How much energy is saved by using an LED bulb instead of a High-efficiency Incandescent bulb?


How much energy is saved by using an LED bulb instead of a High-efficiency Incandescent bulb?


In this essay, I will discuss how much energy can be saved by replacing high-efficiency incandescent bulbs with LED bulbs.  Also, I will demonstrate why the LED bulb is better than high-efficiency incandescent by comparing their electronic use, temperature differentiation, and the component of each bulb. Have you wondered about difference between incandescent bulb and LED? Let’s explore the differences.

I will answer the following mathematical questions:

How much energy is consumed a month in an example household both for the incandescent and LED light bulbs?

How much energy is consumed a month with LED light bulbs?

How much energy can be saved by using LED bulbs instead of incandescent?

How much money is saved by switching from incandescent to LED?

To begin with, what is LED? LED stands for light emitting diode. LED is a  light-emitting diode (LED) is a two-lead semiconductor light source. It is a p–n junction diode that emits light when activated. When a suitable voltage is applied to the leads, electrons can recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence, and the color of the light (corresponding to the energy of the photon) is determined by the energy band gap of the semiconductor. LEDs are typically small (less than one mm2), and integrated optical components may be used to shape the radiation pattern.

The advantages of LED bulbs include:

More energy efficient

Full brightness reached more quickly

Up to 100,000 hours of life (as much as 100 times greater than that of incandescent bulbs)

Shock resistance because it is made up of solid-state components (no filament, glass cover, etc.)

Small size – its own volume can be made very small (less than 2mm)

Easy to focus whether the light angle needed large or small

Large color variety available

Also the LED has disadvantages, including the following:

Less efficient in extreme heat (lowering hours of life to as little as 40,000, which is still at least 20 times greater than an incandescent bulb)

As the LED drive voltage is low, the general household voltage of 100V ~ 240V, the need for LED and transformer packaging for the lamp or lamp can be used in the home, and in reducing the cost of consideration, many commercially available products with the poor quality transformer, And accelerate the possibility of damage.

The luminosity of the LED is not linear with the current, and the photometric adjustment is slightly more complicated.

Higher initial cost per bulb

Because the light-emitting diode for the light source area is small, more concentrated distribution, for lighting purposes will be dazzling, the need to use optical design scattered light source.

Advantages of the incandescent light bulb include:

Incandescent lighting has a long history. It is reliability, as its existence has spanned nearly two decades. Humphry Davy is credited with inventing the first electric light, which ran off an electric battery. Early incandescent bulbs focused on finding material for the filament that burned long enough while providing efficient lighting as well. Thomas Edison eventually invented a light that could last for 1,500 hours, which was continually improved throughout the 20th century.

Incandescent bulbs light up instantly when turned on. Many other types of bulbs—such as sodium lighting—have delays of up to 10 minutes before working efficiently.

Third, Color Rendition Incandescent light bulbs offer an excellent color rendition and provide a warm, inviting light. This type of lighting can easily be dimmed, which is a feature that many homeowners use to add elegance to their rooms. They are also available in the majority of colors in the visible spectrum.

Bulbs are readily available and can be purchased at very low prices, depending on the wattage.

Lighting products generate light approximately 90% more efficiently than incandescent light bulbs. How does this work? An electrical current passes through a microchip, which illuminates the tiny light sources we call LEDs, and the result is visible light. To prevent performance issues, the heat LEDs produce absorbed into a heat sink.


Disadvantages of incandescent light bulbs include:


Incandescent bulbs need more energy. The less energy you use, the less you cost for electricity. The less electricity that is produced, the less carbon and other air pollutants released into the atmosphere.

Lighting Color Options

If you want specific colors of light to match you’re for task lighting; your options are limited. Color temperature is the measure of the color of light. The cooler the color temperature will generate more red the light. Sunlight has a high, full spectrum of light. Almost all incandescent bulbs are at the low end of the color temperature scale and thus produce an orange-like glow.


So now let us see how much energy is saved by using an LED bulb instead of a High-efficiency Incandescent bulb in my home? I have 50 light bulbs in my house and spend 11.88 cents per kWh. And I use each light bulb for 4 hours a day therefore per month it would be 120 hours. Incandescent light bulbs are 60 watts per bulb, and LED are 9.5 watts per bulb.


How much energy is consumed by 50 bulbs per hour with incandescent light bulbs?



How much energy is consumed by 50 bulbs per hour with LED light bulbs?



How much energy can be saved per hour and per month by using LED bulbs rather than incandescent?

3-0.475=2.525Kw can be saved per hour

2.252×120=75.75Kw can be saved in a month


How much energy is consumed a month with incandescent light bulbs?


3kW×$0.1188×120 hours=$42.768


How much energy is consumed per month with LED light bulbs?

0.475kW×$0.1188×120 hours=$6.785

How much money could I save per month by switching from incandescent to LED?

$42.768−$6.785=$35.983 per month

According to the calculation, using LED light instead of Incandescent light cannot only save energy but also can save money.

However,  the high-efficiency light uses the filament to generate the light, An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated to such a high temperature that it glows with visible light (incandescence). The filament, heated by passing an electric current through it, is protected from oxidation with a glass or fused quartz bulb that is filled with inert gas or evacuated. In a halogen lamp, filament evaporation is slowed by a chemical process that redeposits metal vapor onto the filament, extending its life. The light bulb is supplied with electric current by feed-through terminals or wires embedded in the glass. Most bulbs are used in a socket which provides mechanical support and electrical connections.

LEDs emit less heat; by contrast, “incandescent bulbs release 90% of their energy as heat, CFLs release about 80% of their energy as heat,” according to Another LED light benefit is that LEDs because they emit light in a specific direction, do not need diffusers or reflectors that trap lights.

Also, the energy efficiency is different. LED is much more efficient than the incandescent bulb.

This picture shows how much energy is used for four different types of light bulbs including the red line for the incandescent and the blue for LED as well as two other types of bulbs.




So, to sum up, 75.57Kw energy can be saved if I replace the incandescent bulbs with LED bulbs. Besides, LED is more efficient than incandescent because it can transfer more energy to lighting instead on heating. LED not only saves energy but also is more environmentally friendly.




“ Energy Efficient Lighting.” Eartheasy,

Accessed 24 Sept. 2017.


Gadient, Matt. “From regular to LED bulbs – How much of a power savings can you expect?” Mattgadient, Accessed 24 Sept. 2017.


Crawford, Trent. “LED vs. CFL vs. Incandescent Light Bulbs.” Sewell Direct,

Accessed 24 Sept. 2017.


“Learn About LED Bulbs.” Energy Star,

Accessed 24 Sept. 2017.

“Incandescent light bulb.”

Accessed 24 Sept. 2017.

Montes de Oca, Samantha. “LED vs. Incandescent & Halogen.” Superbrightleds,

Accessed 24 Sept. 2017.


“LED vs CFL Bulbs: Which is More Energy Efficient?”

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6 Responses to How much energy is saved by using an LED bulb instead of a High-efficiency Incandescent bulb?

  1. Haley Brown says:

    Chaoyang, I enjoyed reading your Write and Respond post. It contained a lot of information that I hadn’t thought about before. My dad only uses LED bulbs to light our home. He thinks they are much more efficient than regular light bulbs and this post helped me understand why. According to your calculations, it shows that the LED light bulbs save more energy and also save more money. It seems like a win-win to me to use LED bulbs over High-efficiency Incandescent bulbs. One question to you would be, is it more safe to use LED bulbs because they use less heat to light? Thank you for informing me on this topic because now when I shop for light bulbs I will buy LED.

  2. Sarah Sobel says:

    Hello, Great post! Similarly, I wrote my Write and Respond 1 post on the benefits of using a LED bulb over a CFL bulb. I liked how you discussed how much energy can be saved by replacing high-efficiency incandescent bulbs with LED bulbs. Your calculations were both accurate and informative. I enjoyed how you calculated both the energy you can save and the money. I too believe that we should switch to LED lights both for environmental benefits. I did not include a graph about the electricity use per bulb, so it was informative for me to read. It is shocking how much less electrical consumption LED bulbs use when compared to other bulbs! Overall, I thoughroughly enjoyed your post and I hope you got a chance to read mine!

  3. Kevin McInerney says:


    Very interesting topic; I feel like this is a very commonly discussed question within sustainability and energy use. You did an excellent job stating your argument in the first portion of your response, clearly saying that an LED bulb is better than high-efficiency incandescent bulbs. Throughout the course of your response, I learned a lot about both types of bulb and the advantages/disadvantages of each. The watt-per bulb ratio is something that really stood out to me, with incandescent light bulbs using 60 watts per bulb and LED bulbs using 9.5 watts per bulb. In your calculations of ‘how much energy is consumed by each light bulb per hour,’ I was a little confused as to why you divided by 1,000 (eg. 60watts x 50bulbs /1,000 = 3kW). Other than that, I found your calculations to be very thorough and informative. The conclusion of one of your calculations, that you could save roughly $36 per month by switching from 50 incandescent to 50 LED bulbs was pretty interesting to learn. It was also interesting to learn that about 75.57kW of energy could be saved if you replaced the same amount of incandescent bulbs with LED bulbs. Overall, this was a very informative and well thought-out response which I learned a lot from. Upon conducting some brief research regarding incandescent vs LED bulbs, I came across an article online at which said that “incandescent bulbs cost much less than their energy efficient alternatives- LEDs.” However, much to what you proved through your calculations, although incandescents may be cheaper upon initial purchase, they are far less efficient, which ends up being more expensive in the long run. Something interesting to know would be the point at which the value of an incandescent bulb meets that of an LED bulb. In other words, because incandescents are actually cheaper, at what point during their usage do they become more expensive than LEDs? Although you did an excellent job covering both incandescent and LED bulbs, what is there to be said about CFLs (compact fluorescent lamps)? I thought that it would be interesting to learn the answers to these questions, but overall, I think it’s safe to say that you’ve influenced me into using LED bulbs from now on.

  4. Jonathan Demi Ajayi says:

    Hi very thoughtful write up. Lighting is a major part of where our energy consumption goes too. And comparing and contrasting the distinct types to examine where energy is wasted and saved is important. Examining how many watts is each type requires to function is a good step and kwh is a great unit to study it at. I think the timespan you looked at could have been larger. Maybe you could have studied over the course of a year. This could have yielded a higher value and given a better sense of how much is saved when an individual switches to LED from incandescent bulbs. I think this topic is very relevant because lighting is an aspect so crucial to our architecture as well as out door spaces and are required almost everywhere. I like how you take into account the amount of heat that is wasted by each bulb. This is a good thing to look at as this waste product is where energy is going. I do think more could have been elaborated on with the heat waste but I think it is helpful for your argument. Also the amount of heat waste is another interesting thing to consider especially in terms of safety.

  5. Yu-Tzu Chang says:

    Hi, I am enjoying reading this, and I think this is a very interesting topic since this is something that related to our daily life. I always thought the incandescent bulbs will be cheaper since the initial cost of LED light bulbs is more expensive; however, after reading your post, I understand that we can actually save more money and energy in the long run if we are using LED light bulbs. Moreover, we as human are all have the responsibility to protect the earth. Replacing incandescent bulbs with LED light bulbs is a very simple step that only makes our world a better place but also makes our own life better.

  6. gcg5081 says:

    This was so interesting to read! Personally, I always consider the environmental benefits of switching lightbulbs but have never quite fully grasped what the actual difference is between bulbs. You thoughtfully laid out the differences between them, and made it clear the benefits of switching bulbs. Your argument was well-articulated, yet you continued to follow it up with your actual scientific backing data. The information provided was informative yet comprehensive and approachable to someone who doesn’t know much about the subject – such as me! Additionally, your graphs and visuals helped to supplement the information you previously provided throughout the post. Your calculations were well presented as well; $35 might not seem like that much money, but to a broke college student, I’m all about it. I am definitely going to switch out all of my incandescent bulbs now!

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