How do I choose which light bulb to buy?






November 2, 2020                                                                                                                                             Home

It used to be that when you went to the store to buy a light bulb, you picked one that had the right amount of watts for the lamp or fixture you needed:  40, 60, 75, 100.  These were very similar to the original incandescent bulb invented by Thomas Edison and also British scientist Joseph Swan in 1879. Over time more types of lights became available – with regular size or various narrow sizes of screw-in bases (for chandeliers or stoves or ceiling fans).  There are floodlights and spotlights and three way bulbs.

There are fluorescent lamps and halogen lamps. Replacing those is easy as you have to use fluorescent bulbs and halogen bulbs.   What about CFLs, the compact fluorescent lightbulbs?  And now, the LEDs, that are light-emitting diodes?  Now, many bulbs also have a “lumen” or level of brightness rating.

Most important is to choose a bulb which does not exceed the requirement for the lamp that you need.  Most fixtures state the maximum watts that a bulb should be.  Then the next choice might be brightness.  This would be lumens.  Bulbs with the same watts can have different brightness.  Lumens are listed on most packaging today.

Then the choice involves buying the incandescent (“regular”), or the CFL, or the LED bulb.  As you will see with the CFL and LED bulbs, on the package it will list the amount of watts that are actually used to provide the power of the bulb you are replacing.  For example, for 60 watts of power for a “regular” bulb. a CFL bulb uses 14 watts of power, while an LED bulb uses only 10 watts to give 60 watts of power.

This difference in use of kilowatt hours is important, because you pay (for us, to our Powell Valley Electric Cooperative) for all your kilowatt hours (kWh) on your monthly electric bill.  The current kWh rate for Powell Valley is about 10 cents.

Say you need a new 60 kilowatt bulb.  The incandescent consumes 60 watts of power, the CFL 14 watts, and the LED 10 watts.  So, with the above rate, if you use a bulb about 3 hours a day, for a year (about 1,000 hours) the cost for electricity would be:  incandescent $6.00,  CFL $1.40, LED $1.00.  And this is for just one bulb.  How many bulbs do you have in your house?

There is also bulb replacement.  How long will each of these three bulbs last?  An incandescent 60 watt bulb running 4 hours per day would be expected to last one year; the CFL 6-7 years;  the LED 15-20 years.  

So, although the LED bulb may cost a bit more to purchase (and the cost continues to go down, now $2 each in quantity), it pays back in cost savings in the first year.  Don’t forget using LED bulbs – that require many fewer replacements – also helps keep many “regular” bulbs out of our ever growing landfills.

Everyone needs to learn more about our electric cooperative.  For more information, go to

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