While museums and galleries could use lighting technology to significantly reduce energy and labor costs—it costs more than you’d think to change a light bulb--they’re moving into the world of LEDs with caution.
Earlier this week I talked to Naomi Miller, senior lighting engineer at Pacific Northwest National Laboratory (PNNL) in Portland, Ore., one of the Department of Energy's 10 national laboratories. Miller’s group is trying to develop standards for LEDs. They put out fact sheets, anonymously test products on the market to make sure they do what manufacturers claim, and track how well LEDs are doing compared to other lighting technologies.
Lighting is a tremendous expense for museums, but most of the institutions are apprehensive about making too many changes before we know about the long term benefits and the effects on priceless works of art. Excerpts of our conversation are below.
You just returned from LightFair International in Philadelphia. What was the most interesting thing you learned?
The most interesting thing is that products are getting better. We used to have a lot of weird and cold-color LEDs. Over time the color has gotten more consistent from LED to LED. There’s starting to be less flicker. The manufacturers are learning about the technology and how to make products that are more comparable to what we expect.
Also, manufacturers are learning that they don’t just take LEDs and stick them into the same fixtures that used to have fluorescent light. We’re actually seeing dedicated LED products and don’t have to reproduce a form factor from the past. It’s taken years for that to happen. We're starting to see office products and track lights for retail applications that are dedicated LED lights. We’re also seeing more attention paid to the dimabilty of LEDs. A lot of manufacturers have claimed that their products were dimmable but in the past, the color wasn’t right or they flickered. That’s still a big problem, but a lot of manufactures are figuring out how to make the products better.
One of their biggest concerns is whether the spectrum of the LED going to deteriorate our artwork faster than the halogen we’ve been using. There is some research going on at the Getty Conservation Institute, and they’re looking at standard fading materials so they know how they react under certain conditions and the number of hours a piece of art can be exposed before it starts deteriorating. Different materials have different sensitivities to light.
One thing we’ve learned so far from the Getty Conservation Institute is that LEDs don’t seem to be doing any more damage than the halogens. They may be performing a little bit better. We just have to wait and see what the research sows.
The other thing museums are concerned about is how to make the art visible and bring out the colors the artist intended us to see. The early LEDs weren’t very good in color, but now the color of LED products has gotten so good it’s very similar to halogen. There’s a little more energy in the blue portion of the spectrum.
So that will bring out more blue and purple in the artwork?
Everyone is being very careful, and they don’t want to have a dramatic change in how their artwork looks. In some museums they are making sure it’s not a dramatic difference, so they may filter out of some of that blue. Each museum will have a different philosophy.
I understand the National Gallery in London is switching over its lights?
I don’t know if they’re switching over, but they’re trying it in a few galleries. And that’s the best thing to do. LEDs are so expensive and the technology is changing so quickly. It’s best to test in a few galleries in case they don’t end up working out in the long run. Maybe you’ll find that a particular bulb fails prematurely. We don’t know; we don’t have enough history with LEDs.
That’s right. Part of the process is trying different manufacturers’ bulbs, seeing how they perform over time. Every museum is going to have to figure that out themselves.
But I have to tell you, there are good LED products out there and there are bad ones. There is some stuff that has dreadful color and some stuff that won’t hold up.
So it’s just trial and error?
Well, that’s partly why PNNL is here. We’re trying to establish standards and give them the metrics to examine LED products. We’re also publishing data about the performance of these products.
How are museums dealing with the expense of LEDs?
They may cost between $50 and $130 per bulb where halogen was $10. Theoretically it lasts a long time and it saves so much energy it will pay back over time. But we want to document how long it will last, how much power it draws. We can do the calculations to show that it saves energy and money over time. It will pay back quickly depending on the hours of use.
In places where you have high electricity costs--if you‘re in New York or Washington or San Francisco or San Diego--those are places where electricity is very expensive and everything you can do to use a more energy efficient is beneficial.
Then there’s the cost of changing the light bulb. You’re probably aware there are lot of museums that have extremely valuable art. You don't have a $10-an-hour teenage kid up on the ladder to change the light bulb. So changing light bumps in museums is very expensive—it happens after hours and by a crew that has to be careful with the art, the light, the 30-foot ceilings. Because it’s expensive to change a light bulb, if you can have a bulb that lasts 25,000 hours—and that’s conservative-- versus 3,000, you’re changing it one-eighth as often and you’re saving on labor costs.
What type of light users are leading the way with LEDs?
There are some large retailers that are using LEDs in parking lots and in window displays. The Macy’s here in Portland put LEDs in their window displays, which makes sense because they are operating 24 hours a day. The large retailers see the benefit. You’re also seeing some cities, towns and highway departments replacing them largely because it’s reducing the cost of getting up there and changing bulbs. It may not be a big energy savings in the case of roadway lighting, but it may reduce long term costs because of the labor.
But they aren't changing out everything. In most cases, they’re trying it out and once they feel like it’s a worthwhile investment they’ll use more.
Photos: courtesy PNNL