1. Chapter 21: Conventional Energy
In this chapter the following topics will be covered:
Current energy sources and how energy was used through history
Energy consumption in the USA compared to the rest of the world
The resources and reserves of fossil fuels in the world
Evaluation of the costs of using coal, oil, and natural gas
Nuclear reactors: how they work and how they can be made safer
Options available to store radioactive waste and to dispose of it

2. What is Energy and Where Do We Get It?
Work is the application of force through a distance
Energy is the capacity to do work.
Power is the rate of flow of energy, or the rate at which work is done.
Food energy (chemical energy) is measured in calories (cal).
1 cal = the amount of energy to heat 1g of water 1o Celsius.
A joule (J) is the amount of work done when a force of 1 Newton is
exerted over 1 meter.

3. Table 21.1 Some energy units
1 joule (J) = the force exerted by a current of 1 amp flowing through
a resistance of 1 ohm
1 watt = 1 joule (J) per second
1 kilowatt (kwhr) = 1 thousand watts exerted for 1 hour
1 megawatt (MW) = 1 million watts
1 Gigawatt (GW) = 1 billion watts
1 Petajoule ((PJ) = 1 trillion joules
1 British thermal unit (BTU) = energy to heat 1 lb of water 1o F
1 PJ = 947 billion BTU, or billion kwhr
1 standard barrel (bbl) of oil = 42 gal (160 l) or 5.8 million BTU
1 metric ton of standard coal = 27.8 million BTU or 4.8 bbl oil

4. A Brief Energy History
Fire was the first human energy technology.
Wind and water power have been important for about the last 10,000
years.
Coal has been replaced by oil this century due to the ease of shipping
and use.
World oil use peaked in 1979, when daily production passed 66
million barrels per day.
The early 1980's saw an increased concern with energy conservation.

5. Current Energy Sources
Fossil fuels (petroleum, natural gas, and coal) provide about 85% of
all commercial energy in the world.
Biomass fuels (wood, peat, charcoal, manure) provide about 6% of
commercial energy.
Renewable sources (water, wind) make up about 4 to 5% of our
commercial power.
Nuclear power is about 4 to 5% world-wide, but makes up about
20% of all electrical power produced in more developed countries.

7. Per Capita Consumption
The twenty richest countries in the world consume nearly 80% of
the natural gas, 65% of the oil, and 50% of the coal produced each year. Although we make up less than 1/5 of the world's population, we use more than 1/2 of the commercial energy supply.
On average, each person in the United States uses more than 300 GJ
(60 barrels of oil) per year. In contrast, the average person in the poorest countries on earth use less than 1 GJ per year.

9. How Energy Is Used
The largest share (36%) of the energy consumed in the United States
is used by industry.
Transportation consumes about 26% of all energy used in the United
States each year.
About half of all the energy in primary fuels is lost during
conversion to more useful forms.
Natural gas is our most efficient fuel. Only 10% of its energy is lost
in shipping, and it generally requires very little refining.

10. Coal
Coal is fossilized plant material preserved by burial in sediments
and altered by geological forces that compact and condense it into a carbon-rich fuel.
Because coal takes so long to form, it is essentially a nonrenewable
resource.

11. Coal Resources and Reserves
World coal deposits are vast, ten times greater than conventional
oil and gas resources combined.
Mining
Coal mining is a hot, dirty, dangerous, and often ecologically
damaging business.

13. Air Pollution
Coal burning releases radioactivity and many toxic metals
(uranium, lead, cadmium, mercury, zinc). You are likely to get a higher dose of radiation living next to a coal-burning plant than living next to a nuclear plant.
Coal contains up to 10% sulfur, and the release of this sulfur from
coal burning is the largest single source of acid rain in many areas.

14. Oil Petroleum is derived from organic molecules created by living
organisms millions of years ago and changed by geological forces.
Oil and gas deposits often accumulate under layers of shale or other
impermeable sediments.
Pumping oil out of a reservoir is much like sucking liquid out of a
sponge. Methods for squeezing more oil from a reservoir are called secondary recovery techniques.

16. Oil Resources and Reserves
The total amount of oil in the world is estimated to be about 4 trillion barrels, half of which is thought to be recoverable. Approximately 465 billion barrels of oil have already been consumed.
In 1990, there was only enough recoverable oil left in the world to maintain the supply at the current rate of consumption for 50 years.
The largest supply of proven-in-place oil is in Saudi Arabia. The Persian Gulf countries contain nearly 2/3 of the world's proven oil supplies.

18. Oil Imports and Domestic Supplies
The United States imports more than half its total oil consumption.
The United States has already used about 40% of its original
recoverable oil reserves.
Oil Shales and Tar Sands
Shale oil and tar sands could double our total oil reserve if they can
be extracted with reasonable social, economic, and environmental costs.
Oil shale is a fine-grained sedimentary rock rich in solid organic
material called kerogen. Mining this material is expensive, uses vast quantities of water, and has a high potential for air and water pollution.

19. Natural Gas
Natural gas is the world's third largest commercial fuel (after oil and
coal).
It is the most rapidly growing energy source because it is convenient,
cheap, and clean burning.
Natural Gas Resources and Reserves
The former Soviet Union has 44% of known natural gas reserves.
The United States has about 6% of the world's proven reserves.
Unconventional Gas Sources
Methane hydrate is composed of small bubbles of natural gas trapped
in a matrix of ice. There are bountiful supplies of methane hydrate in arctic regions.
Methane can also be collected by digesting garbage or manure.

21. Nuclear Power
Increasing construction costs, declining demand for electric
power, and safety fears have made nuclear power less attractive than early promoters once thought.
Orders for nuclear reactors are on the decline, and it appears
that the industry will never take hold.

23. How Do Nuclear Reactors Work?
Purified, concentrated U235 is formed into rods.
A fuel assembly is approximately 100 of these rods bound together.
When struck by a high speed atomic particle, uranium in these rods
undergoes nuclear fission and a self-sustaining chain reaction takes place.
Control rods of neutron absorbing material keep the reaction from
getting out of hand.

25. Kinds of Reactors in Use
70% of the world's nuclear reactors are pressurized water reactors
(PWR). This type of plant uses steam power to generate electricity.
There are many variations on this theme, some using deuterium in
the water, and others which use graphite as the primary material comprising the reactor core.

27. Alternative Reactor Designs
High-Temperature, Gas-Cooled Reactors use helium as a coolant
gas to keep small amounts of uranium in ceramic-coated pellets. This type of design almost negates the possibility of a serious, meltdown accident.
Process-Inherent Ultimate-Safety Reactors contain the reactor
core in a massive steel and concrete container with boron filled cooling water.

28. Breeder Reactors
Breeder reactors create fuel rather than consume it. They create fissionable plutonium isotopes from stable forms of uranium.
Questions about using breeder reactors include safety concerns and concerns about the excess bomb-grade plutonium they produce.

30. Radioactive Waste Management
One of the most difficult problems associated with nuclear power is the disposal of radioactive waste.
Ocean Dumping of Radioactive Wastes
Until 1970, the United States, Britain, France, and Japan disposed of radioactive wastes in the ocean.
It is feared that the former USSR has permanently contaminated the Arctic Ocean by large scale dumping of radioactive wastes. The USSR has dumped twelve times more radioactive waste in the ocean than the other twelve "nuclear" countries combined.

31. Land Disposal of Nuclear Waste
Enormous piles of mine wastes in uranium-producing countries
represent another serious waste disposal problem. Winds carry this material into streams, contaminating areas far from the source.
Many companies are beginning to store radioactive waste in large,
metal casks next to plants. This is being met with fierce opposition from local residents who fear they will leak.
The U.S. Department of Energy is currently constructing a high-level
waste repository in Nevada to store radioactive wastes safely.
Some experts believe that monitored, retrievable storage is a better
way to handle wastes. This way, storage containers may be monitored for leakage and other problems.

32. Decommissioning Old Nuclear Plants
Nuclear power plants are designed to last about 30 years and
then must be decommissioned.
They must be taken apart carefully and the most radioactive
parts stored away safely.
It costs more to decommission an old nuclear power plant than
to build a new one.

33. Changing Fortunes of Nuclear Power
Nuclear power was originally promoted has a wonder of
technology that could change the world.
In the United States, about 2/3 of the public opposes nuclear power
primarily because of safety concerns.

34. Nuclear Fusion
Nuclear fusion energy is released when two smaller atomic nuclei
fuse into one larger nucleus. This only occurs temperatures over a million degrees Celsius and pressures of several billion atmospheres.
Magnetic confinement involves the containment and condensation of
plasma in a powerful magnetic field. This creates the correct conditions for fusion.
Inertial confinement involves bombarding a small pellet from all
sides with laser light. The sudden absorption of energy causes an implosion, also creating the right conditions for fusion.
Fusion creates much less radioactive wastes than does fission.
However, fusion reactors have never been created that produce more energy than they consume.