Sustainable Energy

1. Sustainable Energy Chapter 20 Emily Damon Period 4/5 APES Dr. Unfried

2. Conservation • Much of the energy Americans use is wasted; used for trivial or extravagant purposes • Many conservation techniques are simple and cost effective • Compact fluorescent bulbs produce 4x as much light and last 10x longer, one can save $30-50 in a lifetime • Light-emitting diodes (LEDs) consume 90% less energy than regular bulbs • In 1980s, U.S. businesses saved $160 billion per year through conservation

3. Household Energy Conservation • Today’s homes use 50% less fuel than a home built in 1974, but can still be reduced • Better insulation, double or triple glazed windows, thermal efficient curtains or window coverings, sealing cracks and loose joints, reducing air infiltration • National standards passed in 2001 required all new washing machines to use 35% less water in 2007 • Reduce water use in the U.S. by 40 trillion liters per year

4. U.S. Energy Consumption

5. Simple Solutions • Turn off appliances; standby mode still uses a lot of power • Standby appliances represent 25% of a monthly electric bill • Home office equipment biggest consumer • Putting computer on sleep mode saves 90% of energy, but best to turn it off

6. Foreign Programs • R-2000 program in Canada • Special double-glazed windows have internal reflective coatings and are filled with an inert gas (argon or xenon) • Have an insulation factor of R11, 10x as efficient as a single-pane window • Superinsulated homes in Sweden require 90% less energy for heating and cooling than an American home

7. Natural Solutions • Designing homes with living spaces near sun for the winter and shaded by tress or overhang in the summer • Earth-sheltered homes built in south-facing side of slopes or protected on three sides by an earth berm are efficient energy savers • Maintain constant subsurface temperatures • Sod roofs provide good insulation, prevent rain runoff, last longer than asphalt shingles • Straw-bale construction offers high insulation qualities and a renewable, inexpensive, easy to construct building material

8. Carbon Zero Home

9. Energy Efficiency • Measurement of the energy produced compared to energy consumed • Thermal-conversion machines (steam turbines in coal-fired or nuclear power plants) can only use 40% of energy in primary fuel into electricity or power because of waste heat • Some waste heat is recaptured and used for space heating • Fuel cells convert chemical chemical energy directly to electricity without a combustion cycle

10. Transportation • Automobiles and trucks account for 40% of U.S. oil consumption and produce 1/5 of carbon dioxide emissions • EPA states raising average fuel efficiency of a passenger fleet by 3 mpg, American consumers would save$25 billion a year, reduce carbon dioxide emissions by 140 million metric tons per year, and save more oil than the minimum expected production from Alaska’s Arctic National Wildlife Refuge • Bureau of Transportation reports more vehicles than drivers in U.S. • Cars used for 1 billion trips per day • Census Bureau reports 3/4 of workers commute alone in private vehicles • < 5% use public transportation or carpool, 0.38% walk or ride a bike

11. Automobiles • Gas mile averages are dependant on fuel costs • In 2004, EPA stated SUVs averaged 17.9 mpg and cars averaged 24.6 mpg • Nearly half of all passenger vehicle sales in U.S. are SUVs and light trucks • Conservationists state efficiency standards should be raised to 44 mpg for cars and 33 mpg for SUVs and light trucks • SUVs and pickup trucks more dangerous than midsize automobiles and no safer than compact or subcompact cars • Daimlerchrysler ‘smart car’ from Europe gets 60mpg and easy to maneuver

12. Diesel-Power • Some European models get 78 mpg • Clean-diesel technology much cleaner and quieter than years before • Diesel fuel in U.S. is 10x higher in sulfur (causes acid rain) than in Europe • Diesel soot linked to asthma and lung cancer

13. Net Energy Yield • Measure of energy efficiency • Based on total useful energy produced during the lifetime of an entire energy system without the energy required to make useful energy available • Often expressed as a ratio between output of useful energy and energy costs for construction, fuel extraction, energy conversion, transmission, waste disposal, etc. • Yield/cost ratio and conversion-cycle efficiency also helpful considerations

14. Moneysaving Programs • Utility companies pay less to finance conservation projects than build new power plants • Pacific Gas and Electric in California, Potomac Power and Light in Washington, D.C., both instituted conservation programs • Found conservation costs $350 per kilowatt saved • New nuclear power plant costs $3,000 and $8,000 per kW • Conservation programs also do not consume fuel or produce pollutants • South Korea began conversation program with energy standards and economic incentives for eco-friendly practices

15. Cogeneration • Simultaneous production of electricity and steam or hot water at the same plant • Net energy yield increased from 30-35% to 80-90% • Cogeneration is not a significant part of power supply • Combined-cycle coal-gasification plants highly efficient and cleanly operated • Small power-generating units burn methane, natural gas, diesel fuel, or coal • Inexpensive, produce relatively large amounts of energy, reliable

16. Cogeneration Plant

17. Solar Energy • All biomass results from converting light energy into chemical bond energy • Simplest use of solar energy is passive heat absorption • Using natural materials or absorptive structure with no moving parts to gather and hold heat • Modern adaptation greenhouse, glass walls with energy-storing materials (bricks, stone, etc.) • Interior, heat-absorbing wall called Trombe wall is good heat collector • Active solar systems reduce water heating energy • Accounts for 15% of U.S.’s domestic energy budget • Solar energy stored in a large, insulated bin containing stone, water, or clay

19. High-Temperature Solar Energy • Parabolic mirrors are curved reflecting surfaces that collect light and focus it to a concentrated point. • Two ways to collect solar energy with mirrors • Mirrors focused on a central tube containing heat-absorbing liquid; fluid reaches higher temperature than a basic flat panel collector • Thousands of small mirrors in rings around a tall central tower; track the sun and focus light on heat absorber at power tower • Used in solar cookers

20. Energy Policies • Encourage conservation and alternative energy sources • Iowa’s Revolving Loan Fund provides low-interest loans for renewable energy and conservation • Colorado among first to promote green pricing (profits from conservation programs) • Customers agreed to pay higher electric rates to fund wind farm • 1997 British Petroleum PLC put $20 million into solar cell manufacturing facility

21. Photovoltaic Cells • Captures solar energy and converts directly to electrical currents • First observed by Alexandre-Edmond Becquerel in 1839 • Used in U.S. space exploration, since then prices have dropped • Part of the invention of amorphous silicon collectors • Lightweight, require less material than conventional photovoltaic cells

23. Fuel Cells • Use ongoing chemical reactions to produce electrical current • NASA developed modern fuel cell to provide water and electricity for shuttles • Small size, high efficiency, low emissions, net water production, no moving parts • Positive electrode (cathode) and negative electrode (anode) separated by electrolyte (allows passage of charges atoms, but impermeable to electrons) • Proton exchange membrane (PEM) used in automobiles, lightweight, operates at low temperature, fuel efficiency less than 40% • Stationary electrical generation uses phosphoric acid immobilized in a porous ceramic matrix • Higher efficiency, 40-50%, heavier and larger, less sensitive to carbon dioxide contamination

24. PEM and Phosphoric Acid Fuel Cell

25. Biomass • Wood provides <1% of U.S. energy • Still prominent(95%) in poor countries of world • Northern countries burn wood to avoid rising oil, coal and gas prices • Produces smoke, soot, carbon monoxide and hydrocarbons • EPA ranks wood burners on list of heath risks, recommend switching to low-emission models • Catalytic combustors placed inside stovetops, burn carbon monoxide and hydrocarbons, recapture heat • 40% world population depends on firewood and charcoal • 3/4 do not have enough

26. Other Options • Dry and burn animal manure • Intensifies food shortages, reduces crop productions • Burned in open fires, 90% potential heat and most nutrients lost • More efficient to produce methane gas with methane digester • Produced by anaerobic decomposition of organic material when organic wastes are placed in a container with warmth and water • Remaining sludge excellent fertilizer

27. Hydropower • Many countries produce their electricity from water • Norway depends on water for 99% of power • 2.3 of economically feasible potential remains undeveloped • Recent development in large-scale dams • Bring unwanted social and environmental effects • Can cause catastrophic floods and thousands of deaths • Sedimentation, rotting vegetation, human displacement, wildlife losses, pesticide pollution • Low-head hydropower technology, small scale dams cause less damage • High-efficiency turbines submerged into streams, do not require dam, minimal environmental damage • Micro-hydro generators provide enough energy for one home • Public Utility Regulatory Policies Act of 1978 included economic incentives for small-scale energy projects

28. Wind Energy • High oil prices in 1970s created new interst in wind power • Can generate 5 MW of electricity, 5,000 American homes • Cheapest source of new power generation • Shorter planning and construction times than fossil fuel or nuclear power plants • No fuel costs or air emissions • Intermittent source,not useable in every location • Germany get 1/3 of electricity from wind power • Construction cheap and simple • Farmers could cultivate 90% of fields white earning $2,000 or more in rent • High bird mortality, some object to physical appearance, not located near cities, difficult to store energy

29. Geothermal Energy • Areas around continental plates have energy in forms of hot springs, geysers and fumaroles • Yellowstone National Park in U.S., ad Iceland, Japan and New Zealand all high concentrations of geothermal springs and vents • Electric power production, industrial processing, space heating, agriculture, aquaculture • Long life span, no mining or transportation of fuels, little waste disposal • Geothermal system with reduce home heating and cooling by 50% and pay for itself in 5 years • Potential of noxious gases in steam, noise problems from steam-pressure relief valves

30. Tidal and Wave Energy • Tidal station similar to hydropower dam, turbines spin as tide flows through • Fears of saltwater flooding freshwater aquifers, flooding and discursion of shoals, salt flats, breeding grounds of aquatic species, vital food source for shorebirds • Heavy siltation, scouring of seafloor as a result of water shooting through dam • Still not well researched, wave power could contribute to 16% of world electrical output

31. Ocean Thermal Electric Conversion • Differences in temperature between upper and lower layers of ocean water potential source of renewable energy • Ocean thermal electric conversion system heat from warmed upper lawyers evaporates a working fluid like ammonia or Freon • Gas pressure high enough to spin turbines to generate electricity, cold water pumped to cool gas • Best for locations on top of volcanic seamounts • Hawaii, west coast of Africa, south coast of Java, and South Pacific islands all usable

32. Works Cited Cunningham, William P., Mary Ann Cunningham, and Barbara Woodworth Saigo.      Environmental Science: A Global Concern. Boston: McGraw-Hill, 2007.      Print. "Fuel Cell." Udomi. N.p., 2009. Web. 8 Feb. 2010. <http://www.udomi.de/      fuelcell/fuelcell-basics.html>. "How Fuel Cells Work." PBS. N.p., July 2005. Web. 8 Feb. 2010.      <http://www.pbs.org/wgbh/nova/sciencenow/3210/01-fcw.html>. "Renewable Hydropower." U.S. Energy Information Administration. N.p., n.d. Web.      8 Feb. 2010. <http://tonto.eia.doe.gov/kids/      energy.cfm?page=hydropower_home-basics>. "Sustainable Energy." World Nuclear Association. N.p., Aug. 2009. Web. 8 Feb.      2010. <http://www.world-nuclear.org/info/inf09.html>.