Chapter 15 - Nonrenewable Energy

United States Energy Usage

United States Energy Usage

The U.S. is the world’s second largest energy consumer (behind China) and the 8th largest energy user per capita.

Nonrenewable Resources

resources that cannot be replaced - ex. fossil fuels (coal, oil) nuclear (uranium)

Renewable Energy Resources

are continually replaced - ex. solar, wind, hydroelectric, geothermal, biomass

Fossil fuels

created by the decay and compression of organisms that lived millions of years ago

OIL STATISTICS

• Oil (petroleum) currently provides 36% of the world’s energy.

• This resource will be exhausted in 40-90 years at the current rate of consumption.

• The only countries that have not already hit peak oil production are in the Middle East.  Untapped resources of unknown amounts do exist under the Arctic Ocean.

• Alternative oil sources, including shale oil and tar sands are increasing marketshare over traditional petroleum sources

Primary Oil recovery

involves drilling a well and pumping out the oil that flows by gravity into the bottom of the well

Secondary oil recovery

occurs when water is injected into nearby wells to force some of the remaining heavy oil to the surface

Tertiary oil recovery

involves the injection of steam or CO2 to force some of the remaining heavy oil into the well cavity (enhanced oil recovery.)

OPEC, the Organization of Petroleum Exporting Countries

Made up of 13 countries. OPEC controls 70-80% of the world’s proven crude oil reserves.

Oil shale

is a fine grained rock that contains a solid, waxy mixture of hydrocarbon compounds called kerogen.  The kerogen can be isolated to form shale oil.  There are large supplies of shale oil but is much more expensive to process.

tar sand

contains bitumen (a high-sulfur heavy oil).  The source is more plentiful but the processing is expensive.  It often takes more energy to produce these oil alternatives than the energy provided.

Coal provides

27% of the world’s energy and will last about 100 years at the current consumption rate.

Coal electricity generation

40%

Coal reserves

About 25% of the world’s coal reserves are located in the U.S., followed by Russia with 15%.

Coal

is a solid, rocklike fossil fuel.  It is mostly carbon (40-98% depending on the type)

Each stage of coal formation occurs from increasing pressure and heat:

• Peat

• Lignite

• Bituminous coal

• Anthracite

Peat

(not a coal) is partially decayed plant matter in swamps and bogs

Lignite

(brown coal) has low heat content

Bituminous Coal

(soft coal) is extensively used because of its high heat content but it has high sulfur content and therefore does not burn clean

Anthracite

(hard coal) is the most desirable fuel because of its high heat content and low sulfur content but supplies are limited

Natural gas

is a mixture of 50-90% methane (CH4) with the remaining volume consisting of heavier gaseous hydrocarbons

Natural gas use has risen

to provide 23% of the world’s energy, primarily due to increased fracking in the United States.  The world supply of natural gas should last about 200 years.

Hydraulic Fracturing or fracking

is a means of natural gas extraction.  Once a well is drilled, millions of gallons of water, sand and chemicals are injected, under high pressure. The pressure fractures the shale and props open fissures that enable natural gas to flow more freely out of the well

The U.S. Energy Bill of 2005, commonly called the Halliburton Loophole

exempts natural gas drilling from the Safe Drinking Water Act of 1974.

Fracking has resulted in

extensive groundwater contamination and the release of VOC’s (volatile organic compounds) into the air.

As of May 2011

the NC senate cleared the way for hydraulic fracturing in North Carolina, including Chatham County – home of Jordan Lake, which is the water source for Cary.

Advantages of natural gas over other nonrenewable resources

• cheaper than oil and easier to process

• easy to transport (by pipeline)

• higher net energy yield (burns hotter)

• combustion produces less air pollution than any other nonrenewable resource

Disadvantages of Natural Gas

• must be converted to __________ before tanker transport (expensive and dangerous)

• leaks into the atmosphere

  • The process of __________ is extremely dangerous to both groundwater and air quality

Fission of Uranium-235 (Nuclear Power)

provides provides about 20% of the electricity used in the U.S. from 61 plants.

France is the world’s nuclear leader

getting 75% of its electricity from nuclear, although the U.S. produces more total power from nuclear power.

Advantages of Nuclear Power

No emission of air pollution, Water pollution and land disruption are minimal

Disadvantages of Nuclear Power

Potential reactor meltdown, Radioactive waste disposal, Currently more expensive than fossil fuels

This is the most significant nuclear accident in U.S. history.

Three Mile Island, Middletown, PA, USA. On March 28, 1979 this reactor suffered a partial meltdown.  No direct injuries or deaths resulted, but sweeping changes by the U.S. Nuclear Regulatory Commission occurred along with a loss of confidence in nuclear energy by the American public.

The April 25, 1986 reactor meltdown is the most severe nuclear disaster in world history.

Chernobyl, USSR. There are 56 fatalities attributed to the accident, but approximately 7 million are receiving, or are eligible to receive benefits as “___victims”.  Various forms of cancer are the primary consequences of radiation exposure.

On March 11, 2011,

the Tohoku earthquake and tsunami led to the meltdown and release of radioactive material from the Fukushima Daiichi power plant in Japan.  The long-term effects of this disaster are yet to be seen.

Nuclear Fusion

occurs when lightweight atomic nuclei combine to form a heavier nucleus

Elements of Fusion

hydrogen and helium

Fusion facts

the process of stars, fusion is incredibly powerful.  However, atomic nuclei must be maintained at very high concentrations, be properly confined, and achieve temperatures of 100,000,000 oC