How Efficient Is LED Lighting?

How Efficient Is LED Lighting?

One of the key advantages of LED lighting is its high efficiency, as measured by its light output per unit power input.
When LED technology first entered the more mainstream lighting market, it very quickly matched and overtook the efficiency of standard incandescent lighting systems.

In 2002, Philips Lumiled made five-watt LED’s available with a luminous efficacy of 18–22 lumens per watt [lm/W], for comparison, a conventional 60–100 Watt incandescent lightbulb produces around 15 lm/W, and standard fluorescent lights produce up to 100 lm/W.
A recurring problem with LED is that efficiency will fall dramatically with increased current. This effect is known as droop and effectively limits the light output of a given LED, increasing heating more than light output.
In September 2003, a new type of blue LED was demonstrated by the company Cree, Inc. to provide 24 mW at 20 milliamperes [mA]. This produced a commercially packaged white light giving 65 lm/W at 20 mA, becoming the brightest white LED commercially available at the time, and more than four times as efficient as standard incandescents.
In 2006 they demonstrated a prototype with a record white LED luminous efficacy of 131 lm/W at 20 mA.
Seoul Semiconductor had 145 lm/W by 2008, which was approaching an order of magnitude improvement over standard incandescents and better even than standard fluorescents.
High-power (≥ 1 W) LEDs are necessary for practical general lighting applications and typical operating currents for these devices begin at 350 mA.

As of early 2010, Cree were producing LED’s achieving 208 lumens per watt at room temperature and currently, in mid-2010, the highest lumens per watt LED’s available are pushing 600 lm/W with LED Chip Clusters going into the thousands; which means that LED technology is now outperforming halogen lighting.

Governments have in the past few years passed measures to prohibit the sale of incandescent light bulbs. The aim is to encourage use of more energy efficient lighting alternatives, such as compact fluorescent lamp (CFLs) and LED lamps.

Did you know? The UK government announced in 2007 that incandescent bulbs would be phased out by 2011. The 60W incandescent ceased production in September 2011. Brazil and Venezuela started to phase them out in 2005, and the European Union, Switzerland, and Australia started to phase them out in 2009. Likewise, other nations are planning scheduled phase-outs: Argentina, Russia, and Canada in 2012, and Malaysia in 2014.