A standard 60 watt incandescent light bulb uses 60 joules of energy each second. The equivalent fluorescent light bulb uses 13 joules of energy each second. The equivalent LED light bulb uses 9 joules of energy per second. Assuming a light bulb is on 3 hours per day (considered standard usage), I computed the following annual energy usages for each style of bulb.
Incandescent = 236,520,000 Joules = 65.7 kwh
Fluorescent = 51,246,000 Joules = 14.2 kwh
LED = 35,478,000 Joules = 9.9 kwh
Assume an electricity cost of $0.10 per kwh of energy use and you find an incandescent light bulb costs $6.57 per year, a fluorescent light bulb costs $1.42 per year and an LED light bulb costs $0.99 per year to operate. My house has about 75 light bulbs. It seems high, but walk around your house and count up the number of light bulbs. You'll probably find just as many, if not more! For my home, annual costs add up to:
Incandescent = $492.75
Fluorescent = $106.50
LED = $74.25
I don't know about you, but $74.25 is a LOT less than $492.75. Not too mention the frequency of changing light bulbs is drastically reduced and much less energy is used! The moral of this story? Go out and purchase LED light bulbs for your home!