Learning Center
Why LED Lighting? FAQ's Sponsor the Environment Glossary of Terms Green Articles

 

 

Why LED Lighting?

 

 

There are several reasons to switch to LED lighting. For starters, they are the most energy efficient lighting solution available, as well as the most affordable over the lifespan of the bulb. In fact, they use only a fraction of the energy that their counterparts use.

 

Furthermore, LED lighting is the most eco-friendly solution available, and does not contain hazardous materials such as mercury compared to compact fluorescent lighting (CFL), which also have to be properly disposed of. 

 

 

ledideaWhat are the benefits of LED Lighting?

Long-Lasting - LED bulbs can last up to 50,000 hours. That is approximately 97% longer than an incandescent and 77% longer than a CFL bulb

Durable - Because LEDs are in a solid state, they are more difficult to damage with external shock, unlike fragile fluorescent and incandescent bulbs

 

Cool - An LED bulb radiates very little heat. If it makes contact with sensitive objects such as fabric, it avoids potential fires.

Mercury-free - No mercury is used in LEDs

More Efficient - LED light bulbs use less energy than CFLs and incandescent. A 6 watt LED bulb puts out a similar amount of light to a 14 watt CFL and a 60 watt incandescent

Cost Effective - Although LEDS are currently more expensive when you first buy them, they last so much longer  and save much more energy that they are by far the cheapest light in the long run.

 

How LEDs Work

 

 

Drawing of a box. The left side marked P has positive bubbles (protons); the right side marked N has negative bubbles (electrons); the center area shows where protons and electrons meet, with arrows leaving the box at this point, marked Light. Junction (depletion region) is marked above the N section. Electrons flow through a wire connecting the P section to the positive terminal of a battery, and through another wire connecting the battery's negative terminal to the N section.

LEDs differ from traditional light sources in the way they produce light. In an incandescent lamp, a tungsten filament is heated by electric current until it glows or emits light. In a fluorescent lamp, an electric arc excites mercury atoms, which emit ultraviolet (UV) radiation. After striking the phosphor coating on the inside of glass tubes, the UV radiation is converted and emitted as visible light.

 

An LED, in contrast, is a semiconductor diode. It consists of a chip of semiconducting material treated to create a structure called a p-n (positive-negative) junction. When connected to a power source, current flows from the p-side or anode to the n-side, or cathode, but not in the reverse direction. Charge-carriers (electrons and electron holes) flow into the junction from electrodes. When an electron meets a hole, it falls into a lower energy level, and releases energy in the form of a photon (light).

 

The specific wavelength or color emitted by the LED depends on the materials used to make the diode.

Red LEDs are based on aluminum gallium arsenide (AlGaAs). Blue LEDs are made from indium gallium nitride (InGaN) and green from aluminum gallium phosphide (AlGaP). "White" light is created by combining the light from red, green, and blue (RGB) LEDs or by coating a blue LED with yellow phosphor. 

 

 

 

LEDs verses Compact Fluorescent Lights

 

 

LED lighting provides several advantages in comparison to compact fluorescent lighting. They have lower energy consumption, longer life cycle, and better light distribution.

 

More Energy Efficient – LEDs use around 10-50% less electricity to deliver the same level of lighting. LEDs also use less heat output, which helps to reduce the HVAC load.

 

Dimmable – Unlike compact fluorescent lighting, LEDs are dimmable.

 

More Cost Efficient – Although LED fixtures have a higher initial cost, they provide more cost savings over the lifetime of the bulb. In fact, some bulbs last as high as 50,000 hours. LEDs also have a lower maintenance cost.

 

No Hazardous Materials- LEDs do not contain mercury or other hazardous materials like compact fluorescent lighting.