geoffrey iwata
phy h190
2/22/2012
What are the Light Bulb Wars
Artwork by bloggerknight2009
What are the Light Bulb Wars
 Energy Independence And Security Act of 2007
 Requires roughly 25 percent greater efficiency for light bulbs, phased in from 2012 through 2014
b
lb h d i f
h
h  Effectively bans the manufacturing and importing of most current incandescent light bulbs
 Rationale:
 22% of US electricity consumption due to lighting (2010)
 That’s 13% of our total energy
Wikipedia.org
What are the Light Bulb Wars
 Should incandescent bulbs be banned from production?
?
Why are they controversial?
 "We are taking away a choice that continues p p
y
to let people waste their own money” –Secretary Chu
How did this battle arise?
Where does the energy go?
US Energy Report 2001
How many lumens do we need?
What’s the matter with incandescent?
Why is incandescent under attack?
What’s the matter with incandescent?
 Let’s look at how they work
 Low pressure inert gas (argon, nitrogen, krypton, xenon)
i
k
)
 Tungston Filament ~ 3000K
 Mostly infrared spectrum
M tl i f
d t
 Get Hot!
What’s the matter with incandescent?
 Let’s look at how they work
 Low pressure inert gas (argon, nitrogen, krypton, xenon)
i
k
)
 Tungston Filament ~ 3000K
 Mostly infrared spectrum
M tl i f
d t
 Get Hot!
What’s the matter with incandescent?
Associated Press
What’s the matter with incandescent?
 How are they made:
 Cheaply
 Recipe since 1879 – filament, gas, bulb, wires
Why are CFLs smarter?
Why are Compact Fluorescent Bulbs Better?
 How do they work?
 Electric current through mercury vapor excites ionized H t
Hg atoms
 Hg atoms emit UV light – 253.7 and 185 nm
 Phosphor coating on glass fluoresces in visible range
 Current regulated by “ballast”
Howstuffworks.com
Why are Compact Fluorescent Bulbs Better?
 Power converted to visible light:
 CFL: ~22% (50‐70 lumens/watt)
(5 7
)
 Incandescent ~2% (10‐17 lumens/watt)
 Heat production: Hot bulbs increase building’s air conditioning costs (in warm climates)
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(
l
)
Why are Compact Fluorescent Bulbs Better?
 Power converted to visible light:
 CFL: ~22% (50‐70 lumens/watt)
(5 7
)
 Incandescent ~2% (10‐17 lumens/watt)
 Heat production: Hot bulbs increase building’s air conditioning costs (in warm climates)
d
(
l
)
 Last Longer
 CFL: 6000‐15000 hours
CFL: 6000 15000 hours
 Incandescent: 750‐1000 hours
Energystar CFL report 2007
Why are Compact Fluorescent Bulbs Better?
CFL
Incandescent
Why are Compact Fluorescent Bulbs Better?
CFL
Incandescent
How can we compare CFLs to incandescent?
1991
How can we compare CFLs to incandescent?
Why are Compact Fluorescent Bulbs Better?
CFL
Incandescent
Low production impact
Easy bake oven
Power‐>light
More efficient
L l
Last longer
Cheap
No mercury in the bulb
How can we compare CFLs to incandescent?
 Consider 8000 hours of use:
CFL
13Watt
104 kWh
Incandescent
60 Watt
480 kWh
‐Maryland Energy Administration
‐Energy Star.gov
How can we compare CFLs to incandescent?
 But how about the mercury used?
 National Average Mercury emissions
 0.012 mg/kWh
11.2 mg from 2 mg from electricity use
0.44 mg 0
44 mg from landfilling
1 6 mg
1.6 mg
CFL (uses 104 kWh) 5.76 mg from electricity use
0 mg from landfilling
5 76 mg
5.76 mg
Incandescent (uses 480 kWh)
‐Maryland Energy Administration
‐Energy Star.gov
H can we compare CFLs
CFL to incandescent?
i
d
?
How
Energy Star.gov
Why are Compact Fluorescent Bulbs Better?
CFL
Incandescent
How much money do we really save?
 Incandescent: 32c / bulb
 CFL: $4.47 / bulb
The Home Depot
How much money do we really save?
 Incandescent: 32c / bulb
 CFL: $4.47 / bulb
 At best lifetime ratio: 15,000/750 = 20, saves ~$2/bulb
$2/bulb
How much money do we really save?
 Incandescent: 32c / bulb
 CFL: $4.47 / bulb
 At best lifetime ratio: 15,000/750 = 20, saves ~$2/bulb
$2/bulb
 At worst lifetime ratio: 6000/1000 6, loses 6000/1000 = 6, loses ~$2.5/bulb
But how about electricity costs?
 Incandescent: 32c / bulb
 CFL: $4.47 / bulb
 Reasonable estimate of electricity cost – 20c /kWh
 For 8000 hours:
F 8
h
 CFL: $20.80
 Incandescent: $ 96.00
Incandescent: $ 96 00
 !!!
Why are Compact Fluorescent Bulbs Better?
CFL
Incandescent
Why all the fuss?
"It was never my goal for Washington to decide what type of light bulbs Americans should use
Americans should use“
‐Fred Upton (R., Mich.)
WSJ.com
Why all the fuss?
"It was never my goal for Washington to decide what type of light bulbs Americans should use
Americans should use“
‐Fred Upton (R., Mich.)
In 2011, new bill introduced to disallow government spending to enforce new standards.
WSJ.com
Why all the fuss?
"It was never my goal for Washington to decide what type of light bulbs Americans should use
Americans should use“
‐Fred Upton (R., Mich.)
In 2011, new bill introduced to disallow government spending to enforce new standards.
Light bulb manufacturers have already replaced fabrication lines:
“A delay in enforcement undermines those investments and creates regulatory t i t ” Joseph Higbee
J
h Hi b (National Electrical Manufacturers Association)
(N ti
l El t i l M
f t
A
i ti )
uncertainty.” ‐
WSJ.com, poltico.com
Why all the fuss?
"The American people want less government intrusion into their lives, not more, and that includes staying out of their personal light‐bulb choices."
‐Michele Bachmann (R., Minn.)
(The bill) “was passed at the height of the global warming fad scare when all proper fad‐scare when all proper thinkers were supposed to sacrifice to the anticarbon gods.”
‐WSJ editorial
WSJ.com, physicstoday.org
Why all the fuss?
"I will concede over the life of the bulb...that you probably do save some money, but it takes a long time to save it ”
long time to save it.
‐Rep. Joe Barton (R., Texas)
WSJ.com
Why all the fuss?
"I will concede over the life of the bulb...that you probably do save some money, but it takes a long time to save it ”
long time to save it.
‐Rep. Joe Barton (R., Texas)
Life of CFL bulb – 15000 hours at most Life of CFL bulb 15000 hours at most – is about 2 years.
WSJ.com
Conclusion
 CFLs do make sense over incandescent bulbs.
 Lots of the rhetoric seems to be about re‐
L f h h
i b b election.
 This remains a patch to a greater issue.
This remains a patch to a greater issue