1. Chapter 14: Energy: Some Basics

2. Overview Outlook for Energy Energy Basics Energy Efficiency
Energy Sources and Consumption
Energy Conservation, Increased Efficiency and Cogeneration
Sustainable Energy Policy

3. 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 person’s right to solar energy

5. 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

6. 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

7. 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

8. 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

9. Energy Basics Energy quality Second law of thermodynamics
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

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

11. 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

13. 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

14. 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 world’s population
Uses ~25% of the total energy consumed

15. 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

16. 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

17. 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!

20. 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….

21. 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

23. 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.

24. 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)

25. Energy Conservation, Increased Efficiency and 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

26. 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

27. 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

28. Automobile design Early 1970s, By 1996 1996–1999 2004
Ave US automobile = 14 mpg
By 1996
Ave = 28 mpg (highway)
1996–1999
Fuel consumption rates did not improve much
2004
Many vehicles sold were SUVs and light trucks with fuel consumption of 10–20 mpg
SUVs fell into loophole in fuel efficiency regulations
SUVs purchases in 2006

29. 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

31. 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 (gasoline–electric)
Turn off lights when leaving rooms
Take shorter showers
Turn down the thermostat
Use energy-efficient compact florescent lightbulbs
Purchase energy-efficient appliances

32. 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

33. 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

34. 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?

35. 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

36. 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

37. 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 Earth’s resources

38. 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

39. 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