Nonrenewable Energy

Nonrenewable Energy

Chapter 15

Nonrenewable Resources

Things human use that have a limited supply; they cannot be regrown or replenished by man

Possible Solution– using less of a resource or reusing a resource, ex. refilling plastic laundry jugs, reusing plastic bags, etc.

Problems – • Requires a change in our lifestyle and some

people will resist.

Dealing with Nonrenewable Resources

Restoration

Definition – recycling our resources Examples – aluminum, glass, tin, steel,

plastics, etc.

Problems – recycling a resource often costs more than using the raw material; we don’t have the technology to recycle everything

Sustainability

Definition – prediction of how long specific resources will last; ex. we have a 200 year supply of coal in the U.S.

Problems – these are only predictions; they may not be accurate

Ownership costs – equipment, labor, safety (insurance), environmental costs (reclamation, pollution control, air monitors, water treatment, etc.), taxes

External costs – processing the resource, transporting the resource

Marginal costs – research: finding new sources of the resource and new ways to harvest it

Harvesting Nonrenewable Resources-COSTS

Direct – money received for resources; provides many jobs

Indirect – land can be reclaimed (brought back to original condition) and sold for profit.

Harvesting Nonrenewable Resources-BENEFITS

Original sources that are used to make electricity or heat

Primary Resources

Secondary Sources

Heat and electricity that we use for energy

Cogeneration

Production of two useful forms of energy, such as high-temperature heat or steam and electricity, from the same fuel source.

Ex. An industry using natural gas for manufacturing and using the waste heat to produce electricity.

Fossil Fuels Energy conversion – chemical to electrical, heat or

mechanical• Only about 30% efficient

Benefits – easy to use, currently abundant Costs – a nonrenewable resource, produces pollutants

that contribute to acid rain and the greenhouse effect

Oil- Supplies the most commercial energy in the world today. People in the U.S. use 23 barrels of petroleum per person or 6 billion barrels total each year!!!

Examples of Primary Sources

Saudi Arabia could supply the world with oil for about 10 years.

The Alaska’s North Slope could meet the world oil demand for 6 months. (U.S.: 3 yrs.)

Alaska’s Arctic National Wildlife Refuge (ANWR) would meet the world demand for 1-5 months. (U.S.: 7-24 months)

Core Case Study: How Long Will Supplies of Conventional Oil Last?

We have three options:• Look for more oil• Use or waste less oil• Use other energy sources

Core Case Study: How Long Will Supplies of Conventional Oil Last?

About 82% of global commercial energy comes from nonrenewable fossil fuels with the remainder coming from renewable sources.

SOURCE : DEPARTMENT OF ENERGY Annual Energy Review 2009

Fossil Fuels Supply Most of Our Commercial Energy

Commercial Energy Use by Source for the World and the United States

How Power Plants How Power Plants Produce ElectricityProduce Electricity

Natural Capital: Important Nonrenewable Energy Resources

Case Study: A Brief History of Human Energy Use

A Brief History of Human Energy Use

• Muscle power: early humans

• Discovery of fire

• Agriculture

• Use of wind and flowing water

• Machines powered by wood, then coal

• Internal combustion engine

• Nuclear energy

• Energy crisis

OIL / PETROLEUM

Only 35-50% can be economically recovered from a deposit.

We Depend Heavily on Oil

Crude oil (petroleum): thick liquid containing hydrocarbons that we extract from underground deposits and separate into products such as gasoline, heating oil and asphalt.

Science: Refining Crude Oil

An oil refinery uses distillation to separate crude oil into it’s components:• Based on boiling points,

components are removed at various layers in a giant distillation column.

• The components with the lowest boiling points are removed at the top.

Twelve OPEC countries have 60% of the world’s proven oil reserves and most of the world’s unproven reserves.• Organization of Petroleum Exporting Countries

OPEC Controls Most of the World’s Oil Supplies

Rising Oil Prices

Possible effects of steeply rising oil prices:• Higher food prices• Airfares higher• Reduce energy waste• Upgrade of public transportation• Smaller more fuel-efficient vehicles• Shift to non-carbon energy sources• Higher prices for products made with petrochemicals

Global oil production peaked around 2005 Sharp increases in oil prices could threaten the

economies of countries that have not shifted to new energy alternatives.

The U.S. – the world’s largest oil user – has only 2.4% of the world’s proven oil reserves.

The U.S. uses 24% of worldwide crude oil. The U.S. imports 60% of the oil it uses.

The United States Uses Much More Oil Than It Produces

Case Study: Oil and the U.S. Arctic National Wildlife Refuge

The Arctic National Wildlife Refuge (ANWR)• Not open to oil and gas development• Fragile tundra biome

Decrease dependence on foreign oil??• “Drill baby, drill!”

OIL

PROs Relatively Cheap Easily transported –

pipelines, oil tankers Versatile

CONs CO2 emissions

H2O pollution from tanker spills

Habitat destruction from pipeline construction and oil spills

Heavy and tarlike oils from oil sand and shale oil could supplement conventional oil, but there are environmental problems.• High sulfur content• Extracting and processing produces toxic sludge• Uses and contaminates larges volumes of water• Requires large inputs of energy which reduces net energy

Will Heavy Oil from Oil Sand or Shale Oil Be Viable Options?

Canada has 75% of the world’s oil sand. The Western U.S. has 72% of the

world’s shale oil.

Trade-Offs: Heavy Oils from Oil Shale and Oil Sand

NATURAL GAS

Natural gas, consisting mostly of methane (CH4), is often found above reservoirs of crude oil.• Coal beds, bubbles of methane trapped under the

arctic permafrost and beneath deep-ocean sediments, and landfills are unconventional sources of natural gas.

Natural Gas Is a Useful and Clean-Burning Fossil Fuel

Russia, Iran, and Qatar have about 3/4 of the world’s reserves of conventional gas, and global reserves should last 62-125 years.


Fuel burning in a combustion chamber produces hot gases that pass directly through the turbine, which spins a generator to produce electricity. Then these hot gases are used to turn water to steam, which pushes a second turbine producing more electricity.


Produces electricity X 2

Natural gas is transported through dense networks of pipelines

Liquefied petroleum gas (LPG)• Pressurized tanks used in rural areas

Liquefied natural gas (LNG)• Gas is cooled and pressurized in

order to ship across the ocean


Natural Gas

Natural Gas: Fracking

Coal Comes in Several Forms and Is Burned Mostly to Produce Electricity

Coal: solid fossil fuel that is formed in several stages as the buried remains of land plants that lived 300-400 million years ago.

Burned in 2100 power plants, generates 40% of the world’s electricity (49% in the U.S.)• Inefficient process that burns coal to boil water which

produces steam that turns a turbine

Coal

Most abundant fossil fuel! 4 types:

• Lignite• Low energy, low sulfur

• Sub-bituminous• Intermediate energy, low sulfur

• Bituminous• Intermediate energy, high sulfur

• Anthracite• Hard coal: high energy, low sulfur, small

quantities

Stages in Coal Formation over Millions of Years

Science: Coal-Burning Power Plant

Coal

Major use: electricity Our current supply will last 150 – 200

years Largest reserves: US, Russia, China

Coal Is a Plentiful but Dirty Fuel

Environmental costs of burning coal:• Single biggest air polluter in coal-burning countries

• CO2 – one-fourth of the annual global emissions

• Sulfur released as SO2 (acid rain)

• Large amount of soot• Mercury (Hg)• Radioactive materials

Environmentalists call for:• Taxation on CO2 production by power plants

• Cleaner coal-burning plants

NUCLEAR POWER

The blue glow is known as Čerenkov radiation – when charged particles (electrons) passes through an insulator (water).

Nukes

A Little Chemistry Review:•Nucleus = protons + neutrons

– Protons: positive, = to atomic #

– Neutrons: no charge, same mass as proton

– Atomic mass = protons + neutrons

•Electrons– Orbit nucleus, negative charge, = to protons

•Isotope: different neutrons– Same number, same protons

•Ion = charged particle

Nukes

Fission!• Breaking down into 2 smaller atoms

Fusion• Combining atoms (the sun!)

Radioactivity• Spontaneous decay of unstable

nuclei

How Does a Nuclear Fission Reactor Work?

Isotopes of uranium and plutonium undergo controlled nuclear fission, the resulting heat produces steam that spins turbines to generate electricity.• The uranium oxide consists of about:

• 97% non-fissionable U238

• 3% fissionable U235

• The concentration of U235 is increased through an enrichment process (normally only 0.7%).• Uranium enrichment is a difficult process

An uncontrolled nuclear fission reaction is used in/for atomic weapons.


The nuclear fission reaction takes place in a reactor Fueled by uranium dioxide and packed as pellets in

fuel rods and fuel assemblies• Each eraser-sized pellet contains the energy of a TON of coal

Control rods absorb neutrons• Moved up/down to control the

speed of the reaction Water is the usual coolant Containment shell around the core for protection

Nukes

Nuclear Power Plant

Nuclear Power Plant:Light-Water-Reactor

Nuclear power plants are highly inefficient• Lose as much as 83% of its energy as waste heat

After three or four years in a reactor, spent fuel rods are removed and stored in a deep pool of water contained in a steel-lined concrete container.

After spent fuel rods have cooled considerably, they are sometimes moved to dry-storage containers made of steel or concrete.• Typically stored on-site


What Is the Nuclear Fuel Cycle?

Mine the uranium Process the uranium to make the fuel Use it in the reactor Safely store the radioactive waste Decommission the reactor

• Safely shut it down and seal it up

What Happened to Nuclear Power?

After more than 50 years of development and enormous government subsidies, nuclear power has not lived up to its promise of “almost limitless energy at a very small cost per kWh” because:• Multi billion-dollar construction costs• Higher operation costs and more

malfunctions than expected• Poor management• Public concerns about safety and

strict government safety regulations• Low net yield of energy

Nuclear Power: Explained

Case Study: Worst Commercial Nuclear Power Plant Accident in the U.S.

The accident occurred at the Three Mile Island Unit 2 (TMI-2) nuclear power plant near Middletown, PA on March 28, 1979.• Human and mechanical errors lead to part of one of

the reactor cores melting (meltdown).• Unknown amounts of radioactivity escaped• People fled the area

Case Study: Worst Nuclear Power Plant Accident in the World

The world’s worst nuclear power plant accident occurred on April 26, 1986 near Chernobyl, Ukraine.• Poor reactor design and human error led to a series of

explosions causing the roof of a reactor building to blow off• Partial meltdown and fire for 10 days• Huge radioactive cloud spread over many countries and

eventually the world • 350,000 people left their homes

A 1,000 MW nuclear plant is refueled once a year, whereas a coal plant requires 80 rail cars a day.

When a nuclear reactor reaches the end of its useful life, its high-level radioactive wastes must be stored safely for 10,000 – 240,000 years• Deep burial: safest and cheapest option• Change it into harmless or less harmful isotopes?

At least 228 large commercial reactors worldwide (20 in the U.S.) are scheduled for retirement by 2012.• Many reactors are applying to extent their 40-year

license to 60 years

What Do We Do with Worn-Out Nuclear Power Plants?

Dealing with Radioactive Wastes Produced by

Nuclear Power Plants Is a Difficult Problem

Case Study: Experts Disagree about What to Do with

Radioactive Wastes in the U.S.

1985: plans in the U.S. to build a repository for high-level radioactive wastes in the Yucca Mountain desert region (Nevada)

Problems• Cost: $58–100 billion• Large number of shipments to the site

• protection from attack?

• Rock fractures• Earthquake zone• Decrease national security

Nuclear fusion is a nuclear change in which two isotopes are forced together.• No risk of meltdown or radioactive releases• May also be used to breakdown toxic material• Still in laboratory stages after 50 years of research

and $34 billion dollars• So far, more energy is put in

than we get out

Will Nuclear Fusion Save Us?

Nonrenewable Energy

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