Energy Efficiency
By: Maura and Austin
What is Energy Efficiency?
Energy efficiency is the percentage of total energy input into
an energy conversion device or system that does useful work
and is not converted to low-quality, essentially useless heat
Improving energy
efficiency of a
system involves
using less energy
to do more work.
84% of all commercial energy used in the United
States is wasted, 41% is automatically wasted due
to the second law of thermodynamics but 43% is
unnecessarily wasted by using fuel-wasting motor
vehicles, furnaces etc and living and working in
leaky, poorly insulated, poorly designed buildings
Unnecessary energy waste costs the
U.S. $300 billion a year which is an
average of $570,000 per minute.
http://www.treehugger.com/cars_transportation/
Improving Energy Efficiency
We can’t recycle energy but we can slow the rate at which waste heat flows
into the environment when high-quality energy is degraded.
For your home:
-insulate it thoroughly
-eliminate air leaks
-equip it with an air-to-air heat exchanger to prevent buildup of indoor
pollutants
For your office:
-collect and distribute waste heat from lights, computers, and other
machines to reduce heating bills during cold weather and vent the collected
heat outdoors during hot weather to reduce cooling bills
-drive a type of air conditioner called an absorption chiller
Saving Energy in Industry
Cogeneration-combined heat and power systems in which two
useful forms of energy are produced from the same fuel source.
These systems have an efficiency of up to 80% compared to the
normal 30-40% for coal-fired boilers and nuclear power plants, emit
2/3 less CO2 per unit of energy produced than conventional coal-fired
boilers, and in 6-8 years they pay for themselves in saved fuel and
electricity. It produces 9% of the electricity in the United States.
Replacing energy-wasting electric motors-most of these motors
are inefficient because they run only at full speed with their output
throttled to match the task. The cost of replacing these motors with
new adjustable-speed drive motors would be paid back in about a
year and save an amount of energy equal to that generated by 150
power plants.
Switching to high-efficiency lighting
http://www.lowimpactliving.com/pages/impactcalculator/impactcalculator?gclid=COyL9eGylpkCFSQMDQodbFxKUw
Saving Energy in Transportation
Between 1973-1985, the average fuel
efficiency rose sharply for new cars
sold in the U.S. and to a lesser
degree for pickup trucks, minivans,
and SUVs. This occurred because of
the government-mandated Corporate
Average Fuel Economy (CAFE)
standards. But the average fuel
efficiency between 1985-2001 leveled
off or declined. This was caused by
the increased popularity of SUVs,
minivans, light trucks, and large
autos that produce approximately
20% of U.S. CO2 emissions and
failure of elected officials to raise
CAFE standards due to opposition
from automakers.
Fun Fact
By 2020, the cost of
solar power is expected
to drop by nearly 20%
of its cost in 1980. This
drop in price is due to
both lower upfront
costs, lower operating
costs and more efficient
PV (photovoltaic)
systems.
NEWSFLASH
Do you believe in “clean” coal?
Although many people believe in the idea of “clean” coal, there is not a single demonstration
large-scale “clean” coal plant in the U.S. today. All new coal plants which have been proposed
will release 100% CO2 into the air, just like their predecessors. Three times as many jobs can be
produced with an investment in wind power as the same investment in coal power. And an
investment in solar power can produce four times as many jobs, and energy efficiency as coal
power.
Article Reviews
By: Maura Kush
“Energy Intensity and Energy Efficiency”
Energy efficiency and energy intensity make up energy policy. Energy efficiency refers to the ratio between
energy output (services such as light, heat and mobility) and input (fuels). The energy efficiency of a country
is not determined by it’s energy intensity. For Japan and the United States, who have comparable
technological knowledge and technical energy efficiency, other factors such as energy prices, climate,
geography and lifestyles are included in the calculation. Due to these cultural differences, Japan has an energy
intensity of roughly half that of the United States.
IEA (2000), World Energy Outlook 2000
http://www.iea.org/textbase/papers/2002/improving.pdf
Energy Efficiency in the Power Grid
by: Bob Fesmire
Due to certain environmental, economic and political issues, improving energy efficiency has taken a front
row seat in the United States. Much has been done but we are still a long way from the finish line. We
may never reach this line but we still need to improve energy efficiency and other energy sources. A coal
plant generally wastes anywhere from 65-40% in the transformation of coal to usable energy. As we rotate
our focus from coal, uranium and natural gas to renewable resources such as wind and sun, the concept of
energy efficiency is less of a problem. Some energy may be lost but wind and sun are free and
inexhaustible. We have not yet taken advantage of the role these resource have to offer. But as we stray
away from importing oil, natural gas or even coal from foreign fuel supplies, we increase our dividends
from a security standpoint and the less we use, the less we have to buy.
http://www.renewableenergyworld.com/rea/news/article/2007/07/energy-efficiency-in-the-power-grid49238
Questions
1. What is energy efficiency?
2. How did CAFE (Corporate Average
Fuel Economy) affect gas emissions
from vehicles?
3. Industry can have greater efficiency
using what three methods?
4. How could you make your home
more energy efficient?
5. How much commercial energy is
wasted in the United States?
Bibliography
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on_energy.jpg
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