List the ways you depend upon energy in your everyday lives.
Identify those activities that are dependent upon fossil fuels.
Fossil fuels: hydrocarbon fuels formed from organic matter.
The Need for Energy
Fuel – is any substance from which energy can be obtained.
To produce electricity, fuel is burned to boil water, producing steam.
The steam exerts pressure on giant machines called turbines, causing them to turn.
Non-renewable Energy Sources
Non-renewable Resource : A resource that is not being replenished or formed at any significant rate on a human timescale.
Hydrocarbon – a compound composed only of carbon and hydrogen.
Ex. Methane, propane, butane, octane
Fossil Fuels – Fuels derived from the remains of organisms that lived long ago.
Formation of Oil and Natural Gas Deposits
Petroleum or oil is not a single chemical compound. Oil is comprised of a variety of liquid hydrocarbons.
Oil and natural gas were formed when life in the early seas brought organic material raining down onto the seafloor faster than it could decay as sediments buried the material.
As this material became buried deeper, the heat and pressure under the ground slowly cooked this organic material into oil by breaking down complex organic molecules into smaller, hydrocarbon molecules.
Then the oil and natural gas were collected in a trap of porous sandstone or limestone, contained by an impermeable cap of shale or salt (Appenzeller, 2004).
United States Oil Facts
1 barrel of oil = 42 gallons
The US consumes nearly 7 billion barrels of oil per year, to supply about 40% of all energy used.
The US alone consumes 25% of the oil used worldwide.
Over ½ of the oil consumed has been imported from other countries.
Uses of Oil
2/3 of oil goes to fuel for vehicles
Hydrocarbon based fertilizers and pesticides
Plastics (Appenzeller, 2004)
Coal is formed from the remains of land plants that were rapidly deposited and buried in a swampy environment.
The process requires anaerobic conditions, in which oxygen is absent or nearly so, since reaction with oxygen destroys the organic matter.
It is found in sedimentary rocks in well defined beds.
Prehistoric Coal Swamp
Types of Coal
Peat plant material with lots of water and a low level of carbon.
Lignite Soft brown coal – 40% carbon
Types of Coal
Bituminous Medium hardness ~85% C
Anthracite Hardest coal ~95% C
As the coals become harder, the carbon content increases, and so does the amount of heat released by burning a given weight of coal.
The US possess about 25% of the world’s coal reserves (270 billion tons).
Coal currently supplies about 20% of total US energy needs.
Coal-fired power plants account for more than half of US electric power generation.
The US coal supply could satisfy US energy needs for more than 200 years at current levels of energy use if coal could be used for all energy purposes. (Montgomery, 2006)
Environmental Consequences of Fossil Fuels
Coal is a very dirty fossil fuel and can have large environmental effects.
Coal mining hazards
Methane is a greenhouse gas.
Motor vehicles emit carbon oxides, nitrogen oxides, sulfur oxides, and fine particulates.
Fossil Fuel Reserves
Nuclear Fission is the splitting apart of atomic nuclei into smaller ones with the release of energy.
The fissionable nucleus used most in modern nuclear reactors is the isotope uranium-235 .
Worldwide, 95% of known uranium reserves are found in sedimentary rocks.
The rare isotope U-235 is in such short supply that the US could use up our reserves within several decades.
Problems: Disposal of nuclear waste, limited supply of U-235 and reactor meltdowns
Conservation is the use of natural resources in a way that ensures their continuing availability to future generations.
USE ENERGY EFFICIENTLY
Turn off unused lights and appliances
Use fluorescent or halogen bulbs
Buy fuel efficient cars
REMEMEBER, THESE RESOURCES ARE FINITE ON A HUMAN TIMESCALE!
US Energy Production
US Energy Consumption
Fuels Substances that provide energy as the result of a chemical change.
Combustion The process of burning a fuel to change chemical energy into thermal energy .
Fusion The combining of 2 atomic nuclei to produce one large nuclei and energy. It produces more energy than nuclear fission.
Nucleus The central part of an atom.
Chapter 17 Alternative Energy Sources
Renewable resources : are those resources which are replaceable on a human life timescale.
Are responsible for just 8% of the total energy consumed in the US in 2002.
Hydropower is the energy generated due to falling or flowing water through turbines.
Use: Hydroelectric power is the most widely used nonrenewable resource and has consistently supplied a small percentage of US energy needs for several decades; it currently provides about 3% of US energy.
We have already harvested most of our feasible water energy.
Sediment buildup and ecosystem disruption cause problems.
Wind energy is produced from turbines in windmills Aerogenerators
Is actually an indirect form of solar energy.
Uses: Generating electricity, and pump ground water
Limitations: Can only be produced in windy areas, higher cost, wind can be erratic
Gamesa wind turbine installed at Bald Mountain in Bear Creek Township, PA
Energy captured from the sun by photovoltaic cells or solar cells.
Uses: generate electricity, especially in remote regions of the earth and for satellites.
Advantage: This source will last for at least a billion years.
Limitations: very expensive to produce, uses vast areas of land to harvest, not a consistent source of energy
Passive solar heating – The sun’s energy is collected, stored and distributed naturally in an enclosed dwelling.
ex. Greenhouse, windows
Active solar heating – Devices are used to collect, store, and circulate heat produced from solar energy. Ex. Solar collectors, Photovoltaic cells Use thin wafers of semiconductor material to produce electricity.
Heat from cooling magma heats ground water near the earth’s surface.
Geothermal energy is harvested by capturing the energy out of this heated water.
Large amounts of energy can only be generated in geologically active zones.
Uses: to heat/cool houses and household water supplies, very few utility plants
Limitation: Ground cools eventually
Nuclear fusion occurs when two atomic nuclei fuse to become one larger nucleus.
Occurs in the sun.
Fuel used is usually deuterium or H-2.
Must be subjected to extremely high temperatures and pressures supplied by either magnetic field or lasers.
Advantages: Much less radioactive waste
Disadvantage: Very hard to do.
E = mc ²
Two protons stuck together have less mass than two single separate protons!
When the protons are forced together, this extra mass is released ... as energy!
Typically this amounts to about 7% of the total mass, converted to an amount of energy predictable using the formula.
C = speed of light (3 x 10 8 ) m/s
Alternative Energy Sources for the Future
Ocean Thermal Energy Conversion
Rebirth of Wood Burners
Alcohol and Ethanol
World Energy Production By Source
We know there is a limited amount of non-renewable resources on earth.
As technology improves, we may be better able to harness renewable resources and find new sources of energy.
It is still our responsibility to conserve the resources we have today for future generations and to help preserve the earth.
Please list five things you can do to conserve energy.
Appenzeller, Tim. (2004, June). The end of cheap oil. National Geographic, 205(6), 88-89.
Montgomery, Carla W. (2006). Environmental Geology (7 th ed.). New York: McGraw-Hill.