Do Dimmer Switches Save Electricity?

Do Dimmers Save Electricity

Do dimmer switches save electricity and lower your bill, or are they just a waste of money?

How much energy and money can a lighting dimmer save you? What kinds of light bulbs do they work with? And are the savings worth the cost of buying them an installing them?

These questions and more, I will be answering in this short article in order to help you know where to put your money.

Without further ado, let’s begin!

But first of all, in order to understand why dimmers save (or don’t save) electricity and money, we need to answer an important question:

How Do Dimmer Switches Work?

Dimmer switches work on reducing the voltage level that supplies the lighting bulbs, which results in causing them to run at a lower capacity than their rated capacity, and results in causing them to give lower lighting levels (lumens).

Assuming that the utility supplies you with a 110V voltage level, then the dimmer can be used to reduce this voltage only on the lighting circuit to which it is connected.

Are Dimmer Switches Safe?

When implemented properly, dimmer switches can operate safely for many hours in row, but can feel warm to touch, and that’s fine.

However, if you the were overloaded with many lighting bulbs with a total capacity that exceeds the dimmer’s rating, then they might get hot to touch, wear out sooner, and might cause fire hazards.

It is advised to check out the rating of the dimmer switch and see how much total Watts of bulbs you can connect to it, which might differ based on the type of bulbs.

Are Dimmer Switches Safe

Do Dimmer Switches Save Electricity?

Yes, dimmer switches do save electricity by dimming the lights in order to save energy, which is supposed to translate into savings on the electricity bill.

Some people think that dimmer switches draw more power and cost more money, which is not true at all.

Dimming lights saves power while providing a comfortable level of lighting.

Does Dimming Lights Save Money?

Yes, dimming lights saves you money and lowers the electricity bill since it reduces the energy consumption that is used by the dimmed light bulbs.

How Much Money Can You Save with Dimmers?

The amount you save on electric bill depends on the original consumption of the light bulbs, their number, how low you dim the lights with the dimmer switch, for how long you keep the lighting dimmed, and on the electricity rates.

And the original consumption of the light bulbs depends on their size (rating in Watts), which depends on the amount of illumination you want and the type of the bulb (halogen, incandescent, LED, CFL, …etc.)

We will take two examples, one with the traditional incandescent bulbs that consume a lot of energy, and one with the LED bulbs, the most efficient bulbs so far.

Savings from dimming incandescent bulbs:

To take a simple example and estimate the savings, let’s assume that in a certain room you have one incandescent lamp of 150W rating.

How Much Money Dimmers Save

First, we have to calculate how much electricity the dimmer saves.

Let’s assume that you use this light bulb for one hour a day, which means that it consumes around 0.15 kWh per day.

For a complete month, that’s around 4.5 kWh per month.

If you dim this bulb into half of its consumption, 75W, then it consumes around 0.075 kWh per day.

Multiply that by 30 days a month, and the total consumption would be around 2.25 kWh per month.

That means that you reduce the consumption of electric energy by around 4.5 – 2.25 = 2.25 kWh per month, just by dimming this one light bulb into 50% of its power capacity.

To translate that into money, let’s assume that the utility charges you around 20 cents ($0.2) per kWh consumed.

This means that you save around 2.25 X 0.2 = $0.45 per month.

And within one year, this means that you save 12 X 0.45 = $5.4 per year.

This is assuming that you use the dimmer switch to dim one 150W light bulb into half of its power consumption for one hour per day.

If you have three 150W bulbs on the same dimmer switch, then the savings would be 3 X 5.4 = $16.2 per year.

And if you turn the lights on for 2 hours a day, this means that the savings on dimming one 150W bulb would be $10.8 per year, and on three bulbs $32.4 per year.

And if you use dimmers for more than one place or room, then the savings would be more.

Now these calculations all are based on using 150W incandescent lamps for lighting.

Savings from dimming incandescent bulbs:

Let’s assume that you are using LED bulbs instead, which are highly efficient that the 19W LED bulb would give the same lighting amount of a 150W incandescent lamp.

Based on dimming one 19W LED bulb for one hour a day, the energy savings would be at the end of the month around 0.019 X 0.5 X 30 = 0.285 kWh per month.

And for a year, 0.285 X 12 = 3.48 kWh.

At the same rate of $0.2/kWh, then you save 0.2 X 3.48 = $0.684/year.

In case that you use it for two hours a day, then the savings would be around $1.4 per year.

And if you use the same dimmer on three 19W LED bulbs, which you dim for two hours a day, then you save around $4.2 per year.

The real question is:

Are Dimmer Switches Worth it?

Taking the most conservative example of dimming one 150W bulb for one hour per day, which results in saving $5.4 per year, and assuming that you are using the TOPGREENER Dimmer Switch that costs around $10 per unit, then you can get back your money within two years, and then save $5.4 per year afterwards.

And for two hours of operation per day, you can get back your money at the end of year one.

And in case that you installed the switch on a circuit that contains three 150W bulbs that you turn on for two hours per day, then you get back your money within four months.

And when using the same dimmer switch for LED bulbs, and based on the example of one 19W LED bulb that operates for one hour a day, then it takes around 15 years to get your money back.

In case that you use it for two hours a day, then would need around 7 years to get your money back.

And if you use the same dimmer on three 19W LED bulbs, which you dim for two hours a day, then you get your money back in around two years.

And for CFL (compact fluorescent lamp) bulbs, which are more energy efficient than incandescent lamps, but not as efficient as LED bulbs, the numbers would average in the middle of the range between the numbers of dimming incandescent and LED bulbs in the examples above.

Based on the conservative examples above, lighting dimmer switches are worth the investment, especially when used to dim incandescent or CFL bulbs regardless of their numbers, and even with LED bulbs if you have many of them installed on the same circuit, or even one of them, but you turn it on for long hours every day.

Dimmable Light Bulbs

Dimmable LED Bulbs

LED bulbs use less energy and are the most efficient type of lighting bulbs out there, and many of them are not manufactured to be dimmable, but rather, work based on on/off scenarios.

However, many manufacturers now offer dimmable LED light bulbs, which could be useful and money saving in case if you keep them on for long hours, or in case that you have many LED bulbs connected to the same circuit.

Check out the description of an LED bulb before you buy it in order to make sure that it is of the dimmable type.

Dimmable LED Bulbs Save Electricity

Dimmable CFL Bulbs

Originally known as energy efficient dimmable light bulbs, or energy saving dimmable light bulbs, are fluorescent bulbs that can be dimmed.

Originally, fluorescent bulbs cannot be dimmed due to the mechanism that operates them, which requires the voltage to not drop below a certain level.

However, many manufacturers have now developed dimmable CFL bulbs that you can control through a dimmer switch.

Like it is with LED bulbs, emember to check out the packaging or the description of a CFL bulb in order to know if it was dimmable before you buy it.

Dimmable CFL Bulbs Save Energy

Dimmable Halogen Bulbs

Halogen bulbs can be dimmed in order to save energy and money if the transformer in their fixtures allows for dimming the halogen lights.

Most commercially available halogen fixtures are not designed to be suitable for dimming lights, but a qualified electrician could be able to replace the existing transformer with a dimmable one.

Dimmable Halogen Lights Save Money

Incandescent Bulbs

These are the traditional bulbs that consume a lot of energy compared to LED and CFL bulbs for example, and therefore, it is more worth to install a dimmer if you already have them installed.

A Note to Consider When Installing a Lighting Dimmer

Some types of bulbs might not be dimmable like some LED or CFL bulbs, and some halogen lighting fixtures don’t come with a dimmable transformer inside them, so, you better check out the description of any bulb or fixture you want to buy for dimming purposes.

And if you already have these bulbs installed, you better check the writing on them, their packaging, or the manufacturer’s website for any details on this matter.

Also, some dimmer switches might not be suitable for all kinds of bulbs such as LED or CFL bulbs, and you better check their details to see if they were compatible with the lighting bulbs you have, or intend to add, before buying them.

Choosing a Dimmer Switch to Save

And remember to check the details of each dimmer in order to see how much Wattage you can connect to it, which differs based on the type of bulbs even for the same dimmer switch.


Dimmer switches save electricity and money when used for dimming lights in order to save energy, and they can help lower your electricity bill when used properly, and all while still providing comfortable lighting levels.

Consider getting dimmer switches that are compatible with the type of bulbs you have, or you intend to install, and make sure that the bulbs are of the dimmable type, and follow the manufacturer’s recommendations for the number and size of bulbs to be connected to each dimmer switch.

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