What is LED ?
A light-emitting diode (LED) is a two-lead semiconductor light source. It is a p–n junction diode that emits light when activated. When a suitable voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence, and the color of the light (corresponding to the energy of the photon) is determined by the energy band gap of the semiconductor.
What are the advantages of LED?
- Efficiency: LEDs emit more lumens per watt than incandescent light bulbs
- Energy Saving: LED use 90% less electricity than incandescent version
- Longer lifetime: One report estimates 35,000 to 50,000 hours of useful life, though time to complete failure may be longer. Fluorescent tubes typically are rated at about 10,000 to 15,000 hours, depending partly on the conditions of use
- Very Small in Size: Could be smaller than 2 mm2
- Safety: LED don't heat up like other light bulbs, which can reduce the risk of lighting-caused fires or burns
What are the disadvantages of LED?
The biggest drawback to LED lighting is the initial cost, which is more than your standard incandescent light bulbs. But because LED lights are more durable and longer lasting than their traditional counterparts, you will incur fewer lighting expenses over time, bringing the overall cost of these LED lights down significantly.
A typical 13-watt LED lamp emitted 450 to 650 lumens, which is equivalent to a standard 40-watt incandescent bulb.
Example: See the chart below for a comparison of common light types
|Type of Lights||LED||CFL||Incandescent|
|Lightbulb Projected Lifespan||50,000 hours||10,000 hours||1,200 hours|
|Watts Per Bulb (equiv. 60 watts)||10||14||60|
|Cost Per Bulb||$2.00||$7.00||$1.25|
|kWh of Electricity Used Over 50,000 Hours||500||700||3000|
|Cost of Electricity (@ 0.10 per kWh)||$50||$70||$300|
|Bulbs Needed for 50,000 Hours of Use||1||5||42|
|Equivalent 50,000 Hours Bulb Expense||$2.00||$35.00||$52.50|
|TOTAL Cost for 50,000 Hours||$52.00||$105.00||$352.50|