Most of the questions relate to basic understanding of LED and using LEDs for environment, to saving up electricity and reduce global warming.

1. Question: what is an LED?
2. Question: what color of light can LED emit?
3. Question: can LEDs be used to replace conventional incandescent and florescent light bulbs?
4. Question: what are the advantages of LEDs compared with conventional incandescent lights?
5. Question: why are LEDs of some colors are more expensive than LEDs of other colors?

1. What is an LED?
Answer: a light emitting diode (LED) is a semiconductor device that emits visible light when electrical current passes through it, it is a special kind of diode.

2. What color of light can LED emit?
Answer: most LEDs are monochromatic. Light color is associated with the light wavelength. LEDs made with different semiconductor materials emit lights in different wavelengths. LED light wavelengths range from 400 nanometers (blue) to 800 nanometers (red). The colors of popularly available LEDs in the market are red, orange, amber, yellow, green, blue , white and warm  white.  Interms of color temperature in Kelvin,  LEDs range from  xxx (blue) to zzz (red).

• Warm White - By far the most popular colour for homes and villas is  a warm white,  around  2000 Kelvin, - the color of candle light. Whilst the closest that  LED lights can come at this stage is 2500 – 3000 Kelvin, the colour can be achieved with the simple addition of a coloured lens over a white LED.
  

• Low power consumption
  Generally speaking, LED lamps use only 10% of the power used by conventional lighting. So for the cost of running one 60 watt bulb, you can light a whole garden with 12 LED lights.
  


• Long lasting
  In most cases LED lights are rated 50000 hours or 100000 hours continuous on. That means they will perform for 5.5 to 11 years, as against 1000 hours for conventional bulbs.


• Cold lightingLED lights emit no heat.
  So they don’t have the problems associated with  incandescent bulbs of burning out, discolouring  lenses and lampshades,. Of course,  cool running also means savings on power for airconditioners as well.
  
  
• Simple to use
  LED lights come in the same formats as incandescent lights. They will simply plug and play into MR16, E27, E24, PAR fittings and GU and even fluro fittings too.
  The rated average working life of LED is 50 -100,000 hours compared with 1,000 hours of incandescent bulbs.
  LEDs emit cold lights as working LEDs generate very small amount of heat, so LEDs are much safer than equivalent incandescent light bulbs in terms of danger of fire. LEDs don’t have filaments to heat up in order to emit lights just like the case of incandescent bulbs. Lights are emitted from LEDs as a result of energy exchange occurring in the different semiconductor materials an LED is made of.
  LEDs are usually shielded with solid transparent plastic materials so they are more rugged than incandescent and florescent bulbs that are usually sealed with glass.
  LEDs can be powered by either AC voltage or DC voltage. The circuit that is required to appropriately drive LEDs is much simpler than that for florescent bulbs.