17 Energy SourcesEnergy SourcesC

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ER

Energy Sources and UsesEnergy Sources and Uses•Energy Sources•Renewable: Nearly always available or replaceable in a relatively short time

•sunlight, wind, flowing water, biofuels

•Nonrenewable: Cannot be replaced in a reasonable time

• fossil fuels and nuclear energy

•Energy Sources•Renewable: Nearly always available or replaceable in a relatively short time

•sunlight, wind, flowing water, biofuels

•Nonrenewable: Cannot be replaced in a reasonable time

• fossil fuels and nuclear energy

Lesson 17.1 Energy: An Overview

Wind power is a renewable energy source.

Question!Question!

What type of energy source(s) does the United States use?

What type of energy source(s) does the United States use?

Lesson 17.1 Energy: An Overview

Exit Slip!Exit Slip!

1. List three ways the development of an oil field affects the habitats of wildlife.

2. Describe three ways fossil fuels affect air quality.

1. List three ways the development of an oil field affects the habitats of wildlife.

2. Describe three ways fossil fuels affect air quality.

Lesson 17.1 Energy: An Overview

Answer!Answer!Lesson 17.1 Energy: An Overview

Fossil FuelsFossil Fuels

Lesson 17.2 Fossil Fuels

• Include coal, oil, and natural gas

• Formed from the remains of organisms over millions of years

A front loader piles coal at a steam station in Dunkirk,New York.

Fact!Fact!Lesson 17.1 Energy: An Overview

About half of the electricity used in the United States is generated by COAL.

Disadvantages of using Fossil Fuels:

Disadvantages of using Fossil Fuels:

Lesson 17.3 Consequences of Fossil Fuel Use

• Climate Change: Burning fossil fuels releases carbon dioxide

• Air Pollution: When coal and oil burn, sulfur dioxide and nitrogen oxides are released, which contribute to smog and acid rain.

• Water Pollution: Oil spills, equipment ruptures, and oil in runoff pollute waterways, oceans, and coastal areas.

• Combustion: Coal-fired power plants release mercury, which harms human health.

Did You Know? Coal-burning power plants cause 40% of mercury emissions due to human activity in the United States.

Did You Know? Coal-burning power plants cause 40% of mercury emissions due to human activity in the United States.

Fossil Fuel SupplyFossil Fuel Supply

Lesson 17.2 Fossil Fuels

•Consumption is still rising, but new fossil fuels do not form on a human timescale.

•Coal sources are still relatively abundant, but not infinite.

Did You Know? Some studies suggest we have extracted nearly half Earth’s oil, and that U.S. coal supplies may last just 130 years.

Did You Know? Some studies suggest we have extracted nearly half Earth’s oil, and that U.S. coal supplies may last just 130 years.

Natural GasNatural Gas

Lesson 17.2 Fossil Fuels

• Primarily methane gas with small amounts of other gases mixed in

• Much less polluting than coal or oil and releases more energy when combusted

Lesson 17.2 Fossil FuelsLesson 17.2 Fossil Fuels

One quarter of global coal reserves are found in the United States.One quarter of global coal reserves are found in the United States.

CoalCoal

Lesson 17.2 Fossil Fuels

• Compared to other fossil fuels, coal is cheap, needs little processing, and is abundant.

• Provides 1/4 of the world’s energy

Did You Know? Coal is the most abundant fossil fuel on Earth.

Did You Know? Coal is the most abundant fossil fuel on Earth.

How Coal Forms

Coal MiningCoal Mining

Lesson 17.2 Fossil Fuels

Strip mining: Overlying rock and soil are removed to access coal (safer for miners).

Subsurface mining: Underground shafts are dug to access coal under Earth’s surface.

Lesson 17.3 Consequences of Fossil Fuel UseLesson 17.3 Consequences of Fossil Fuel Use

The United States imports two thirds of its crude oil.The United States imports two thirds of its crude oil.

Gulf of Mexico Oil Well ExplosionsGulf of Mexico Oil Well Explosions

Lesson 17.3 Consequences of Fossil Fuel Use

• 1979: Ixtoc I exploratory oil well • 50 m below surface

• Released 126 million gal oil; containment efforts took 9 months

• What didn’t work: cap, siphoning, controlled burn, “top kill”

• What did work: relief wells

• 2010: Deepwater Horizon oil well • 1500 m below surface

• Largest U.S. offshore oil breach as of 2010—21.2–33.5 million gal oil released during first 6 weeks, based on USGS rough estimates

• Hundreds of miles of coastal habitats threatened

• Methods tried: dome, cap, siphoning, controlled burns, “top kill,” “junk shot,” and relief wells

Controlled burns attempt to contain oil pumping into the Gulf, one month after the 2010 well blow-out.

Damage Caused by Extracting FuelsDamage Caused by Extracting Fuels

Lesson 17.3 Consequences of Fossil Fuel Use

• Mining:

• Humans risk lives and respiratory health.

• Ecosystems are damaged by habitat destruction, acid drainage, and heavy metal contamination downslope of mines.

• Oil and gas extraction:

• Roads and structures built to support drilling break up habitats and harm ecosystems.

• The longterm consequences of accidents can be uncertain or unpredictable

Acid drainage from a coal mine

Lesson 17.4 Nuclear PowerLesson 17.4 Nuclear Power

Scientists estimate that nuclear power helps us avoid emitting 600 million metric tons of carbon each year worldwide.

Scientists estimate that nuclear power helps us avoid emitting 600 million metric tons of carbon each year worldwide.

Nuclear FissionNuclear Fission

Lesson 17.4 Nuclear Power

• Splits an atomic nucleus into two smaller nuclei

• Releases neutrons and large amounts of energy. If enough unstable nuclei are present, a nuclear chain reaction can occur.

Did You Know? About 20% of electricity produced in the United States comes from nuclear power.

Did You Know? About 20% of electricity produced in the United States comes from nuclear power.

Generating Electricity Using Nuclear Energy

Generating Electricity Using Nuclear Energy

Lesson 17.4 Nuclear Power

How a nuclear reactor works

Benefits and Costs of Nuclear Power

Benefits and Costs of Nuclear Power

Lesson 17.4 Nuclear Power

Benefits Costs

No air pollution Expensive to build and maintain

Requires little uranium fuel and little mining

Catastrophic accidents are possible-MELTDOWN

Under normal conditions, nuclear power plants are safer for workers than coal-burning power plants.

Nuclear waste must be stored for thousands of years.

Chernobyl

Nuclear WasteNuclear Waste

Lesson 17.4 Nuclear Power

• Waste is currently held at power plants as a stopgap, but a long-term storage location is needed.

• Long-term storage sites must be distant from population centers, protected from sabotage, have a deep water table, and be geologically stable.

• Yucca Mountain, Nevada, was chosen by the U.S. government in the 1980s, and a storage site was constructed there. But, as of 2010, the Yucca Mountain project is no longer under development.

Yucca Mountain storage site

Nuclear MeltdownNuclear Meltdown

Lesson 17.4 Nuclear Power

• Chernobyl Documentary

• True or False: A nuclear meltdown occurs after an atomic explosion in the nuclear reactor.