Why Is LED The Most Efficient Light Source?

Lighting is essential for everyone since it improves visibility in low-light conditions. Until recently, we cared less about the source of light we used. Today, emphasis is placed on the efficiency of the light sources we use. As such, researchers invest heavily in improving the most efficient lighting source — LED. But why is LED considered efficient lighting? Keep reading to find out.

What is Energy-efficient Lighting?

There are many aspects that are considered when classifying lighting as either efficient or inefficient. One of these aspects is the amount of energy consumed versus the luminous flux or intensity of the light produced. 

Efficient lighting systems are said to have high luminous flux without affecting the level of energy consumed. In other words, the energy in Watts remains the same but the luminous flux is high. In some cases, they consume less energy and produce high light output.

Inefficient lighting consumes the same amount of power or more, but its light intensity is usually quite low. This means that they are consuming more energy and producing less light, thereby making them inefficient.

Apart from the energy consumed and light output, another aspect that indicates the efficiency of a light source is the amount of heat produced. To clarify, all lighting fixtures produce heat that is a result of the heat energy produced as electrical currents flow through.

Energy-efficient lighting systems produce barely any heat while inefficient lights produce up to 90% of heat from the energy they receive. As you can tell, this is bad because it means that your energy bills will be quite high if you are using inefficient lighting. This loss is energy can be avoided if you use energy-efficient lighting such as LED.

How Much Energy is Lost in LED? 

While LED lights are considered highly energy-efficient, they also lose some energy in the lighting process. Specifically, research has shown that LEDs convert over 90% of the energy received into light and the remaining 10% to heat.

In comparison to inefficient lights such as incandescent lights, this loss is negligible. Since more light than heat is produced from the electric current, the amount of electricity in Watts needed is also reduced. Therefore, LEDs save energy and burn more brightly than other types of lights.

The Technology of Energy-efficient LED  

To understand why LED lights are so effective at converting energy into light, we have to also understand the technology behind LED lights.

LED stands for light emitting diode. It is a technology that has evolved quite fast and saturated various industries that require lighting solutions. LEDs are tiny semiconductor devices. In physics, semiconductors are devices that emit light when an electric current passes through them.

LEDs can produce white or multi-colored light. This type of light falls in the low range of the ultraviolet spectrum known as visible light. Still, LED semiconductors can be engineered to produce light that is outside the visible range known as IR LEDs.

LED semiconductors are grown using various chemicals depending on the type of LED. This means each specific color of the LED is manufactured separately. The common elements used to manufacture LED semiconductors include gallium, arsenic, and phosphor. The whole process happens under specific conditions with multiple steps.

Energy Consumption of LED Lights

The amount of electricity consumed by LED luminaires is expressed in Watts. Therefore, if you see a 10-watt bulb, it means that it consumes 10 Watts of power when it is on. Due to the high light intensity of LED bulbs, an LED bulb consuming 10 watts will shine more brightly than another type of light consuming even twice that wattage.

The US Department of Energy reported that LED bulbs are the most efficient light sources. This is because they use up to 75% less energy when compared to other types such as incandescent bulbs. 

In the ENERGY STAR rating system, LEDs lead with the highest rating of A+ or A++. This rating was developed by the U.S. Environmental Protection Agency (EPA) to help consumers like you make informed decisions about the lighting fixtures they use.

Are LED Lights 100% Efficient?  

As we have said severally, the efficiency of light sources is based on the conversion of electric current to light. Typically, in this process, luminaires have to produce heat, which would indicate that they are inefficient.

In this case, for a light source to be considered 100% energy-efficient, it would mean that it does not produce any heat in the process. Therefore, provided that LEDs convert about 10% of their watts to heat, they would not be considered 100% energy efficient.

All in all, LED lights have the best energy conversion efficiency. The value is about 40 – 50%. This means that for every 100 watts, 50 watts is converted to light. Other light sources have an efficiency value of less than 20%. 

Reasons Why LED is the Most Efficient Light Source

Having established that LED light is the most efficient lighting solution in the market, we need to lay out reasons why this is the case. Here are some of the common reasons why;

Produces Unidirectional Light 

When light moves in the same direction, there is less energy waste. LED lights are known to shine light in one direction, hence the term unidirectional. For this reason, there is no need for diffusers and reflectors to focus the light in one direction. This has contributed to much energy savings in terms of energy bills.

Little Heat Released

The amount of heat that is produced by LED lights can be considered negligible in comparison to other luminaires. For this reason, they are considered energy efficient. If LED lights produced as much heat as incandescent lights, they would not be considered energy efficient.

Long Lifespan  

LED semiconductors have a lifespan of about 10 – 15 years, according to research data. This is about 3 – 5 times longer than other luminaires. Within this period, these devices have demonstrated constant light intensity without losing their illumination. This has also been experienced in displays made using LED display technology. 

The lifespan of a luminaire is an aspect that indicates its efficiency. In the case of LED lights, it means that you can use the same LED bulb for over 10 years without needing a replacement. Still, you will need to perform basic LED maintenance practices for you to experience this expected LED lifespan.

Multiple Color Temperature Ranges

What is color temperature

You have probably experienced different shades of light from LED light sources. Some of the common ones are;

  • Warm white
  • Daylight 
  • Cool white

All these colors or shades of light are a result of the color temperatures of the lights. These temperatures then depend on the LED material that the LED chip uses to produce the light as wave particles.

The production of different color temperatures by LED lights is beneficial since it can be used to evoke various moods. For instance, lower temperature produces warmer lights, which can be considered relaxing. High temperatures produce more refreshing and bright light.

Other Reasons to Choose LED Lights

LED lights are efficient for other reasons apart from their energy consumption and savings. Let us explore some of these reasons;

  • They are safe. UV radiation that is produced by LED lights is negligible if any. This means that they are a safer light source. Another safety feature is the lack of heat production which can cause burns or fires.
  • They are cost-effective. The cost-effectiveness of LED lights is based on the principle that you save significantly in energy bills due to the energy efficiency of these bulbs.
  • Highly reliable. Another reason to choose LED lights is their reliability. You will not have to deal with setbacks such as loss of light intensity. 

Energy Consumption of LED Lights vs. Other Types of Lights

Incandescent and CFLs are the other common light sources apart from LEDs. The two are much dated also. Given the period that they were invented, you can expect that they use old technology that is quite ineffective in regard to current concerns of energy use. Let us see how they compare to LED lights.

LED vs Incandescent lights

Incandescent lights produce light by burning a special kind of filament that is enclosed by a glass housing. In most cases, this housing is riddled with an inert gas that stops the bulb from undergoing oxidation.

These types of lights are the most inefficient of all three for various reasons. To start with, incandescent lights produce a lot of heat as the filament burns to produce light. As you can tell, this is a waste of energy that would be otherwise used to produce light.

When you compare incandescent lights to LEDs, you can see the big difference between the two. For one, the energy efficiency value of the LEDs is incomparable to that of incandescent. Moreover, LED lights have more use cases than incandescent lights. Finally, LEDs are more popular and modern than incandescent lights.

LED vs Compact fluorescent lamps (CFLs)

Compact fluorescent lamps are the ‘middle child’ in the common lights trio. In other words, they are more efficient than incandescent but not as efficient as LEDs.

In terms of energy consumption, CFLs have a good performance. They consume 75% less energy than incandescent bulbs. This is almost the same as the energy consumption of LED lights. As such, their energy efficiency is almost on par with LEDs.

The only reason why LEDs are more efficient than CFLs is the process by which light is produced. LED lights produce light in a process called electroluminescence. This process is the reason why LED lights produce less heat because the electrons combine with the electron holes directly.

On the other hand, CFL lights produce light when the mercury tip is excited by electrons. This process can lead to high-energy use and loss, which makes CFLs less efficient than LEDs.


LED lights have been popularized not only for their efficiency but their contribution to the green energy movement. The call for the use of energy-efficient products is meant to caution the general public on safer and cleaner energy products for the betterment of the environment. Therefore, the high efficiency of LED lights is guaranteed to make the world safer for generations to come.

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