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Energy resources and consumption. Unit #5 Review Test percentage: 10-15%. Definitions. Energy : ability to do work or cause changes, releases heat Potential Energy : stored energy available for use Kinetic energy : energy of movement
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Energy resources and consumption Unit #5 Review Test percentage: 10-15%
Definitions • Energy: ability to do work or cause changes, releases heat • Potential Energy: stored energy available for use • Kinetic energy: energy of movement • Chemical energy (potential) energy stored in a fuel (gas, food) Units: • calories: amount of energy needed to heat 1 g of water 1 degree C • Joule (J): work done to accelerate 1 kg to 1 m/s2 • 1 calorie = 4.184 J • BTU British thermal unit heat required to raise the temperature of 1 pound of water by 1degree F • 1 Mega Watt(MW)= 106 watts
Laws of Thermodynamics • First Law: energy is neither created nor destroyed- conservation of energy • Second Law: energy is constantly degraded/lost • Entropy- all things tend to disorder, less useful energy is available when a process is completed than when a process is begun
History: industrial revolution • Earth Energy: >99% originally comes from the sun including plant materials (fossil fuel; wood) wind, water, solar • Wood was the original energy source, eventually proved to be very polluting and hard to come by • Coal was discovered and fueled the industrial revolution (late 18800’s) • Then Oil overtook coal in the mid 1900’s • Price is driven by supply and demand, OPEC controls the supply and thus the prices
OPEC and the energy crisis • OPEC: Organization of Petroleum Exporting Countries • Twelve developing countries made up of Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates, and Venezuela. • Price is driven by supply and demand, OPEC controls the supply and thus the prices • influence on the market widely criticized, since it became effective in determining production and prices • 1973: OPEC embargoes exports of oil due to US support of Israel “oil weapon” • 1979 Iranian revolution • 1980’s oil glut: due to reduced prices and overproduction by OPEC members • 1990: first gulf war- conflict between Iraq and Kuwait, OPEC internal conflict
Present global energy use • US 1998 net imports of oil > than domestic production • US 25% of world oil supply
Formation of coal • Coal is called a fossil fuel because it was formed from the remains of vegetation that grew as long as 400 million years ago. Stored sun energy; carbon • about 300 million years ago, much of the earth was covered by steamy swamps. • Layers of plant material (peat) accumulated and were pressed and heated over time (coal) the higher the heat and pressure the higher the grade of coal • 1 million year old coal in Okefenokee Swamps (GA) and Everglades (FL) - lignite- sedimentary, low sulfur, low heat -bituminous (most common) high sulfur, sedimentary rock -antrhacite- smaller supply, low sulfur, high energy, metamorphic rock
Coal Formation • Layers of plant material (peat) accumulated and were pressed and heated over time (coal) the higher the heat and pressure the higher the grade of coal
Coal: extraction/purification • Subsurface mining (dangerous), mine disasters • strip mining (very environmentally damaging): remove overburden, scrape up coal with heavy machinery; disturbs topography, vegetation and wildlife, pollutes water • tailings are left after removing the coal • must reclaim land (repair topography, replace topsoil, replace vegetation)
Over long periods of time the bodies of dead organisms (algae, plankton) sometimes plants in continental settings) accumulate and are buried (anoxic, increased heat and pressure and the C from the dead organisms turns to oil. This oil is usually trapped in a non-permeable rock crude oil must be refined (http://www2.wwnorton.com/college/geo/egeo/flash/12_1.swf) Formation of oil and natural gas
extraction/purification methods • In 2005: the United States • produced an estimated 9 million barrels of crude oil per day and • imported 13.21 million barrels per day from other countries. • This oil gets refined into gasoline, kerosene, heating oil and other products. • Oil is removed from the ground by drilling and pumping out the crude oil • Natural gas often is formed along with oil- the higher the temperature the more NG, either burned off or trapped and used
reserves and global demand resource is the part we use reserve is what we know about and could economically use as a resource but don’t currently Synfuels Liquid fuels created from coal natural gas oil shale (less common) tar sands (less common) waste plastic Advantages/Disadvantages: less particulate matter, more CO2, lower energy than the coal or NG they were derived from more coal mining
Pro abundant in US and worldwide high net energy, US subsidized, stable Con strip mining, disrupt land acid drainage high waste percent (20%) lots of CO2/sulfur release expensive to transport Coal environmental advantages/disadvantages of energy sources
Pro: inexpensive (but increasing) easy to transport (pipelines) high net energy US subsidies versatile Con: limited world reserve, declining, pollution (SO2, NOx, CO2) wastewater from production land disturbance oil spills habitat disruption environmental advantages/disadvantages of energy sources Oil
Pro: easy to distribute (pipelines) easy to process inexpensive 125 yrs world reserves high net energy yield lower pollution than coal, gas, less environmental damaging extraction Con: H2S and SO2 released during processing LNG processing expensive CH4 leakage (global warming) land subsidence environmental advantages/disadvantages of energy sources Natural Gas