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CAHABA SCHOOL SCIENCE RESOURCES
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ENVIRONMENTAL SCIENCE
Chapter 7: Renewable
& Non Renewable Energy
How Energy Effects the
Environment
Energy
has been a part of human existence for thousands of years, ever since people
first used fires to cook and stay warm. Energy is fundamental to modern life.
Energy turns on your lights, heats water for your shower, keeps you warm in
the winter, and powers your family’s car and television. Currently, most of
our energy is obtained by burning fossil fuels (oil, coal, and natural gas)
—formed over millions of years from the remains of plants and animals. It
took the Earth about one million years to produce the fossil fuels we consume
in a single year, and we are using fossil fuels at faster and faster rates.
Even if supplies were unlimited (which they are not), the environmental
problems caused by our use of fossil fuels would still require us to develop
alternative sources of energy and increase the efficiency of our energy use.
Energy
production and use account for nearly 80% of all air pollution.
The
availability of “cheap” fossil fuels has powered huge changes since the
onset of the Industrial Era. However, this has come at a high price. Pollution
caused by fossil fuels at every stage of use (extraction, transport,
refinement, burning, and waste disposal has caused or worsened environmental
and health problems.
Human Health: Air
pollution from fossil fuels causes adverse environmental effects by
contaminating the food chain, our water supply, and our air. Some of the
health symptoms of pollution are headaches, asthma, lung disease, skin damage,
cancer, eye irritation and heart disease.
Environmental Impacts:
Acid Rain and Mercury Pollution from
coal power plants damage vegetation, wildlife, and
human health.
Oil Spills and Energy-Related Toxic Wastes have
devastated marine ecosystems and
contaminated soil.
Global Warming and Climate Change are
caused primarily by fossil fuel use. Rising concentrations of carbon dioxide
and other heat-trapping gases are warming the Earth.Carbon dioxide, a
heat-trapping gas released when fossil fuels are burned, is the number one
contributor to global warming. In the 21st century, the amount of
warming and the severity of its impacts will depend on how much, and how soon,
we reduce our fossil fuel use.
In
recent decades, remarkable progress has been made in developing sustainable
energy production methods that are far less polluting. In the 21st century we will move
away from fossil fuels
and nuclear power and make the switch to clean energy technologies. This
transition is already underway. The U.S. Department of Energy has estimated
that America could potentially produce up to 70% of its total energy from sun,
wind, water, geothermal, and biomass resources within the next 40 years. By
tapping the limitless potential of renewable sources such as the sun and wind,
we can produce the energy we need in environmentally sustainable ways.
Switching to clean, renewable energy sources will create tremendous benefits
to society, including huge reductions in pollution,
improved human health, and greater energy security.
The
United States, with less than 5% of the world’s population, uses 25% of all
energy consumed worldwide. Over the course of a lifetime, the energy used by
the average American is the equivalent of 4,800 barrels of oil.
The
average person in the United Kingdom and Japan each consumes half as much
energy as the average American.
Coal:
52%
Nuclear
Power: 19%
Natural
Gas & Petroleum: 18%
Hydroelectric
& Renewable Energy: 11%
Coal, the most polluting fossil fuel, is the source of over 50% of the total electricity produced in the U.S.
Fossil-fuel Dependency
With the
growing concerns over the high use of fossil-fuels, such as gas, oil, and
coal, people, businesses, and governments are wondering what alternatives are
available. The prices of oil and gasoline have reached sky-high levels. There
is also the knowledge that oil supplies will not last forever, especially when
worldwide consumption is increasing. As consumptions increases, supplies
dwindle and become more and more expensive to extract. Supplies of Coal are
more abundant, yet this still presents the problem of pollution and as these
supplies decrease we are forced to use less pure and more polluting supplies..
The
burning fossil-fuels releases greenhouse gases, namely carbon dioxide into the
atmosphere that were previously trapped in the fuel. These gases contribute to
the atmospheric greenhouse effect, causing more of the suns energy to be
trapped and increasing the planet’s overall temperature. This climate change
through our heavy use of fossil fuels in turn melt the polar ice caps,
consequently affecting our ocean levels which then impacts weather patterns,
agriculture, health, and our environment.
While
nuclear energy is often presented as an environmentally-friendly approach to
energy, there are still risks from the disposal of radioactive waste.
Furthermore, scientists believe that the world’s uranium fuel will run out
in fifty years. The infrastructures for hydrogen fuel cells, which could be
used in cars, for example, have not become a reality yet. It is therefore time
to examine some of the developing sources that will create clean, sustainable
energy for the future.
The
chart above shows the economic cost of energy prices (by U.S. Cents per
kilowatt-hour), for new power plants coming online in 2013. While solar energy
seems the most expensive, industry experts say the price will drop with time
as more investment is made into improving the technology.
Solar Energy
Solar energy can warm our houses, heat bath water, and generate electricity. Solar energy uses special panels to harness the energy of the sun’s rays. There are no emissions from solar-powered systems. While at one time this form of clean energy was considered prohibitively expensive, the price has been dropping consistently for years, and is expected to continue to do so. Perhaps the major drawback to solar energy is collecting energy when the sun isn’t shining or in areas where there is a lack of sunlight. Solar panels have batteries to store energy for overcast days and night time. Many people are using solar energy for their homes and businesses. By installing solar panels the roof of one’s home, for example, one could power an entire household without using other forms of energy. As the panels are lightweight and can be used on existing structures it would be possible to create power in very crowded areas and cities without having to disrupt the existing infrastructure and buildings.
Biomass
Energy
Biomass
energy, or bioenergy, is humanity’s oldest source of renewable energy. It is
a
form of solar energy produced by plants through photosynthesis. It is stored
in organic matter such
as
wood, agricultural wastes, and animal wastes. Biomass can be converted into
liquid or gaseous fuels, or it can be burned to generate electricity. Recent
advances are making it economical to draw energy from plant materials. They
can be converted into liquid or gaseous fuels, or they can be burned to
generate electricity.
Wind Energy
Like
solar power, wind power has many applications for “distributed energy.”
This term means that power can be made on a small scale near the consumer.
Wind power uses turbines to created energy from moving air currents. No
emissions are created, and like solar energy, batteries store energy for calm
days without wind. Europe, in particular, has made a huge use of wind power.
Denmark, for example, currently gets 20 percent of its total energy needs from
large wind turbines all across the countryside. The drawbacks to wind power
are that the turbines needed to harness it can be considered ugly, and can
create noise pollution. Wind is the fastest growing
energy source. Denmark already gets about 10% of its electricity from wind
power
Hydro Energy
While
relatively a new concept, the tidal process of the ocean utilizes the natural
motion of the tides to fill reservoirs, which are then slowly discharged
through electricity-producing turbines. Another method includes using
buoy-like devices that created energy from the bobbing motion caused by the
waves and tides. Hydro energy has been used in countries such as The
Netherlands to great effect. In good locations, wave energy density can
average 65 megawatts per mile of coastline. According to the Department of
Energy’s “Energy Efficiency and
Renewable Energy" website, thermal heat from the oceans can
also produce energy, while creating desalinated water in the process.
Hydropower is the largest share of nonfossil fuel energy currently in use. (Note:
Although it does not produce greenhouse gas emissions, hydropower affects the
environment by flooding valuable habitat and by blocking fish from
reaching their spawning grounds.)
Most
renewable energy systems have no fuel costs once they are built.
When
you use less energy, you are reducing your share of the pollution that fouls
the air and water, damages human health, harms wildlife, and contributes to
global warming.
Renewable
Energy and Energy Efficiency are key solutions to global warming and its
impacts. Along with their environmental pluses, their economic benefits
include:
Be
Energy-Smart!
Wasting
energy is pointless and hurts the earth. Energy efficiency does not mean
“doing without,” or shivering
in the dark. It simply means being smart about our energy use.
Conserving
energy and using energy-efficient products help reduce environmental problems,
create new jobs, and save money. When less energy is used, less energy
generation is needed. By
extending
the supply of nonrenewable resources, energy efficiency gives us more time to
develop other energy sources that will free us from our dependence on
nonrenewable fossil fuels.
According
to a recent study by the Union of Concerned Scientists5, the three areas of greatest consumer
impact on the environment are how we go from place to place, what we eat,
and how we operate our homes (heating, cooling and lighting). These three
arenas account for about three-quarters of our consumer impacts on global
warming, air pollution, water pollution, and habitat destruction. Environmental
action is the sum of all the little things we do each day. Day-to-day choices
can have an enormous impact when we all act together.
For the
individual, you can help conserve energy by switching to alternative energy
sources, and by using energy efficient electrical appliances. By visiting the
website of Energy Star, a
government program that works for energy efficiency, you can find out ways to
save energy and money. According to Energy Star, Americans have “saved
enough energy to power 24 million homes and avoid greenhouse gas emissions
equivalent to those from 20 million cars - all while saving $10 billion.” Try buying appliances such as dishwashers and refrigerators
that have the “Energy Star” seal of energy efficiency. Use
energy-efficient light sources such as compact fluorescent light bulbs that
use less energy than standard light bulbs. Insulation helps use less energy
heating and cooling the home and buildings. If available in your area, try
switching to “green energy” made from clean sources.
Suggestions
1.
The average family spends $1,500 a year on energy bills, with nearly half of
that spent on heating and cooling. Basic home improvement as well as more
efficient equipment, can definitely help you save on energy costs. Also,
don’t underestimate the simple things. For example, shades and drapes around
your home can help you conserve energy and reduce costs. During winter, open
window shades or drapes to let in the natural warmth of the sun, and close
them at night to insulate windows against heat loss. In hot climates, closed
shades or blinds help keep rooms cool.
Finally,
many local utilities and contractors offer home energy audit and home
improvement services, which help you identify and fix areas in your home where
you may be wasting energy. Many utilities also offer low-income assistance for
winter heating bills. Check your utility bill stuffers for services they may
offer.
2.
Common household problems such as hot, cold, or drafty rooms, and the growth
of mold and mildew are often the result of inefficient heating/cooling systems
and inadequate insulation. Addressing this issue can be as simple as sealing
air leaks, adding insulation and replacing windows. For cost-effective
solutions, visit ENERGY STAR’s Home Improvement site at
www.energystar.gov/homeimprovement.
3.
Sealing up your home is one of the most cost effective ways to improve your
home’s comfort and reduce energy costs. Hidden gaps and cracks in a home can
add up to as much airflow as an open window and cause your heating and cooling
system to work harder, use more energy, and cost more. Seal these leaks with
caulk, spray foam, and weather stripping. Next, inspect your
attic,
to be sure it’s properly insulated — it’s the easiest place to add
insulation and make a big impact on energy bills. Together, sealing air leaks
and adding insulation can reduce your annual energy bill by 10 percent and
improve comfort. Many of these steps are easy to do yourself, or you can hire
a professional contractor to help. For details on how to do it yourself, get
the
ENERGY
STAR Home Sealing DIY Guide. Finally, keep your fireplace damper closed,
unless a fire is going.
4.
To keep your home’s heating and/or cooling system running at peak
performance, have a licensed and insured contractor check your equipment
seasonally. Have your heating system checked in the Fall, and your cooling
system checked in the Spring. If your cooling or heating system is more than
10 – 15 years old, it could be considerably less efficient than newer
models. Changing out old equipment with ENERGY STAR qualified models can cut
your annual energy costs by 20 percent. To find a qualified contractor to have
new equipment installed, or to perform any home improvements such as home
sealing or duct work, plan ahead.Schedule home energy audits during the spring
or fall, since contractors tend to get busy around summer and winter months.
5.
ENERGY STAR qualified programmable thermostats automatically adjust your
home’s temperature setting to help save energy when you’re asleep or not
at home. When used properly, a programmable thermostat with 4 temperature
settings can save you up to $100 on annual energy costs.
6.
Making your home more energy-efficient helps to reduce air pollution and
prevent global warming. The average house is responsible for twice the
greenhouse gas emissions as the average car, annually (22,000 lbs. vs. 11,500
lbs.). That’s because every time you flip on a light switch, run your
dishwasher or turn on your air conditioner or furnace, you use energy, which
means more pollution from power plants. The more energy we save at home, the
more we can help protect the environment.
7.
There are many different actions you can take on your own. Regardless of what
kind of heating or air conditioning system you own, routine maintenance will
improve your comfort and save energy around the home. By regularly changing
and cleaning air filters in your home’s heating and cooling system, you will
help them perform more efficiently.
8.
Ceiling fans improve comfort in both winter and summer. During winter, run
them clockwise (upward motion) at a low speed, to circulate heat that gathers
near the ceiling. In summer, or in hot climates, run them counterclockwise (or
downward) to cool. Most fans have a switch to reverse the spin. When cooling,
always turn off your ceiling fan when you leave the room, just as you do your
lights (a fan only cools you, not a room, by creating a “wind-chill
effect”).
9.
Lighting can account for as much as 20 percent of your household energy use.
Don’t sit in the dark, but whenever possible, keep lights off if they’re
not in use, and replace high-use, standard incandescent bulbs with efficient
compact fluorescent bulbs (look for the ENERGY STAR label). These bulbs use
2/3 less energy and last up to 10 times longer. Replacing 5 of your home’s
most
frequently
used lights will save $60 each year on energy costs.
10.
Almost all home improvement projects can incorporate energy savings. In
winter, sealing and insulation can make a big difference. For kitchen,
bathroom, home office and other remodeling projects, don’t forget to
incorporate energy-saving appliances, lighting, window or skylights,
ventilation fans, and other products. Look for the government’s ENERGY STAR
to save
energy,
money, and help the environment. Other recommendations are available at
www.energystar.gov/homeimprovement.
11.
Practice the “Three R’s”: Reduce,
Reuse and Recycle.
Did
you know...along with reducing waste in landfills and conserving material
resources, recycling saves energy and reduces pollution.
By
recycling a one-foot tall stack of newspapers, you save enough energy to power
a hot shower every day for a week. For every soft drink bottle you recycle,
you save enough energy to run a television set for an hour and a half. Making
aluminum from recycled material uses only a tenth as much electricity as
making the same aluminum from bauxite ore. When you throw away an aluminum
can, you waste as much energy as if you filled the can half full of gasoline
and poured it onto the ground.
Also,
see if you can create your own energy, such as solar of
wind, for your home.
Look
into energy-efficient vehicles and vehicles
that use green energy. Check buying guides as well for more information.
Your
fuel costs. Pollution. Our country's dependence on foreign oil. The vehicle
you choose to drive and how you drive it affect all of these issues. To
minimize these effects, here you can learn about advanced vehicle
technologies, alternative fuels, and ways to improve your vehicle's fuel
efficiency. RESEARCH THE LINKS BELOW
Power
a vehicle with alternative fuels, such as biodiesel, electricity, ethanol,
natural gas, or propane. Help
extend your bicycling trips without fatigue. Drive
a vehicle that produces no exhaust or emissions. Learn
about hydrogen-powered vehicles with the potential to significantly reduce
energy use and emissions.
Cahaba
School 
Virtual
Cell
Environmental
Science 
Chemistry introduces
students to the theoretical
principles behind basic
inorganic chemical concepts.
The course covers advanced
chemical principles and
mathematical problems that will
prepare a student for further
Chemistry study at the college
level. It is highly
recommended that students have
at least a B in previous
math and science courses.
Chemistry requires that students
come to the course with the
ability to perform advanced
algebraic operations and
independently solve word
problems. This course requires
laboratory work.
Natural History
Biodiversity & The Ecosystem
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