Changing from CFL, incandescent, or halogen bulbs into LED bulbs is a popular advice that you find whenever you look for ways to lower your lighting bill.
But is it really a good advice?
Do LED lights use less energy? Or is it another myth that is being used in order to sell you products that you don’t really need.
You are in the right place to the answers you need.
I’m an electrical engineer with more than ten years of experience, and I’m going to show if you can save money with LED lights or actually pay more, how much is the difference, and what other steps you can take in order to reduce the lighting bill.
Do LED Lights Use Less Energy?
Yes, LED lights use less energy compared to other types of lighting bulbs, such as fluorescent, incandescent, and halogen bulbs, while giving the same, or more, amount of lighting flux.
And since LED lights use less electricity, then it is a really wise decision to replace the existing lighting bulbs with them.
And when you do so, and since LED lights use less power to give the same amount of lighting, then you replace a certain halogen, incandescent, or fluorescent with an LED bulb that has a lower power rating in Watt.
How Much Energy Do LED Lights Save?
It depends on each light bulb that you want to replace, as each one consumes a certain amount of energy per hour of operation, and each one requires a certain size of an LED bulb to replace it and give the same amount of lighting.
Let’s make a simple calculation:
Let’s say that you have a 160 sq.ft. (around 15 sq.m.) bedroom.
The required amount of flux for a bedroom of this area is between 1,600-3,200 lumens.
Let’s take the low end value of 1,600 lumens.
To get this amount of lumens, you need to use a 100W incandescent bulb, a 72W halogen bulb, or a 23W CFL bulb.
However, you can get almost the same amount of lighting flux with a much smaller LED bulb, which is a 18W LED bulb in this case.
Now to make sense of these numbers, we need to calculate how much energy LED lights save you based on the number of hours they are turned on.
For a bedroom, let’s say that you need to keep the lights on for around two hours per day on average.
Two hours per day with an incandescent lamp consumes 0.1 kW X 2 hours = 0.2 kWh per day, just for the bedroom.
And for a month, 30 X 0.2 = 6 kWh.
With a halogen lamp, it’s 0.072 X 2 = 0.144 kWh per day.
And for a month, 0.144 X 30 = 4.32 kWh.
With a CFL bulb, 0.023 X 2 = 0.046 kWh per day.
And for a complete month, it becomes 0.046 X 30 = 1.38 kWh.
While with an LED bulb that gives the same amount of lighting flux, then you consume around 0.018 X 2 = 0.036 kWh per day.
And in a month, it’s around 1.08 kWh that you consume with an LED bulb for the 160 sq.ft. bedroom.
Therefore, if you replace the incandescent lamp at the bedroom with an LED light bulb, you save around 5 kWh per month.
And if you were using a halogen lamp and you replace it with an LED light bulb, you save around, 3.2 kWh per month.
And if you were using a CFL lamp, then you save around 0.2 kWh per month by replacing it with an LED light bulb.
As you can see, replacing the traditional and older technologies of lights with an LED light can save you electric energy.
And to calculate how much you can save on replacing all the lights in the house or apartment with LED lights, you need to make the measurement the same way for each room individually.
Do LED Lights Save Money on Electric Bill?
Yes, LED light bulbs save you money on the electric bill, since they use less electricity than the other types of light bulbs while giving the same amount of lighting.
To calculate how much money LED lights save, we need to calculate how much energy they save per month as in the previous section, and then calculate them money they save based on the tariff rates that your utility company offers.
How Much Do LED Lights Save per Month?
Continuing with the previous example, for the lamp in the 160 sq.ft. bedroom, replacing an incandescent lamp with an LED lamp saves you around 5 kWh in electric energy per month.
To calculate the money savings, we need to know how much you pay per kWh, based on the company that supplies your place with electricity.
The electricity rates for residential consumers in US range from one state to another between 10-30 cents/kWh.
Taking the average, 15 cents per kWh, then the amount you save by replacing the bedroom’s incandescent lamp with an LED one is around 5 X 15 =75 cents per month, or $0.75/month.
Note that this is only taking into consideration the lamp in the bedroom.
Now assuming that you have a 200 sq.ft. living room, then the amount of lumen you need is around 2,000-4,000 lumens.
Let’s take the low-end value, 2,000.
To get this amount of lighting, you need a 150W incandescent lamp.
For a similar time of operation, two hours per day, they consume around 0.15 X 2 = 0.3 kWh per day.
That’s around 30 X 0.3 = 9 kWh per month.
While a 24W LED light bulb, which gives around the same amount of lumens, consumes around 0.024 X 2 = 0.048 kWh per day, and 0.048 X 30 = 1.44 kWh per month.
Therefore, you save around 9-1.44= 7.56 kWh per month in energy just from replacing the living room’s incandescent lamp with an LED one.
In money, you save around 0.15 X 7.56 = $1.3 per month.
Together for the one bedroom and the living room, you save around $2 per month.
And for the kitchen, since the amount of lighting required is higher than the lighting required for the living room and the bedroom, then you save even more replacing the light bulb in the kitchen with an LED one.
And the same goes for the corridor, laundry room, hallway, …etc.
Let’s say that you end up saving around $10 per month replacing all the light bulbs with LED ones.
Now while that might seem not worthy for you, but you should not calculate savings for replacing existing light bulbs with LED ones based on the monthly bill, but take into considerations.
How Much Do LED Lights Save per Year?
Sticking to the examples above, for the bedroom, you save around $9 per year by replacing an incandescent lamp with an LED bulb, and for the living room, you save around $15.6 per year.
And for the kitchen the savings would even be more.
But taking the same assumption above, that you save on electric bill around $10 per month in total by replacing all the existing incandescent lights with LED ones, then you save around $120 per year.
That’s a good amount of money to save on electricity bill just by replacing existing lights with LED lights.
These are very conservative numbers.
If you have a big house, and if you turn the lights on for more hours than what I assumed in the above examples, then you end up saving several times the numbers we got in the calculation above by replacing the existing lights with LED ones.
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Is it Worth it to Replace Existing Lights with LED Lights?
Now I made the calculations above based on the fact that you replace incandescent lamps with LED bulbs.
But what if you have other types of lamps like halogen or CFL lamps, which originally consume less than the Incandescent lamps?
The answer is that you will still save energy and money on electric bill when you replace these types of lights with LED ones, but the savings will be less than the ones compared to replacing incandescent lamps with LED ones.
If you have incandescent or halogen lights, then I recommend replacing them with LED ones the soonest you can in order to save as much as you can.
But in case that you have CFL lamps, then you can wait until each one is burnt out, and then replace it with an LED one.
LED Light Bulbs FAQ’s
There are some misconceptions about LED lights that make people unable to decide whether to use them in place of other types of lights, and here are the answers to some of the most frequently asked questions asked about this matter:
Do LED Lights Make Your Electric Bill High?
No, LED lights do not make your electric bill high, but on the contrary, LED lights lower your electric bill by consuming less energy compared to other types of lights.
Do LED Lights Save Use Less Energy Than Fluorescent Lamps?
Yes, LED lights use less power, and therefore energy, than fluorescent lamps.
Do LED Lights Live Longer Than Other Types of Lights?
Yes, LED lights work up to 2-4 times CFL lamps total hours of operation, up to 25-35 times compared to the normal incandescent lamps, and up to 25-50 times the lifetime of a halogen lamp.
Do Smart LED Bulbs Save Energy?
Yes, smart LED bulbs can save energy as they automatically switch off when there’s nobody in the room, because leaving the lights on all the time wastes electricity, and it is a good habit to turn lights off whenever the room is empty.
Conclusion – Do LED Lights Save Energy & Lower Electric Bill?
Yes, LED lights save energy and can help you lower your electric bill immediately, in addition to the long-term savings based on the fact that they work for longer hours than CFL, halogen, and incandescent lamps.
It is a recommended thing to do to replace all teh existing halogen and incandescent lights with LED ones as soon as possible, and for the CFL lamps, you may either replace them now, or wait until each one is burnt, and then replace it with an LED one.
I hope that my answers were helpful to you and that you now understand that LED light bulbs save energy and save you money on the electric bill.
If you still have other questions, or if you need help in anything related to saving on lighting bill, then please, ask me in the comments’ section below, and I will do my best to help you out asap 🙂
And please, feel free to share this article with anyone who might benefit from it.
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