1. Chapter 9 Energy Sources
Section 1 Fossil Fuels

2. How Often do you
Use energy??

3. Can energy be created or destroyed??No
It can only be converted to different types of energy

4. Name one example of how energy is transformed.

5. Energy Usage in the U.S.
37% is used by industry and agriculture to manufacture products and produce food
27% is used for transportation
20% is residential related (heating, cooling, appliances in homes)
16% is business related

6. Sources of Energy in U.S.
85% comes from burning petroleum, natural gas, and coal
The other 15% comes from nuclear, hydroelectric, and biomass etc.

7. Fossil Fuels
These are formed from the decaying remains of ancient plants and animals
Examples:
Coal, petroleum (or oil), and natural gas

8. The energy in fossil fuels
Which do you think has more chemical potential energy: Coal or Wood??

9. Petroleum
Very Flammable!
Mixture of mainly carbon and hydrogen

10. Fractional Distillation
Occurs in oil refinery plants
Crude oil is heated in the tower
Some of the chemicals boil and vaporize to the top and are collected
The others like asphalt and waxes remain liquid and are drained off

11. What are uses for petroleum?

12. Natural Gas Composed mostly of methane
Use in a stove, furnace, hot-water heater, or a clothes drier

13. Coal
Solid fossil fuel
90% of all coal in U.S. is burned by power plants to generate electricity

14. Chapter 9 Energy Sources
Section 2 Nuclear Energy

15. Nuclear Energy
Over the past decades, power plants that do not burn fossil fuels have been developed
Nuclear plants convert
nuclear energy  electrical energy

16. Called nuclear fission:
Nucleus of atom splits

17. Nuclear Energy
Nearly 20% of electricity in the U.S. comes from nuclear power plants
In 2003, there were 104 nuclear reactors producing electricity in 65 nuclear plants in U.S.

18. Nuclear Reactor
Uses the energy from controlled nuclear reactions to generate electricity
Fig. 12 on p. 265

19. Parts of a Nuclear Reactor
Fuel
Undergoes nuclear fission

20. Parts of Nuclear Reactor
2. Control Rods Control nuclear reactions

21. Parts of Nuclear Reactor
3. Cooling System Keeps the reactor from getting to hot and being damaged.

22. Parts of Nuclear Reactor
4. Core Where fission takes place.

23. What is Nuclear Fuel?? Only uses certain elements
Uranium isotope: U-235
Most commonly used
Naturally occurring uranium must be enriched so that it will contain more of the U-235 isotope.

24. What is Nuclear Fuel??
The uranium dioxide is in pellet form (about the size of your pencil eraser)
These pellets are placed end to end in a long tube
Several hundred tubes are bundled together and placed in the reactor’s core

25. What is Nuclear Fuel??
One reactor contains about a hundred thousand kilograms of uranium
For energy kilogram of uranium that undergoes fission, 1 g of matter is converted into energy
Equal to burning over 3 million kg of coal!!

26. Nuclear Fission The uranium-235 nuclei decay which releases neutrons
These neutrons are absorbed by other U-235 nuclei which causes them to split into two separate nuclei that release more neutrons
The process then repeats

27. Controlling the Reaction
The reaction must be controlled or it will release energy in explosive amounts

28. Controlling the Reaction
This is where the control rods come in
Made of boron or cadmium
Absorb some of the neutrons

29. Nuclear Power Plants
The heat produced during the fission process heats water and produces steam

30. Nuclear Power Plants
Steam turns turbine
Rotates electric generator

31. Nuclear Power Plants
And then like magic,
BAAM! Electricity!

32. What about the Risks??
Although it doesn’t release harmful air pollutants, nuclear power can be harmful

33. Risks
The water must be cooled before being released back into the environment

34. Risks Elements used are very radioactive
Could damage any living organism

35. Examples of Accidents Occurred in 1986 in Chernobyl, Ukraine
A reactor core overheated and caught fire which led to an explosion that destroyed the building’s roof
Radioactive material were carried via wind over a large area
28 people died from radiation sickness and over 260,000 other may have been exposed

36. Disposal of Nuclear Waste
After three years the spent fuel (uranium) must be disposed of

37. Low Level Waste
Can be sealed in containers and buried 30 m deep in special locations
Examples:
Clothing, air filters smoke detectors

38. High Level Waste
Stored in deep pool of water to absorb the nuclear radiation.
They are placed in ceramic glass and sealed off in metal-alloy containers.
Buried in stable rock formations or salt deposits hundreds of meters below the ground.

39. Chapter 9 Energy Sources
Section 3 Renewable Energy Sources

40. Energy Options More fuel is needed but fossil fuel is decreasing
Nuclear Reactors produce too much radioactive waste

41. Renewable Resource Energy source that can be replaced after use
Alternative energy source

42. Sun’s Energy Solar Energy
Devices use photovoltaic cell- converts radiant energy  electrical energy
A.K.A. Solar Cells

43. Energy from Water
Uses moving water to turn a turbine and rotate an electric generator
Dams built for this are hydroelectric dams

44. Energy from Water
Hydroelectricity- electricity from energy of moving water
Supplies 8% in U.S.

45. Disadvantage of Hydroelectric Dams
Disturbs balance of natural ecosystem
Blocks fish migration
Location far from regions that need power

46. Wind Energy Use energy of wind to turn propeller
Propeller spins electric generator
Produces electricity

47. Advantages of Wind Energy
Do not consume nonrenewable resources
Do not pollute the atmosphere or water

48. Disadvantages of Wind Energy
Not everywhere has enough wind
Only 20% efficient
Noisy and change landscape
Disrupt migration patterns of birds

49. Geothermal Energy Thermal Energy from hot magma
Used to generate electricity

50. Geothermal Power Plants
Drill well and pump in water
Magma heats and turns to steam
Steam returns and spins turbine

51. Geothermal Power Plants
16% efficient
Releases some sulfur compound containing gases
Limited supply

52. Alternative Fuels Cars with electric motors
Biomass fuel- organic matter
wood, sugarcane fibers, rice hulls, and animal manure