Last fall, we changed all of the lightbulbs in the track lighting system at one of our stores to those screwy looking new bulbs. Our electric bill has decreased by about 60%. The electric savings will pay for the bulbs in about 15 months. The bulbs should last 5 to 10 years. This is a real profit maker for me. And, it's helping to save energy too. Pretty damn Conservative if you ask me!
I've done this in my own home also and we've noticed similar savings there.
I think some people don't realize how much of our electricity is generated by Natural Gas and Oil. It's a lot! And if we save electricity, we may help to avoid another Gulf Oil Spill because we could eventually eliminate the need to drill off shore for our carbon energy sources.