LED - a little history, a few facts

LED Light Development

LED stands for Light Emitting Diode and it is a relatively new, and cost effective way to illuminate the world around us. Go back 10 years, and LED was considered a good idea but not quite ready for full commercial or home use. They were too expensive and they didn’t give out enough illumination to make the cost worthwhile. Now the research and development of this green technology has caught up with expectations, bulb prices have come down and they are giving out enough light to compete with CFLs and incandescent alternatives.

The idea of electroluminescence had been around since the turn of the 20th century but it wasn’t until 1962 that Nick Holonyak, Jr. from the General Electric Company in America developed the first visible (red) LED. It wasn’t then until 1976 that the first ‘high’ brightness LED was invented by T P Pearsall that could be used in fibre optic telecommunications. The discovery of blue LED led to a more effective way to produce white light but the first ones that were produced were expensive and not commercially viable.

In Japan the combination of blue, red and green LEDs were brought together that could produce any colour of light in combination and the scientists who discovered it, Isamu Akasaki, Hiroshi Amano and Shuji Nakamura, received the Nobel Prize for Physics in 2014 for their work. This advance has led to the next generation of LED lightbulbs which can produce a decent amount of light and have a much longer shelf life than incandescent bulbs.

One of the first buildings to go entirely LED was the Sentry

Equipment Corporation in Wisconsin in 2008 and a year later a Christmas tree in Finland was lit by 720, 2 watt bulbs. By 2010, many businesses were beginning to switch to LED lighting with the advantage that it was more cost effective over time and cut down on energy bills.

Less Power

LED bulbs use less power than any other makes. According to many manufacturers, LED offers a 90% saving over the old fashioned incandescent bulbs. And they can be about a third more efficient than the CFL bulbs that we were all encouraged to use to be greener. For instance, a 25 w incandescent bulb equates to a 6 watt CFL and a 4 watt LED bulb.

Longer Lasting

The major benefit of LED bulbs is that they last significantly longer than the old incandescent bulbs. They have great thermal management properties and a well manufactured bulb should last around 50,000 hours compared to an incandescent bulb that cold last 1,500 hours. This major difference presents a real cost saving for those who switch to LED lighting and is even better than CFL bulbs.

Better Brightness

It used to be the problem with LED bulbs that they couldn’t provide enough light. It’s a tribute to the research and development of this technology that in the last couple of years this problem has been largely solved. LED bulbs now compare favourably with other light sources and, unlike CFL lights, they provide full light immediately rather than taking time to ‘warm up’.

Comparable Range

The other thing that has changed with LED bulbs is the range of different ones available. From just a couple of designs you can now get candles, spotlights, golf balls, tube, reflector and GLS. There are also the fittings that you would expect including bayonet and screw which means that offices and households will be able to find a bulb to fit their needs.

Safer Technology

The problem with Compact Florescent Lamps is they contain mercury and are therefore more problematic when it comes to disposal. LED bulbs are entirely safe and they also do not give out high temperatures when lit and are therefore easier to handle than a hot bulb. You also don’t get the glass enclosures that you find with other bulbs and you don’t have to worry about things like broken glass.

LED Colour

The light emitted by normal LED bulbs comes in three different varieties which are: Warm white which is used in most homes and is similar to current halogen bulbs. Cool white is a similar colour to fluorescent tubes such as those you find in shops and offices. Daylight colour is a stark white light and has a hint of blue to it, used mainly for highlighting real colour.

LED terms

SMD stands for Surface Mounted Device and they are one of the new generation of LED lighting. Bulbs contain SMD chips that add the extra brightness that has made it a more viable choice for both households and offices.

COB stands for Chip on Board which are another new generation of LED technology and provides a denser amount of light compared to SMD and great optics because you get a consistent beam of controlled light. It provides a better lumen to watt ratio which means that they are considered highly efficient.

The Future of LED Lighting

Many experts believe that the introduction of LED lighting is one of the most important developments in recent times, allowing us to have a low energy lighting solution that can be used in a wide range of situations. As performance improves, more and more homes and businesses will begin to have it installed and the cost will continue to fall.

source: renewableenergyhub.co.uk