Only 10% of the energy used by an incandescent bulb produces light; the rest is given off as heat. Compact fluorescent lightbulbs (CFLs) are up to 4 times as efficient as incandescent bulbs.
Replacing one incandescent lightbulb with a compact fluorescent light can save 150 pounds of carbon dioxide per year. CFLs produce the same amount of light, use 1/3 of the electricity and last up to 10 times as long.
Artificial lighting accounts for 44% of electricity use in office buildings. Make it a habit to turn off the lights when you’re leaving any room for 15 minutes or more and utilize natural light when you can.