Energy Conservation
A Major Part of the Solution to
Energy Generation and
Global Warming
Dennis Silverman
U. C. Irvine Physics and Astronomy
Why Us (U.S.)?
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With 5% of the world’s population, the U.S. uses
26% of the world’s energy.
A U.S. resident consumes 12,000 kWh of electricity
a year, nine times the world’s avg.
The average American household emits 23,000
pounds of CO2 annually.
Two billion people in the world do not have
electricity.
Using just using off the shelf technology we could
cut the cost of heating, cooling, and lighting our
homes and workplaces by up to 80%.
Scientists in Energy
James Joule
First Law of
Thermodynamics
Sadi Carnot
Second Law of
Thermodynamics
Carnot Cycle
Thomas Edison
Light Bulb, etc.
Alexander
Graham Bell
Telephone
Scientists in Energy
Albert Einstein
E=mc²
Enrico Fermi
First Nuclear
Reactor
William Shockley
Transistor
Bill Gates
Computers
Electric Energy Conservation
in the Home
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Some of the following slides are from a talk by John
Wilson, Advisor to Commissioner Art Rosenfeld of the
California Energy Commission
Annual Electricity Use Per California
Household (5,914 kWh per household)
Total Electricity Use, per capita, 1960 - 2001
kWh
14,000
12,000
12,000
U.S.
10,000
8,000
KWh
8,000
7,000
6,000
California
4,000
2,000
2000
1998
1996
1994
1992
1990
1988
1986
1984
1982
1980
1978
1976
1974
1972
1970
1968
1966
1964
1962
1960
0
Average Energy Use per
Refrigerator, 1947 to 2009
1800
Estimated Standby
kWh (per house)
1600
1400
Refrigerator kWh per
Unit
1978 Cal Standard
1200
1987 Cal Standard
1000
1980 Cal Standard
800
1990 Federal
Standard
1993 Federal
Standard
2009
2007
2005
2003
2001
1999
1997
1989
1987
1985
1983
1981
1979
1977
1975
1973
1971
1969
1967
1965
1963
1961
1959
1957
1955
1953
1951
1949
0
1995
2001 Federal
Standard
200
1993
400
1991
600
1947
Average Energy Use per Unit Sold (kWh per year)
2000
Conservation Economic
Savings
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If California electricity use had kept growing at
the US rate, kWh/person would have been 50%
higher
California electric bill in 2004 ~$32 Billion…
so we’ve avoided ~$16 B/yr of electricity bills.
Net saving (accounting for cost of conservation
measures and programs) is ~$12 B/year, or
about $1,000/family/yr.
Avoids 18 million tons per year of Carbon
Appliance standards save ~$3B/year (1/4)
Lighting
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Compact Fluorescents or Long Fluorescents using
plasma discharges use only 1/3 of the energy and
heat of incandescent lights, which derive their light
from heating filaments hot enough to emit visible
light.
If every home changed their five most used lights,
they would save $60 per year in costs.
This would also be equal to 21 power plants.
The fluorescents also last up to 10 times as long.
Replacing one bulb means 1,000 pounds less CO2
emitted over the compact fluorescent’s lifetime.
Traffic signal LEDs use 90% less energy and last 10
years rather than 2 years.
Household Energy Use for Entertainment Electronics
Plasma HDTV
Primary TV
DVD/VCR
HD set top box
Analog CRT
Secondary TV
DVD/VCR
Digital cable set top box
Combined energy use0
~ 1200 kWh per year
200
400
Annual Energy Use (kWh)
NRDC, "Tuning in to Energy Efficiency: Prospects for Saving
Energy in Televisions," January 2005.
600
“Zero energy” new homes
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Goals:
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Electronics are a problem!
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70% less electricity => down to ~2,000 kWh/yr
1 kW on peak
1,200 kWh/ yr for TVs, etc.
100-200 W for standby
TV Power
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Plasma TV (50”)
400 W
Rear Projection TV (60”) 200 W
Large CRT (34”)
200 W
LCD (32”)
100 W
Information Technology in the Home
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Imagine the following conversations in the near future:
Household Info System: I detect you are now in the
living room but left all of the lights on in six other rooms.
I am turning them all off now, okay? OK
HIS: There is an electricity shortage due to the high
demand for air conditioning in this heat. I cannot run the
dishwasher until 10 pm. Overriding this will cost 10
times the average rate.
HIS: Your kids are playing computer games past their
bedtimes. I am shutting them off now, okay? OK
HIS: I detect that you have put an old fashioned
incandescent bulb in the bathroom. How dare you! I am
cutting off all power for fifteen minutes as punishment.
Change that bulb now!
(Interval meters and hourly px pricing)
Home Energy Conservation
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Department of Energy: Energy Efficiency and
Renewable Energy
Central resource for the following slides on
home energy technology
We only select some topics of interest
Other sources
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California Consumer Energy Center
California “Flex Your Power”
Heating and Cooling in the Home
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Accounts for 45% of energy bill or $1,000 per
year
HVAC – Heating, Ventilating and Air
Conditioning
SEER efficiency rating of AC
Before 1992, typically 6.0
After 1992 required 10.0
Jan. 2006, required minimum 13.0
Annual Usage of Air Conditioning in New Homes in California
Annual drop averages 4% per year
3,000
Initial California Title 24
Building Standards
100%
California Title 20
Appliance Standards
1976-1982
2,000
Estimated Impact of
2006 SEER 13
Standards
1,500
1,000
33%
1992 Federal Appliance
Standard
500
Source: CEC Demand Analysis Office
2006
2004
2002
2000
1998
1996
1994
1992
1990
1988
1986
1984
1982
1980
1978
1976
1974
1972
0
1970
kWh/YEAR
2,500
Impact of Standards on Efficiency of 3 Appliances
110
=
Effective Dates of
National Standards
=
Effective Dates of
State Standards
100
90
Index (1972 = 100)
Gas Furnaces
80
75%
70
60%
60
Central A/C
50
40
30
20
1972
Refrigerators
1976
1980
1984
1988
1992
Year
Source: S. Nadel, ACEEE, in ECEEE 2003
Summer Study, www.eceee.org
1996
25%
2000
Setback Thermostats
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Program to lower temperature setting at night
and if gone on weekdays.
Required in California
Winter suggested: 55° at night, 68° when at
home
Summer suggested: 85° when gone, 78°
when at home
20 to 75% energy savings
Solar Water Heating
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Water heating uses 14-25% of energy use
Solar water heating replaces the need for 2/3 of conventional water
heating.
Virtually all homes in Greece and Israel (700,000) use solar water
heating. Japan has over 4 million units.
The US over a million, with most systems in Florida and California,
and Hawaii has 80,000.
Each saves 1.5 to 2.5 tons of CO2 a year.
Typical cost is $3,000 for 50 square feet.
DOE is trying to lower this to $1,000 to $1500.
Energy saved would be about 3,000 kWh per year per household
DOE would like to have 3 million new units by 2030.
Current payback is 10-13 years (solar lobby says 4-8 years),
whereas for 50% market penetration, 5-6 years is needed.
Tankless Water Heaters
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These heat water on demand with gas or electricity.
With gas heating their energy efficiency is 0.69 to
0.84, compared to gas tank heaters that range from
0.55 to 0.86.
However, they require a start up time.
They also have a limited volume flow compared to a
tank.
And they may require larger gas lines to do more
heating in a short time.
Heat Insulation
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Heat flow is proportional to the temperature
difference across a material of thermal resistance R
Q / t = A ΔT / R
Analogous to current I = Voltage / Relectrical
R is also the sum of all R’s in a series of materials
Current FHA requirements:
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Ceiling R38
Walls R19
Floors R22
Recommended Insulation
Building energy efficiency
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Structural Insulated Panels are 4-8 inches
thick and are foam filled. They can be faced
with drywall and plywood. They give R-4 to
R-8 per inch of thickness.
Insulation includes batts and rolls, loose fill
(blown in), rigid and reflective.
Cool Roofs: white reflective roofs on a
summer’s day lower roof temperature from
150-190° F to 100-120° F. Saves 20% on air
conditioning costs.
Estimated savings for a typical home from
replacing single pane with ENERGY STAR
qualified windows are significant in all regions of
the country, ranging from $125 to $340 a year.
Window Ratings
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Ratings include solar heat gain coefficient or SHGC
which is the fraction transmitted, from 0 to 1.
U-value (which indicates how well the window
insulates) is inverse of R value, so lower is better.
and visible transmittance (which indicates how well
light passes through the window), lower means
more shading, from 0 to 1.
High-tech efficiency options include windows with
argon between the window panes and low-emissivity
(low-e) coatings.
Reflective coatings and outside shades are also
effective at less cost.
Additional Advantages of Energy
Conservation (Moralizing)
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Less need to secure oil overseas with attendant
military and civilian casualties while costing
hundreds of billions of dollars
Fewer power plants and liquid natural gas ports are
needed
Less air pollution
Less drilling for oil in Alaska and near national parks
Less global warming and attendant environmental
destruction
Conclusions on Energy
Conservation
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Energy conservation has saved the need for many power plants
and fuel imports.
It has also avoided CO2 and environmental pollution.
Energy conservation research is only funded at $306 million this
year at DOE, which is low considering the massive amounts of
energy production that are being saved by conservation.
Regulations on efficiency work, but voluntary efforts lag far
behind.
Much has been done, but much more can be done
In this new era of global warming and high energy costs and
energy shortages, the public must be informed and politicians
sought who are sensitive to these issues.