The term GLS stands for “general lighting service.”  The GLS bulb is one of the most recognisable shapes of light bulb; so much so that if you picture a bulb in your mind it will most likely be a GLS type bulb.   It has been the standard choice of bulbs for general use within the home for a very long time.  Whilst the term originally referred to the typical shape for an incandescent bulb this shape of bulb has carried on into LED bulbs as well.  

The GLS shape has a rounded somewhat elongated body that tapers towards the base.  This design has been proven to be highly functional as it offers excellent light distribution and it remains a popular choice for bulbs being made today even in LED.

The Evolution of the GLS Bulb

1. Incandescent GLS 

Incandescent GLS bulbs have a tungsten filament that glows when heated by an electric current.  These bulbs are often cheaper to purchase and they offer a warm white colour of light but are not very energy efficient as they convert only a small percentage of energy into visible light and the rest is wasted as heat.   Incandescent bulbs are also being phased out in the majority of countries due to updated global regulations aiming for better energy efficiency. 

2. Halogen GLS

Halogen GLS bulbs are a more efficient replacement when compared to incandescent bulbs.  They incorporate a small amount of halogen gas in their start up process to light up which helps to recycle any evaporated tungsten back onto the filament.  This process extends the life of the bulb compared to an incandescent as it can run hotter and can also produce a brighter whiter light for a lower wattage than its incandescent counterpart. 

3. LED GLS 

LED bulbs are the latest current standard for energy-efficient bulbs.  LED technology uses a semiconductor diode to convert electricity into light and offers a very bright light for a much lower wattage than halogen or incandescent technology.  LED bulbs come in a variety of wattages and colour temperatures meaning that there are plenty of options available to help you choose a replacement bulb that is as close as possible to the halogen or incandescent bulb that you had previously.

Are GLS Bulbs Energy Efficient?

The shape of the bulb will have little to no effect on the amount of energy used.  To ensure you choose an energy efficient bulb you will need to focus on the technology that bulb has been made from.  LEDs are the current most energy efficient option available as they use up to 90% less energy than an incandescent bulb to produce the same amount of light.