Tuesday, December 18, 2012

What are the benefits of LED lighting?

Benefits of LED

LED really is the ideal lighting with all industry forecasts predict that LED lighting will become the dominant technology in a few years to replace all"traditional" light bulbs and fluorescent tubes in the next 20 years.

Energy efficient LED lighting should not be confused with Compact Fluorescent(CFL) light bulbs.

What are the benefits of LED lighting?

---Energy Efficient

LED's key advantage is that it can output the same light as a conventional source for significantly less electrical power.More than 65% energy can be saved by using LED lighting.

The chart below ploits the energy efficiency of different lighting technologies.Back in the 1940's and 50's, fluorescent tubes were seen to be significantly more economical than traditional technologies,but since the tum of the century, the emerging technology has been LED, rapidly outpacing traditional technologies and now more efficient than Fluorescent.The evolution is set to continue, but LED doesn't mean lights have to be a bulb or a tube any more.


--- Long Lasting

LEDs can have a lifetime in excess of 100,000 hours, but will generally be quoted as having a lifetime of up to 50,000 hours as LED will tend to outlast the electrical components that drive the LED. However, enven at 50,000 hours,that's 30 times the life a 60W light bulb(~1,500 hours) or 5 times a fluorescent tube (~10,000 hours).

--- Cost Saving

LEDs are more expensive to buy than traditional lighting, but they are far more economic to run and ultimately save the investment many times over. As a simple example, LED T8 tube light replaces traditional fluorescent lamp. Pls see the following:


T8 LED tube light
Traditional fluorescent lamp
Specification
T8/1200mm
T8/1200mm
Power consumption
18W
45W
Luminous flux
1500LM
1500LM
Installation way
Traditional light fixture without starter and ballast
Traditional light fixture
Electricity bill
365(day)×12(h)×0.018kw×3000pcs=236520kwh;
236520kwh×$0.15=$35478/year
365(day)×12(h)×0.045kw×3000=591300 kwh;
591300kwh×$0.15=$88695/year
Saving Ratio
≥60%
Saved electricity bill
$88695-$35478=$53217
Cost of tube
$30/pcs  $30*3000pcs=$90000
$6.7/pcs  $6.7*3000pcs=$20100
Maintenance cost(on minimum standard)
No need of maintenance
LED lifespan: 50000h
$450 including cost of lamp, ballast,starter.
LED tube cost recovery
The cost is recovered in one year after using LED tube light. And it will save over 75% of electricity bill annually and 95% of maintenance cost.


Remarks:
1. Refer to 3000pcs of 18W T8 LED tube replacing 36W fluorescent lamp. The figure is based on tubes working 12 hours every day for one year
2. The actual power consumption of traditional 36W fluorescent lamp with ballast is 45W; that of LED tube is 18W.
3. Electricity bill is figured by $0.15 per kwh.


Unlike Compact Fluorescent bulbs, there's no need to wait a few seconds for the light to build up as LED is instantly on. With the right control, LED can also be dimmed more effectively to lower levels without a buzz or visible flicker.


If more energy efficient lighting is used,less power is required, therefore fewer stations need to be built and run. There are many arbitrary "facts" thrown into this discussion and a few are listed below for you to poner or reject, but whichever way you look at it and whatever your position on wind farms, nuclear power ,coal or gas,the bottom line is that we need far fewer of them which is why governments are forcing the phase out of conventional lighting.

   * Different studies claim that between 12% and 22% of global energy is needed for lighting and that LED can reduce this figure by 60%.
   * 40% of all lighting is for incandescent light bulbs,this represents 2000 Twh/year.
   * The spend on energy for global lighting is  £140 billion a year.
  * "Energy consumption for illumination can range from 10-12 percent of total consumption for households to 40 percent in the commercial sector.


Logically, if we require less power we generate less CO2 pollution

   * Globally 630 million tons of CO2 are produced every year to power lighting.
   * Different bodies quote different CO2 values based on their agenda and the fuel used to produce the energy with values varying from 0.3kg to 0.8kg per kwh. A 60 watt light bulb run for 5 hours a day consumes 110kw per year, generating around 6kg of CO2. If there are 2 billion 60W bulbs, that's 12 million tons accounted for. Converted them to LED light bulbs and CO2 production is reduced by over 10 million tons every year.
   * Replacing current monenergy-efficient light sources with energy-efficient light sources will provide substantial economic benefit while at the same time reducing CO2. The investment for substituting incandescent or CFL lighting with LED is a fifth of the investment for installing solar power, calculated on a CO2 e p.a. basis, which means subsidizing LED is a more efficient investment than subsidizing solar power from a government perspective.


Fluorescent tubes and Compact Fluorescent light bulbs, whilst more energy efficient than conventional light bulbs, still require mercury in their manufacture.LED has no mercury and so when such time as disposal  needs to be considered ( a longer time into the future) this hazardous chemical is avoided.


For many , replacing a light bulb is something we are resigned to doing every month, but he bulb above the stairwell or in the sealed cupboard fitting always seem to "blow" more often than the others. With LED the mantra is "Fit and Forget" as it is likely that you'll change the light fitting long before you need to consider changing the bulb. However, put this into an out of home situation and replacing the lights on the gym ceiling, the lecture theatre roof or the car park flood lights required a logistcal and expensive project that needs planning, labour and often unnecessary expense as you'll tend to also replace the bulbs that haven't failed at the same time to prolong the interval until the next swap.

LED is a cool running technology, although lamps are designed with significant heat sinks to removes heat build-up in the electrical circuitry powering the LED. However, the LED itself emits minimal heat and no UV radiation making them ideal for illuminating objects, such as works of art or perishable food items, that are sensitive to heat and UV light. A secondary saving is a lower requirement for air conditioning to remove the heat generated by conventional light. Many industrial freezer and designs now incorporate LED lighting for this reason.
LED lamps have no moving part, filament or glass tube to break and their internal parts are rigidly supported, making them far more resistant to vibrations or impacts. Additionally, because they draw significantly less current, the wiring and electrical fitting will suffer less from deterioration and last longer.
LED lamps have a much greater operating range than conventional lighting and although many will only be quoted as operating to -20o C they can perform at lower temperatures