kinetic,
Good information but I have a couple of quibbles.
First off the price for incandescent lamps is way off. Looking at Home Depot's website (where many consumers would shop for light bulbs) a 4-pack of Phillips DuraMax (long life) lamps is $1.44 or 36¢ per (not $1.35 as in the spreadsheet).
Second $2.98 for compact fluorescent is really low too. Again from HD, more like $5 per Philips lamp.
Third, there's no mention of lumens. CF's (and any fluorescent) have a decreased light output over time.
Finally some of the calculations are based on a 60k hours. Well, at 5 hours per day 60k hours is 32 years. If I have the math right replacing the 30 lamps with LED would cost me $1650. At my current electric rate (8.5¢ per kWh) it would take me 6+ years just to break even for the outlay on the lamps. And I think the 30 lamps and 5 hours per day is way off too.
Mike
