Various types of light bulbs surround an LED bulb with the text" energy efficiency" transposed above the image

Are you wondering what light bulb type is the least energy-efficient? With energy bills rising, it’s essential to know which bulbs use the most energy and which are more cost-effective.

In this post, we’ll explore the range of energy-efficient light bulbs so you can find one that best meets your needs.

So, let’s get started!

Which Light Bulb Is the Least Energy-Efficient?

Incandescent light bulbs are the least energy-efficient light bulb type. They consist of a metal filament inside a glass bulb that must be heated by electricity to produce light. This heat has significant waste energy, and only 2% of electricity is used to generate light output, while 98% is heat waste. 

By replacing incandescent bulbs with more energy-efficient options, you can save a lot of money over the long run.

Closeup on a homeowner's arms who's swapping an incandescent bulb for a LED light bulb in a hanging ceiling fixture
Swapping to a new LED bulb can save you 90% on your energy bill!

Efficiency Metrics of Different Types of Light Bulbs

Lighting TechnologyEfficiency MetricsRating
Incandescent10 lumens/watt Poor 
Halogen12 lumens/wattPoor 
Compact Fluorescent (CFL)50 lumens/wattModerate 
Metal Halide75 lumens/wattModerate 
High-Intensity Discharge (HID)95 lumens/wattHigh 
Light Emitting Diode (LED)110 lumens/wattHighest 

Bulb Types With the Worst Energy Efficiency

As energy costs continue to rise, it pays to be mindful of the light bulbs you use in your home. Knowing which bulbs require the most electricity can help you make informed decisions when shopping for replacements. 

Let’s look at the least energy-efficient light bulb types on the market today. 

Incandescent Bulbs 

Incandescent bulbs are the type of bulb traditionally used in home lighting throughout history. While they have existed for over a hundred years, their design has remained relatively unchanged for almost as long, making them among the least energy-efficient light sources available. 

A glowing A19 light bulb hanging from a fixture trasnsposed against a dark background

On average, you can expect to pay much more for electricity if you opt for an incandescent over LED or CFL bulbs. Additionally, due to their short lifespan (1,000-2,000 hours) compared with alternative options (20,000+ hours), incandescents need to be replaced much more frequently than their modern counterparts, further driving up costs.

Halogen Bulbs 

Halogen bulbs appear similar to standard incandescents visually but contain a different kind of filament and use halogen gas instead of argon as a filler material. Halogens generally produce a brighter light than traditional bulbs but typically only last around 2,500-3,500 hours (less than half that of LEDs or CFLs) while consuming roughly the same amount of power per hour. 

Not only do they cost more upfront, but their shorter lifespan means you’ll likely need to make multiple trips back to the store before finding a more reliable bulb, such as LED and CFL alternatives.

a closeup of a halogen bulb with a blue background

High-Intensity Discharge (HID) Bulbs

High-intensity discharge (HID) bulbs are some of the least energy-efficient light bulb types. They produce high amounts of light but consume large amounts of electricity. 

However, HID bulbs can be used for many applications and are especially well-suited for outdoor lighting.

HID bulbs offer several benefits compared to other types of lighting, including: 

  • High illumination levels
  • Their long life span is ideal for specific applications
  • More efficiency than incandescent and CFL bulbs
  • They’re cheaper to operate in the long run
  • Their brightness is easily adjusted by changing the voltage

However, there are also some drawbacks associated with HID lights, including:

  • They require specialized ballasts and fixtures that may not always be available
  • The initial cost is higher than other types of lighting
  • Due to their intense illumination levels, they can cause glare and excessive brightness if improperly installed
  • They don’t perform well in colder temperatures and must be turned off outdoors during winter

High-intensity discharge bulbs have their place in specific applications where their power consumption is offset by the benefit they bring. But these lights are far from being the most energy-efficient lighting option today.

Compact Fluorescent Lamp (CFL) Bulbs 

Compact fluorescent lamp (CFL) bulbs are the most popular energy-saving alternatives to incandescent, and for a good reason. CFLs significantly increase energy efficiency over traditional bulbs, consuming around 75% less power while lasting up to 15 times as long.

Additionally, with their lower purchase price, CFLs can often pay for themselves in energy savings within a few months of use. The only downside to these bulbs is their slower warm-up time, which can take up to three minutes before reaching full brightness. 

A CFL bulb stacked on a pile of cash and coins, indicating the savings provided by using this energy-efficient light bulb

Still, overall, CFLs are a solid option for those looking to attenuate their home’s electricity consumption without sacrificing quality.

Light-Emitting Diode (LED) Bulbs

Light-emitting diodes (LED) are the most long-lasting and energy-efficient light bulbs available today, lasting up to 25 times as long as traditional incandescent bulbs. Though they may cost more upfront, their low power consumption and long lifespan allow them to pay for themselves in as little as one year of use. 

In addition to their energy efficiency, LED bulbs are highly durable and can withstand vast temperature fluctuations. They also come in various shapes, styles, and colors. The only potential drawback is they don’t work with dimmer switches, often preferred for more intimate lighting situations. 

4 old 60 watt light bulbs in the back of one new led A19 light bulb in the front with orange background

Ultimately, LED bulbs are the clear choice for those looking to invest in a quality, long-lasting light source that can help reduce their electricity bill. And with the ever-growing availability of LED bulbs, there’s never been a better time to switch and save energy today. 

Why Energy Efficiency Matters When Choosing a Light Bulb

These days, energy efficiency is one of the most important factors to consider, as it can save you time and money in the long run. 

Some reasons why energy efficiency matters when choosing a light bulb include the following:

  • Lower electric bills energy-efficient light bulbs use less electricity than traditional ones, leading to lower electric bills over time. These bulbs may cost more upfront than incandescents, but their savings on electricity will likely make up for it in the end.
  • Longer life span energy-efficient light bulbs last longer than other bulbs—up to 20 years longer! The energy efficiency of these bulbs also helps them get through more power outages without breaking or burning out.
An energy-efficient LED light bulb is screwed into a hanging socket
  • Eco-friendliness – one of the most significant benefits of using energy-efficient light bulbs is they’re far better for the environment than traditional incandescent lights. Because they use less electricity, they create fewer emissions, which helps reduce air pollution and save resources. And since they last longer, there’s less waste from replacing burnt-out bulbs regularly.
  • Versatility – energy-efficient light bulbs come in different sizes and shapes to fit any space, and they also come in shades of white that mimic natural outdoor lighting. This variety allows you to create the perfect atmosphere indoors without worrying about eye strain or headaches due to harsh lighting fixtures.

Researching and selecting an energy-efficient light bulb that matches your budget and fits your lifestyle is vital. This way, you’ll be sure to benefit from its many advantages.

How To Calculate the Efficiency of a Light Bulb

Here’s what you need to know to calculate the efficiency of a light bulb.

Understanding Lumens and Watts

The two critical measurements for light bulbs are lumens and watts, which both play a role in determining how efficient a particular light bulb is. 

Lumens measure brightness—the higher the number, the brighter the bulb. On the other hand, watts refers to the amount of electricity consumed by a lightbulb.

Using Watt Ratings

By comparing watt ratings between different bulbs, you can know which ones are more energy-efficient than others. 

For example, suppose one type of bulb uses 40 watts while a similar product uses 60 watts. In that case, it’s probably safe to presume that the first one is more energy-efficient and, therefore, better for your budget (and our environment).

Calculating Efficacy

Once you’ve figured out how many lumens each type of bulb uses per watt (this number is called efficacy), you can calculate its overall efficiency. 

To do this, simply divide the lumen rating by the watt rating and multiply by 100. This figure will tell you how much brightness per watt each light bulb offers so that you can easily compare similar products.

Knowing how to calculate efficacy will help you pick an energy-efficient lighting option and ensure your money goes further in savings over time. Plus, it’s good for our planet!

Final Thoughts

As energy-efficient light bulbs become more popular, it’s essential to understand their benefits. 

These bulbs can save you money on electricity bills and last longer than traditional incandescents. Moreover, they’re eco-friendly due to their lower emissions output and come in various shapes and sizes for all your energy-efficient lighting needs. 


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