Just How Do LED and Other Light Bulbs Work, Anyway?

Just How Do LED and Other Light Bulbs Work, Anyway?

LED lights are one of the hottest growing trends in green energy and lighting efficiency. There are many reasons for this. The longevity and versatility of LED lighting technology makes them perfect for many applications and they are programmable in ways that make them ideal for long term, low cost use.

LEDs are uniquely poised to replace both the less efficient incandescent bulbs, but also compact fluorescent bulbs which have gained in popularity because of their energy savings. A compact fluorescent light bulb will give you approximately 8,000 the amount of life of an incandescent light of the same wattage. An incandescent light bulb will only last about 1,000 hours on average. Even with this more efficient energy uses, they can still pose some environmental concerns such as mercury ending up in the landfill and eventual seepage into groundwater. LED bulbs can last between 50,000 to 100,000 hours before they need to be replaced and there are far fewer detrimental effects to the environment.

LED’s Explained

So what are LEDs? The term LED simply stands for Light Emitting Diode. An LED is a light producing, two lead semiconductor. A diode is a semiconductor that is very simple. All semiconductors conduct electrical current. LED’s fit onto a circuit board and conduct light without producing heat such as incandescent and even compact fluorescent lights do. They also don’t have a filament that will burn out so that makes them especially long-lasting.

The diodes that make up LEDs are made from aluminum, gallium and arsenide (AlGaAs). Impurities are added to this so that it creates free electrons which help the semiconductor conduct electricity and it helps to create the color that the LED comes across as such as red, green, blue, and so on. This addition of impurities is called doping. Because you need positive or P-type along with negative or N-type of electrons to find holes in those impurities, make electricity and therefore make light.

All diodes emit light but not all are very good at doing so. Most semiconduction material will absorb the atoms of light or light energy. LEDs on the other hand, are specially made that rather than absorbing the light, instead release the light energy or light photons in an outward direction. This is process is accomplished when the light emitting diode is contained inside of a bulb, mostly made of plastic. The bulb focuses and concentrates the light. housed in a plastic bulb that concentrates the light in a particular direction.

LED bulb construction

Because an LED bulb or LED type of light is made up of several LED bulbs together, that makes them a bit more durable. There can be degradation of the light over time when a diode begins to give out, but usually this does not happen all at once.

led diode diagram

Here is what a disassembled LED light bulb looks like. It certainly is a bit different than what you might have seen before in other light bulbs. It may be a very long time before you even notice that there has been any degradation at all.

LED bulb assembly

It is estimated that approximately 25% of all energy that is generated and consumed on our planet goes into lighting. LEDs afford us bright, dependable light because they draw a mere fraction of energy that incandescent and compact fluorescent lights do. While a typical 100 watt incandescent bulb generates heat and will consume a few hundred dollars’ worth of energy per year, by comparison, it costs approximately 1/10th in terms of energy cost! Because LED’s produce light without heat induction, that makes them far more efficient.

The end benefit is that the carbon footprint that results from its use will also be less. LEDs when turned on go from having been off to their full brightness without needing those few seconds of warm up time. This also adds to the life of the LED bulb compared to that of fluorescent lighting. This warm up time tends to reduce the life of the bulb through the process of switching on and off. This means that they will end up being replaced far less often.

LEDs are still in the early adoption phases for wider use and even though LED lights don’t cost nearly as much as they did initially when introduced onto the market, there can still be a bit of a sticker shock between what most people have spent on light bulbs previously. This is why many homeowners often opt to make the switch over a time rather than all at once. Of course, LED bulbs will last on average between 50,000 hours and up in typical settings. Considering that one year is made up of 8,760 hours. That means a typical LED bulb can last more than 7 years! It may be a very long time before you even notice that there has been any degradation at all. In that amount of time, the price will undoubtedly have decreased even further making them less costly in terms of replacement and energy consumption.

LED’s are not ‘new’, except in the way that they have gained broader use and acceptance over a fairly long space of time. LEDs have been used for decades in watches, clock, computer hardware, remote controls and other similar applications for electronics and appliances. Today, because of the retirement of incandescent lighting globally, and because of increased public awareness and demand for greener, cleaner and lest costly forms of lighting, LED’s have been adapted to fit various lighting applications from outdoor lighting to typical floor and table lamps and every other household lighting uses such as environmental and task lighting that earlier types of bulbs were used for.

For some, the only down side may be that it could take a while for homeowners to get used to the spectrum of light that LEDs give off. If not considered carefully, room decor and how a room feels can be thrown off considerably. This is because the light tends to be much cooler or bluer compared to the typical yellow-warm glow that is given off by incandescent light bulbs. LED technology has advanced to enough a degree that LED bulbs are now being manufactured to emulate that same sort of warm glow that most people tend to desire when making indoor lighting choices. Many home improvement, lighting specialty stores and big box retailers have displays that show a wide range of different colors and wattages or lumens that are available. This will allow homeowners to get a real feel for how LED lights will look.

Converting from thinking of lumens instead of watts when choosing a light bulb may be a little confusing at first. A typical 60 watt incandescent bulb converts typically to an 800 lumen LED light bulb. The more lumens you have, the more light is emanated from the bulb. When you are shopping for LED lighting, look for the Energy Star label whenever possible to more energy efficient lights. Below is a simple guideline for choosing the right amount of watt to lumens for the various types of bulbs around your home.

100 Watt Bulb = 1,600 Lumens

60 Watt Bulb = 800 Lumens

40 Watt Bulb = 450 Lumens

An 800 -1,600 Lumen LED bulb will only use approximately 1 Watt of power to emit the same amount of light. Already, it is easy to see why there would be a substantial energy savings.

LED bulbs come suitable not only for indoor home use, but also for locations that are wet, cold or higher temperatures and are specially made to withstand those settings that have less than ideal temperatures and moisture. Unlike their compact fluorescent predecessors, LED lights are dimmable and can be used with a dimmer switch.

Other great reasons why to choose LED lights over incandescent and even compact fluorescent bulbs are:

LED bulbs can take being bumped or jostled, while incandescent bulbs will either break or rupture easily. LED lights rarely fail, while incandescent bulbs and compact fluorescent bulbs sometimes do. Also, with an LED there is never any broken glass to sweep up.

Incandescent bulbs generate 85 btu’s (British Temperature Units) per hour. Compact fluorescent bulbs are significantly less but generate approximately 30 btu’s per hour. Because of the heat generated by incandescent bulbs and the potential fire hazard that has occurred with compact fluorescent bulbs where the bulb has fused or melted with its ballast, this makes both of them potentially less safe than LED’s. LEDs generate very little heat and have less potential to cause a fire hazard as their predecessors making them a far safer alternative.

Most LED bulbs are unaffected by temperature or humidity, but there are bulbs that are better suited for either locations than others. Compact fluorescent bulbs are often affected by humidity factors and they may not work at all in temperatures below 10 degrees F.

Compact fluorescent bulbs use mercury vapor which can cause issues in the landfill. They also emit carbon dioxide to the tune of 1051 pounds per year. LED’s do not contain toxic mercury and only emit 450 pounds of carbon dioxide or Co2 per year.

Like incandescent bulbs, LED light bulbs turn on instantly and take no time to warm up. Compact fluorescent bulbs do not come on immediately and flicking a switch on and off rapidly known as on and off cycling can significantly reduce the life of a CFL.

Some types of LED’s can be programmed to create complex combinations of intense colored light without the need of using gels or filters to create that light. This can make them both less expensive to produce and far less expensive to use in spaces that make use of various types of dramatic, completely customizable special lighting effects. Because LEDs can be made to focus without the use of extra reflectors or lenses, this also further reduces the cost without sacrificing on the effect.

The added versatility of LED lights make it possible for you to have light even if you don’t have electrical outlets nearby. Many LED light strands or strips can be powered by self-contained battery packs rather than being directly wired. Because LED’s use very little energy, changing the batteries will not need to be done but maybe a few times per year. If you use rechargeable batteries this will cut down on your overall energy costs even more.

LED outdoor and flood lighting can illuminate your property and make it more secure. Home and business owners can light the grounds surrounding their property to illuminate walk and entryways, focus on architectural and landscape features and create outdoor “rooms” in ways that were never before possible with incandescent, halogen or other types of lighting. Again, with LED’s humidity and temperature is less of a factor so even in rainy or snowy months, they are not affected.

The Energy Independence and Security Act of 2007 

Signed by President George W. Bush and passed by Congress was introduced as a way to increase US energy security and independence. A direct side effect of this was to make for the production of clean renewable energy and increased efficiency for greener more energy efficient buildings, vehicles and other products. It is because of this move by the government that the way has been paved legislatively toward the complete phasing out and eliminating the manufacture and import of incandescent bulbs. That means that sooner or later consumers will have to think about converting over from old style incandescent and compact fluorescent bulbs to LEDs.

With this broader use that increases more each day, LED’s are quickly becoming the alternative to fill the gap that the elimination of incandescent bulbs have left in the marketplace and can light our path in a far more energy efficient and less costly way. 

If your looking for other resources on different lamp types, our good friends at the  Servc Group produced a nice slideshare of the different types of lightbulbs. The gif below gives you a quick overview. 

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