• Non-Renewable Energy - Energy sources
used faster than can be replenished.
Coal - Oil - Natural Gas
• Renewable Energy - Continuously present as
a feature of the environment (solar energy),
or is continually replenished.
Some forms are referred to as perpetual
All Energy Sources
2. What percent of fossil fuels are used?
• Fossil fuels supply 90% of world’s
– Oil 40%
– Coal 24%
– Natural Gas 25%
3. What is the difference between
Resources and Reserves
• Resource - Naturally occurring substance of
use to humans that can potentially be
extracted using current technology.
• Reserve - Amount of a known deposit that
can be economically extracted using current
technology, under certain economic
Reserve levels change as technology
advances, new discoveries are made,
and profit margins change.
Resources and Reserves
4. How is coal formed?
– 300 mya plant material began collecting
underwater, initiating decay, forming a
spongy mass of organic material (peat).
Due to geological changes, some of
these swamps were covered by seas,
and covered with sediment.
Pressure and heat over time
transformed peat into coal.
Recoverable Coal Reserves
5. Types of extraction
• Two main extraction methods:
– Surface Mining (Strip Mining)
Removing overburden on top of a vein.
Efficient but destructive.
– Underground Mining
Minimizes surface disturbance, but costly
Black Lung Disease
Surface mining of coal
• Strip mine
• Eco problem – over burden
– Laws in 1990’s now require ground replacement
Deep mining – tunneling for coal
Problems with Coal
• Bulky - causes some transport problems.
• Black Lung Disease: Mining creates dust pollution.
• Mining accidents: collapse of tunnels,
• Ecosystem damage/reclamation efforts
• Burning releases pollutants (C and S).
– Millions of tons of material released into
Acid Rain: Sulfur leads to acid mine drainage
and acid deposition.
Global warming: Increased carbon dioxide
Coal Use Issues
• Coal is most abundant fossil fuel.
– Primarily used for generating electricity.
High moisture content - Least
Most abundant - Most widely used.
Highest energy content - Hard to
7. Oil and Natural Gas
• Accumulations of dead marine organisms on
the ocean floor were covered by sediments.
– Muddy rock gradually formed rock (shale)
containing dispersed oil.
Sandstone formed on top of shale, thus
oil pools began to form.
Natural gas often forms on top of oil.
Organic matter changed to lighter,
more volatile hydrocarbons than
those in oil.
Crude Oil and Natural Gas Pool
Oil rig & ocean drilling for oil
• Primary Recovery – oil rig drilling
– Only removes 1/3 of a deposit.
• Secondary Recovery
– Force water or gas into wells.
As oil prices increase, more expensive
and aggressive secondary recovery
methods will need to be used.
9. Uses of oil - Processing Crude Oil
Oil Use Issues
– As it comes from the ground, oil is not in a
form suitable for use, and must be refined.
Multiple products can be produced from a
single barrel of crude oil.
• Oil Spills
– Accidental spills only account for about 1/3
of oil pollution resulting from shipping.
60% comes from routine shipping
Advantages of oil use
• More concentrated than coal, burns cleaner,
and is easily transported through pipelines.
– Ideal for automobile use.
– Difficult to extract.
– Causes less environmental damage than
Natural Gas Use
• Drilling requirements similar to oil.
• Hard to transport - flamed off at oil fields.
• As demand increases, new transportation
methods will be developed and implemented.
– Liquefaction at -126 F
(1/600 volume of gas)
• Least environmentally damaging fossil fuel.
– Almost no air pollution.
• Use is increasing (45% from 1985-2003).
Renewable Sources of Energy
• Currently, alternative energy sources supply
almost 10% of the world’s total energy.
– Suggested these sources could provide
half of the world’s energy needs by 2050.
Renewable Energy as a Share of Total Energy
• Hydroelectric power is created when flowing
water is captured and turned into electricity.
– Damming a river and storing water in a
reservoir is the most common method.
Pumped Storage Plants - Use two
reservoirs separated by a significant
• Currently supplies 15% of world’s electricity.
– China possesses 10% of world’s potential.
• Reservoir construction causes significant
environmental and social damage.
– Loss of farmland.
– Community relocation.
– Reduction of nutrient-rich silt leading to
loss of wetlands.
Three Gorges Dam on Yangtze River
Environmental Effects of Hydroelectric
• Flooding of vast areas of land behind dams.
• Prevention of fish migrations.
• Trapping of silt.
– Stops flow of nutrients downstream.
– Fills in reservoir.
• Mercury Accumulation
• Decaying vegetation produces greenhouse
• Daily rise and fall of ocean levels relative to
coastlines (tides) are a result of gravitational
forces and the revolution of the earth.
– As water flows from a higher level to a
lower level, it can be used to spin an
electricity - generating turbine.
Since tidal changes are greatest near
the poles, and accentuated in narrow
bays and estuaries, suitable sites are
• In some areas, molten material is close
enough to surface to heat underground water
and form steam - drilled and captured.
– Only practical in limited areas.
– California produces 40% of world’s
– Can cause unpleasant odors and high
mineral content leads to high maintenance.
Corroded pipes and equipment.
• As warm air becomes less dense and rises,
cooler, denser, air flows in to take its place.
• U.S. Department of Energy has stated the
Great Plains could supply 48 states with 75%
of their electricity.
– Cost becoming very competitive with
various fossil fuel sources.
Currently 3-6 cents per kilowatt hour.
• Potential Problems
– Steady,dependable wind source is critical.
Wide open areas are most desirable.
– Can be hazardous to birds.
– Produce noise and visual pollution.
– Vibrations can cause structural damage.
• Daily energy from the sun is six hundred
times greater than energy produced each
day by all other energy sources combined.
– Major problem as an energy source is its
Three Major Use Categories
• Passive Heating - Sun’s energy is converted
directly to heat and used at collection site.
– South-Facing Windows.
• Active Heating - Sun’s energy converted into
heat, but transported elsewhere to be used.
– Domestic Water Heating
• Electrical Generation - Solar energy is
transformed into electrical energy.
– Photovoltaic Science
• Solid-state semiconductors that allow direct
conversion of sunlight to electricity.
– Developed in 1954 by Bell Laboratories
essentially as a novelty.
Amount of PV power installed worldwide
has increased from 100 megawatts in
1992 to 1,200 megawatts in 2002.
Film technology has made it possible
to build solar cells into roof tiles,
skylights, and building facades.
• Photovoltaics will be the most practical
choice for generation of electricity in rural
areas and less developed countries.
– In place of generators that require fuel and
centralized power plants that require
• Biomass is still the predominant form of
energy used by people in less-developed
– Account for 14% of world energy use.
• Three Distinct Sources:
– Municipal and Industrial Wastes
– Agricultural Crop Residue
– Energy Plantations
• Releasing chemical energy stored in biomass.
– Burned directly for heat.
– Burned to produce electricity.
– Converted to alcohol or used to generate
• Costs depends on type of technology used,
size of the power plant, and the cost of
– Currently as low as 9 cents per kilowatt
• In less-developed countries, fuelwood has
been major energy source for centuries.
• Fuelwood is primary energy source for nearly
half world’s population.
• Due to intense population growth, an
estimated 1.3 billion people cannot get
enough feulwood, or are using it faster than
rate of regeneration.
• Source of air pollution and fly ash.
• Using municipal waste as a source of energy:
– Reduces landfill volume.
Not economically profitable.
Must be sorted.
Requires large, sustainable volume.
– Produces air pollution.
Chlorine-containing organic compounds.
• Hydrogen is abundant and generates heat
and pure water when it reacts with air.
– Hydrogen Fuel Cells
Proton Exchange Membrane Fuel Cell
Low Operating Temperature
Successor to internal combustion
Simple Fuel Cell
• Conservation is not a way of generating
electricity, but a way of reducing need for
additional energy production/consumption
and saving money for the consumer.
– Lighting and air conditioning account for
25% of U.S. electricity consumption.
Widespread use of energy-efficient
lighting could significantly reduce energy
• Energy-inefficient machines can be produced
– Long-term vs. short-term costs.
• Electrical utilities will lead energy
– Conservation is cheaper than building more
power plants to meet increased demands.