Making Cents of LED Lighting

Making Cents of LED Lighting

Making cents of LED lighting

LED lighting has taken center stage in home lighting. In recent years the technology has matured and LED lighting now offers nearly everybody the ability to both enhance their home, be more sustainable and save money at the same time. LED light bulbs are now made to be used in almost all types of situations, from standard lamps, to ceiling fixtures to decorative sconces & chandeliers. .

Now that LED lights look great,  should you switch to LEDs as your incandescent bulbs burn out? Or, should you jump in with both feet and make a total household switch to LED? I have done some homework to help you understand LED lights’ costs and environmental impacts. To me, the math is clear.

Understanding the difference between LED and Incandescent Bulb Specifications

Before diving into LED economics, it is important to understand a bit about some terminology. Most notably, two of the most important characteristics of any light bulb are its “color” and its “brightness.” However, all incandescent light bulbs produced the same color and historically, their “brightness” was described in watts (even though watts are not a measure of brightness) so this can create confusion.

The following table shows a simple comparison of the power used, light brightness and light color of typical LED bulbs versus Incandescent Bulbs


Bulb Type

Power Used

(in watts)

Bulb Brightness
(in Lumens)

Light Color
(K value)

Bulb Life

(in hours)


60 Watt

800 Lumens

2700 K (warm)

1,500 hours


100 Watt

1500 Lumens

2700 K (warm)

1,500 hours


9 Watts

800 Lumens

2700-6000 K
(warm to cool)

15,000 hours


15 Watts

1500 Lumens

2700-6000 K

(warm – cool)

15,000 hours

All light bulbs, whether LED bulbs, incandescent or fluorescent, come different sizes and shapes to fit different applications like an overhead light versus a lamp versus a chandelier. In practice, an LED light bulb will typically use 15-20% of the power of an older technology incandescent light to produce the same amount of light, with flexibility in the color of the light. Most LED bulb packages include a “watts versus lumens” and light color comparison to incandescent bulbs.

With the wide variety of available colors and styles, most light bulbs can be replaced with LEDs, but do LED lights make sense from a pure dollars and cents perspective?  

Replacement Bulb Costs

 First let’s compare cost of a single LED bulb over its lifetime against the cost of using an incandescent light over the same lifetime. A 100-watt equivalent LED bulb can be purchased these days for under $4.00; typically rated for a 20,000-hour life. Assuming 3 hours of use a day, this bulb would last nearly 20 years!

On the other hand, an average incandescent bulb costs $2.00 and will last only 750-2,000 hours, or about 1,000 hours on average. So at 3 hours a day, a typical bulb would need to be replaced every year at a cost of $2.00 per year. Over the 20-year life of the LED, just replacing the bulbs every year would cost $40.00 (vs. $4.00 for a single LED).

 Electricity Costs

 Next, let’s look at how much it costs to power an LED vs. an incandescent. Currently in Illinois electricity costs on average $0.12 per Kwh (the amount of power used by a 100-watt light bulb when operated for 10 hours) As an incandescent bulb on average has a 1,000-hour life, the cost to power a 100 watt bulb for 1,000 hours would be $12.00 ($0.12*(1000 / 10).

Compare this result to a 100-watt equivalent, 1500 lumen LED, which only requires 15 watts of power. This bulb can be powered for 66 hours on 1 Kwh. Thus, the cost to power this LED bulb is only $1.80 ($0.12* (1000 / 66.7) for the same 1000 hours



100w Incandescent

15w LED

Initial Replacement Bulb Cost



Annual Electricity Cost



Total First Year Cost




In the year of purchase, this one LED would save you about $10 in electricity costs and $8 after taking into account the cost of the bulb. However, if you factor in the cost of replacing the bulbs each year over the expected 20-year life of the LED, and the savings become even more substantial.


100w Incandescent

15w LED

Electricity Cost Over 20 Years



Total Bulb Costs Over 20 Years



Total Cost Over 20 Years




Over 20 years, a single $4.00 LED light bulb could save you about $240 (not to mention the time & hassle of replacing the bulb 19 times – especially important if the bulbs are in high ceilings or other difficult-to-access locations.

Potential Household Savings

The next question: should you switch all your home’s lights over to LED now? According to the Department of Energy (DOE) the average household uses 85 bulbs. That seems like a lot of lights, but it includes bathrooms, closets, garages, outdoor lighting, and appliances, plus multiple bulbs in multi-bulb ceiling fans or chandeliers, etc. It adds up!

Obviously not every lightbulb in your house is 100 watts, and many may be an unusual size or shape which cannot be easily replaced. Some will be in infrequently accessed spaces like attics, while desk lamps may be in more constant use.

Even if you were only able to replace the most heavily used half of them (40), if these 40 bulbs were used 3 hours a day on average, you could still save 40 x $8 ($320) in the first year. Over 20 years, that would amount to $4,800 in savings.

Better for the Environment

And not to be forgotten, the less power you use, the less power that needs to be generated, some of which is generated by burning natural gas and coal. This ultimately results in less CO2 being released into the environment. In a manner similar to the above cost analysis, we can compare the amount of coal it takes to power an LED vs. an incandescent

As shown in the appendix, based on DOE information, if the average home switches from incandescent to LED lightbulbs, when the power is generated by coal, that one change alone could reduce the amount of coal required from nearly 3600 pounds to less than 500 pounds.

If you’ve made the decision to save energy & positively impact the environment by converting your lighting to LED bulbs, we have attached some additional tips to make your conversion go smoothly.

There are several local programs that will help you save money and you can both improve your lighting while saving money and helping the environment.

Thanks for helping create a more cost effective and sustainable Glencoe and world!


 If you’ve made the decision to investigate incandescent bulbs, here are three additional tips to make your conversion go smoothly.

Free and Discounted LEDs through ComEd

 First, as recently as 3 to 5 years ago, LEDs were noticeably more expensive than Compact Florescent Lights (CFL’s) and incandescent. Now, not only have costs plunged to being competitive with higher-energy consuming alternatives, but Glencoe residents are able to obtain free or heavily discounted bulbs through ComEd’s Energy Savings program.

ComEd offers a free home energy assessment program. With a virtual inspection, ComEd’s assessors will help identify inefficient light bulbs and drop off free bulbs for you to use. With a more in-depth in-person assessment (also free) they will also provide free bulbs and can also install other energy savings devices for you (e.g., programmable thermostats and low-flow faucets and showerheads). ComEd also offers discounted LED bulbs through their online marketplace and through partner retailers.

Warranty Claims

 Because of their historically premium pricing, most LED bulb manufacturers offer a warranty based on rated hours of use. If your bulbs fail prior to their rated lifetime, you can make a warranty claim, and most will replace the bulbs for free. However, most will request some documentation. So when you purchase your bulbs, keep your receipts. And when you install bulbs, either keep a log of when they are installed or use a permanent Sharpie-style marker to write the installation date on the bulb base so you have some data to support your claim.

Lighting Temperature

Last, unlike incandescent bulbs, who derive their yellow-ish color from the burning of a wire filament, LED bulbs use sophisticated “light emitting diodes” that can emit light in a variety of colors. Because of this, LED bulbs are available in a wide range of color “temperatures” measured on a “K scale” (in Kelvins). So, in addition to a brightness rating (in lumens), most  LED packaging will also indicate the bulb’s “K value.” A 2700 K LED is equivalent to a warm white incandescent bulb, while a 4300 K LED is a cooler white, more like a traditional fluorescent office light. Most LED bulbs will be in the 2000 K to 6500K range, or may even be adjustable to improve appearances (for example, to keep you from looking green or purple on a Zoom call). The K value does not impact the economic or environmental equations, just the desired aesthetics.

More Information

To learn more about color temperature, please visit: https://www.westinghouselighting.com/color-temperature.aspx  

For more information about ComEd’s free energy assessments, please visit: https://www.comed.com/WaysToSave/ForYourHome/Pages/Default.aspx

For more information about the ComEd marketplace, please visit: https://secure.comed.com/marketplace/