THE LED LESSON
A detailed Q&A about LEDs including; energy efficiency, saving money, incandescent comparison, light quality, longevity, etc.
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, trade show exhibits, retail chains, 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:
- 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 ladder-climbing 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 hours-a-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.