- #36
jim hardy
Science Advisor
Gold Member
Dearly Missed
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From Don's link:
I like to check such claims.
$52 at 14 cents/kwh is 371.43 kwh which a 60 watt lamp will consume in about 6190.5 hours.
A CFL drawing 15 watts over that same 6190.5 hours will consume just 92.8 kwh, costing $13.00
So the saving in energy cost is about (52 -13 )$ / (6190.5) hours = 0.630 cents per hour (that's to three decimal places, $ 6.299976E-3)
that's a dollar every 1/0.00630 =158.8 hours = 6.62 days
To make $52 would be 52 X 6.62 = 344 days not quite a year.
So we might as well round off that energy saving number to a dollar a week if it's on continuously like my kitchen light .
Hmmm first time I've ever done this arithmetic.
They'll last a lot longer than a year if power isn't cycled often and the electronics in the base stays cool.
My kitchen light stays on continuously and the bulb mounts upright not base up like a ceiling fixture, so heat rises away from its base.. And since it's always on i don't suffer that aggravating initial dimness.
First CFL there lasted seven years so i made out like a bandit on it.
Second one lasted just a couple months
Third one i think three years, memory is growing dim
Fourth is in about year four now.
So even a curmudgeon like me has to admit
CFL's do have that one redeeming feature. I guess ...
old jim
I like to check such claims.
$52 at 14 cents/kwh is 371.43 kwh which a 60 watt lamp will consume in about 6190.5 hours.
A CFL drawing 15 watts over that same 6190.5 hours will consume just 92.8 kwh, costing $13.00
So the saving in energy cost is about (52 -13 )$ / (6190.5) hours = 0.630 cents per hour (that's to three decimal places, $ 6.299976E-3)
that's a dollar every 1/0.00630 =158.8 hours = 6.62 days
To make $52 would be 52 X 6.62 = 344 days not quite a year.
So we might as well round off that energy saving number to a dollar a week if it's on continuously like my kitchen light .
Hmmm first time I've ever done this arithmetic.
They'll last a lot longer than a year if power isn't cycled often and the electronics in the base stays cool.
My kitchen light stays on continuously and the bulb mounts upright not base up like a ceiling fixture, so heat rises away from its base.. And since it's always on i don't suffer that aggravating initial dimness.
First CFL there lasted seven years so i made out like a bandit on it.
Second one lasted just a couple months
Third one i think three years, memory is growing dim
Fourth is in about year four now.
So even a curmudgeon like me has to admit
CFL's do have that one redeeming feature. I guess ...
old jim
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