We are in the midst of a lighting revolution.
The past decade has seen LED light usage soar in the U.S. as traditional incandescent bulbs went into the trash bin.
In 2010, incandescents were 68% of the bulbs installed in U.S. homes. By 2016, that number had declined to 6%.
That change has shaken up the industry in a good way. Mark Rea, professor at the Lighting Research Center at Rensselaer Polytechnic Institute, tells Here & Now’s Jeremy Hobson that the benefits of LED lights “really make it kind of a slam dunk for a transformation in the way light sources are sold.”
He says those benefits include how many lumens per watt LED lights provide, long-lasting capabilities, ease of control, their glow and the ability to have multiple color options.
Interview Highlights
On the benefits of LED lights
“I think there are two touted benefits. One is how many lumens per watt you get out of it. So an incandescent lamp might be 12 to 15 lumens per watt, and depending on the LED you might get 100 lumens per watt. So that’s a big jump. And the other is longer life. That depends on the application, but generally speaking incandescent lamp might last, say, six months in your home. These can last up to 10 years. So those are really big differences but there are other benefits that people don’t talk so much about. They’re easy to control. So you can do some fancy stuff with them whether you put them on a bridge or you want to have a disco. There’s no filtering that you have to do. It will directly emit the wavelengths you want so you can have a red one or a blue one or a white one.”
On LED lights’ effects on the lighting industry
“People hate change. That’s the first thing. I don’t think anybody anticipated what a disruptive technology [this] was really going to be. For 100 years, we’ve had just a handful of major manufacturers and they pretty well set the standards [and] the policy. And the reason was it was very expensive to try to be in that business. It took a huge capital expense that no one wanted to commit to, to say produce fluorescent lamps or incandescent lamps. With LEDs, they’re cheap and anybody can be a lighting manufacturer now. So it’s really brought down … these major players that really set the tone for lighting for literally 100 years. That all changed with LED.”
On new lighting rules from Congress, scheduled to go into effect in 2020
“Incandescent would be outlawed and halogen would also. They can’t reach that level. That number was picked primarily to still allow for fluorescent lamps, which are very common still in commercial and some residential applications.
On whether fluorescent lamps will be phased out
“I don’t know if legislation will be needed. If you’re getting 100 lumens per watt as opposed to 45 lumens per watt probably the marketplace will just switch naturally, but I can’t predict that.”
On whether LEDs are just as good as incandescent lights
“No. The point I want to make is that they’re better than incandescent, from a color [perspective] and the glow and the perception of the light is better now than any of those technologies up to this point.”
On how important lighting is to one’s mood — and life in general
“I can’t think of anything more important! … We’ve done studies here, not those market surveys, but laboratory studies and gone to fields and given the choice, people prefer LED to incandescent. That means that people will more readily adopt that technology. And I think that particularly for home and restaurant, the mood that lighting can create makes a big difference in terms of sales. Not specific to LEDs but a fluorescent bulb in a high end restaurant just isn’t going to cut it. That’s just not going to work.”
On light pollution
“All of the lighting recommendations we live with today were all based on old technology. You’ve probably seen the orange which call high pressure sodium street lights and they’ll measure how many lumens per square inch that you’re going to get underneath that and that’s what you designed for. You designed the wattage and this is what you’re going to need on a roadway or a sidewalk or a parking lot. As it turns out LEDs because they’re white, the light meter is not responding to that light the same as it did to the old technology and the old standards. And people complain because things are too bright in parking lots and roadways today. It’s too bright to the eye even though the light meter says gee, there’s no difference. You can reduce an LED relative to sodium by as much as 80% and still have the same visibility you did with the old technology. So reducing the amount of light you’re putting on the roadway means less light bounces up into the atmosphere and you have less light pollution.”
On automatic lights
“One shouldn’t light any place that’s not being used, but it’s an interesting oblique response to your comment. When we feel safe in a parking lot, we want to see in remote areas that that area is lighted. So if the motion sensor is only looking at a small corner of that parking lot and you’re at the other corner of the parking lot, you might feel that is not a place I want to go because the lights are off. So it has to do not just with what is in close proximity your ability to see, but what your ability to predict what’s gonna be happening at some more remote location also becomes important. So if you are driving, we all over drive our headlights, the headlights do not provide enough illumination for us to drive safely, and what we judge as good headlights is what we see right in front of us which by the time we got to that spot, we would have hit what we’re going to hit. So you want to be able and some of the new technology headlights, LED headlights, are very good at projecting down the roadways so you really do have enough time to respond. So I think it must be remembered that remote visibility is as important depending on the application is near term. So you have to think of the context to have a successful application like that.”
On LED car headlights
“That’s another nice advantage of LEDs. Instead of bending a piece of metal or cutting a piece of glass to do the refraction, the LEDs as point sources can be directed very precisely to a location ahead of you. And so we’ve worked with major headlight manufacturers to develop some of those lighting systems. So imagine now you’re driving with your bright lights on all the time but a camera system is looking at the windscreen of the car coming next to you and creates a shadow where that windscreen is. That you could never do with the old technologies but LEDs enable you to turn off certain small elements [of] that headlight. That’s a really neat innovation.”
Francesca Paris produced this interview and edited it for broadcast with Kathleen McKenna. Serena McMahon adapted it for the web.
This article was originally published on WBUR.org.
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