CHAPTER 15:
NONRENEWABLE
ENERGY
By: Cari Spivey
WHAT IS NET ENERGY AND WHY IS IT
IMPORTANT?
 The two laws of thermodynamics govern all physical and
chemical changes involved in the use of fossil fuels and other
energy alternatives.
 The first law of thermodynamics, it takes high -quality energy to
get high-quality energy.
 For example, before oil becomes useful to us, it must be found,
pumped up from beneath the ground or ocean floor, transferred
to a refinery, converted to useful fuels, and delivered to
consumers.
 Each of these steps uses high -quality energy, mostly obtained by
burning fossil fuels such as oil and coal.
 The second law of thermodynamics tells us that some of the
high-quality energy used in each step is automatically wasted
and degraded to lower-quality energy.
 No matter how hard we try, we cannot violate the two scientific
laws of thermodynamics .
 The usable amount of high -quality energy available from a given
quantity of an energy resource is its net energy.
 The total amount of useful energy available from an energy
resource minus the energy needed to make it available to
consumers
 It is calculated by estimating the total amount of energy
available from the resource over its projected lifetime and then
subtracting the estimated amount of energy used, automatically
wasted because of the second law of thermodynamics, and
unnecessarily wasted in finding, extracting, processing, and
transporting the useful energy to consumers .
 Net energy is like the net profit earned by a business after it
deducts its expenses .
 We can express net energy as the ratio of energy produced to the
energy used to produce it. The net energy ratio would be 10/9, or
approximately 1 .1 . As the ratio increases, its net energy yield
also rises.
 Any energy resource with a low or negative net energy yield
cannot compete in the open marketplace with other energy
alternatives with higher net energy yields unless it is subsidized
by the government or by some other outside source of funding .
 Relying on these energy resources is like investing in a business
that has a low profit or that always loses money unless the
government or some outside benefactor holds it up.
 Another component of any net energy ratio is the energy that is
unnecessarily wasted in making useful energy available for use.
 We can control this factor by reducing such unnecessary waste
and thus raising the net energy yield of a resource .
 Roughly 41% of all commercial energy is automatically wasted
because of the second law of thermodynamics.
 Americans unnecessarily waste about 43% (the rest of the total
wasted 84%).
WHAT ARE THE ADVANTAGES AND
DISADVANTAGES OF USING OIL?
 Oil supplies about one-third of the world’s commercial energy
and 40% of that used in the United States.
 Oil is the lifeblood of most of the world’s economies and modern
lifestyles and is the world’s largest business.
 We use oil to grow most of our food, transport people and goods,
and make most of the things we use every day, from plastics to
asphalt on roads.
 Petroleum, or crude oil, is a black, gooey liquid consisting of
hundreds of different combustible hydrocarbons along with small
amounts of sulfur, oxygen, and nitrogen impurities.
 This conventional oil, also known as light or sweet crude oil,
makes up about 30% of the world’s estimated supply of oil.
 Deposits of conventional crude oil and natural gas often are
trapped together under domes deep within the earth’s crust on
land or under the seafloor.
 After years of pumping, usually a decade or so, the pressure in a
well drops and its rate of conventional crude oil production starts
to decline.
 This point in time is referred to as peak production for the well.
 The same thing can happen to a large oil field when the overall
rate of production from its numerous wells begins to decline.
 Global peak production is the point in time when we reach the
maximum overall rate of conventional crude oil production for
the whole world.
 Once we pass this point, the rate of global production of
conventional oil begins to decline.
 If we continue using conventional oil faster than we can produce
it, its price rises.
 Some of the products of crude oil distillation, called
petrochemicals, are used as raw materials in industrial organic
chemicals, cleaning fluids, pesticides, plastics, synthetic fibers,
paints, medicines, and many other products.
 World oil consumption has been growing rapidly since 1950 and
conventional crude oil is now the single largest source of
commercial energy in the world and in the United States.
 Proven oil reserves are identified deposits from which
conventional crude oil can be extracted profitably at current
prices with current technology.
 Other deposits of potentially recoverable oil are classified as
unproven reserves.
 They consist of probable reserves with a 50% chance of
recovery and possible reserves with a 10% to 40% chance of
recovery.
 The world is not about to run out of conventional oil in the
near future.
 Geologists project that proven and unproven global reserves
of conventional crude oil will be 80% depleted sometime
between 2050 and 2100, depending on consumption rates.
 It is extracted from crushed oil shales after they are heated in
a large container, a process that yields a distillate called
shale oil.
WHAT ARE THE ADVANTAGES AND
DISADVANTAGES OF USING NATURAL
GAS?
 Natural gas is a mixture of gases of which 50 –90% is
methane and it also contains smaller amounts of heavier
gaseous hydrocarbons such as propane and butane, and small
amounts of highly toxic hydrogen sulfide.
 It is a versatile fuel with a high net energy yield that can be
burned to heat space and water, to produce electricity, and to
propel vehicles.
 Conventional natural gas lies above most reservoirs of crude
oil.
 When a natural gas field is tapped, propane and butane gases
are liquefied under high pressure and removed as liquefied
petroleum gas.
 LPG is stored in pressurized tanks for use mostly in rural
areas not served by natural gas pipelines.
 The rest of the gas is purified and pumped into pressurized
pipelines for distribution across land areas.
 Russia, the Saudi Arabia of natural gas, has about 25% of the
world’s proven natural gas reserves, followed by Iran and
Qatar.
 The United States has only 3.4% of the world’s proven natural
gas reserves but uses about 22% of the world’s annual
production.
 Burning natural gas releases the greenhouse gas carbon
dioxide and several other air pollutants into the atmosphere.
 Natural gas can be converted to liquefied natural gas at a
high pressure and at the very low temperature of about –162
oC.
 There are also several sources of unconventional natural gas
and one is coal bed methane gas found in coal beds near the
earth’s surface across parts of the United States and Canada.
 Another is natural gas trapped in underground shale beds that
are found in many parts of the United States and that could meet
U.S. natural gas needs for up to 100 years.
 Residents of the United States who rely on aquifers for their
drinking water have little protection from pollution of their water
supplies from these two unconventional sources of natural gas
because the 2005 Energy Policy Act excluded natural gas
companies from regulation under U.S. water pollution control
laws.
 Another unconventional source is methane hydrate, methane
trapped in icy, cage-like structures of water molecules.
 it costs too much to get natural gas from methane hydrates, and
the release of methane to the atmosphere during removal and
processing would speed up atmospheric warming and the
resulting climate change .
WHAT ARE THE ADVANTAGES AND
DISADVANTAGES OF USING COAL?
 Coal is a solid fossil fuel that was formed in several stages from
of the remains of land plants that were buried 300 –400 million
years ago and then exposed to intense heat and pressure over
those millions of years.
 Coal is responsible for 42 % of the world’s electricity, 46% of the
electricity used in the United States, and 70% of that in China
and it is also burned in industrial plants to make steel, cement,
and other products .
 Coal is the world’s most abundant fossil fuel, and the world has
depended on it as a major energy resource for several hundred
years.
 Identified and unidentified global supplies of coal could last for
214–1 ,125 years, depending on how rapidly they are used.
 The U.S. Geological Survey estimates that identified U.S. coal
reserves should last about 250 years at the current consumption
rate.
 The problem is that coal is by far the dirtiest of all fossil fuels
and before it is even burned, the processes of making it
available severely degrade land and pollute water and air.
 When coal is burned without expensive pollution control devices,
it severely pollutes the air.
 Coal is mostly carbon but contains small amounts of sulfur,
which is released into the air as sulfur dioxide when the coal
burns.
 According to a 2007 study by the Center for Global Development,
coal-burning power plants account for 25% of all human generated CO2 emissions in the world, and 40% of such
emissions in the United States .
 Another problem with burning coal is that it emits trace amounts
of radioactive materials as well as toxic and indestructible
mercury into the atmosphere .
 A coal-burning power plant releases about 100 times more
radioactivity into the atmosphere than does a nuclear power
plant with the same energy output .
 The use of coal is growing, especially in China, which has
relied on coal to help fuel its rapid economic growth.
 In 2009, on average, China was building the equivalent of one
large coal-fired power plant every week, most of them without
modern air pollution control equipment.
 We can convert solid coal into synthetic natural gas by a
process called coal gasification, which removes sulfur and
most other impurities from coal.
 We can also convert coal into liquid fuels such as methanol
and synthetic gasoline through a process called coal
liquefaction.
 We can also convert coal into liquid fuels such as methanol
and synthetic gasoline through a process called coal
liquefaction.
WHAT ARE THE ADVANTAGES AND
DISADVANTAGES OF USING NUCLEAR
ENERGY?
 Nuclear power is a source of energy that we learned how to
use fairly recently, primarily for generating electricity.
 A nuclear power plant is a highly complex and costly system
designed to per- form a relatively simple task: to boil water
and produce steam that spins a turbine and generates
electricity.
 The fission reaction takes place in a reactor and the most
common reactors, called light -water reactors, produce 85% of
the world’s nuclear-generated electricity.
 Control rods are moved in and out of the reactor core to
absorb neutrons, thereby regulating the rate of fission and
amount of power produced.
 A containment shell with thick, steel -reinforced concrete walls
surrounds the reactor core.
 A nuclear power plant is only one part of the nuclear fuel
cycle, which also includes the mining of uranium, processing
and enriching the uranium to make fuel, using it in a reactor,
and safely storing the resulting highly radioactive wastes, in
the form of depleted or spent fuel rods, for thousands of years
until their radioactivity falls to safe levels.
 Each step in the nuclear fuel cycle adds to the cost of nuclear
power and reduces its net energy yield.
 In the 1950s, researchers predicted that by the year 2000, at
least 1 ,800 nuclear power plants would supply 21% of the
world’s commercial energy and most of the world’s electricity.
 The U.S. government has provided huge subsidies, tax breaks,
and loan guarantees to the nuclear power industry.
 Chernobyl is known around the globe as the site of the world’s
most serious nuclear power plant accident.
 According to UN studies, the Chernobyl disaster was caused by
a poor reactor design and by human error, and it had serious
consequences.
 After about 3 or 4 years, the high -grade uranium fuel in a
nuclear reactor becomes spent, or useless, and must be
replaced.
 A 2005 study by the U.S. National Academy of Sciences
warned that the intensely radioactive waste storage pools and
dry casks at 68 nuclear power plants in 31 U.S. states are
especially vulnerable to sabotage or terrorist attack.
 The long-term goal is to find a way to store these dangerous
radioactive wastes safely at a central site .
THREE BIG IDEAS
 A key factor to consider in evaluating the usefulness of any
energy resource is its net energy yield.
 Conventional oil, natural gas, and coal are plentiful and have
moderate to high net energy yields, but using any fossil fuel,
especially coal, has a high environmental impact.
 Nuclear power has a low environmental impact and a very low
accident risk, but high costs, a low net energy yield, long -lived
radioactive wastes, and the potential for spreading nuclear
weapons technology have limited its use.