LED Breakthroughs Are Revolutionizing Low-Cost, High-Efficiency Lighting

LED Breakthroughs Are Revolutionizing Low-Cost, High-Efficiency Lighting

http://www.reelcaribbeanenergy.com

LED light bulbs are about four times more efficient than conventional incandescent lights and, because they contain no mercury, more environmentally friendly than compact fluorescent bulbs.

LEDs are also longer lasting than conventional lighting, lasting as long as 15 years before burning out.

When first developed, LEDs were limited to single-bulb use in applications such as instrument panels, electronics, pen lights and, more recently, strings of indoor and outdoor Christmas lights.

However, they’re now able to be constructed to have the same brightness as incandescent bulbs.If all incandescent and compact fluorescent bulbs were replaced with LEDs, there would be dramatic energy and environmental ramifications.

There’s no question that LED lightbulbs are great for the environment. However, traditionally LEDs have been cost-prohibitive, usually triple the cost of a standard incandescent.

Because initially, LEDs were created with a first layer, the substrate, made of sapphire. The sapphire-based technology was too expensive for widespread domestic-lighting use, costing at least 20 times more than conventional incandescent and compact fluorescent light bulbs.

Why?

Because initially, LEDs were created with a first layer, the substrate, made of sapphire.

The sapphire-based technology was too expensive for widespread domestic-lighting use, costing at least 20 times more than conventional incandescent and compact fluorescent light bulbs.

However, new breakthroughs have led to the development of a low-cost, metal-coated silicon wafer to use instead.

The silicon wafer was developed by researchers at Purdue University in 2008.

Another reason for the high cost is that the sapphire-based LEDs require a separate mirror like collector to reflect light that ordinarily would be lost.

In the new silicon-based LED research, engineers from Purdue University “metallized” the silicon substrate with a built-in reflective layer of zirconium nitride.

Until the advance, engineers had been unable to produce an efficient LED created directly on a silicon substrate with a metallic reflective layer.

Using silicon will enable industry to “scale up” the process, or manufacture many devices on large wafers of silicon, which is not possible using sapphire.

The silicon also dissipates heat better than sapphire. This improves the reliability and life of an LED.

If you replaced all existing lighting with solid-state lighting, it could reduce the amount of energy consumed by one-third. By the same token, it also reduces carbon emissions.

LEDs are 5 to 6 times more efficient than incandescent bulbs. Incandescents are approximately 10% efficient, with the other 90% going off into heat. LEDs are 47%-64% efficient.

Another technological advance in LEDs has been in the bulb designs.

With LEDs, the light is directional, as opposed to incandescent bulbs which spread the light more spherically. While it can be an advantage with recessed lighting or under-cabinet lighting, it's not ideal for table lamps.

New LED bulb designs address the directional limitation by using diffuser lenses and reflectors to disperse the light more like an incandescent bulb.

Visit us at www.reelcaribbeanenergy.com to check out more about our Caribbean LED program and other resources on LEDs.

Thanks to references from EarthEasy.com (http://eartheasy.com/blog/2009/01/led-breakthrough-may-revolutionize-lighting/

), Purdue University (http://www.purdue.edu/) and Science Daily (http://www.sciencedaily.com/releases/2008/07/080717134601.htm).