How Much Electricity Do Lights Use? Get the Facts Here

Ian Mutuli
Updated on
Ian Mutuli

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
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In our modern world, lighting plays an essential role in our daily lives, providing illumination and enabling us to carry out various activities easily, regardless of the time of day. However, have you ever wondered, “How much electricity do lights use?” Whether it’s the gentle glow of a bedside lamp or the brilliant radiance of stadium floodlights, lighting fixtures contribute to a significant portion of our overall energy usage.

For most individuals, lighting remains one of the largest energy consumers in the home, accounting for up to 15% of a typical household’s electricity bill or more.

In this article, we will delve into the factors influencing the electricity usage of lights, examine different types of lighting technologies, and provide insights into how you can reduce your home’s energy usage while enjoying adequate illumination.

By understanding our energy costs, we can contribute to a more sustainable future and make informed choices about lighting our homes, workplaces, and public spaces.

What Determines the Electricity a Light Bulb Uses?

Several factors affect how much energy a light bulb will consume, namely:

Light Bulb Electricity Usage

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1. The Type of Light Bulb 

It is the most essential factor determining how much energy a light uses. Different bulbs have different energy use efficiencies. Incandescent lights are the least efficient light bulb and use up to 10 times more power than an LED bulb. A CFL bulb, on the other hand, is more energy-efficient than an incandescent light bulb but is still less efficient than an LED light bulb.

2. The Wattage of the Bulb 

A 60-watt incandescent bulb has twice the energy usage as a 30-watt incandescent bulb. An LED light bulb will consume far less energy than an incandescent bulb, even at the same wattage. For example, a 60-watt LED bulb has about the same electricity consumption as a 10-watt incandescent bulb.

3. The Duration of Light Bulb Use

The electricity a bulb uses also depends on how long they are on. A bulb that’s turned on 10 hours a day will use more electricity than one that’s only on for 2 hours.

4. The Amount of Heat Loss

One primary source of energy inefficiency in a traditional incandescent light bulb and lights is heat loss. As the bulb emits heat, more energy is transmitted, so the cooler a light bulb is, the more efficient it is.

A 75-watt incandescent bulb can be a scorching 335 degrees, while an equivalent 15-watt CFL would only be 131 degrees. But again, the LED lighting bulb wins out: the equivalent 10-watt bulb would only heat to 87 degrees.

So, How Much Electricity Does a Light Bulb Use?

The primary thing you’ll need to know to determine the cost of running your specific light bulb is the price of electricity per kWh in your area. Next, you need to find out the bulb’s wattage.

Let’s take a look at the individual light bulb wattages for the three main types of bulbs available to consumers:

Types of Light Bulbs

Image Credits: lumennow.org

1. Incandescent Light Bulbs 

These are the typical, old-fashioned light bulbs. They are also the oldest and least efficient type of light bulb and typically only last a short time. They work by heating a filament until it glows. This inefficient process results in incandescent lights only converting about 10% of their electricity into light.

Higher energy bulbs, such as incandescent (up to 100W) and halogen, are being phased out. However, you may still have some of them working in your home.

2. Compact Fluorescent Light Bulbs (CFLs) 

These are the “spiral-y” light bulbs many think of when discussing energy-efficient lighting. They are the most common energy-saving bulb and are more efficient than incandescent ones. They work by using a fluorescent tube to produce light. CFLs typically use 60-80% less energy than an incandescent light bulb, yet they can be up to four times more efficient and last up to 10 times longer. Their wattages range between 6-22W.

3. Light-Emitting Diode (LED) Light Bulbs 

They are the most energy-efficient light bulbs and use the least electricity. An LED bulb emits light when electrons pass through a semiconductor material. LEDs are about five times more energy-efficient than CFLs and can last up to 25 times longer. Their wattages range between 4-18W.

Assuming the average price per kWh of electricity in your area is 34p. If a 100W light bulb uses 0.1kW an hour, ten 100W (incandescent) light bulbs turned on simultaneously would require 1kW, costing 34p every hour.

Swap that for ten 18W LED light bulbs, and the cost is significantly less: 18W is 0.018kW x 10 = 0.18kW, so every hour costs just over 6p.

How Can I Cut My Lighting Costs?

Aside from the methods discussed, here are some additional energy savings tips for reducing the electric bill on your lighting:

Cutting Lighting Costs

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1. Switch to Energy-Efficient Bulbs

Replace old light bulbs with more efficient models and add them to your home inspection checklist. Traditional incandescent bulbs have a higher power consumption and a shorter lifespan than energy-efficient alternatives such as LED or CFL bulbs. LED light, in particular, is highly energy-efficient, has a longer lifespan, and produces less heat. Although they may have a higher upfront cost, they save money in the long run due to lower energy consumption and reduced frequency of replacements.

2. Install Dimmer Switches or Timers

With dimmer switches, you can adjust the brightness of the light according to your needs, enabling you to use less electricity when full brightness is not required. On the other hand, timers can automatically turn lights on and off at predetermined times, ensuring they are only on when needed. Dimmers can save you up to 30% on your lighting costs.

3. Consider Motion Sensors 

Use motion sensors to turn off lights when they are not in use. It is a great way to save electricity in areas where lights are often left on, such as garages, hallways, or outdoor spaces, by ensuring that lights are only activated when someone is present. It also eliminates the possibility of lights accidentally being left on.

Energy-Saving Features to Consider When Buying a Light Bulb

Energy-Saving Features

1. Smart Connectivity

Smart light bulbs controlled by an app like Hive or Hue open up a new world of other energy bill-saving options. These include setting lights to switch off at sunrise when there’s natural light, turning off all your light bulbs, or even turning off lights in another room that are accidentally left on.

2. Energy Efficiency Rating

A new light bulb is rated from A to G, with A being the most efficient so that you can see the energy efficiency at a glance. The label should also show energy consumption for 1,000 hours (kilowatt hours) of use so you can quickly determine how much it’ll cost to power each one. 

3. Lower Wattage

The lower the light bulb’s wattage, the lower its energy usage. Look for energy-saving bulbs (such as an LED bulb) and light fixtures that provide the brightness you need (lumens measure) with the lowest kWh per unit possible.

The Future of Lighting

The future of lighting is bright. With the development of new technologies, we are shifting towards even more efficient and sustainable light sources. For example, organic light-emitting diodes (OLEDs) are a new light bulb that is even more efficient than LEDs. OLEDs are also very thin and flexible, making them ideal for various applications.

The Future of Lighting

Image Credits: vietnamnet.vn

As these new technologies continue to develop, we can expect even more dramatic reductions in the electricity that lights use. These advancements will lead to significant savings for consumers and businesses and help protect the environment.

Conclusion

The amount of electricity that lights use can significantly impact your electricity bill and the environment. You can save money and help the environment by switching to more efficient light bulbs. 

While energy-saving light bulbs are often more expensive up front, LED lights come in several varieties and usually save you money in electric bills over the long term.

Even if you consider yourself a savvy saver regarding electricity usage, it can’t hurt to do a quick energy audit of your home and ensure you’re using efficient light bulbs wherever possible.

Frequently Asked Questions on How Much Electricity Do Lights Use

1. Do lights use a lot of electricity?

The electricity that lights use depends on the light bulb type, the bulb’s wattage, and how long the bulb is on. Incandescent bulbs are the least efficient type of light bulb and use up to 10 times more energy than LED bulbs. While CFL bulbs are more efficient than incandescent bulbs, they still need to be more efficient than LED bulbs.

2. How much electricity do lights use per day?

The electricity that lights use daily depends on the number of lights in your home, the type of light bulbs you use, and how long you leave the lights on. For example, if you have ten 60 watts incandescent bulbs that you leave on for 8 hours daily, your lights will use about 4800 watt hours (4.8-kilowatt hours) of electricity daily.

3. How much does a light cost in electricity per hour?

The lighting cost per hour of light in electricity depends on the type of light bulb you use and the cost of electricity in your area. For example, if you use a 60 watts incandescent bulb and the cost of electricity in your area is 10 cents per kilowatt-hour (per kWh), then your light will cost about 2 cents per hour to operate.

4. How much electricity does a TV use?

The amount of electricity that a TV uses depends on the size of the TV, the type of TV, and the brightness of the TV. For example, a 55-inch LED TV set to medium brightness will use about 100 watts of electricity per hour.

Ian Mutuli

About the author

Ian Mutuli

Founder and Managing Editor of Archute. He is also a graduate architect from The University of Nairobi, Kenya.
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