Are fluorescent lights more energy efficient?

Comparing Fluorescent lights with Incandescent bulbs

How Standard Incandescent Light Bulbs Work

A  regular standard light bulb is also known as an “incandescent” light bulb. This type of light bulb has a narrow, thin tungsten filament that sets in a glass bulb. They are typically measured watts as in “60 watt,” or “100 watt” etc. The concept is very elementary. Electricity is run through the filament and since the filament is so small, it provides enough resistance to the electricity, that the resistance turns electrical energy into heat. The heat is enough to make the filament glow white hot, and the glowing hot portion is what we see as the light.  The term incandesce comes from the “glowing because of heat”.

The Problem With Incandescent Bulbs

The problem with incandescent light bulbs is that the heat wastes a lot of electricity. Heat is not light, and since the purpose of the light bulb is to provide light, all of the energy spent creating heat is a waste. Incandescent bulbs are therefore very inefficient. They produce perhaps 15 lumens per watt of input power. That is not effective.

And, what about fluorescent lights?

A fluorescent bulb has a completely different way to produce light, without heating up an element like the incandescent. There are basic electrodes at each end of a fluorescent light bulb which is more like a tube, and a gas containing a mix of argon and mercury vapor that is sealed inside the tube. A stream of electrons in delivered through the gas from each electrode to the other. Those electrons continue to bump into the mercury atoms and excite them. As the mercury atoms move from the excited state down to the unexcited state, they emit ultraviolet photons. These photons hit the phosphor coating that is on the inside of each fluorescent tube, and then the phosphor creates light that you can see. It sounds complicated, so lets go through it again in slow motion:

There is a stream of electrons flowing between the electrodes at both ends of the fluorescent bulb. The electrons interact with mercury vapor atoms floating inside the bulb.

fluorescent lights

The mercury atoms become excited, and when they return to an unexcited state they release photons of light in the ultraviolet region of the spectrum. These ultraviolet photons collide with the phosphor coating the inside of the bulb, and the phosphor creates visible light.

So, are fluorescent lights more energy efficient?

Yes! The phosphor fluoresces to produce light and than means that Fluorescent lights produces less heat, so it is much more efficient. A fluorescent bulb can produce between 50 and 100 lumens (light) per watt of energy used. This obviously makes fluorescent lights / bulbs approximately 4 to 6 times more energy efficient than the counterpart – the incandescent bulbs. That also is the reason that you can go buy a 13 watt fluorescent bulb that produces just about the same amount of lumens (light) as a 60-watt standard ‘incandescent’ bulb.

Compact fluorescent lights

You know those curly-q compact fluorescent lights are just like their big brothers, the long fluorescent light tube, but put together in such a way that the tube wraps around itself and then adapts to a normal light bulb fixture base. This means that in a light fixture or lamp that normally uses and incandescent bulb you can now use “compact fluorescent lights”.

compact fluorescent lights


Best Uses for Fluorescent lights

There are many applications for fluorescent lights. Uses include office buildings, industrial uses and other places where the lights are not frequently turned off or on. Many homeowners have found that the best places for them to use the tube style fluorescent lights are in the garage or basement.