1. Energy Notes- Ecology Fossil Fuels, Nuclear Energy

2. Energy Sources and Consumption
Energy sources used to be local
Now they are worldwide
Fossil fuels
Nuclear energy
Electricity
Energy consumption is different between developing and developed nations
20% of world’s population use 60% of the world’s energy sources

4. Energy consumption in the US
Industries (production) use the most
Heating, cooling, and illuminating building is 1/3

5. Fossil Fuels Combustible deposits in the Earth’s crust
Composed of the remnants (fossils) of prehistoric organisms that existed millions of years ago
Includes coal, oil (petroleum) and natural gas
Non-renewable resource
Fossil fuels are created too slowly to replace the reserves we use

6. How Are Fossil Fuels Formed?
300 million years ago
Climate was mild
Vast swamps covered much of the land
Dead plant material decayed slowly in the swamp environment

7. How Are Fossil Fuels Formed
Over time, layers of sediment accumulated over the dead plant material
Coal
Heat, pressure and time turned the plant material into carbon-rich rock (coal)
Oil
Sediment deposited over microscopic plants
Heat pressure and time turned them into hydrocarbons (oil)
Natural Gas
Formed the same way as oil, but at temperatures higher than 100 °C

8. Coal Occurs in different grades Lignite Subbitumimous Bituminous
Based on variations in heat and pressure during burial
Lignite
Subbitumimous
Bituminous
Anthracite
Most, if not all, coal deposits have been identified
Primarily in northern hemisphere

9. Coal US has 25% of world’s coal supplies
Known coal deposits could last 200 years
At present rate of consumption

10. 2 Types of Coal Mining Surface mining (right) Subsurface mining
Chosen if coal is within 30m of surface
mineral and energy resources are extracted near Earth’s surface by first removing the soil, subsoil, and overlying rock strata
Subsurface mining
Extraction of mineral and energy resources from deep underground deposits

11. Environmental Impacts of Mining Coal
Surface Mining Control and Reclamation Act (1977)
Requires filling (reclaiming) of surface mines after mining
Expensive!
Reduces Acid Mine Drainage
Requires permits and inspections of active coal mining sights
Prohibits coal mining in sensitive areas
Mountaintop Removal
Fills valleys and streams with debris

12. Environmental Impacts of Burning Coal
Releases large quantities of CO2 into atmosphere
Greenhouse gas
Releases other pollutants into atmosphere
Mercury
Sulfur oxides
Nitrogen oxides
Can cause acid precipitation

13. Making Coal Cleaner
Fluidized Bed Combustion (below)

14. Oil and Natural Gas
Oil and gas provide 60.6% of world’s energy

15. Petroleum Refining
Numerous hydrocarbons present in crude oil (petroleum) are separated
Based on boiling point
Natural gas contains far fewer hydrocarbons than crude oil
Methane, ethane, propane and butane

16. Oil and Natural Gas Exploration
Oil and natural gas migrate upwards until they hit impermeable rock
Usually located in structural traps

17. Oil Reserves Uneven distribution globally
More than half is located in the Middle East

18. Natural Gas Reserves Uneven distribution globally
More than half is located in Russia and Iran

19. Environmental Impacts of Oil and Natural Gas
Combustion
Increase carbon dioxide and pollutant emissions
Natural gas is far cleaner burning than oil
Production
Disturbance to land and habitat
Transport
Spills- especially in aquatic systems
Ex: Alaskan Oil Spill (1989), BP oil spill (2010)

20. Day 2:
Nuclear energy

21. Nuclear Energy

22. New York Times

23. Introduction to Nuclear Energy
Energy released by nuclear fission or fusion
Nuclear fission
Splitting of an atomic nucleus into two smaller fragments, accompanied by the release of a large amount of energy
Nuclear fusion
Joining of two lightweight atomic nuclei into a single, heavier nucleus, accompanied by the release of a large amount of energy

24. Atoms and Radioactivity
Nucleus
Comprised of protons (+) and neutrons (neutral)
Electrons (-) orbit around nucleus
Neutral atoms
Same # of protons and electrons

25. Radioactive Isotope Unstable isotope Radioactive Decay Example
Emission of energetic particles or rays from unstable atomic nuclei
Example
Uranium (U-235) decays over time to lead (Pb-207)
Each isotope decays based on its own half-life

26. Nuclear Fission U-235 is bombarded with neutrons
The nucleus absorbs neutrons
It becomes unstable and splits into 2 neutrons
2-3 neutrons are emitted and bombard another U-235 atom
Chain reaction

27. Nuclear Fission Nuclear Fuel Cycle
processes involved in producing the fuel used in nuclear reactors and in disposing of radioactive (nuclear) wastes

28. How Electricity is Produced

30. Pros and Cons of Nuclear Energy
Less of an immediate environmental impact compared to fossil fuels

31. Pros and Cons of Nuclear Energy
Pros (continued)
Carbon-free source of electricity- no greenhouse gases emitted
May be able to generate H-fuel
Cons
Generates radioactive waste
Many steps require fossil fuels (mining and disposal)
Expensive

32. Cost of Electricity from Nuclear Energy
Cost is very high
20% of US electricity is from Nuclear Energy
Affordable due to government subsidies
Expensive to build nuclear power plants
Long cost-recovery time
Fixing technical and safety issues in existing plants is expensive

33. Safety Issues in Nuclear Power Plants
Meltdown
At high temperatures the metal encasing the uranium fuel can melt, releasing radiation
Probability of meltdown or other accident is low
Public perception is that nuclear power is not safe
Sites of major accidents:
Three Mile Island
Chornobyl (Ukraine)

34. Three-Mile Island 1979- most serious reactor accident in US
50% meltdown of reactor core
Containment building kept radiation from escaping
No substantial environmental damage
No human casualties
Elevated public apprehension of nuclear energy
Led to cancellation of many new plants in US

35. Chernobyl 1986- worst accident in history
1 or 2 explosions destroyed the nuclear reactor
Large amounts of radiation escaped into atmosphere
Spread across large portions of Europe

36. Fukushima Daiichi nuclear complex

37. Film clips Meltdown at Chernobyl

38. Chernobyl Radiation spread was unpredictable
Radiation fallout was dumped unevenly
Death toll is 10, ,000

39. Radioactive Waste Low-level radioactive waste-
Radioactive solids, liquids, or gasses that give off small amounts of ionizing radiation
High-level radioactive waste-
Radioactive solids, liquids, or gasses that give off large amounts of ionizing radiation

40. Radioactive Wastes Long term solution to waste
Deep geologic burial –Yucca Mountain
As of 2004, site must meet EPA million year standard (compared to previous 10,000 year standard)
Possibilities:
Above ground mausoleums
Arctic ice sheets
Beneath ocean floor

41. Radioactive Waste Temporary storage solutions
In nuclear plant facility (require high security)
Under water storage
Above ground concrete and steel casks
Need approved permanent options soon.

42. Case-In-Point Yucca Mountain
70,000 tons of high-level radioactive waste
Tectonic issues have been identified

43. Decommissioning Nuclear Power Plants
Licensed to operate for 40 years
Several have received 20-year extensions
Power plants cannot be abandoned when they are shut down
Three solutions
Storage
Entombment
Decommissioning (dismantling)