Non-renewable energy
Chapter 15
This lecture will help you understand:
Our energy sources
Coal, natural gas, oil use
Depletion of oil supplies
Alternative fossil fuels
Environmental impacts of fossil fuels
Political, social, and economic impacts of fuel use
Energy conservation and efficiency
Nuclear power
Central Case Study: Offshore Drilling and the Deepwater Horizon Blowout
On April 20, 2010, the Deepwater Horizon drilling rig exploded in the Gulf of
Mexico
Killed 11 people
Spilled 230 million gallons (2,000 gallons/minute) of crude oil into the Gulf
It took 86 days to seal the well
The oil spill was the largest accidental spill in history
Due to careless corporate shortcuts and weak governmental oversight
We are addicted to oil
The Deepwater Horizon’s oil spill resulted from our insatiable appetite for
petroleum
Particularly for cars
The oil industry has drilled farther and farther out to sea
Increasing risks for major accidents
We must reduce our dependence on oil
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
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
Fossil fuels are created from fossils
Fossil fuels were formed from organisms that lived 100–500 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 (CH4)
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
The world’s most abundant fossil fuel
Created 300–400 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
Coal use has a long history
The U.S. and China are the primary producers and consumers of coal
Coal varies in its qualities
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 Earth holds enough coal to last a few hundred years
Natural gas burns more cleanly than coal
The fastest growing fossil fuel in use today
25% of global commercial energy consumption
It is versatile and clean-burning
Emits ½ as much CO2 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
World supplies are projected to last about 60 more years
We drill to extract oil
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
Not all oil can be extracted
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
Offshore drilling produces oil and gas
We drill for oil and gas on land and under the sea
Drilling rigs are fixed or floating
The Gulf of Mexico has 35% of U.S. oil (10% gas)
It has 90 drilling rigs and 3,500 platforms
Companies must drill deeper and deeper for oil
Up to 10,000 feet deep
Deep water drilling is risky
It took 86 days to plug the leaking Deepwater Horizon’s well
In 2008 Congress lifted a moratorium on off shore drilling
Obama opened up most of the U.S. coast to drilling
The public’s reaction to the Deepwater Horizon’s spill forced Obama to
backtrack
Cancelled drilling permits until new safety measures were devised
Oil refineries create petroleum products
Once extracted, oil is refined
Hydrocarbons are sorted for different uses
Oil is used for fuel,
plastics, tar, asphalt, fabrics, etc.
Petroleum products have many uses
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
Predicting an exact date for peak oil is hard
We won’t recognize that we have passed peak production until several
years have passed
Companies and governments do not disclose their true amount of oil supplies
Most estimates say oil will peak between 2010 and 2040
Peak production will occur
It will have momentous economic, social, and political consequences
Our lives will be profoundly affected
The long emergency
“The long emergency”: lacking cheap oil to transport goods, our economies
collapse and become localized
Large cities will have to have urban agriculture
Fewer petroleum-based fertilizers and pesticides would mean increase in
hunger
Suburbs will become the new slums, a crime-ridden landscape littered with
the hulls of rusted-out SUVs
More optimistic observers argue that as supplies dwindle, conservation and
alternative energies will kick in
We will be saved from major disruptions
Canada is mining oil sands
Oil sands (tar sands) are sand deposits with bitumen
A form of petroleum rich in carbon, poor in hydrogen
Degraded and chemically altered crude oil deposits
Removed by strip mining
Requires special
extraction and
refining processes
Most is in Venezuela
and Alberta, Canada
Oil shale is abundant in the U.S. west
Oil shale is sedimentary rock filled with kerogen (organic matter)
Can be processed to produce liquid petroleum or burned like coal
Extracted by strip mines or subsurface mines
World’s supplies may equal 600 billion barrels
40% is in the U.S., mostly on federally owned land in Colorado, Wyoming, and
Utah
Methane hydrate shows potential
Methane hydrate (methane ice) are molecules of methane in a crystal
lattice of water molecules
Occurs in arctic locations and continental shelves
Immense amounts could be present
Twice as much as oil, gas, coal combined
We do not know how to extract it safely
Extraction could release large amounts of methane—a greenhouse gas—
and cause landslides and tsunamis
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
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
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 CO2 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
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
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
Fossil fuel use has consequences
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
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
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 (238U)
It does not emit enough neutrons for a chain reaction
It must be processed into 235U
238U is formed into pellets (UO2) 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
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
Coal versus nuclear power
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
The Chernobyl accident
The destroyed reactor was encased in a massive concrete sarcophagus
which is still leaking radioactive material
Fukushima Daiichi
On March 11, 2010, 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
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
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