1. Chapter 17: Energy: Some Basics

2. Energy Crisis in Ancient Greece and Rome
Greeks and Romans used wood to heat there 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
In Rome laws pasted to protect a person’s right to solar energy.

4. Energy Today and Tomorrow
Energy situation facing the US today is similar to that faced by Greeks and Romans.
Use of wood peaked 1880s
Coal use peaked 1920
Reaching the peak of oil and gas use
The decisions we make today will affect energy use for generations.

5. Energy Basics
To understand energy it is easiest to begin with the idea of force
We have all exerted force by pushing or pulling
The strength of force can be measured by how much it accelerates an object
Think of pushing a car uphill

7. Energy Basics In physicists’ terms
Exerting force over a distance moved is work
Work is the product of a force times a distance
Energy is the ability to do work
When the car id higher on the hill the potential energy of the car has increased
Energy can be converted from one kind to another
The total energy conserved
First law of thermodynamics

8. Energy Basics
To illustrate the conservation and conversion of energy think of a tire swing
At highest position all energy is stored potential energy
At lowest position all energy is kinetic energy
Energy of motion
With each swing friction slows the swing generating heat energy
Eventually all the energy converted to heat and the swing stops

10. Energy Basics Energy quality Second law of thermodynamics
The ability of the energy to do work
The higher quality of the energy, the more easily it can be converted to work.
The lower the energy quality, the more difficult it is 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.

11. Energy Efficiency
Two fundamental types of energy efficiencies are derived from the first and second laws of thermodynamics:
the first-law efficiency and the second-law efficiency.
First-law efficiency deals with the amount of energy without any consideration of the quality or availability of the energy.

12. 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.

14. 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 of the electricity generated in the world today comes from heat engines
Use nuclear fuel, coal, gas, or other fuels.

15. Energy Source and Consumption
Industrialized countries small percentage of the world’s population, but consume a disproportionate share of the total energy produced in the world.
E.g. US with only 5% of the world’s population, uses approximately 25% of the total energy consumed.

16. 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
Include geothermal, nuclear, hydropower, and solar
Referred to as alternative energy sources.
Solar and wind, are not depleted by consumption and are known as renewable energy.

17. Energy Consumption in the US Today
US dependent on the three major fossil fuels
coal; natural gas; and petroleum.
From 1950 to late-1970s, energy consumption increased tremendously
From 30 exajoules to 80 exajoules.
Since about 1980, energy consumption has increased by only about 20 exajoules.
Suggests that policies to improve energy conservation through efficiency improvements have been at least partially successful.

20. Energy Consumption in the US Today
Energy losses are associated with
the production of electricity and transportation.
Most occur through the use of heat engines
Looking at the generalized energy flow of the US for a particular year
We imported considerably more oil than we produced
Consumption distributed in three sectors: residential/commercial, industrial, and transportation.
We remain dangerously vulnerable to changing world conditions affecting the production of oil.

23. Energy Conservation, Increased Efficiency and Cogeneration
Conservation of energy
Simply getting by with less demand for energy.
Increased energy efficiency
Involves 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).

24. Energy Conservation, Increased Efficiency and Cogeneration
Processes designed to capture and use waste heat rather than release it as a thermal pollution.
Using that waste heat, can increase the overall efficiency of a typical power plant from 33% to as much as 75%
Could provided an estimated 10% of the power capacity of the US

26. Building Design
A spectrum of possibilities exists for increasing 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.
U.S. industry consumes about one-third of the energy produced.
More industries are using co-generation and more energy-efficient machinery.

28. Automobile design Early 1970s, the average US automobile got 14 mpg.
By 1996, the average was 28 mpg for highway driving.
Fuel consumption rates did not improve much from 1996 to 1999.
In 2004 many vehicles sold were SUVs and light trucks with fuel consumption of 10–20 mpg.
A loophole in regulations permits poorer fuel consumption
SUVs declined 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, w/ engines constructed of lighter materials
Combination of a fuel-burning engine with an electric motor

30. Values, Choices, and Energy Conservation
Ways of modifying behavior to conserve energy include the following:
Ride a bike, walk, or take a bus or train to work.
Using carpools to travel to and from work or school
Purchasing a hybrid car (gasoline-electric)
Turning off lights when leaving rooms
Taking shorter showers (conserves hot water)
Putting on a sweater and turning down the thermostat

31. Values, Choices, and Energy Conservation
Using energy-efficient compact florescent lightbulbs
Purchasing energy-efficient appliances
Sealing drafts in buildings with weather stripping and caulk
Better insulating your home
Washing clothes in cold water whenever possible
Purchasing local foods to reduce energy in transport
Using powerstrips and turning them off when not in use

32. Energy Policy
U.S. energy policy during the past half-century has not moved us closer to energy self-sufficiency.
We import more oil than ever.
In the late 1990s, the US spent $2 billion per year on R and D for energy.
By comparison, $45 billion per year went to R and D for the military.

34. Energy Policy Act of 2005 Some of the provisions are as follows.
1. Promotes conventional energy sources
2. Promotes nuclear power
3. Encourages alternative energy
4. Promotes conservation measures
5. Promotes research
6. Provides for energy infrastructure

35. Hard Path vs. Soft Path
Hard path involves finding greater amounts of fossil fuels and building larger power plants.
Continuing the past emphasis on quantity of energy used.
Requires no new thinking; no realignment of political, economic, or social conditions; and little anticipation of coming reductions oil.

36. Hard Path vs. Soft Path According to hard-path proponents, we should
1. Let the energy industry develop the available energy resources
2. Let industry, free from government regulations, provide a steady supply of energy with less total environmental damage.

37. Hard Path vs. Soft Path
The second road of energy policy is called the soft path.
It involves energy alternatives that emphasize
energy quality, are renewable, are flexible, and are environmentally more benign than those of the hard path.

38. Hard Path vs. Soft Path
These alternatives have several characteristics:
They rely heavily on renewable energy resources, such as sunlight, wind, and biomass.
They are diverse and are tailored for maximum effectiveness under specific circumstances.
They are flexible, accessible, and understandable to many people.
They are matched in energy quality, geographic distribution, and scale to end-use needs.

39. Energy for Tomorrow
Future changes in population densities as well as intensive conservation measures will probably change existing patterns of energy use.
To stabilize the climate in terms of global warming, use of energy from fossil fuels would need to be cut by about 50%.
Reductions in energy use need not be associated w/ lower quality of life.

41. Energy for Tomorrow
What is needed is increased conservation and more efficient use of energy:
More energy-efficient land-use planning that maximizes the accessibility of services and minimizes the need for transportation.
Agricultural practices and personal choices that emphasize
1. Eating more locally grown foods
2. Eating more vegetables, beans, and grains.
Industrial guidelines for factories that promote energy conservation and minimize production of waste.

42. Integrated, Sustainable Energy Management
Integrated energy management recognizes that no single energy source can provide all the energy required.
Range of options that vary from region to region will have to be employed.
The mix of technologies and sources of energy will involve both fossil fuels and alternative, renewable sources.

43. Integrated, Sustainable Energy Management
A basic goal is to move toward sustainable energy development, implemented at the local level.
Would have the following characteristics:
It would provide reliable sources of energy.
It would not cause destruction or serious harm to our global, regional, or local environments.
It would help ensure that future generations inherit a quality environment with a fair share of the Earth’s resources.

44. Integrated, Sustainable Energy Management
A good energy plan is part of an aggressive environmental policy with the goal of producing a quality environment for future generations.
A good plan should do the following:
Provide for sustainable energy development.
Provide for aggressive energy efficiency and conservation.

45. Integrated, Sustainable Energy Management
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.

46. 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.
Choosing to own fuel-efficient automobiles and living in more energy-efficient homes are consistent with a sustainable energy system.