Transcript Energy Resources and Human Impact on the Environment SPI 0707.7.7 Analyze and evaluate the impact of man’s use of earth’s land, water, and atmospheric.

Energy Resources and Human
Impact on the Environment
SPI 0707.7.7 Analyze and evaluate
the impact of man’s use of earth’s land,
water, and atmospheric resources.
Energy and Fossil Fuels
•Most of the energy we use
comes from nonrenewable
fossil fuels. Fossil fuels were
formed from the remains of
plants and animals that lived
long ago.
•All living things are made up
of the element carbon. All
fossil fuels are made of
carbon, most of it in
compounds called
hydrocarbons.
•Fossil fuels may exist as
solids, liquids, or gases.
Fossil Fuels
Coal, oil and gas are called "fossil fuels" because
they have been formed from the organic remains of
prehistoric plants and animals.
How it works:
Coal is crushed to a fine dust and burned.
Oil and gas can be burned directly.
Burn fuel->>heat water to ->steam turns _>turbines turn->electrical
power
make steam
turbines
generators
• Petroleum, or oil, is a fossil fuel. It was
formed more than 300 million years ago.
• Petroleum is commonly known as crude oil.
• Examples are gasoline, jet fuel, kerosene, diesel
fuel, and fuel oil.
• More than 40% of the world’s energy comes
from petroleum products.
• Crude oil is so valuable that it is called “black
gold”.
• Natural gas provides around
20% of the world's
consumption of energy.
• Like oil, it forms from the remains of
microscopic sea organisms that
settle on the ocean floor.
• Over millions of years, through
chemical and physical changes, the
remains become petroleum and
natural gas.
• Rock forms above the rocks
containing the fossil fuel and the
fossil fuels move through
permeable rock.
• To collect petroleum and gas,
engineers must drill wells into the
reservoir rock that holds them.
As well as being burned in power
stations, natural gas is used by many
people to heat their homes.
It is easy to transport along pipes, and
gas power stations produce
comparatively little pollution.
Coal
•
Coal is a hard, black colored rock-like substance. It is made up of carbon,
hydrogen, oxygen, nitrogen and varying amounts of sulphur.
•
There are three main types of coal – anthracite, bituminous and
lignite. Today, the precursor to coal—peat—is still found in many
countries and is also used as an energy source.
•
Coal is found in many of the lower 48 states of U.S. and throughout the
rest of the world. Coal is mined out of the ground using various methods.
• The coal is then shipped by
train and boats and even in
pipelines.
• At the other end, the coal is
used to fuel power plants and
other factories.
• Coal provides around 28% of
our energy, and Oil provides
40%
Advantages of
Using Fossil Fuels
• Very large amounts of electricity can be
generated in one place using coal, fairly cheaply.
• Transporting oil and gas to the power stations is
easy.
• Gas-fired power stations are very efficient.
• A fossil-fuelled power station can be built almost
anywhere, so long as you can get large
quantities of fuel to it.
Disadvantages of Fossil Fuels
• Fossil fuels take millions of years to
make. Once they are gone they are
gone.
• Basically, the main drawback of
fossil fuels is pollution.
Burning any fossil fuel produces carbon
dioxide, which contributes to the
"greenhouse effect", warming the Earth.
• Oil spills like the most recent one in the
Gulf destroy wildlife, the environment,
and disrupt the ability of people to make
a living.
Disadvantages of Fossil Fuels
continued
• Coal mining causes pollution, destroys land
and animal habitats and puts miners at risk due
to possible mine collapse and personal health
problems.
• Coal mining produces sulphur dioxide, a gas
that contributes to acid precipitation. We can
reduce this before releasing the waste gases into
the atmosphere.
• Smog is produced when sunlight reacts with
industrial pollutants and burning fuels.
ALTERNATIVE ENERGY RESOURCES
Renewable energy sources including biomass,
hydropower, geothermal, wind, and solar provide
8% of the energy used in the United States. Most
renewable energy goes to producing electricity.
What Is Renewable Energy?
Renewable energy sources can be replenished.
The Role of Renewable Energy Consumption in the Nation's
Energy Supply, 2010
The five renewable sources used most often are:
• Biomass — including:
wood and wood waste,
• Water (hydropower)
municipal solid waste,
landfill gas and biogas,
• Geothermal
ethanol
• Wind
biodiesel
• Solar
Nuclear Power-Fission/Fusion
• Nuclear energy is energy in the nucleus (core) of an
atom. Atoms are tiny particles that make up every object
in the universe. There is enormous energy in the bonds
that hold atoms together.
• Nuclear energy can be used to make electricity. But first
the energy must be released. It can be released from
atoms in two ways: nuclear fusion and nuclear
fission.
Fission and Fusion compared
• In nuclear fission, atoms
are split apart to form
smaller atoms, releasing
energy. Nuclear power
plants use this energy to
produce electricity.
• In nuclear fusion, energy
is released when atoms are
combined or fused together
to form a larger atom. This
is how the sun produces
energy. Fusion is the subject
of ongoing research, but it is
not yet clear that it will ever
be a commercially viable
technology for electricity
generation.
Advantages of Nuclear Power (Fission)
•
Nuclear Power Plants Generate About One-Fifth of U.S. Electricity
•
Nuclear power accounted for almost 20% of the total net electricity
generated in the United States in 2010, about as much as the electricity
used in California, Texas, and New York, the three States with the most
people.
•
Unlike fossil fuel-fired power plants, nuclear reactors do not produce
air pollution or carbon dioxide while operating. However, the processes
for mining and refining uranium ore and making reactor fuel require large
amounts of energy.
Disadvantages of Fission
•
The main environmental concerns for nuclear power are
radioactive wastes such as uranium mill tailings, spent (used) reactor
fuel, and other radioactive wastes. Wastes must be stored in an isolated
place for thousands of years until they can’t hurt anyone.
•
There is the potential for accidental release
of radiation into the environment.
•
While fusion produces few dangerous wastes,but very high
temperatures are required for the reaction to take place. No material
can withstand such high temperatures so controlled fusion reactions have
been limited to laboratory experiments.
Hydrogen Chemical Energy
• Like electricity, hydrogen is a secondary source of
energy. It stores and carries energy produced from
other resources (fossil fuels, water, and biomass).
• Hydrogen fuel cells make electricity. They are very
efficient, but expensive to build. Small fuel cells can
power electric cars. Large fuel cells can provide
electricity in remote places with no power lines.
Fuel Cells
Advantages
Portable fuel cells are being sold to
provide longer power for laptop
computers, cell phones, and military
applications.
The only byproduct of fuel cells is water.
They are also more efficient than
internal combustions engines are.
Fuel cells combine the best of batteries
(quiet, no emissions) and internal
combustion engines (easy refueling
once the infrastructure is in place).
They have a simple construction, so
mass production costs would become
extremely low.
There has been a 10-fold increase in the
power density of fuel-cell stacks and a
10-fold decrease in their cost within the
past 5 years.
Disadvantages
Fuel cells are currently very expensive,
but since they have a simple
construction, mass production costs
would become extremely low.
Prototype fuel cells last only 1/5th as
long as would be needed to make fuel
cells cost-effective.
They are energy losers because it
costs more to produce hydrogen than
is earned by using hydrogen in fuel
cells:
Electricity generated by fuel cells in
cars costs thousands of dollars per
kilowatt: This would have to fall by a
factor of 10 for fuel cells to become
economically viable.
SOLAR ENERGY
• When converted to thermal
(or heat) energy, solar
energy can be used to:
• Heat water — for use in
homes, buildings, or
swimming pools
• Heat spaces — inside homes,
greenhouses, and other
buildings
• Heat fluids — to high
temperatures to operate a
turbine to generate
electricity
• The three main types of
solar thermal power
systems are:
• Parabolic trough (the
most common type of
plant).
• Solar dish
• Solar power tower
Using solar energy produces no
air or water pollution and no
greenhouse gases, but does
have some indirect impacts on
the environment.
Advantages/Disadvantages of Solar
Energy
Advantages
Disadvantages
•
Solar energy is
renewable
•
Solar energy systems
do not produce air
pollutants or carbondioxide
When located on
buildings, they have
minimal impact on the
environment
•
•
•
•
The amount of sunlight
that arrives at the
Earth's surface is not
constant. It varies
depending on location,
time of day, time of
year, and weather
conditions.
Because the sun
doesn't deliver that
much energy to any
one place at any one
time, a large surface
area is required to
collect the energy at a
useful rate.
Solar cells and
collectors are more
expensive than other
energy systems.
Wind Power
Made indirectly by solar energy through the uneven heating of air. Wind power is the use
of a windmill to drive an electric generator.
Advantages
•It is renewable
•It doesn’t cause pollution
•green energy
•Good availability
•Prices have decreased
•possibility for people to produce
own electricity
•ability to save money
•Works in harmony with other
methods
•can be a lifesaver in emergency
situations
Disadvantages
•In some areas, the wind isn’t
strong enough or frequent enough
to create energy on a large scale.
•Wind is unpredictable
•wind energy is fluctuating
•cost effective? This is highly
debatable
•aesthetics of wind turbines
•Wind turbines kill birds
•repair costs are usually expensive
Hydroelectric Energy
•
supplies about 20% of the entire world’s electricity needs -About 88% of the total electricity that is
generated from renewable energy sources.
•
Hydroelectric energy is potential energy that is converted to kinetic energy through the forces of
gravitation, which again comes from solar energy, driving the water cycle around. To answer the
question, hydroelectric energy is the result of heat energy from the sun and the
gravitational forces from the earth.
•
By letting the water flow through turbines on their way to the sea, we can harness some of the
kinetic energy of water to produce electricity. The flow and head determines the potential energy
of a waterfall.
Advantages
Disadvantages
•Inexpensive to operate
•Expensive to build
•Causes little pollution
•Only available near large bodies of water
•Renewable
•Destroys forests & wildlife habitats
•Reduces our dependency on fossil
fuels
•Disrupts migratory paths of salmon &
steelhead
•Can decrease water quality and cause
erosion
Source: The National Energy Education
BIOMASS
• Biomass is organic material made from plants and animals
(microorganisms). Biomass contains stored energy from the sun.
• When burned, the chemical energy in biomass is released as
heat.
• Biomass can be converted to other useable forms of energy,
such as methane gas or transportation fuels, such as ethanol and
biodiesel.
BIOMASS continued…
• Crops like corn and sugar cane can be
fermented to produce ethanol. Biodiesel,
another transportation fuel, can be
produced from left-over food products like
vegetable oils and animal fats.
• Biomass fuels provided about 4% of the
energy used in the United States in
2010. Of this, about 46% was from wood
and wood-derived biomass, 43% from
biofuels (mainly ethanol), and about 11%
from municipal waste.
Some farmers produce biogas in
large tanks called "digesters" where
they put manure and bedding
material from their barns.
Wood
• The most common form of biomass is
wood. In the United States, wood and
wood waste (bark, sawdust, wood chips,
wood scrap, and paper mill residues)
provide about 2% of the energy we use
today.
Garbage, often called municipal solid waste
(MSW), is the source of about 12% of the
total biomass energy consumed in the
United States
Landfill Biomass
Landfills can be a source of energy. Anaerobic bacteria
that live in landfills decompose organic waste to
produce a gas called biogas that contains methane.
Landfills can collect the methane gas, treat it, and then
sell it as a commercial fuel.
Using Biomass for Energy Can Have
Positive and Negative Impacts
For example, burning biomass may result in more or less air pollution
depending on the type of biomass and the types of fuels or energy sources
that it replaces.
•
•
Positive: Using wood,
and charcoal made from
wood, for heating and
cooking can replace fossil
fuels and may result in
lower CO2 emissions.
Positive: A waste-toenergy furnace burns at
such high temperatures
(1,800 to 2,000°F) that
many complex chemicals
naturally break down into
simpler, less harmful
compounds. This chemical
change is a kind of built-in
anti-pollution device.
•
•
Negative: However, wood
smoke contains harmful
pollutants like carbon
monoxide and particulate
matter. Burning wood in an
open fireplace is very
inefficient and produces
lots of air pollution.
Negative: Plants that burn
waste to make electricity
must use technology to
prevent harmful gases and
particles from coming out
of their smoke stacks.
Gasohol
Advantages
•
•
Domestically
produced—reduces
dependence upon
foreign oil. Alcoholbased liquid fuel
derived from plant
biomass, primarily
corn. Typically used in
Flex Fuel vehicles as a
blend of E85 [85%
ethanol and 15%
gasoline].
Requires massive use
of cropland to supply
meaningful power.
Has less energy per
gallon than gasoline.
Disadvantages
•
Requires massive use of
cropland to supply
meaningful power. Has less
energy per gallon than
gasoline.
•
Ethanol and ethanolgasoline mixtures burn
cleaner and have higher
octane than pure gasoline,
but have higher
"evaporative emissions"
from fuel tanks and
dispensing equipment.
These evaporative
emissions contribute to the
formation of harmful,
ground-level ozone and
smog.
Geothermal Energy
• In some areas, groundwater is
heated by magma, or melted rock.
• Geysers are natural vents that
discharge steam into the air. The
steam and hot water can escape
through wells drilled into the rock.
From these, geothermal power
plants can harness this energy.
• “The Geysers” in California is the
world’s largest geothermal plant
and produces electricity for 1.7
million households!
Geothermal Power continued..
•
•
•
Advantages
it is a very “green”
way to receive energy,
Geothermal energy is
very clean; it does not
cause air, water, or soil
pollution.
It is a renewable
source of energy.
The hot water or steam
is returned back into
the Earth after being
used.
•
•
Disadvantages
There is currently
a very high cost
of geothermal
exploration and
building of the
energy generating
plants.
It can’t be built
anywhere-there
would have to be
a source
available.
Our World is a Gift-let’s
take care of it!-it’s up to
you!
THE END……..