ENERGY TODAY

Energy for the Global Economy

The U.S. is the largest consumer of energy.

Energy use is increasing in most countries.

How We Use Energy Residential and commercial= houses,

office buildings, shopping malls… Industrial sector= manufacturing plants,

paper mills, oil refineries, steel mills, automobile plants, agriculture, mining, construction

Transportation= light duty vehicles, freight trucks, air transport, trains, boats/ships

8.2 Historical Uses of Energy First, humans used sunlight for energy-

ate plants/animals and burned wood for fuel

Mid-1700s – burned coal (also energy from the sun)

1900’s + - coal, oil and natural gas (advanced technology = greater need for more fuel and more energy content.

8.3 America’s Energy Transitions

When wood burns, it produces about 2760 calories per gram. Coal contains more than 2 times the energy as wood. Therefore, wood replaced coal.

Oil/natural gas use became more common in the 1920s. Oil is easier to use and cleaner than coal. They are also easier and cheaper to transport. By the end of WWII, petroleum was the dominant fossil fuel.

Fossil Fuels – oil, gas, coal

Oil:is easily stored, transported and consumedis the leading energy source in the U.S.

Crude oil is the decay of organic matterMost petroleum is in the form of either liquid crude oil or vapor called natural gas.

Petroleum also exists in solids-

tar sands (Alberta, Canada) and shale beds (Colorado, Utah, Wyoming)

Most scientists believe oil formed from remains of tiny oceanic plants/animals. These organisms formed layers and layers of material that eventually, under pressure, formed sedimentary rocks such as limestone, and shale.

Oil is a hydrocarbon, formed from H and C atoms

After the petroleum formed, it migrated through the rock into permeable and porous rocks. Concentrations of petroleum form reservoirs.

Oil and gas seep up and out until capped by impermeable rock. The lighter gas then migrates to the top.

Most Oil If Found Deep Within The Earth’s Crust

In deciding where to drill for oil, scientists look for 1) shale and limestone 2) permeable/porous rock such as sandstone and limestone that may be reservoir rock and 3) a layer of impermeable rock

Oil + Oxygen → CO2 + H2O + heat energy + wastes

Wastes may be unburned hydrocarbons, carbon monoxide, nitrogen oxides and sulfur gases.

Uses of Petroleum

The many uses of petroleum

List 5 items from the list that surprised you.

8.5 Natural Gas

Burns cleaner than coal and oil Burns almost completely and

produces almost no harmful byproducts

Natural gas + oxygen → CO2 + H2O + heat

The Industrial Sector Is The Largest User Of Natural Gas

More homes are heated with natural gas than any other type of fuel.

Natural gas is used for raw material processing, food preparation, refinery fuel and power generation

Natural gas provides the base ingredients for products such as plastic, fertilizer, anti-freeze, and fabrics

Is a component of petroleum. Is mostly methane (CH4) with some

ethane, propane and butane. Natural gas is less dense than

petroleum so it is found above petroleum

NATURAL GAS

8.6 Coal Main source of producing electricity

in the U.S. Large reserves in the U.S.

Coal + O2 → CO2 + heat + waste

Wastes are sulfur dioxide, nitrogen oxides, carbon monoxide, soot, and fly ash

Sulfur is naturally found in coal Nitrogen oxides form in extreme heat in

furnaces and engines Soot is unburned coal CO2 is released when coal (C) is burned .

Because it is a greenhouse gas, technologies are developed to reduce the amount released.

ORIGIN OF COAL Coal is fossilized plant matter (can often

see bits of wood, bark, leaves and roots) It is an organic substance made of mostly

carbon with small amounts of hydrogen, oxygen, nitrogen and sulfur

Forms in hot, moist places, in stagnant waters- equatorial regions.

Plants die, are buried by water and sediments, and then attacked by anaerobic bacteria. H and O are released by the bacterial action, leaving mostly carbon.

peat → subbituminous coal (lignite) → bituminous coal → anthracite

As heat and pressure affect the peat, water is squeezed out, methane gas escapes and the carbon content becomes more concentrated.

Peat = organic material subbituminous (lignite) and bituminous coal =

sedimentary rock Anthracite = metamorphic rock

Fig. 15-11, p. 383

Increasing moisture content Increasing heat and carbon content

Peat (not a coal)

Lignite (brown coal)

Bituminous (soft coal)

Anthracite (hard coal)

Heat Heat Heat

Pressure Pressure Pressure

Partially decayed plant matter in swamps and bogs; low heat content

Low heat content; low sulfur content; limited supplies in most areas

Extensively used as a fuel because of its high heat content and large supplies; normally has a high sulfur content

Highly desirable fuel because of its high heat content and low sulfur content; supplies are limited in most areas

Stepped Art

Anthracite is most desirable for heating because it burns with little smoke. Hard to ignite because most volatiles are gone. Lignite lights easily with lots of smoke. Dangerous because of its high volatility.

Energy content of coal determines its quality and usefulness as a fuel. Anthracite has highest heat content. Bituminous is used mostly for electric power generation.

Coal deposits in the east are of higher quality (bituminous) than those in the West (lignite) which are closer to the surface.

1/8 of U.S. land lies over coal beds.

MINING METHODS In past, coal was mined underground, where

large rooms were mined with pillars left to support the roof. Work was dangerous, hard and unpleasant.

Now, mining is automated.

60% OF COAL TODAY IS SURFACE MINED

Overlying surface rock (overburden) is removed.

Surface mining(open pit mining) is less dangerous to miners and recovers more coal than underground mining.

Less than 10% of coal, however, is shallow enough to be surface mined

Coal is often located under farm land which must be reclaimed.

Natural Capital Degradation: Mountaintop Coal Mining

in West Virginia

Fig. 14-15, p. 356

NATURAL CAPITAL DEGRADATION

Extracting, Processing, and Using Nonrenewable Mineral and Energy Resources

Steps Environmental Effects

Mining Disturbed land; mining accidents; health hazards; mine waste dumping; oil spills and blowouts; noise; ugliness; heat

Exploration, extraction

Processing Solid wastes; radioactive material; air, water, and soil pollution; noise; safety and health hazards; ugliness; heat

Transportation, purification, manufacturing

Use Noise; ugliness; thermal water pollution; pollution of air, water, and soil; solid and radioactive wastes; safety and health hazards; heat

Transportation or transmission to individual user, eventual use, and discarding

Fig. 15-15, p. 385

TRADE-OFFSCoal

Advantages DisadvantagesSevere land disturbance, air pollution, and water pollution

Ample supplies (225–900 years)

High net energy yield Severe threat to human health when burnedEnvironmental costs not included in market price

Low cost

Large government subsidies

Well-developed technology High CO2 emissions

when produced and burned

Air pollution can be reduced with improved technology

Radioactive particle and toxic mercury emissions

Come up with an acronym (saying) to remember the 4 stages of coal.

Which type of coal is considered a metamorphic rock?

8.7 ELECTRICAL ENERGY

Coal may be the largest and most important source of energy for generating electricity, are also used.

Hydropower, nuclear and natural gas are 3 other energy sources used to produce electricity.

HYDROPOWER Used almost entirely for generating

electricity. Produces 2.7% of electricity in the U.S.

(2005) Low cost and clean energy Few sites available to expand use

Buford Dam

8.9 THERMAL POLLUTION The goal of power plants is to produce

steam. To produce steam, you need large amounts of water that need to be heater to high temperatures. What do you do with all that hot water?

The hot water cannot be released directly into the air or a body of water because:

Blue-green algae may replace more desirable algae. This algae can multiply rapidly and use up oxygen in the water, resulting in fish kills.

Trout may die off because warm water cannot hold as much dissolved oxygen as cold water.

Cooling towers and ponds are used. Most water that cools is reused.

20% OF THE WORLD’S POPULATION DOES NOT HAVE ACCESS TO ELECTRICITY (1.4 billion)