TechReport (UK)

LED Bulbs - The Background

‘Incandescent’ Light bulbs (the ones with the clearly visible glowing ‘filament’ in the glass envelope) have been around in a barely changed form since back in the days of the great inventors Swan and Edison back in the 19th Century.

They have served us well in bringing light to virtually every dark place in the Western World for all these years, but their use does have a number of drawbacks, with the biggest by far being their incredibly inefficient use of electricity.

The introduction of fluorescent tubes from the 1930s led to the large scale replacement of incandescent lighting in commercial buildings (but not in domestic applications, where their efficiency benefits were offset by their size / unattractive appearance).

New technology led to the ‘compact’ fluorescent light (CFL), which started to become popular in houses from the 1990s.

LED lighting started out as a cheap and simple way of providing indicators in electronic equipment, but enormous improvements in efficiency and the invention of the Blue LED (which when added to the long-standing Red and Green LEDs gave us the ability to create a White LED) meant that LEDs could now provide high quality / high brightness lighting.

LED technology by its very nature is highly reliable, long-life, extremely efficient, can provide a whole gamut of colours, does not contain any harmful chemicals, easily direct able (so no light wasted going into the back of a fitting) and can be fashioned into all manner of containers (from the very large, such as street lighting, to the very small, such as back-lighting for LCD TVs).

The question many people are asking is ‘Would it be worth replacing my incandescent / halogen lighting with LEDs?’

According to the Department of Energy and Climate Change, domestic electricity usage for lighting purposes decreased by 31% over the period 1990 to 2014, moving it from the 2nd greatest to the 5th greatest consumer of electricity, behind Consumer Electronics, ‘Wet’ appliances (Washing machines, Dishwashers), Cooking and ‘Cold appliances (Refrigerators, Freezers):

This reduction in energy usage has been attributed to a combination of the phasing out of higher powered incandescent bulbs, but more especially to the replacement of such bulbs by more efficient technologies (as above).

So what do you need to know about replacing conventional bulbs (normal incandescent or halogen bulbs) with LED bulbs? There follows a summary of the major considerations in undertaking such an exercise.

Caution:     For any electrical work other than direct plug-in replacement, please be aware of the risks and the regulations that apply.

In the UK, private individuals can undertake basic work themselves, such as replacing lights, sockets and fittings or adding single lights / power-points to an existing circuit in locations not close to water sources (i.e. not in kitchens, bathrooms or in a garden). In any other cases, it is a legal requirement that all work must be either undertaken by an approved electrical contractor, or has to be separately verified by the local authority.

As a general statement, any electrical work potentially involving mains electricity should only be undertaken by those with a good understanding of household electrical systems – be careful!

Next: LED Bulbs - What do I need to consider?

Back to Technology Reports