LED 101
SOURCE: CREE
What does LED stand for? Light Emitting Diodes.
What’s so great about LEDs? LEDs can be used to build energy-efficient lighting
products that save energy, help protect the environment, reduce maintenance costs
and make people and things look much more attractive than traditional lighting. And
they can last much longer than traditional lighting.
Just how energy-efficient are LED lights? LED lighting can save up to 85 percent
of the electricity used by incandescent bulbs and up to 50 percent of electricity used
by fluorescents
When comparing LED lighting to fluorescent lights, energy savings depend on the
type of fluorescent light. For example, LED lighting can save up to 50 percent of the
energy used by CFLs and between 20 to 30 percent of the energy used by
fluorescent tube lighting.
Where are LED lights being used? Since LED lights are so energy-efficient, the
most common applications are places where lights are switched on for an extended
period of time. You can find LED lights in restaurants, offices, parking lots,
streetlights, dorm rooms, ice skating rinks and, of course, in homes. You can see
some places that have installed LED lights here.
Can LED lighting really save energy and money? Take a look at the statistics.
The U.S. Department of Energy estimates that widespread adoption of LED lighting
by 2025 will:
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Reduce electricity demands from lighting by 62 percent.
Eliminate 258 million metric tons of carbon emissions.
Reduce the amount of materials being put into landfills.
Avoid the building of 133 new power plants.
Save the US over $280 billion.
Why is LED lighting better than incandescent bulbs? Most of the energy emitted
from incandescent bulbs is converted to heat instead of light. That’s why you’ll burn
yourself if you try to touch an incandescent bulb once it’s turned on.*
LED lighting is about 85 percent more efficient than incandescent bulbs. Since LEDs
consume significant less energy, they don’t emit as much heat. That’s why you
typically won’t burn yourself if you try to touch an LED light once it’s turned on.*
LED lights are also designed to last about 50 times longer, which means less ladderclimbing maintenance and less waste.
*We do not recommend touching lights to see if they are hot or not. Instead, watch
this chocolate bunny demonstrate the heat difference between incandescent and
LED lights.
Why is LED lighting better than fluorescent lighting and CFLs? LEDs don’t
contain hazardous materials, such as mercury. Since fluorescent tubes and CFLs
contain mercury, they must be properly disposed of in order to prevent mercury from
poisoning landfills. Here are some tips from the U.S. Environmental Protection
Agency on how to dispose of fluorescent lights.
Also, most fluorescent lights cannot be dimmed and many can flicker. Some people
are sensitive to this flicker and experience headaches, migraines and eye strain.
LED lighting uses solid-state technology, which allows effective dimming in many
applications and eliminates flickering.
Fluorescent lights can also take several minutes to achieve full brightness and even
longer in cold environments. LED lights are also instant-on and can withstand
extremely cold conditions – such as those in freezer cases or on the streets of
Alaska.
And, high quality LEDs produce better light that shows color more effectively than
fluorescents. (More on that below).
What type of light quality can I expect with LED lights?You should be satisfied
with the light quality coming from any light—LED or otherwise. The best way to
ensure this is to know what color light you want and how to ask for it. If you want
warm light, look for lighting that is close to 2700K. If you want a more neutral light,
look for something closer to 3500K and if you want a cooler light, look for 5000K or
more. But that’s not all… You also need to be aware of color rendering.
The ability to make colors look true – that is to have a tomato look like a tomato – is
called color rendering. The color rendering index (CRI) characterizes light sources in
view of their ability to produce “natural light” and can be between 0 and 100. The
closer an LED light comes to 100 on the color rendering index (CRI), the more
naturally colors are rendered, and the light is perceived as more pleasant. The CRI
of fluorescent tubes is often around 72. Cree LED lighting fixtures have a CRI of
between 92 and 94.
How long can LED lights last? With the right design, LED lights can have a lifetime
of 50,000 hours and more in continuous operation. Depending on how many hoursa-day they are operating, that can be from 6 to 7 years to as many as 20 to 30.
Unlike other lighting technologies LEDs do not completely fail—they grow dimmer. At
the 50,000 hour mark, Cree’s LED lights are designed to provide at least 70 percent
of their initial light output. Many different factors (such as fixture design and
operating conditions like temperature and current) determine the actual lifetime of an
LED.
Aren’t LED lights too expensive? A main challenge with LED lighting is that it
costs more upfront, but really, it’s no different than requiring insulation in homes and
buildings. It can pay for itself over time with energy savings and lower maintenance
costs. Keep this in mind when you initially invest in LED lights.
Besides, how do you define expensive? Is it purely the up-front cost of a light or do
you factor in the cost of the energy to run that light and, if you’re a business or
government, the cost to change the lightbulb? And if you’re building a new building,
installing LED lighting is often just about the same cost as traditional technology—
and you’ll start saving money, through reduced energy consumption, the minute you
flip the switch.