CFL versus LED bulbs
Posted by Max Dunn Thu, 20 Nov 2008 15:05:00 GMT
I have always thought that LED bulbs should provide the best energy efficiency and lowest lifetime cost of any bulb. However, looking into this more, I am not so sure.An article on Salon by Ask Pablo (who happens to be a graduate of the Presidio School of Management) showed this comparison:
|Bulb||Cost||Output||Power||Efficiency||Lifetime Bulb Cost||Lifetime Power Cost||Lifetime Total Cost|
|CFL||$7||500 lumens||10 watts||50 lumens/watt||$35||$55||$90|
|LED||$60||500 lumens||7 watts||71 lumens/watt||$60||$38||$98|
(Note: Lifetime is 50,000 hours, and I used an electricity cost of $0.11/kWh)
Even though LED bulbs are much more expensive than CFLs (compact fluorescent), they are also about 40% more efficient, so adding in lifetime electricity costs their total cost would be about the same.
However, there is a catch. If an LED bulb is used 4 hours per day, it would last almost 35 years – and what is the chance that over those 35 years the LED bulb gets broken or there is a power surge that damages it? Probably pretty good! So assuming that LED bulbs actually last on average only 10 years, this would make them twice as expensive as CFLs.
So until the cost of LED bulbs come down quite a bit, CFLs will still be the better buy.