How to Calculate the Energy Cost for a Light Bulb
There are many things you can do to save energy in your current home, and one of the first steps is calculating the cost for lighting. Calculating the energy cost of a light bulb is a simple step in determining your overall energy costs. High-use or high-cost lights can easily be replaced with energy-saving bulbs, reducing the amount of electricity you use, and therefore replacing them can significantly reduce your overall electricity bill. Does this Spark an idea?
Instructions
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1
Determine the wattage of the light bulb. The wattage is clearly marked on the bulb. You may have to unscrew the bulb from the fixture to read the wattage.
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2
Determine the time (in hours) that the light bulb is typically on per month. A simple estimate can be determined by taking the average time the bulb is on per day and multiplying that time by 31. For example, a bulb that is on 10 hours per day would be on a total of 3,100 hours per month (10 x 31).
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Multiply the time the bulb is on per month (in hours) by the wattage of the bulb to determine the total wattage used per month. For example, a 100 watt bulb on for 3,100 hours would equal 310,000 watts.
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4
Divide the total watts used per month by 1,000. This will give you the total kilowatts used per month. For example, 31,000 divided by 1,000 would equal 31 kilowatts used per month.
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Multiply the total kilowatts used per month by the cost per kilowatt charged by the electric company. This value is shown on your monthly electric bill. This will give you the total cost of the light bulb per month. For example, if the cost of electricity is 10 cents per kilowatt hour, then 31 times $0.1 would equal $3.10 per month.
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Tips & Warnings
Fluorescent bulbs are a great replacement for incandescent bulbs because they use less energy
Always allow a bulb to cool off before removing it from the fixture.
References
Resources
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