Energy Resources

1. Energy Resources • Two types of energy resources • Nonrenewable- resources that when used can not be made fast enough to replenish supply • Renewable- resources that can be regenerated to replenish supply

2. Nonrenewable resources • Fossil fuels • Fossil – any remains or evidence of ancient life • Fossil fuels- energy resources that formed from the remains of once living organisms

3. Oil and Natural Gas • Oil and Natural gas • Formation- • Requires a large amount of organic matter; organic matter is rich in Carbon and Hydrogen. • Organic matter must be buried quickly. • As it is buried increased temperature and pressure changes organic matter to hydrocarbons.

4. Oil and Natural Gas • Migration- • Source rock- usually fine grained clastic rocks of low permeability • Kerogen (hydrocarbons) are forced out of rock by increased temperature and pressure (takes a long time) • Note gas and oil are less dense than water and will tend to float.

5. Oil and Natural Gas • Reservoir rocks- rocks where hydrocarbons can be found. • Oil and gas can move to the surface and evaporate. • Trapped by geologic contacts • anticline • reef bounded by impermeable rocks • fault trap • salt dome

6. Oil and Natural Gas • Time factor- • Geologists range the formation of oil from 10’s of thousands of years millions of years • Practically too long • Supply and demand- • Units of oil are referred to as barrels (42 gallons) • World has an estimated 1 trillion barrels which can be produced. • Estimated world consumption is 400 billion barrels • ½ of the consumption has taken place in the last 20 years  

7. Oil and Natural Gas • Future prospects- • Supply and demand- prices will rise as reserve decreases. • As prices rise, exploration and discovery of new resources may be made.

8. Oil and Natural Gas • Removing the oil- • Primary recovery • Pressure in oil reservoirs creates a “gushing” of oil (like artesian wells). • Secondary recovery • filling reservoir with water will force the oil to float to the top • Primary + secondary yields 1/3 of oil in trap. • Research needs to be done to be able to recovery more of the oil. • Enhanced recovery • Explosives and high pressure water- increases permeability • Pressurized CO2- can force out oil under pressure • c.Hot water- quickens oil movement

9. Coal • Coal • Burning coal accounts for 20% of US energy consumption. • Geology of coal- • Made of organic matter in ancient fresh to brackish water swamps. (Ex. Estuaries, coastal lagoons…) • Formation starts with swamp plants. • Decomposed plants and oxygen poor soil creates peat. • With increased pressure, the water and gases in the peat are squeezed out. • With burial, the peat is compressed forming coal.

10. Coal • Classification of coal- • Rank- is based on % of carbon and heat value • Sulfur content- determines pollution potential of coal when burned. • low 0-1% • medium 1.1-3% • high >3%

11. Coal • Mining of Coal- • Strip mining- open pit • coal needs to be within 50m of surface • area mining- relatively flat areas • contour mining- hilly to mountainous areas • Impact • With abundant rainfallacid mine drainage • Need to have water diversion and treatment • Destroys scenic beauty • *Federal guidelines state coalmines should be reclaimed

12. Coal • Underground mining • Mine a seam of coal in mines • Mine accidents are becomes less and less frequent in the US. • Future uses of coal- • Coal is limited resource; but not as limited as oil and gas. • Demand for coal will increase. • More land will be stripped. • Coal after burning produces ash. 85% of the ash is useless and must be disposed of in a sanitary landfill.

13. Other fossil fuels • Other fossil fuel sources • Oil shale- immature source rock • Oil shale resources in the US are estimated to be 2 trillion barrels (3 trillion world wide) • 1.8 trillion barrels in the Green River Basin. • Removal of oil from oil shale is very costly. • Rock must be “heated”.

14. Other fossil fuels • Tar sands- shales, limestones and sandstones that have a thick oil tar in its pores. • Very difficult to remove oil by today’s methods. • Must remove rock when it is cold to almost freeze the oil in place. • Wash out the oil with heated water. • Very expensive. • Only 10% can be removed. • Possibly, 35 billion barrels may be recovered in the US.

15. Alternative fuel resources • Nuclear fission – splitting of atomic nuclei by neutron bombardment • releases 3 neutrons which react with other atoms “chain reaction” • Types of reaction: • Uncontrolled reaction- explosion • Stable- power plants • Reactors are made 4 important parts: • core- where reaction takes place • control rods- material which captures free neutrons • coolant- usually water cools reaction and transfers energy • Reactor vessel- surrounds the reactor

16. Alternative fuel resources • Problems with Nuclear fission: • Produces radioactive isotopes • What to do with this waste product? • Plutonium produced can be used to make nuclear weapons. • Risk of an uncontrolled reaction.

17. Alternative fuel resources • Fusion- combining of light elements to form heavier ones; this reaction releases energy in the process. (Example our sun) • Benefits: • Land use impacts are small • Doesn’t produce radioactive isotopes • Lower risk of an accidental accident. • Theoretically less expensive than fission reaction. • Detriments: • Will use harmful items to humans (lithium) • Produces strong magnetic and microwave fields.

18. Alternative fuel resources • Geothermal Energy- natural heat from earth’s interior • vapor dominated geothermal system • hot water geothermal system • Found where magma is near the surface of the earth. • Ground water systems • At 100m ground water is 13 degrees celcius (55.4 F). • This is cool for a bath but: warm for the winter months and cool for the summer months • Can cut heating costs.

19. Renewable energy- • Replenished quickly to maintain a constant supply. • Solar energy • Depends greatly on the amount of sunlight in an area. • Hydropower • Wind power.