1. Renewable & Inexhaustible Energy Sources
Control Power
CVHS

2. Energy vs. Power Energy is defined as “the ability to do work”
Power is a term used to describe the measure of work being done (rate)

3. Energy & Society Without energy, Life would not be possible
Energy not only powers modern technologies including transportation, etc., but is also necessary to power living organisms (people, animals, plants, etc.)

4. Sources of Energy
Nonrenewable
Renewable
Inexhaustible

5. Nonrenewable Energy
This is a source of energy that once used, cannot be replenished
Examples: Coal, Natural gas, Nuclear, etc.

6. Renewable Energy
This is a source of energy that can be replenished if it is used.
Examples: wood, ethanol, food, etc.

7. Inexhaustible Energy
This is a source of energy that can be considered permanent (at least for a few million more years).
Examples: Sun, Wind, Waves, Geothermal

8. Renewable & Inexhaustible Energy
To combat the ill effects, and high costs of nonrenewable energy sources, new technology must be developed.
These new energy technologies must heavily rely on renewable and inexhaustible resources in order to be sustainable

9. Renewable Energy Sources
Animals
Plants
Biomass

10. Animals
Source of food
Source of work energy (especially in underdeveloped countries)
Why are animals considered to be renewable and not inexhaustible?

11. Plants: Wood One of the earliest used fuels
Despite a decline in the 1900’s, wood is once again a popular choice as a home heating fuel.
Can be converted to “wood gas” (methanol) in liquid or gaseous forms
Concerns:
Trees must be immediately replanted to compensate for long growth periods
Burning wood releases pollutants
Creosote Build-up
                                                         

12. Plants: Alcohol
Can be produced from a variety of plant life including: Corn, Sugar beats, Sugar cane, and wood.
Used to run internal combustion engines, etc. (E85, Regular gas usually includes ~ 10% ethanol)
Major Forms: Ethanol & Methanol
Concerns:
Corn ethanol cuts in on a source of food
Still produces pollution

13. Biomass
Bioconversion is a process that burns or converts waste organic material into a useable form of energy
Incinerators burn biomass to produce electricity
Anaerobic Digestion can be used to produce methane gas which can be burned like Natural Gas or Propane

14. Inexhaustible Energy Sources
Sun
Water
Wind
Geothermal

15. Sun
Most energy sources derive their stored energy from the sun, including plants, trees, wind, etc.
The sun provides an almost limitless source of energy that can be collected to produce heat (thermal) or electrical energy.

16. Water: Hydroelectric
Used for decades as an energy source for electricity generation
Uses the power of moving water to spin a turbine, which turns a generator to produce electricity
Most large scale sites have been developed in the US, meaning that only smaller sites may yet be utilized
Three Gorges Dam Expected Finished output 22,500 MW

17. Water: Tides & Waves
Uses the force of tides and waves to produce electricity
Very clean, but may interfere with natural ecosystems, and fishing locations
Tide generators can only be used in certain locations

18. Water: OTEC
Uses the temperature differential between surface water and deep water (energy stored in water by the sun)
Warm water creates steam (spins turbine) cool water condenses steam back into a liquid
Can be used to produce electricity at remote ocean locations
Problems:
Can only be used in certain locations (temp. differential)
Dumping large amounts of cold water into the ocean can damage the ecosystem

19. Water: Hydrogen
Hydrogen is a very energetic & clean fuel source, but is scarce in its natural state
Water molecules can be split to produce Hydrogen and Oxygen
Requires large amounts of energy
Two Forms: Electrolysis & Pyrolysis
Pyrolysis

20. Wind Used for hundreds of years as a mechanical energy source
Now used to produce electricity in large scale wind farms, and residential settings
Problems
Noisy
Large areas of land/ sea required

21. Geothermal
Uses steam from the earth to spin a turbine and produce Electricity
Problems:
Loud
Smelly
May produce Pollution
Heat pumps can also be used to heat water to ~ 55° F for home heating
Problems
Must be used in conjunction with another energy source

22. Conclusions
Dependence on Fossil fuels must change sooner or later due to environmental concerns, and the fact that they will someday run out
Many forms of energy will need to be implemented to replace fossil fuels
Each, has problems associated with it that must be weighed against its benefits