LED (Light Emitting Diodes) lights

LED Lighting are they better? A comparison with traditional lights:

Traditional light bulbs (CFL & Incandescent) pass electricity through a filament that creates heat and light. However, the heat is never used and therefore this energy is lost or wasted. LED lights use a semiconductor material which can emit a lot more light for the same amount of electricity (or conversely, the same amount of light using a lot less electricity). By producing less heat there is also less energy wasted in the process.

Additionally, LED lights are a very rigid product, with very few moving parts and thus have a very long life expectancy. The Energy Saving Trust found that the average lifespan for an LED light will be some 15 years. They are also suited for conditions where they are switched on and off frequently as this has no effect on the inner workings of the lights.

Two criticisms of LED lighting have been that they are very high in cost and that the technology produced a very narrow light beam. However, whilst costs are still relatively high when compared to traditional light bulbs, especially the initial installation cost, they are now much more efficient and easily pay for themselves over the life of the bulb. Furthermore the technology has progressed significantly, using clustering to produce more light and diffuser lenses to spread the light over a wider area, and the light emitted is just as good as traditional light fittings.

When comparing LED’s to other lights we need to measure how much light is emitted by each product. To do this we use a measure called “Lumens” which measures the flow of light. The number of Lumens emitted will tell us how much light is emitted by each light source – the greater the number of Lumens, the brighter the light. For the 3 different types of light on the market we have:

Light Output

LEDs

CFLs

Incandescent

Lumens

Watts

Watts

Watts

450

4 – 5

8 – 12

40

300 – 900

6 – 8

13 – 18

60

1100 – 1300

9 – 13

18 – 22

75

1600 – 1800

16 – 20

23 – 30

100

2600 – 2800

25 – 28

30 – 55

150

 

Thus, if you wanted to replace a 40Watt incandescent bulb with an LED, you would want an LED of between 4 and 5 Watts to get the same amount of light emitted. Other characteristics of LED lights (compared to others) include:

LEDs

CFLs

Incandescent

Average Lifespan (hours)

20,000

10,000

1,250

Heat Emitted

Low

Medium

High

Frequent On/Off Switching

No Effect

Shortens   Lifespan

Shortens   Lifespan

Turns on instantly

Yes

No

Yes

Durability

Very   Durable

Fragile

Fragile

 

Using these statistics, we can see the performance of each type of bulb as being:

LEDs

CFLs

Incandescent

Cost

£30

£5

£1

Watt

5

10

40

Lumens

450

450

450

Average Lifespan (hours)

30,000

10,000

1,250

No bulbs needed for 30,000hrs

1

3

24

Electricity cost (kWh)

£0.12

£0.12

£0.12

Amount of elec over 30,000hrs (kWh)

150

300

1200

Cost of Elec over life

£18.00

£36.00

£144.00

Cost of bulbs over 30,000hrs

£30

£15

£24

Cost of bulbs & elec over   30,000hrs

£48.00

£51.00

£168.00

 

Here you can see that LEDs are comparable in cost to CFLs and much cheaper over their lifespan when compared to traditional incandescent light bulbs.

Example:

The average lifespan of an LED bulb is 30,000 hours versus just 1,250 for a traditional incandescent bulb. This means that over the life of the LED bulb (30,000 hours of use) you will need to replace the traditional bulb some 24 times!

Thus, whilst an LED bulb costs £30, over the lifespan of this bulb you will need to spend £24 on traditional bulbs.

Meanwhile, because the LED bulb uses less electricity (5 Watts to achieve 450 Lumens compared to 40 Watts for the traditional bulb), there will be lower running costs associated. In our example where electricity costs £0.12 per kWh, the LED bulb will cost just £18 to run versus £144 for the traditional bulb!

Thus, over 30,000 hours of use, the LED will cost in total (purchase and running costs) £48 versus £168 for the traditional bulbs, giving a saving of £120 – or a Return on Investment of 250%!

LED Lights in practice:

LED lights come in all shapes and forms. You can get down lights, lamp bulbs and strip lighting. Bulbs and down lights should fix into existing fittings, however, if they do not you will need to replace the fittings.

led

Energy Efficient Lighting Controls:

To reduce energy consumption of lighting you can install dimmers. Please note that not all LED bulbs are suitable for dimmers, and those that are can be as much as 40% more expensive than those that are not. That said, the energy savings will be greater.

Other controls that can be installed to reduce energy consumption include presence sensors and detectors. These will automatically turn off lights when the sensor views the room as being empty and are largely in use for bathrooms and the like. If you would like to find out more on being energy efficient or are thinking about buying LED lighting then give us a call on 01223852267 or drop us a line via our ask the experts tab and contact us page

Independent Studies:

Finally, Just in case you were still not convinced, the Energy Saving Trust has conducted a test on LED bulbs in practice and the findings of this report suggest that: http://www.energysavingtrust.org.uk/Publications2/Energy-efficiency/Lit-Up-an-LED-lighting-field-trial

Installed 4,250 LED light fittings in over 35 sites across the UK.

Findings:

1. Lighting levels increased in both phases of the field trial. In phase 1, the increase was 100 per cent. In phase 2, it was 57 per cent.

2. When LED performance is normalised to account for increased light levels it is calculated that the new LED lighting in the sites will generate ongoing savings in excess of 3,372,058kWh per year across both project phases. This is equivalent to the energy needed to light 5,788 typical UK homes for a year.

3. The LED installations increased the “colour temperature” in buildings, giving a brighter, whiter light much closer to that of daylight. (“Colour temperature” is a measure of how “warm” or “cold” a light is. The old lighting systems in the sites had an average colour temperature of 3,344 Kelvin across both phases, which is close to the “warm white” that is typical of fluorescent lighting. The LED lighting typically raised the colour temperature to 5,086 Kelvin.)

4. The brighter, whiter light enhanced the ambience in most of the sites, as can be seen by the photographs in the appendix.

5. Colour rendering improved across most of the sites. This means that colours appear as they would under natural lighting conditions.

6. LEDs in the trial demonstrated an excellent sustained performance. Lighting levels, when measured after about six months of use, maintained an average performance of 93.6 per cent.

7. Using normalised figures, both phases of the trial suggested that return on investment could be around 2 years.