3/23/2015 NON-RENEWABLE ENERGY

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1 NON-RENEWABLE ENERGY C H A P T E R 1 5 WE USE A VARIETY OF ENERGY SOURCES We use energy in our homes, machinery, and vehicles and in products that provide comfort and conveniences Most of Earth s energy comes from the sun Solar, wind, hydroelectric, photosynthesis, biomass Fossil fuels are highly combustible substances from the remains of organisms from past geologic ages Oil, coal, natural gas Fossil fuels provide most of our energy for: Transportation, heating, cooking Electricity is easy to transfer and has lots of uses FOSSIL FUELS: OUR DOMINANT SOURCE OF ENERGY Global consumption of fossil fuels is at its highest level ever RESOURCES ARE RENEWABLE OR NONRENEWABLE Renewable energy: supplies are not depleted by our use Sunlight, geothermal energy, and tidal energy Nonrenewable energy: once depleted, it cannot be renewed (oil, coal, natural gas) We will use up Earth s accessible store in decades to centuries To replenish the fossil fuels we have depleted so far would take millions of years Nuclear power: is nonrenewable because uranium ore s supply is limited 1

2 IT TAKES ENERGY TO MAKE ENERGY We don t get energy for free To harness, extract, process, and deliver energy requires substantial inputs of energy Drilling for offshore oil requires millions of dollars for infrastructure to extract and transport the oil All this requires huge amounts of energy Net energy is the difference between costs in energy invested and benefits in energy received Net energy: Energy returned Energy invested ENERGY RETURNED ON INVESTMENT (EROI) Energy returned on investment (EROI): EROI: energy returned/energy invested Higher ratios mean we receive more energy than we invest Fossil fuels have high EROI EROI ratios can change They decline when we extract the easiest deposits first We now must work harder to extract the remaining reserves U.S. oil EROI ratios have gone from 100:1 to 5:1 RESERVES AND USE ARE UNEVENLY DISTRIBUTED Some nations have large reserves, others don t The Middle East has 67% of the world s crude oil Russia holds the most natural gas The U.S. possesses more coal than any other country People in developed regions consume the most energy The U.S. has 4.5% of the world s population but uses 20% of its energy Developing nations use energy for subsistence activities Agriculture, food preparation, and home heating Developed nations use fossil-fuel-driven machines 2

3 FOSSIL FUELS ARE CREATED FROM FOSSILS Fossil fuels were formed from organisms that lived million years ago Anaerobic decomposition occurs with little or no air Deep lakes, swamps Produces fossil fuels THREE MAJOR TYPES OF FOSSIL FUELS Coal is organic matter (plants) placed under high pressure Natural gas is mainly methane (CH 4 ) Oil (crude oil) is liquid made of hydrocarbons Petroleum is natural gas plus oil Formed from organic material (plankton) in coastal marine waters Biogenic gas is created in shallow water by anaerobic decomposition of organic matter by bacteria Swamp gas, landfill gas Thermogenic gas is formed deep underground COAL COAL USE HAS A LONG HISTORY The world s most abundant fossil fuel Created million years ago Extracted using three methods Strip mining - for deposits near the surface Subsurface mining - for deposits deep underground Mountaintop removal Coal helped drive the industrial revolution Coal is used to generate electricity Converting water to steam, which turns a turbine The U.S. and China are the primary producers and consumers of coal Coal provides half the U.S. electrical generating capacity COAL VARIES IN ITS QUALITIES NATURAL GAS BURNS MORE CLEANLY THAN COAL Coal varies in water and carbon content and its impurities It has sulfur, mercury, arsenic, and other trace metals Coal in the eastern U.S. is high in sulfur because it was formed in marine sediments Burning coal releases impurities The fastest growing fossil fuel in use today 25% of global commercial energy consumption It is versatile and clean-burning Emits ½ as much CO 2 as coal, ⅔ as much as oil It is used to generate electricity, heat homes, and cook Liquefied natural gas (LNG) I sgas converted to liquid Can be shipped in refrigerated tankers Russia leads the world in production The U.S. leads the world in use 3

4 WE DRILL TO EXTRACT OIL NOT ALL OIL CAN BE EXTRACTED Oil accounts for 1/3 of the world s energy use Oil is under pressure and often rises to the surface Drilling reduces pressure, so oil is harder to extract Primary extraction is the initial extraction of available oil Secondary extraction is when solvents, water, or steam is used to remove additional oil Fracturing breaks rocks to release gas We lack the technology to remove every bit of oil Technology limits how much can be extracted Economics limits how much will be extracted It gets harder and more costly as oil or gas are removed The amount of economically recoverable oil and gas is based on the price of the fuel At higher prices, economically recoverable amounts approach technically recoverable amounts Proven recoverable reserve is the amount of a fossil fuel that is technically and economically feasible to remove under current conditions SECONDARY OIL EXTRACTION IS COSTLY UNCONVENTIONAL FOSSIL FUELS In the U.S., many oil fields did not undergo secondary extraction The price of crude oil was too low With higher prices, companies reopen these sites ALTERNATIVE FOSSIL FUELS HAVE DRAWBACKS Their net energy values are low because they are expensive to extract and process EROI ratios are about 2:1 compared to oil s 5:1 Extraction devastates the landscape and pollutes water Immense amounts of water are needed reserves are in arid areas Polluted wastewater is held in huge reservoirs Combustion emits as much greenhouse gases and pollution as oil, coal, and gas 4

5 OIL REFINERIES CREATE PETROLEUM PRODUCTS PETROLEUM PRODUCTS HAVE MANY USES Once extracted, oil is refined Hydrocarbons are sorted for different uses Oil is used for fuel, plastics, tar, asphalt, fabrics, etc. WE MAY HAVE DEPLETED HALF OUR RESERVES We have used half (1.1 trillion barrels) of our oil reserves Reserves-to-production ratio (R/P ratio): The total remaining reserves divided by the annual rate of production (extraction and processing) At current levels of production (30 billion barrels/year), we have about 40 years of oil left We will face a crisis not when we run out of oil, but when We hit peak oil: production peaks then declines Production declines once reserves are 50% depleted WE ARE FACING AN OIL SHORTAGE Geologist M. King Hubbard predicted that U.S. oil production would peak around 1970 His prediction was accurate, and U.S. production continues to fall Hubbard s peak is the peak in U.S. production (1970) GLOBAL OIL PRODUCTION IS PEAKING FUEL EMISSIONS POLLUTE AIR Carbon dioxide is released from land into the air Driving changes in global climate Emissions cause severe health problems Cancer, irritation, smog, poison Technology and legislation can reduce pollution Discoveries of new oil fields peaked 30 years ago, and we are using more oil than we are discovering 5

6 CLEAN COAL TECHNOLOGIES Clean coal technologies are technologies, equipment, and approaches to remove chemical contaminants While generating electricity from coal Scrubbers chemically convert or remove pollutants Coal that contains lots of water can be dried Gasification is when coal is converted into cleaner synthesis gas (syngas) Which can be used to turn a gas or steam turbine These technologies have reduced pollution But clean coal is still a dirty way to generate power CAN WE CAPTURE AND STORE CARBON? Carbon capture and carbon storage (sequestration) CCS captures CO 2 emissions, converts it to a liquid, and stores it underground or in the ocean Is planned for the U.S. $1.5 billion FutureGen project This technology is still too unproven to depend on The gas may escape and contaminate water or acidify the oceans It is energy intensive and reduces coal s EROI It prolongs our dependence on fossil fuels CARBON CAPTURE AND SEQUESTRATION FOSSIL FUELS POLLUTE WATER AND AIR The Deepwater Horizon s spill showed that offshore drilling is very dangerous The Gulf of Mexico suffered many impacts Countless animals (birds, shrimp, fish, etc.) died Coastal marsh plants died, leading to erosion Fisheries were devastated, and fishermen lost jobs Tourism suffered Economic and social impacts will last for years DRILLING FOR OIL IN THE ARCTIC Melting ice in the Arctic is opening up new shipping lanes Nations want to get to oil and gas deposits Any oil spill will pose severe pollution risks Icebergs, pack ice, storms, cold, and winter darkness will hamper response efforts Frigid water temperatures will slow the natural breakdown of the oil COAL MINING DEVASTATES NATURAL SYSTEMS Most water pollution comes from non-point sources Cars, homes, gas stations, businesses, storage tanks, the atmosphere, etc. Mining pollutes water, destroys habitat Coalbed methane sites pump methane into coal seams, contaminating soil and killing vegetation Hydrofracking is water, sand and chemicals are injected into natural gas wells Toxic wastewater is sent to sewage treatment plants that release treated water into drinking sources 6

7 THE PUBLIC PAYS THE ENVIRONMENTAL COSTS Drilling requires land, roads, infrastructure (e.g., houses) Pollutes soil and water, fragments habitats Toxic sludge is stored in ponds Policymakers are debating opening up ANWR Directional drilling is when wells are drilled away from a drilling pad, requiring fewer pads Costs are not internalized in the market price of fuels Taxpayers paid medical costs, cleanup, etc. Gas prices and utility bills don t cover costs of the fuel Government subsidies keep fossil fuel prices cheap RESIDENTS MAY OR MAY NOT BENEFIT Oil companies provide jobs for millions 107,000 work in the Gulf of Mexico alone But more work in tourism, service jobs, and fishing jobs Citizens in developing nations don t benefit from drilling Corporations pay off the governments Few environmental or health regulations exist Many still live in poverty, without water or electricity An Ecuadoran court fined Chevron $9.5 billion for environmental and health impacts A U.S. court issued an injunction to stop payment MANY NATIONS DEPEND ON FOREIGN ENERGY Nations importing fossil fuels are vulnerable to supplies becoming unavailable or costly Seller nations control prices, causing panic The U.S. imports 67% of its crude oil OIL SUPPLY AND PRICES AFFECT ECONOMIES Hurricanes Katrina and Rita (2005) destroyed offshore platforms, causing oil and gas prices to spike The politically volatile Middle East has the majority of oil reserves The U.S. supports nondemocratic leaders e.g., in Tunisia and Egypt Following the 1973 oil embargo, the U.S. enacted policies to reduce its dependence on foreign oil THE U.S. HAS POLICIES TO REDUCE FOREIGN OIL Secondary extraction at old oil wells A 1-month emergency stockpile of oil It capped the price domestic producers can charge Funding research into renewable energy sources Enacting conservation measures Drilling in ever deeper waters Many want drilling in ANWR But drilling won t help much and will destroy the nation s last wilderness U.S. imports more oil from non-middle-eastern countries THE GLOBAL TRADE IN OIL Oil embargoes and natural disasters (e.g., Hurricanes Katrina and Rita) create panic and increase oil prices 7

8 HOW WILL WE CONVERT TO RENEWABLE ENERGY? Fossil fuel supplies are limited Their use has health, environmental, political, and socioeconomic consequences Many people and nations are moving toward clean, renewable energy sources France, Germany, and China are far ahead of the U.S. We need to prolong fossil fuels through conservation Lifestyle changes, reducing energy use, technology to improve efficiency ENERGY EFFICIENCY AND CONSERVATION We need to minimize our use of dwindling fossil fuels Energy efficiency is obtaining a given amount of output while using less energy input Results from technological improvements Energy conservation is the practice of reducing energy use Efficiency is one way toward conservation We can extend our nonrenewable energy supplies Be less wasteful Reduce our environmental impact PERSONAL CHOICE AND EFFICIENT TECHNOLOGIES We can choose to reduce energy consumption Drive less, turn off lights, buy efficient machines We don t have to decrease our quality of life Reducing energy use will also save money Energy-consuming devices can be made more efficient Cars and power plants lose ⅔ of energy as waste heat The U.S. has become more efficient, but we can do better Cogeneration is when excess heat produced during electrical generation can heat buildings or produce other power It can double the efficiency of a power plant EFFICIENCY IN HOMES, PRODUCTS AND CARS Improvements can reduce energy to heat and cool buildings passive solar, insulation, plants, roof color Appliances have been reengineered to increase efficiency Savings on utilities exceeds the appliances costs Vehicles are the best way to easily save fossil fuels Electric cars, hybrids, hydrogen fuel cells, better engines AUTOMOBILE EFFICIENCY AFFECTS CONSERVATION The OPEC oil embargo of 1973 caused increased fuel conservation, but it didn t last Without high prices and shortages, there was no incentive to conserve Government research into alternative energy decreased Speed limits increased Policy makers did not raise the corporate average fuel efficiency (CAFE) standards Low U.S. gas prices do not account for external costs Low fuel taxes reduce incentives to conserve 8

9 CAFE STANDARDS CAFE standards mandate higher fuel efficiency in cars Fuel efficiencies fell from 22 mpg (1984) to 19 (2004) They climbed to 21.1 in 2009 In 2009 Congress mandated that cars must get 35 mpg by 2020 European and Japanese cars are twice as efficient as U.S. cars THE CASH FOR CLUNKERS PROGRAM In 2009, the Obama administration tried to improve fuel efficiency, stimulate economic activity, and save jobs The Cash for Clunkers program paid Americans $3,500 to $4,500 to turn in old cars and buy new, efficient ones The $3 billion program subsidized the sale or lease of 678,000 vehicles averaging 24.9 mpg Replacing vehicles averaging 15.8 mpg 824 million gallons of gasoline will be saved Preventing 9 million tons of greenhouse gases Creating social benefits worth $278 million THE REBOUND EFFECT CUTS INTO EFFICIENCY The rebound effect: increased efficiency is offset by increased energy use e.g., driving a fuel-efficient car more Can erase gains made by efficiency Conservation could save 6 million barrels of oil a day Conserving energy is better than finding a new reserve Decreases health and environmental impacts while extending our access to fossil fuels Along with conservation, we still need energy from somewhere NUCLEAR POWER Nuclear energy occupies an odd and conflicted position in our debate over energy It is free of air pollution produced by fossil fuels Yet its promise has been clouded by weaponry, waste disposal, and accidents Public safety concerns have led to limited development The U.S. generates the most electricity from nuclear power But only 20% of U.S. electricity comes from nuclear power France gets 75% of its electricity from nuclear power FISSION RELEASES NUCLEAR ENERGY Nuclear energy is the energy that holds protons and neutrons together within the nucleus of an atom Nuclear fission is the splitting apart of atomic nuclei The reaction that drives the release of nuclear energy in power plants Neutrons can hit other atoms, causing a chain reaction CONTROLLING FISSION IN REACTORS An uncontrolled chain reaction can cause an explosion Nuclear power plants control fission A moderator is a substance (water or graphite) that slows the neutrons bombarding uranium Allows fission to begin in a nuclear reactor Excess neutrons must be soaked up Control rods are a metallic alloy that absorbs neutrons Placed into the reactor with the water-bathed fuel rods They are moved into and out of the water to control the rate of the reaction 9

10 A TYPICAL LIGHT WATER REACTOR NUCLEAR ENERGY COMES FROM URANIUM Uranium s atoms are radioactive and emit high-energy radiation as they decay into daughter cells Uranium ore is uncommon and finite Over 99% of uranium occurs as uranium-238 ( 238 U) It does not emit enough neutrons for a chain reaction It must be processed into 235 U 238 U is formed into pellets (UO 2 ) and put into fuel rods After years in a reactor, depleted uranium is replaced Spent fuel can be reprocessed, but it is expensive So it is disposed of as radioactive waste NUCLEAR POWER HAS BENEFITS AND DRAWBACKS COAL VERSUS NUCLEAR POWER Nuclear power helps us avoid emitting 600 million metric tons (7%) of carbon each year Power plants pose fewer health risks from pollution They are safer for workers than coal-fired plants Less uranium needs to be mined, damaging less land Disposal of radioactive waste is challenging If an accident or sabotage occurs, the consequences can be catastrophic Governments have decided the good outweighs the bad There are 436 operating nuclear plants in 30 nations NUCLEAR POWER POSES SMALL RISKS, BUT It poses the possibility of catastrophic accidents Three Mile Island in Pennsylvania in 1979 was the most serious accident in the U.S. Due to mechanical failure and human error Coolant water drained from the reactor Temperatures rose inside the reactor core Melting the metal surrounding the fuel rods Releasing radiation Which was trapped inside the containment building Cleanup cost billions and took years CHERNOBYL WAS THE WORST ACCIDENT YET The 1986 explosion at the Chernobyl plant in Ukraine The most severe nuclear plant accident ever seen Was due to human error and unsafe design For 10 days, radiation escaped while crews tried to put out the fires More than 100,000 residents were evacuated The landscape for 19 miles still remains contaminated The accident killed 31 people directly 10

11 THE CHERNOBYL ACCIDENT The destroyed reactor was encased in a massive concrete sarcophagus which is still leaking radioactive material FUKUSHIMA DAIICHI On March 11, 2011, a 9.0 magnitude earthquake struck Japan, causing an immense tsunami Killing 23,000 Flooding the Fukushima Daiichi nuclear plant Without electricity and use of the control rods, the uranium fuel overheated Seawater was used to flood the reactors But 3 reactors had full meltdowns Radiation was released at levels equal to Chernobyl s Trace amounts were detected around the world THE FUKUSHIMA DAIICHI MELTDOWN Thousands were evacuated Restrictions were placed on the area s food and water Radioactivity is still being released The long-term health effects are not known The disaster could have been prevented Generators should not be put in basements NUCLEAR ENERGY IS NEVER COMPLETELY SAFE Despite safer designs, accidents and human errors will occur Older plants need more care and become less safe Radioactive materials can be stolen and used by terrorists Especially in poor nations of the former Soviet Union Hundreds of former nuclear sites have gone without adequate security for years The U.S. is buying up some of the radioactive material Using it to produce power WASTE DISPOSAL REMAINS A PROBLEM Even if nuclear power were completely safe, we would still have the radioactive waste to worry about It will be radioactive for thousands of years Waste is held temporarily in cooling water or steel casks The U.S. stores 60,000 metric tons of high-level waste in temporary sites These sites are vulnerable to terrorist attacks 161 million people live within 75 miles of these sites Nuclear waste managers want one storage site for all waste It can be heavily guarded 11

12 U.S. STORAGE OF HIGH-LEVEL RADIOACTIVE WASTE WASTE STORAGE AT YUCCA MOUNTAIN, NEVADA Yucca Mountain, Nevada, was chosen to store waste $13 billion was spent on its development President Obama s administration ended support for it So, waste will remain at its current locations Yucca Mountain was selected because it s remote and unpopulated It has a deep water table and isolated aquifer It s on federal land and can be protected Transporting waste is subject to accidents or sabotage The U.S. stores nuclear waste at more than 120 sites in 39 states YUCCA MOUNTAIN, NEVADA DILEMMAS SLOW NUCLEAR POWER S GROWTH Concerns over waste disposal, safety, and costs have slowed nuclear power s growth It is enormously expensive to build, maintain, operate, and ensure the safety of nuclear facilities De-comissioning plants is even more expensive Plants have aged faster than expected They serve less than ½ their expected lifetimes Electricity costs more than from coal and other sources Governments must subsidize nuclear power But some advocate more nuclear with safer reactors 12