US Energy Consumption Analyzed

Figure 13-4

41% is wasted due to the second law of thermodynamics and inefficient transfer mechanisms (resistance losses, energy transformations, etc.)
43% of US energy is wasted unnecessarily and could be recovered.

Industry's effect on energy consumption:

Industry uses 60-70% of electricity to drive electric motors.

Each year an electric motor consumes 10 times its cost in electricity.
-Motors are run at full speed with no adjustment for work load.
Energy management is currently not a common practice in US.

Energy efficient adjustable -speed motors provide pay-back in 1-3 years of their installation. Energy expense is not considered in the cost of equipment acquisition.

Questions based on Figure 13-2

1. What was the basis of the energy economy in the US until 1800?
2. What was the basis of the energy economy in the US during 1900?
3. What was the basis of the energy economy in the US during 1960?
4. What is the projected basis of the energy economy by the year 2025?
5. What is the projected basis of the energy economy by the year 2100?


Questions based on Figure 13-3

1. What are the noticeable established fuel patterns?
2. How will these current patterns change based on future trends predicted by Figure 13-2?
3. What is the primary difference between Solar heating and carbon based fuels?
4. How does solar heating impact the stored energy reserves?

Current statistics

If LDCs rise to a level equal to US energy consumption rates by 2025, the total commercial energy output must go up by 5 times.

A Comparison and contrast

The Universe runs under specific laws that govern how it will function. The laws of thermodynamics are among the most fundamental of these laws.

Figure 13-3 describes energy ratio of useful energy & waste energy.

Note: A brief review of the laws of thermodynamics is provided as a separate report to assist with this fundamental concept. Review it if you find these concepts difficult or just for further depth of understanding.

Questions based on Figure 13-3 :
1. How much energy cannot be prevented from being wasted? Why?
2. How much energy is wasted totally and how much unnecessarily?
3. Why is there energy that can not be recovered?

First Law of Thermodynamics

Energy is given off of the process to the surroundings but is not created nor destroyed by chemical processes.

The text refers to "energy quality" - a relative scale of energy's ability to do useful work.

Corollaries:
Heat = spontaneous flow from high temperature areas to low temperature surroundings
Work = force x displacement

So the quantity of energy left in a system that has given off some heat (or energy) to the surrounding environment is lower but the total (total = system + env.) energy is still the same.

Second Law of Thermodynamics

Important corollary statement:
('not all energy is transferred in energy transfer reactions, some is always lost to the environment') although the total is the same, the system reacting no longer has some {that was lost} to use again.

Entropy (S) is a direct measure of the randomness or disorder of a system.
Example recalled
Physical changes ranked according to the entropy of a phase change

Ssolid < Sliquid < Sgas (state)
T °C < T °C < T °C (energy)
Entropy<Entropy<Entropy (entropy)

"Although in any process energy is neither created nor destroyed, (first law) the use of energy inevitably leads to a lowering of the "quality" of the energy. ... the energy has a decreased capacity to perform further work. The energy, although conserved, is also to be degraded." (McQuarrie and Rock, pg. 779)

Concepts:
Heat loss to the environment is an increase in entropy and a decrease in energy of the system that lost the heat to the environment.

High quality energy (usable energy), transformed into low quality energy or entropy, is less usable to do further work.

Examples: To keep the order of molecules and structure of your body, you must use energy or it degrades and increases in entropy. Therefore you burn fuel to keep the energy and order as high as possible and the entropy at a minimum for as long as possible.

Reduction of energy effect of the second law:

Efficiency reduces waste heat and minimizes entropy.

Remember examples of matching energy use to the quality of energy
Example:

Space heating requires lowest quality energy
Use of high quality energy to perform this task is wasteful

Solar heating (passive) is efficient because it captures waste heat.

More efficient motors use less electricity to produce more work so a smaller percentage of waste per the amount of work done is produced.

Figure 13-5 Energy efficiency of some future energy conversion devices.

Questions:
1. Where does the other 77%, 90% and 95% go?
2. How have you personally experienced these waste energies?
3. Which of these is more "high tech"?

Question:
Through Figure 13-6 compare the efficiency of nuclear {fission} power and Passive Solar energy.

1. Introduction
   
   1. Reserves vs. Resources
      1. reserve - quantity of material that has been found and is recoverable
         economically and with existing technology
      2. resource - total quantity of a given commodity on Earth, discovered
         and undiscovered
         

2. Non-renewable

1. Coal
   1. Formation of coal using Pennsylvania as an example
      1. Pennsylvania Period - 290 - 330 MYA
         1. deposition of sediments in receiving basin and broad, alluvial plain at times covered with clastic sediments from mountains to the SE
         2. formation of very extensive swamps
            
         3. tropical to subtropical
      2. 12m thick coal bed represents up to 400,000 years of
         accumulation

   2. Sulfur content
      1. in form of sulfate, pyrite, and organic sulfur
      2. varies with type of coal
         1. PA. anthracite (eastern part of state) ranges from 0.3% - 5.1% with an average of 0.8%
            1. 0.02% sulfate, 0.35% pyritic, 0.48% organic
         2. some deposits in New England, parts of Illinois, Powder River Basin in Montana and WY, Alaska (underlie ~ 9% of its area), VA, and W.Va. - 0.4%- 1% sulfur ( high BTUs)

   3. In general:
      1. Western basins: thick (some > 61m), lignite, subbituminous, bituminous, low in sulfur (‹ 1%)
      2. Eastern basins: thinner (‹ 3m), bituminous and anthracite, range in sulfur (1% - 3%)
      3. BTUs:
         1. lignite: ‹ 8000 ; ‹ 20 % carbon
         2. subbituminous: ‹ 10,000 ; ‹ 40 % carbon
         3. bituminous: 10,000 - 15,000 ; 40 % - 75 % carbon
         4. anthracite: 14,000 - 15,000 ; 90 % - 95 % carbon

   4. Dirtiest fuel to burn
   5. Bituminous coal = 51% of reserve
   6. Resources
      1. estimated to be sufficient to last 900 years at the current rate of usage
      2. if usage increased 2%/year, estimated to last 149 years
      3. U.S. resources
         1. 4 trillion tons
         2. estimated to sufficient to last 100 years

   7. Reserves - coal resources that have been mapped within specific levels of accuracy and reliability. Coal beds meet minimum thickness and depth criteria for economic mining under current technology.
      1. will last 220 years at current usage rate
      2. if usage is increased by 2% / year, estimated to last 65 years
      3. U.S. reserves - 470 billion short ton
         1. because of property rights, land use conflicts, and physical and environmental restrictions, some may not be available or accessible

   8. Recent environmental problem - Grand Staircase - Escalante National Monument

2. Natural Gas
   1. High net energy yield
   2. less air pollution than any other fossil fuel
      
      1. 60 % ‹ that of coal and ‹ oil
   3. World resources
      1. projected to last 80 years
   4. U.S. resources
      1. projected to last 60 years

3. Petroleum
   1. not distributed democratically
   2. economically depleted when 80% of supply has been used
   3. Global reserves - last for ~ 43 years at current rate
      1. undiscovered might add another 2 - 4 years
   4. U.S. reserves depleted by 2018

4. Oil Shale
   1. not always shale, kerogen (waxy and solid)
   2. meet our demands for 40 years
   3. may be 200X estimated supplies of conventional oil
   4. Problems:
      1. low net yield of energy - water usage
      2. water pollution - toxic metal compounds
      3. sulfur dioxide pollution

5. Tar sands
   1. meet only about 3 months of U.S. needs
   2. problems:
      1. low energy net yield
      2. large amounts of air pollution
      3. waste disposal ponds

Middle Pennsylvanian - Cratonic Source

Types of Petroleum Traps

U.S. Oil Shale Deposits