Presentation on theme: "Chapter 14 Energy from Fossil Fuels. Mountaintop removal mining Tourists and climbers visit the White Mountains in New Hampshire – The White Mountain."— Presentation transcript:
Mountaintop removal mining Tourists and climbers visit the White Mountains in New Hampshire – The White Mountain National Forest has 777 acres Mining is allowed in national forests – Huge machines and dynamite are used – Trees, topsoil, and mountaintops are removed – Valleys are filled in and streams are obliterated – Small towns are wiped out No area is safe from mountaintop removal mining due to the U.S.’s insatiable thirst for coal
Mountaintop removal mining (cont) An economical way of reaching coal seams It has devastated parts of West Virginia, Kentucky, Tennessee, and Virginia – 470 mountains have been affected – 1,500 miles of streams have been buried or degraded – Residents who refuse to move have been threatened In 2002, the law prohibiting dumping of waste into stream valleys was changed to allow this “fill” to be dumped Grassroots organizations face formidable politicians and industrialists who say this mining is necessary
Oil spills and drills With millions of gallons of oil in constant transit, it is inevitable that spills will occur – In 1989, the Exxon Valdez spilled 11 million gallons – In 2008, two ships collided, spilling 420,000 gallons Drilling for oil in the Arctic National Wildlife Refuge (ANWR) is a political firefight – President Bush wanted to open it to drilling – At present, with a Democratic Congress and President, it will probably remain closed for the moment
Energy sources and uses Advancing technological civilization has been tied to energy In early times human muscle and livestock provided energy – Slaves, servants, minimally paid workers – Domestic animals were used in agriculture and transportation – Water, wind, and sun power also provided power Inventors in the early 1700s designed machines – The steam engine provided power for ships, shovels, tractors, trains, sawmills, textile mills, etc.
Coal Coal was substituted for fuel – Firewood for steam engines became scarce – It was used for steam engines, heating, cooking, and industrial processes – By 1920, coal provided 80% of all U.S. energy Drawbacks of coal – Smoke and fumes polluted cities – It is hazardous to mine and dirty to handle – Steam engines are bulky and hard to operate
Oil By the late 1800s oil provided an alternative to coal – Due to the internal combustion engine, drilling, and refinement of oil into fuels Benefits of oil – It was more convenient and burned more cleanly – The internal combustion engine is much lighter than a steam engine Oil is now the major energy source for the world – Coal still predominates in eastern Europe and China
Gas, naturally Natural gas: found in association with oil or drilling for oil Natural gas consists mainly of methane, which produces carbon dioxide and water when burned – It burns more cleanly than coal or oil Pipelines now allow it to be transported, instead of venting it to the atmosphere – It is used for heating, cooking, industry – It is clean, convenient, and inexpensive Gas satisfies 24% (U.S.) and 21% (world) of energy demand
Electrical power production Electrical power: the amount of work done by an electric current over a given time – Most energy we use comes from fossil fuels Energy carrier: the electricity itself that transfers energy from a primary energy source (coal, water power) to the point of use Electricity enables modern technological society – Computers, appliances, lights, the Internet More than 33% of fossil fuel production is used to generate electricity in the U.S.
Generators Electric generators were invented in 1831 by Michael Faraday An electric generator: a coil of wire that rotates in a magnetic field – Or a stationary wire within a rotating magnetic field – It converts mechanical energy into electrical energy Energy is lost through resistance and heat – Energy is also lost through transmission through wires Three units of primary energy make one unit of electricity – But electricity is so useful and indispensible
Turbogenerators Generating electricity requires a primary energy source – Coal, oil, nuclear, refuse, solar, geothermal energy – Which boils water to produce steam – Which drives a turbine (a sophisticated paddle wheel) – Which is coupled to a generator – Turbogenerator: the turbine and generator Other generators = gas-, water-, and wind-driven turbines – Burning gas drives the turbine directly – A hydroturbogenerator uses water from a dam or pipe
Clean energy? Electric power is clean and nonpolluting only at the point of use Electricity is an expensive way to heat homes – It is generated mainly from fossil fuels and nuclear energy Coal-burning plants: the major source of U.S. electricity – Implicated in acid deposition and climate change Nuclear energy is distrusted – Potential for accidents, disposal of waste, and mining of uranium ore
Transferring pollution Energy from fossil fuels transfers pollution – Only renewable sources are nonpolluting Producing electricity from fossil fuels is 30–35% efficient Energy is lost in several ways – Heat energy goes up the firebox and out the chimney – Heat energy remains in the spent steam – Transmission of electricity through wires Conversion losses: an unavoidable loss of energy – A consequence of keeping high temperature differences between incoming steam and the receiving turbine
Exploiting crude oil U.S. coal, natural gas, or nuclear power supplies are adequate – But we must import 66% of our crude oil Increasing dependence on imported oil causes trade imbalances, military actions, economic disruptions, coastal oil spills Fossil fuels (crude oil, coal, natural gas) were formed 100–500 million years ago in swamps and shallow seas – Anaerobic conditions slowed decomposition – Pressure and heat converted vegetation to fossil fuels – It takes 1,000 years to obtain 1 day’s worth of fossil fuel use
Estimates of oil reserves Proven reserves depend on economics of extraction – Reserves may be higher or lower depending on the price of oil – Higher oil prices justify exploiting more expensive reserves – Law of Supply and Demand Demand and supply depend on price
Economics determines exploitation The price of a barrel of oil determines the extent to which reserves are exploited – At $10/barrel (late 1960s) only 25–35% of oil was extracted – Higher prices (1970s, 1980s) justified reopening old fields in Texas and Louisiana In 2008, oil peaked at $145/barrel but declined sharply – Demand dropped due to the global economic crisis Low prices are good for consumers – But bad for companies, because they need stable markets
The oil crisis of the 1970s The U.S. and other industrialized countries increased their dependence on imported oil The Organization of Petroleum Exporting Countries (OPEC) – Mostly Arab countries – Restrained production and initiated an embargo to increase prices – Resulted in shortages, panic, and long lines at gas stations – The U.S. willingly paid four times the previous price Devastating results: inflation, unemployment, and recessions – We buy more from others than we sell as exports
Other fossil fuels: natural gas The U.S. imports 16.5% of natural gas used – Most comes from Canada Gas is used in industry, residential, and electrical power generation Costs fluctuate with supply and demand and season U.S. proved reserves = 9 years – New deposits and drilling: supplies = 50 years – Worldwide = four times as much as oil Natural gas is piped or liquefied (liquid natural gas [LNG]) – New LNG facilities are seen as security and safety hazards
Natural-gas-run cars Cars can run on natural gas with installation of a gas tank and engine modifications Natural gas is a clean-burning fuel – Releases carbon dioxide and water – But not hydrocarbons or sulfur oxides Used in buses and car fleets in the U.S. – But there are limited service stations – Detroit automakers no longer sell these cars The fleet is growing in Europe – The U.S. needs stronger public-policy support
Underground mining Underground mines cause land subsidence and fires Centralia, Pennsylvania’s fire started 40 years ago – It could burn another 100 years – The federal government bought the town Worldwide fires release as much carbon dioxide as all cars and trucks in the U.S. At least 50% of the coal must be left in mines to support the roof of the mine
Strip mining Dynamite breaks overlying areas – Giant power shovels remove overlying rocks and coal Deforestation and burying streams destroy ecosystems Federal regulations require reclamation (grading, replanting) – It takes decades for some areas to recover – Arid areas may never recover Erosion, acid leaching, and mine wastes affect surface and ground water Massey Energy violated the Clean Water Act 4,500 times! – It paid $30 million to the EPA
Oil shale Found in Colorado, Utah, Wyoming Oil shale: a fine sedimentary rock containing kerogen – Kerogen: a solid, waxlike hydrocarbon Refining can produce gasoline and other petroleum products One ton of shale produces ½ barrel of oil – Mining, transportation, and waste disposal are prohibitive – Deposits contain 800 BBs of oil Oil companies consider developing oil from deposits – They face stiff opposition due to damaged air and water – Development must get local and state approval
Oil sand Oil sand: a sedimentary material containing bitumen – Bitumen: a hydrocarbon that can be refined like oil Alberta, Canada has the largest deposits (152 BBs) – The cost is competitive with oil – U.S. imports = 10% of our imported oil Mining oil sand causes significant environmental damage – 82,000 acres of boreal forest and wetlands have already been heavily disturbed Developing oil shale and sand will occur with high oil prices
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