Chapter 14: Energy: Some Basics

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Chapter 14Energy Some Basics
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Overview

• Outlook for Energy
• Energy Basics
• Energy Efficiency
• Energy Sources and Consumption
• Energy Conservation, Increased Efficiency and
  Cogeneration
• Sustainable Energy Policy

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Outlook for Energy

• Energy Crisis in Greece and Rome
• Greeks and Romans used wood to heat their homes
• As local supplies ran out had to bring it in from
  farther away
• Eventually both societies learned to build houses
  south facing
• Allows sun to heat house in winter
• Sustainable
• Laws protected a persons right to solar energy

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Outlook for Energy

• Energy situation facing the US today is similar
  to that faced by Greeks and Romans
• Wood use peaked in 1880s
• Coal use peaked in 1920
• Reaching the peak of oil and gas use
• The decisions we make today will affect energy
  use for generations

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Energy Basics

• Force
• Exert force by pushing or pulling
• Strength of force can be measured by how much it
  accelerates an object
• Ex pushing a car uphill

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Energy Basics

• Physics terms
• Work - exerting force over a distance
• Work is the product of a force times a distance
• Energy - ability to do work
• When the car is on the hill, it has potential
  energy
• Energy can be converted from one kind to another
• First law of thermodynamics- total energy must be
  conserved

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Conservation of Energy Illustration

• Tire swing
• Highest position - all energy is stored potential
  energy
• Lowest position - all energy is kinetic energy
• Energy of motion
• With each swing friction slows the swing - heat
  energy
• Eventually all energy is converted to heat and
  the swing stops

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Energy Basics

• Energy quality
• The ability of the energy to do work
• Higher quality of the energy more easily
  converted to work
• Lower energy quality more difficult to convert
  to work
• Second law of thermodynamics
• Energy always tends to go from a more usable
  (higher-quality) form to a less usable
  (lower-quality) form
• When you use energy, you lower its quality

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Energy Efficiency

• Two fundamental types of energy efficiencies
• Derived from the first and second laws of
  thermodynamics
• First-law efficiency
• Second-law efficiency
• First-law efficiency
• Deals with the amount of energy without any
  consideration of the quality or availability of
  the energy

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Energy Efficiency

• Second-law efficiency
• Refers to how well matched the energy end use is
  with the quality of the energy source
• Low values indicate where improvements in energy
  technology and planning may save significant
  amounts of high-quality energy

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Energy Efficiencies

• Electricity generating plants have nearly the
  same first-law and second-law efficiencies
• Generating plants are examples of heat engines
• Produces work from heat
• Most electricity generated in the world comes
  from heat engines
• Use nuclear fuel, coal, gas, or other fuels

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Energy Sources and Consumption

• Industrialized countries
• Small percentage of the total population
• Large user of total energy produced
• Ex United States
• Only 5 of the worlds population
• Uses 25 of the total energy consumed

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Fossil Fuels and Alternative Energy Sources

• 90 of the energy consumed in the US comes from
  fossil fuels
• Petroleum, natural gas, and coal
• They are essentially nonrenewable
• Other sources of energy
• Alternative energy sources
• Geothermal, nuclear, hydropower, and solar
• Renewable energy sources
• Solar and wind
• Not depleted by consumption

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Energy Consumption in the US Today

• US dependent on the three major fossil fuels
• Coal
• Natural gas
• Petroleum
• From 1950 to late-1970s, energy consumption
  increased
• From 30 exajoules to 80 exajoules

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Energy Consumption in the US Today

• Since about 1980, energy consumption has
  increased by only about 25 exajoules
• Suggests that policies to improve energy
  conservation through efficiency improvements have
  been at least partially successful
• Energy losses are associated with
• Production of electricity and transportation
• Use of heat engines
• Energy loss in 2009 was equal to energy usage in
  1965!

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Energy article read

• Read article and highlight important topics
  regarding energy consumption
• Summarize article in 10 sentence and be ready to
  share with a neighbor.

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Energy Consumption in the US Today

• Look at the generalized energy flow of the US for
  a particular year (next few slides)
• We imported considerably more oil than we
  produced
• Consumption distributed in three sectors
• Residential/commercial
• Industrial
• Transportation
• We remain dangerously vulnerable to changing
  world conditions affecting the production of oil

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Energy crisis poster

• Create and Develop an informational poster
  diagramming the energy crisis in the united
  states be sure to include some ideas from the
  article and your own research.
• Make sure it attracts the eyes and makes it known
  the trouble we are having with energy.

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Energy Conservation, Increased Efficiency and
Cogeneration

• Conservation of energy
• Using less energy
• Adjusting our energy needs and uses to minimize
  the amount of high-quality energy necessary for a
  given task
• Increased energy efficiency
• Designing equipment to yield more energy output
  from a given amount of input energy (first-law
  efficiency)
• Better matches between energy source and end use
  (second-law efficiency)

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Energy Conservation, Increased Efficiency and
Cogeneration

• Cogeneration
• Processes designed to capture and use waste heat
  (no thermal pollution)
• Captured waste heat increases overall efficiency
  of a typical power plant from 33 to 75
• Could provided 10 of the power capacity of
  the US

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Building Design

• Many ways to increase energy efficiency and
  conservation in residential buildings
• Design and construct homes that minimize the
  energy consumption
• Design buildings to take advantage of passive
  solar potential
• For older homes insulation, caulking, weather
  stripping, installation of window coverings,
  storm windows, and regular maintenance

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Industrial Energy

• Industrial production of goods continues to grow
  significantly
• US industry consumes 1/3 of the energy produced
• More industries are using co-generation and more
  energy-efficient machinery

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Automobile design

• Early 1970s,
• Ave US automobile 14 mpg
• By 1996
• Ave 28 mpg (highway)
• 19961999
• Fuel consumption rates did not improve much
• 2004
• Many vehicles sold were SUVs and light trucks
  with fuel consumption of 1020 mpg
• SUVs fell into loophole in fuel efficiency
  regulations
• SUVs purchases in 2006

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Automobile design

• Today, some hybrid (gasoline-electric) vehicles
  exceeds 90 mpg on the highway and 60 mpg in the
  city
• Improvement has several causes
• Increased efficiency and resulting conservation
  of fuel
• Cars that are smaller engines constructed of
  lighter materials
• Combo of a fuel-burning engine and an electric
  motor
• Plug-in hybrids

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Values, Choices, and Energy Conservation

• Ways of modifying behavior to conserve energy
  include the following
• bike, walk, or take a bus or train to work
• Carpools
• Hybrid cars (gasolineelectric)
• Turn off lights when leaving rooms
• Take shorter showers
• Turn down the thermostat
• Use energy-efficient compact florescent
  lightbulbs
• Purchase energy-efficient appliances

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Values, Choices, and Energy Conservation

• Seal drafts in buildings
• Better insulate your home
• Wash clothes in cold water whenever possible
• Purchase local foods to reduce energy in
  transport
• Use power strips and turning them off when not in
  use

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Energy Policy

• Business-As-Usual Approach (our current approach)
• Philosophy
• Find more fossil fuel
• Build larger power plants
• Use energy as freely as we always have
• Requires no new thinking
• Requires no realignment of political, economic or
  social conditions
• Does not anticipate reductions in oil production

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Energy for Tomorrow

• Existing patterns of energy use will change based
  on
• Changes in population densities
• Intensive conservation measures
• 2050 energy consumption of US may be 160
  exajoules
• What will the energy source be?
• Will we follow business-as-usual or turn to
  alternative sources?

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Energy Policy for the 21st century

• Promote conventional energy sources
• But reduce our reliance on foreign sources
• Encourage alternative energy
• Wind, solar, geothermal, hydrogen and biofuels
• Provide for energy infrastructure
• Promote conservation measures
• Higher product efficiency standards, less waste
  energy, tax credits
• Evaluate the pros and cons of nuclear power
• Promote research into all energy sources

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Integrated, Sustainable Energy Management

• No single energy source can provide all the
  energy required.
• Range of options that vary from region to region
  will have to be employed
• Fossil fuels
• Alternative, renewable sources

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Integrated, Sustainable Energy Management

• Basic goal is to move toward sustainable energy
  development
• Implemented at the local level
• Would have the following characteristics
• Provide reliable sources of energy
• Not cause destruction or serious harm to our
  global, regional, or local environments
• Help ensure that future generations inherit a
  quality environment with a fair share of the
  Earths resources

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Integrated, Sustainable Energy Management

• A good plan should do the following
• Provide for sustainable energy development
• Provide for aggressive energy efficiency and
  conservation
• Provide for the diversity and integration of
  energy sources
• Provide for a balance between economic health and
  environmental quality
• Use second-law efficiencies as an energy policy
  tool

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Integrated, Sustainable Energy Management

• The global pattern of ever-increasing energy
  consumption led by the US cannot be sustained w/o
  a new energy paradigm
• Includes changes in human values rather than a
  breakthrough in technology
• Examples
• Choosing to own fuel-efficient automobiles
• Living in more energy-efficient homes