Advantages and Disadvantages of LED
Advantages
Efficiency: Compared to conventional light bulbs, LEDs produce more lumens per watt. Unlike fluorescent light bulbs or tubes, the effectiveness of LED lighting devices is unaffected by form and size.
hue: Unlike conventional lighting techniques, LEDs can emit light of the desired hue without the use of any color filters. This can result in reduced initial expenses and is more effective.
Size: LEDs are simple to connect to printed circuit boards and can be made as tiny as 2 mm2.
LEDs turn on and off very rapidly. In less than one microsecond, a standard red indicator LED will reach maximum luminosity. Even quicker reaction periods are possible with LEDs used in networking equipment.
Cycling: Unlike incandescent and fluorescent bulbs, which break down more quickly when frequently cycled, and high-intensity discharge lamps (HID lamps), which take a while to resume, LEDs are perfect for applications exposed to frequent on-off cycling.
LEDs are very simple to reduce, either by reducing the forward current or using pulse-width modulation. When seen on video or by some people, LED lights, especially vehicle headlamps, appear to be flickering or flashing because of this pulse-width modulation. This kind of image is stroboscopic.
Cool light: Unlike most light sources, LEDs emit very little heat in the form of infrared radiation, which can harm delicate items or textiles. Wasted energy is released through the LED's base as heat. LEDs typically fail slowly, dimming over time as opposed to the sudden failure of incandescent lights.
Life: The usable life of an LED can be quite lengthy. According to one account, the useful life is between 35,000 and 50,000 hours, though the period until total failure may be prolonged. According to the conditions of use, fluorescent tubes are usually rated for 10,000 to 15,000 hours of use, while incandescent light bulbs are listed for 1,000 to 2,000 hours. The payback period for an LED product is primarily influenced by decreased maintenance costs from this increased lifespan, not energy savings, according to a number of DOE demos.
Shock resistance: Unlike delicate fluorescent and incandescent lights, LEDs can withstand exterior shocks because they are solid-state components.
Focus: The LED's sturdy container can be made to direct its light. To gather light and guide it in a useful direction from incandescent and florescent sources, an external reflector is frequently needed. Total internal reflection (TIR) optics are frequently used to achieve the same result for bigger LED packages. However, numerous light sources that are challenging to concentrate or collide towards the same objective are typically used when large amounts of light are required.
Disadvantages
High starting cost: Compared to most traditional illumination technologies, LEDs are presently more costly (price per lumen). The price per kilolumen (thousand lights) was about $6 as of 2012. By 2013, it was projected that the cost would be $2 per kilolumen. As of March 2014, at least one maker asserts to have achieved $1 per kilolumen. The comparatively low lumen output, necessary drive circuits, and power sources all contribute to the extra cost.
Temperature dependence: The ambient temperature of the working area, or "thermal management" characteristics, greatly affects LED performance. When an LED is overdriven in a hot environment, the LED module may become overheated, which could ultimately cause the device to malfunction. To sustain a lengthy life, a sufficient heat sink is required. This is crucial for applications in the automobile, medical, and defense industries where equipment must function in a variety of temperatures and have low failure rates. With a working temperature range of -40 to 100 °C, Toshiba has developed LEDs that are suitable for both interior and external use in fixtures like lamps, ceiling illumination, street lights, and floodlights.
Voltage sensitivity: LEDs require a voltage supply that is higher than the cutoff and a current that is lower than the specification. A slight shift in applied voltage causes significant changes in current and lifetime. They thus need a source that is controlled by electricity. (usually just a series resistor for indicator LEDs).
Light quality: Compared to a dark body heater, such as the sun or an incandescent light, the majority of cool-white LEDs have wavelengths that are very different. Due to metamerism, red surfaces are portrayed especially poorly by normal phosphor-based cool-white LEDs, causing the color of objects to be viewed differently under cool-white LED lighting than under sunshine or incandescent sources. However, compared to modern white LEDs, the color rendering capabilities of ordinary fluorescent lights are frequently subpar.
Area light source: Individual LEDs produce a lambertian distribution of light rather than a circular light distribution that comes from a single source of light. Consequently, it is challenging to apply LEDs to applications that require a spherical light field; however, distinct light fields can be controlled by the use of various optics or "lenses." Divergence below a few degrees cannot be produced by LEDs. In comparison, lasers can produce rays that diverge by no more than 0.2 degrees.
Electrical polarity: LEDs will only shine with the proper electrical polarity, in contrast to incandescent light bulbs, which glow independently of the electrical polarity. Rectifiers can be used to instantly match source polarity to LED displays.
Blue hazard: According to eye safety standards like ANSI/IESNA RP-27.1-05: Recommended Practice for Photobiological Safety for Lamp and Lamp Systems, blue LEDs and cool-white LEDs can now emit more blue light than is safe for human eyes.
Blue light pollution: Due to the strong wavelength dependence of Rayleigh scattering, cool-white LEDs can produce more light pollution than other light sources because they emit proportionally more blue light than traditional outdoor light sources like high-pressure sodium vapor lamps. IDA advises against using white light sources with associated color temperatures greater than 3,000 K.
Efficiency droop: As the electric current is increased, LED efficiency declines. Higher currents also result in more heating, which reduces the LED's lifespan. The current that can pass through an LED in high power uses is practically constrained by these effects.
Impact on insects: Compared to sodium-vapor lights, LEDs are much more alluring to insects, raising the hypothetical worry that this could lead to the disruption of food webs.
Use in cold weather: Since LED traffic control lights don't produce as much heat as conventional electrical lights do, snow can obscure them and cause mishaps.
