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

Sustainable EnergySustainable EnergyChapter 20Chapter 20

Emily DamonPeriod 4/5 APESDr. Unfried

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

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

U.S. Energy Consumption

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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

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

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

Carbon Zero Home



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

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

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

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

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

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

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

Cogeneration Plant



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







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

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

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



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

PEM and Phosphoric Acid Fuel Cell



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

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 digesterProduced by anaerobic decomposition of

organic material when organic wastes are placed in a container with warmth and water

Remaining sludge excellent fertilizer

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

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

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

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

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

Works CitedCunningham, 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>.

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