The Nature of Nuclear Energy
Only certain kinds of atoms are suitable for development of a nuclear chain reaction. Uranium 235 (number of neutrons + protons = 235) Plutonium 239 (number of neutrons + protons = 239) Natural Uranium ore only has 0.7% U-235 enriched to 3% to sustain chain reaction fabricated into pellets sealed in fuel rods transported to nuclear power plant
38. Nuclear Power Plants in North America
Illinois Number of nuclear units: 11 Braidwood 1-2, Braidwood, Ill. Byron 1-2, Byron, Ill. Clinton, Clinton, Ill. Dresden 2-3, Morris, Ill. LaSalle 1-2, Seneca, Ill. Quad Cities 1-2, Cordova, Ill.
39. Workings of A Nuclear Reactor
Generates electricity Chain reaction produces heat Converts water to steam Turns a turbine Nuclear Reactor — Device that permits a controlled fission chain reaction.
40. Nuclear Fuel Cycle
As fission occurs, U235 concentration in fuel rods decreases. After about 3 years, fuel rods don’t have enough radioactive material left to sustain a chain reaction Spent fuel rods are replaced by new ones. What to do with the spent fuel rods?
41. Environmental Impacts of Nuclear Power
More than 330 underground storage tanks currently exist with high-level radioactive waste. 5,700 sites have wastes moving through soil. Clean up will take years and cost tens of billions of dollars. Environmental clean up single largest item in DOE budget. Nuclear Wastes
42. U.S. DOE Waste Sites
43. Radioactive Waste Disposal
High Level: At this time, NO country has a permanent storage solution for high-level waste. Politics of disposal are as crucial as disposal method. Waste Isolation Pilot Plant (WIPP) Carlsbad, NM began accepting waste in March, 1999. Environmental Impacts of Nuclear Power
44. High-Level Waste
In 1982, Congress called for a high-level radioactive disposal site to be selected by 1987, and to be completed by 1998. Final Site Selection Occurred in 1989. Yucca Mountain, Nevada Not to be completed before 2015. By that time, waste produced by nuclear power plants will exceed the storage capacity of the site.
45. Low-Level Waste
Currently, U.S. produces about 800,000 m3 of low-level radioactive waste annually. Presently buried in various scattered disposal sites. Includes cooling water from nuclear reactors, material from decommissioned reactors, protective clothing, etc. Prior to 1970, U.S. alone placed 50,000 barrels of low-level radioactive waste on the ocean floor. Banned in 1983.
46. Environmental Impacts of Nuclear Power
In a nuclear power plant, 1/3 of heat used to generate electricity while the other 2/3 is waste heat. Fossil fuel plants are 50:50. Thermal Pollution - Addition of waste heat to the environment Dangerous to aquatic systems
47. Nuclear Power Concerns
Currently, 17% of electricity consumed worldwide comes from nuclear power. Contamination and disposal problems. Accidents raised questions about safety. Life expectancy of reactors originally only 20 years, now extended to 40-60 yearsThree Mile Island—PA March 28, 1979—Partial Core Melt-Down. Pump and valve malfunction Compounded by false readout and operator error No Deaths Very Little Radiation Vented Public Relations Disaster Chernobyl—Ukraine April 26, 1986 Chernobyl — Ukraine Experiments were being conducted on one reactor Reactor Explodes Numerous safety violations Chernobyl—Ukraine Increases in Thyroid cancer rate by 10x 31 deaths 116,000 people evacuated 24,000 evacuees received high doses of radiation Fallout in Scandinavia and Europe New York Times Store Photo: National Guard during October 15, 2004 U.S. Investigating Accident That Shut Down Salem Reactor On Sunday afternoon, operators shut down the Hope Creek nuclear reactor in southwestern New Jersey after a pipe ruptured, sending a cloud of radioactive steam into the building that contains the giant turbine used to generate electricity from the reactor. Federal officials said that as operators worked to shut down the reactor, a key control system malfunctioned and the employees had difficulty finally stabilizing the water that is used to cool the reactor's radioactive core. Officials at the Nuclear Regulatory Commission and at the company that owns the reactor, P.S.E.G. Nuclear L.L.C., said the incident did not pose a threat to the public