[AndyTheBear]

Oh my bad...I put 40 hours in the "per day"! Some how I read it as "per week"! Good catch Fireman. I used the 8.7 cost per killowat hour they had by default.

Revised with an 8 hour "day"...it takes $25.40 per year for the 100 watt standard and $3.05 for the 12 watt LED...so we are looking at maybe 2 years rather than 6 months to get your investment back if the LED is around 45 bucks.

[Romulus]

The payback period is a lot faster than anyone’s suggesting, because no one’s taking into account the heat produced by incandescent bulbs, which requires costly air conditioning to remove.