Do Dimmer Switches Save Electricity? [A Quick Guide]

dimmed lights

You may be thinking about installing dimmer switches in your home to save on your electricity bills, but will dimmer switches actually help do this?

In this article, we’ll look at what dimmer switches are, how they work, and lastly we’ll look at if dimmer switches will actually help you to save money on your energy bills.

What are Dimmer Switches?

A dimmer switch is a convenient and energy-efficient way to control the intensity of the lighting in your home.

Phillips Hue dimmer switch

They allow you to easily adjust the light levels to suit your needs, whether you want a brighter light for tasks or a softer, more relaxing light for relaxation in the evenings.

How do Dimmer Switches Work?

Dimmer switches work by controlling the amount of power that is delivered to a light bulb.

Whenever you turn on a light fixture in your home (like one of our pendant lights), electricity flows from the power source - supplied by the national grid - through the light fixture's wiring, and into the light bulb. The light bulb then converts this electrical energy into light energy, as well as some heat energy.

This heat energy however is just a by-product - in an ideal world 100% of the electrical energy would be converted to light energy, but in practice this isn't possible, and some always gets converted into heat, hence why bulbs get hot when in use)

A dimmer switch works by interrupting this flow of electricity and reducing the amount of power that is delivered to the light bulb. This is typically done by using a small electronic component called a triac, which acts as a switch that can be turned on and off rapidly.

triac dimmer switch

When you turn the dimmer switch to a lower setting, the triac begins to turn on and off at a rapid rate. This creates a pulse-width modulation (PWM) signal that reduces the amount of power delivered to the light bulb. As a result, the light bulb produces a lower intensity of light.

On the other hand, when you turn the dimmer switch to a higher setting, the triac takes longer to turn on and off, which allows more power to be delivered to the light bulb. This then increases the intensity and brightness of the light.

In short, dimmer switches work by electronically controlling the flow of electricity to the light bulb, which in turn adjusts the intensity and thus the brightness of the light.

Do Dimmer Switches Save Electricity?

Yes, dimmer switches will help save you money on your electricity costs, as, put simply, a dimmed bulb consumes less electricity than a fully-lit bulb.

By lowering the amount of power delivered to your light bulb, a dimmer switch can lower the overall energy consumption of your light fixture. And lowering the energy consumption will result in significant energy savings, which will be particularly significant if you usually have many lights on in your home. 

Here’s an example. Let's say you have a 60 watt light bulb in your bedroom floor lamp that you use for reading in the evening.

If you use that reading lamp for an hour in the evening every day, it will consume 60 watt-hours of electricity. However, by using a dimmer switch to lower the brightness of the light bulb to 50% brightness, it will only consume half the electricity over that same hour, or 30 watt-hours of electricity.

Thus, if your light is consuming 50% of the electricity, you’re saving 50% of the cost compared to if you were not using a dimmer switch.

It's should be noted however that not all light bulbs are compatible with dimmer switches. Incandescent bulbs, for example, work well with dimmer switches, but LED bulbs may not, as they require a constant current to function properly, which a dimmer switch disrupts (see explanation above).

If you're unsure whether your light bulbs are compatible with a dimmer switch, it's best to consult the manufacturer or a licensed electrician.

Closing Thoughts

Overall, dimmer switches are a useful and energy-efficient way to control the lighting in your home. They can help you save electricity (and money in the process!), while also allowing you to create the perfect ambiance for any occasion.