3Coal Coal was substituted for wood fuel in the 1800s Firewood for steam engines became scarceIt was used for steam engines, heating, cooking, and industrial processesBy 1920, coal provided 80% of all U.S. energyDrawbacks of coal:Smoke and fumes polluted citiesIt is hazardous to mine and dirty to handleSteam engines are bulky and hard to operate
4Coal China is the world’s leading coal producer Builds two plants/week for electricity49% of U.S. electricity comes from coal-fired power plantsU.S. coal supplies should last another 200 yearsMining is hazardousThere are many coal-mining accidents and illnessesOver 700 died from pneumoconiosis (CWP)—black lung disease
5Strip mining removes mountaintops Strip mining allows quick, complete access to coal veinsDynamite breaks overlying areasGiant power shovels remove overlying rocks and coalEnvironmental effects include deforestation and burying streams, erosion, acid leaching, and mine wastes (which affect surface and ground water)Federal regulations require reclamation (grading, replanting)It takes decades for some areas to recoverSome arid areas may never recover
6Oil Rules By the late 1800s oil provided an alternative to coal Due to the internal combustion engine, drilling, and refinement of oil into fuelsBenefits of oilIt was more convenient and burned more cleanlyThe internal combustion engine is much lighter than a steam engineOil is now the major energy source for the worldCoal still predominates in eastern Europe and China
7Oil spills and drillsWith millions of gallons of oil in constant transit, it is inevitable that spills will occurIn 1989, the Exxon Valdez spilled 11 million gallons2010 in the Gulf of Mexico--largest oil release to dateDrilling for oil in the Arctic National Wildlife Refuge (ANWR) is an ongoing political firefight. It could result in major ecological disruption at a high cost—and for a relatively minor amount of oil.
8Natural gas Natural gas is found wherever you find crude oil Natural gas consists mainly of methane, which produces carbon dioxide and water when burnedBurns more cleanly than coal or oil (but still gives off CO2)Pipelines now allow it to be transported, instead of venting it to the atmosphereIt is used for heating, cooking, industryGas satisfies 24% (U.S.) and 21% (world) of energy demand
9Electrical power production Electrical power: the amount of work done by an electric current over a given timeMost energy we use comes from fossil fuelsEnergy carrier: the electricity itself that transfers energy from a primary energy source (coal, water power) to the point of useElectricity enables modern technological societyComputers, appliances, lights, the InternetMore than 33% of fossil fuel production is used to generate electricity in the U.S.
10TurbogeneratorsGenerating electricity requires a primary energy sourceCoal, oil, nuclear, solar—even geothermal energyThose are used to boil water to produce steam, which drives a turbine (a sophisticated paddle wheel)The turbine is coupled to a generator that stores and transmits the energy as electricity.Turbogenerator: the turbine and generatorBurning gas drives the turbine directlyWindmills (wind generators) have wind-driven turbinesAt a dam, falling water turns a turbine, generating hydroelectric power. This is CO2-free.
11Electricity demand vs. supply In the U.S., demand is rising faster than supplyReserve capacity has declined to 15%Summer heat waves are the greatest cause of sudden increased demandUtilities are being pushed to the edge of their ability to provide electricity on demandAnother serious problem: antiquated systems controlling the power transmission grid, which connects power sources to users
12BlackoutIn 2008 the largest blackout in U.S. history left 50 million people in eight states and two Canadian provinces without powerIt started when power lines brushed against tree branchesIt cost the economies of the two countries $30 billionA “smart grid” can prevent major blackoutsIt monitors problems, reacts to trouble, and isolates troubled areas to prevent cascading failuresThe U.S. Department of Homeland Security rates this as one of its highest priorities
13Clean energy?Electric power is clean and nonpolluting only at the point of use. Electric cars don’t directly emit CO2, but they use electricity—often that was produced by burning fossil fuels.Electricity is an expensive way to heat homesIt is generated mainly from fossil fuels and nuclearCoal-burning plants are the major source of U.S. electricityUnfortunately, they contribute to the formation of acid rain and greenhouse gasesNuclear energy is cleaner but distrustedPotential for accidents, issues with the mining of uranium ore and the disposal of waste
14Matching sources to uses Some forms of energy do well in some uses but not othersNuclear and coal will not reduce the demand for oilMost transportation (cars, trucks, tractors, planes, trains) depends on oil for fuel
15Energy flow Transportation equals 29% of U.S. energy use Depends mainly on petroleumNuclear, coal, water power are used to produce electricityNatural gas and oil are more versatile sources—they can be used for either electricity or for vehicle fuelSaving energy is equivalent to increasing energy supplies. So, conservation stretches our finite energy supply for future generations.
16Exploiting crude oilU.S. coal, natural gas, & nuclear power supplies are adequateBut we import 66% of our crude oilIncreasing dependence on imported oil causes trade imbalances, military actions, economic disruptions, coastal oil spillsFossil fuels (crude oil, coal, natural gas) were formed 100–500 million years ago in swamps and shallow seas. We have used about half of that oil in the past century. When it’s gone, it’s gone!
17Crude oil reserves vs. production Proved reserves: an accurate estimate of how much oil can be economically obtained from a fieldThe Middle East has 61% of proved reservesThe U.S. and others will depend on this area for oil1 barrel = 42 gallonsMost of the world’s large oil deposits have now been located, mapped, and “proved.” It is unlikely that we will “find” significant, new, large oil reserves now.
18Recovery Production from a field does not proceed at a steady rate Oil is trapped in pore spaces of sedimentary rockAt first, pressurized oil may gush from a wellBut only 25% of oil can be removed using conventional pumping (primary recovery)Secondary recovery can remove up to 50% of oilBy injecting steam or brine into the wells. It is like trying to get all the honey out of a honeycomb.Enhanced recovery involves techniques such as injecting carbon dioxide to break up oil, allowing even more oil to be obtained. This is expensive, though.
19Declining U.S. reserves Up to 1970, the U.S. was oil independent In 1970, production decreased but consumption INCREASED.The U.S., Europe, and Japan increased imports from the Middle East during the 70’s and 80’sImported crude oil was cheap and plentifulThe U.S. and other industrialized countries steadily increased their dependence on imported oil
20Adjusting to higher prices In response to higher prices, the U.S. and other nationsIncreased domestic production, e.g., the Alaskan pipeline, re-opening old fieldsIncreased fuel efficiency standards, e.g., lowered speed limits in some places (to 55 mph)Promoted appliance and building efficienciesDeveloped alternative energy sourcesCreated a strategic oil reserve in Louisiana to store 702 million barrels of oil (33 days of oil at 21 million barrels/day use)…but have we really attempted to conserve energy?
21Back to the future Prices rose to over $140/barrel in 2008 People reduced driving and bought hybrid carsOil companies had record profitsFood prices soaredCongress raised efficiency standards and called for increased renewable fuels
22The consequences of U.S. dependency U.S. dependency on foreign oil has three costs:Costs of buying oilRisk of supply disruptions (e.g., political instability in the Middle East)Ultimate resource limitationsIn 2000, the U.S. paid $300 billion in oil importsSince 2000, imports increased 24% and oil’s price rose fivefold
23Persian Gulf oil The U.S. keeps a military capability in the region Recognizes the political instabilityEnsures access to Persian Gulf oilSaddam Hussein of Iraq invaded Kuwait (1990)U.S.-led Persian Gulf War threw Hussein outThe U.S.’s ongoing presence angered radical Islamic Al QaedaLed to the September 11, 2001 attack on the U.S.
24The U.S. still relies on oil exports Military costs represent a significant government subsidy to oil “costs”Costing money and human livesThe U.S. is now importing 44% of our oil from nations other than OPEC nationsCanada, Mexico, Colombia, Russia, NigeriaThese are politically stableBut production in those regions is decreasingFor now, we continue to be dependent on OPEC and Persian Gulf oil.
25Other fossil fuels: natural gas The U.S. imports 16.5% of natural gas usedMost comes from CanadaGas is used in industry, residential, and electrical power generationCosts fluctuate with supply and demand and seasonU.S. proved reserves = 9 years’ worthWorldwide, there is four times as much nat. gas as oilNatural gas is piped or liquefied (liquid natural gas [LNG])New LNG facilities are seen as security and safety hazards
26Natural-gas-run carsCars can run on natural gas with installation of a gas tank and engine modificationsNatural gas is a clean-burning fuelReleases carbon dioxide and waterBut not hydrocarbons or sulfur oxidesUsed in buses and car fleets in the U.S.But there are limited service stationsDetroit automakers no longer sell these carsThe fleet is growing in EuropeThe U.S. needs stronger public-policy support
27Synthetic oil (at a price) The Fischer-Tropsch process turns natural gas into synthetic oilIt is only 10% more expensive than oilNatural gas can be turned into diesel and home-heating fuelsDrilling in the lower 48 states occurs in sensitive areasEnvironmental damage from roads, wells, and pipelinesFederal lands are being drilledA 3,600-mile gas pipe is needed to bring gas from Alaska and CanadaCosting $25 billion and causing environmental harm
28Oil shale Found in Colorado, Utah, Wyoming Oil shale: a fine sedimentary rock containing kerogen, a waxlike hydrocarbonRefining can produce gasoline and other petroleum productsOne ton of shale produces ½ barrel of oilMining, transportation, and waste disposal are prohibitiveOil companies consider developing oil shale deposits;They face stiff opposition due to production of air and water pollution during the processing of oil shale.Development must get local and state approval.
29Oil sandOil sand: a sedimentary material containing bitumen, a hydrocarbon that can be refined like oil; the oil sand is heated to melt and collect the bitumen.Alberta, Canada has the largest deposits (152 BBs)The cost is competitive with oilMining oil sand causes significant environmental damage82,000 acres of boreal forest and wetlands have already been heavily disturbedOil shale and oil sand will inevitably be used in the U. S. and Canada when oil prices climb dramatically.
30Security threats: global climate change Burning fossil fuels releases CO2Coal produces the most greenhouse gas emissionsNatural gas produces the least (of the fossil fuels)Increasing carbon dioxide levels likely increases average global temperaturesMelting ice caps and raising sea levelsCausing more severe storms, droughts, heat wavesThe U.S. is a leading producer of greenhouse gasessince it consumes the most fossil fuels (see next slide)
31Annual carbon dioxide emissions from fossil fuels
32Energy-saving technologies are here! CHP facilities install a small power plant to produce electricityHeats the building with “waste” heatAchieves an 80% efficiencyThe combined-cycle natural-gas unit generates electricityOne turbine burns natural gasA second turbine runs on excess steam from the other turbineAchieves 50% efficiency at half the cost and less pollution
33Final thoughts A human population of 7 billion demands energy. Two pathways can develop non-fossil-fuel energies:Nuclear power (though it needs technological solutions to the disposal of radioactive waste)Renewable energy, such as solar and wind power: needs government support