Save Energy with Your Light Bulbs

A Simple Way to Save Energy (and Money!)

Incandescent vs Compact Fluorescent vs Light Emitting Diodes

There has been much talk on the subject of which light bulbs you should use in the home and how this can impact energy savings.  The subject centers on the use of incandescent light bulbs versus the newer compact fluorescent lights (CFLs) and light-emitting diodes (LEDs).

Incandescent light bulbs have been in use since their invention by Thomas Edison in 1879 and are used worldwide.  In the United States alone the sale of light bulbs is estimated at around 2 billion annually.  They are still the most widely used light bulbs but are slowly being phased out for more energy-efficient lights.  In recent years CFL lights have seen an increase in sales and in some stores the older incandescent bulbs are no longer offered or are being slowly phased out. Most recently, LED bulbs are being offered as a replacement forincandescent bulbs.

Lighting Costs

First, let’s look at the costs of the various types of light bulbs in your average home.  The costs for lighting for an average home is estimated to be about 13% of the total energy cost.

Incandescent – It costs about $0.91 a day as of December 2012 to run a 60-watt incandescent bulb, producing 800 lumens. This translates to roughly $27.38 a month or $328.59 a year in energy costs.  This bulb will last approximately 1200 hours of use (120 days) and costs approximately $1.50 for each bulb.

CFL – It costs about $0.21 a day to run a 13-23 watt compact fluorescent bulb, producing 900-1600 lumens.  This translates to roughly $6.30 a month or $75.60 a year in energy costs. This type of bulb will last approximately 8000 hours of use (2.19 years) and cost approximately $4.00 for each bulb.

LED – It costs about $0.09 a day to run a 3-5 watt light-emitting diode light, producing 800 lumens.  This translates to roughly $2.70 a month or $32.40 a year.  This type of bulb will last approximately 25,000 hours of use (6 years) and cost approximately $13.00 for each bulb.

For the subject of this article, the author will be using his own home as an example.

My home (3 bedrooms, 2 bath w/double garage) has approximately 50 incandescent light bulbs in use with the average bulb being a 60-watt bulb and assuming 10 hours of use daily.  Assume only one-fourth of the bulbs are in use during each day and energy costs remain constant (big assumption!).

Using only incandescent bulbs:

Initial cost (50 bulbs) – $75.00 and annual replacement cost (average daily use x 365days a year / 1200 hour life  x 1/4 bulbs in usex $75) – $57  Annual energy cost – $985.77

Total annual cost – 1st year = $1060.77 and $1042.77 thereafter assuming the cost of electricity remains constant.

Using only compact fluorescent bulbs:

Initial cost (50 bulbs) – $200.00 and annual replacement cost (average daily use x 365 / 8000) – $0.00 for the first two years.

Annual energy cost – $75.60

Total annual cost – 1st year = $275.60,  $76.50 for 2nd year, and then repeating the cycle starting 3rd year.

Using only light-emitting diode bulbs:

Initial cost (50 bulbs) – $650.00 and annual replacement cost (average daily use x 365 / 50,000) – $0.00 for first 6 years.

Annual energy cost – $32.85

Total annual cost – 1st year = $682.85, $32.85 for the next 6 years then repeat the cycle.

Below is a spreadsheet showing the estimated costs for incandescent, compact fluorescent and LED light bulbs for the average home inthe above example, over a 6 year period. You will note that both CFLs and LEDs have a higher initial cost for thebulbs but over a period of 6 years, they both show significant savings over incandescent bulbs.

Year

Incandescent

Compact Fluorescent Light Emitting Diode

1

$1060.77

$275.60

$682.85

2

$1042.77

$76.50

$32.85

3

$1042.77

$275.60

$32.85

4

$1042.77

$76.50

$32.85

5

$1042.77

$275.60

$32.85

6

$1042.77

$76.50

$32.85

Total for 6 Years

$6274.62

$1,056.30

$847.10

LEDs offer slight savings but provide little or no maintenance (replacement) over the period whereas the CFLs require replacementevery 3 years.  Although LEDs are significantly more expensive at the outset, they show a total saving over CFLSfor the 6 year period of 19%.

Incandescent lights are at the low end of the cost which is a major consideration.  Although the initial cost is lower, incandescent lights are at the high end of the recurring energy cost.  CFLs contain a small amount of mercury which makes disposal an issue. Eventually, incandescent bulbs will be phased out completely due to their drain on our overall energy consumption. One final note is that some CFLs and LEDs are not recommended for use in enclosed light housings or damp areas so consider this before switching.  CFL and LEDs will become the standard so begin determining which one is the best choice for your home now.  Although the average homeowner does not reflect on bulb replacement when their electric bill arrives, the replacement costs of both incandescent and CFL bulbs is significant over a long period.  Whichever bulb you choose to replace your old incandescent bulbs with, CFLs or LEDs, they both offer tremendous savings to the homeowner.