A follow up to the previous discussion. I wondered whether the new LED bulbs could pay for themself in electricity savings in an office environment that already uses flourescent tubes that are known to be highly effficient.
From a wikipedia article the lumens per watt of a T8 bulb ( used in commercial office fixtures called Troughers) is 80-100 lm/watt. But Compact Flourescent is lower at 46-75 lm/watt. So apparently Compact Flourescents aren’t as efficient as T8 bulbs - probably because there is a relatively small amount of gas in them relative to the long skinny T8 bulbs used in business fixtures.
The phillips 60 watt bulb that won the prize is right in at 93.4 lm/watt. So, I’d say they’re at parity except for the ridiculous price. For many businesses there appears to be no reason to upgrade unless the LEDs reach price parity OR if the quality of the light is better (or the mercury problem). Eliminating the ballast ought to increase reliablity though. Replacing incandescents certainly makes sense over 3-5 year span if the light quality is acceptable.