Low Energy LED Lighting


As far as energy use is concerned, LED lighting is one of the most efficient light sources. If you want to improve your ‘green’ credentials then this is likely to be a good way.

However, LED lighting isn’t always the best in terms of cost. We’ll come back to this point later.

Why are LEDs so energy efficient?

Compared to incandescent lamps (with a filament) they convert much more power in to light, and much less is wasted as heat. Then, of that light, most of it is within the visible spectrum. As a generalisation, incandescent lamps turn around 20% of the electricity in to light and the rest in to heat. Of that 20%, we can’t see all of the light. Some is ultra-violet and some infra-red.

LED lights can be manufactured to emit certain light, for specific tasks. So energy isn’t wasted.

Compared to fluorescent lights, the efficiency savings are not as large, but they can still be sizeable.

A change to low energy LED lighting isn’t always quite as easy as swapping one light bulb for another. But, as long as you go in to the change with your eyes open, then it can be usually be achieved.

Here are a few points to be aware of:

Be wary of product claims that one LED product is a direct replacement for traditional lamp. They very rarely are. There is a different amount of light, and the light is more directional than the lamps they replace.

Be sceptical of the amount of light (lumens) an LED claims to emit. A lot of LED lamp companies are currently under investigation by the National Measurement Office because of the number of LED lights which don’t live up to the manufacturers claims of performance and life.

Talking of ‘LED lamp life’: Testing one lamp in situ does not confirm it’s suitability for an area. All LED lights gradually get dimmer over their life, and installing one to test in situ does not give you any information about the rate of the lumen depreciation. Once a LED lamp has been tested for 6,000 hours, then it is widely agreed among industry experts that we are able to predict the lumen depreciation. The information you are looking for is LM-80 which specifies the testing procedures up to 6,000 hours and TM-21 which is the method used to calculate the predicted life (before the lumens fall to certain percentage of the original output).

Dimming of LEDs. This can be done effectively, provided it is planned from the start. Factors which influence the quality of the LED dimming are: The LED lamps, the drivers/power supplies, how much electrical load (power) will the circuit use, and how dim do you need the lights to dim to. One option is to test various products together on a ‘trial and error’ basis. The other is involve someone who knows what they are doing and get it right first time.

And last, but certainly not least, lighting is all about using the right light in the right place. LEDs are great, but they are not suitable as a replacement for all lamps yet. Just because there is an LED version available, it doesn’t mean it will do the job required of it.

Assuming that we do find you a suitable LED replacement light (and in most circumstances we can), you will enjoy other benefits than it’s low energy properties:

The long lamp life reduces the time spent changing blown bulbs, and the cost and time to procure bulbs.

LED lights run much cooler, reducing damage to light fittings, air-conditioning costs in the summer and the amount of ‘soot’ which can be deposited on walls and ceilings.

We don’t want to put anyone off switching to low energy LED lighting. But we do want to make sure that when you make an investment in low energy LED lights you invest wisely. Imagine spending money on a load of LED lights, to discover that 9 months down the line you need to do it all over again…

If you would like to discuss your project with us, we’d love to hear about it and help.