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Our Green Programming:  How Longwood Conserves Electricity

If Senior Electrician David Halliday had a motto, it might be, “Let there be highly efficient and cost-effective light!” He and the electrical team are on the forefront of the illumination revolution that is taking advantage of new technology to save energy—and money.

Lighting accounts for approximately nine percent of America’s electricity use, so there is a big opportunity to conserve. “We’ve been converting a lot of the old incandescents into CFLs [compact fluorescents] and also some LEDs [light-emitting diodes] where feasible,” says Halliday. “The Heritage Display in the Peirce-duPont House is currently illuminated by LEDs, which are only about 1 watt apiece. I just changed the lamps in The Garden Shop to dimmable CFL floodlamps.”

Halliday explains that nowadays there is a range of color temperatures for fluorescent bulbs, making their light much more attractive than the sickly glow that characterized them in the past. “We buy the warm white bulbs,” he says, “with a 2700K color temperature. There is a color that’s really bluish and you want to stay away from that.”

In the greenhouses, some lights focus on a plant or display. “We work with the gardeners to understand what they’re trying to achieve,” says Halliday. “It’s important to think about that when we choose the bulb. If a gardener wants to highlight something and you put in the wrong bulb, you’ll spread the light all over.”

No area is immune from Halliday’s scrutiny on his quest to convert Longwood Gardens to energy-saving lighting. “About 25 percent of our lighting is high-efficiency now, and I want to get to 50 percent by the end of the year,” he says. “I’m working in the greenhouse complex, the perimeter buildings, the Visitors Center, offices, and the Heritage Display. Our Christmas lights are already 95 percent LED.”

Recently, the sixteen exit signs in the Terrace Restaurant caught Halliday’s eye. “We were using 50 watts of light in each sign, and they were lit day and night,” says Halliday. “Now they are LEDs. We went from a total of 800 watts consumed by those exit lights to only 60 watts.”

Halliday maintains a detailed spreadsheet to track the changes he makes, and the wattage and cost savings those achieve. He points to the data that show what happened when he used 13-watt fluorescents to replace 60- and 75-watt incandescent bulbs. “We got the same amount of light—sometimes more—with the added advantage of cost-savings,” he says.

Longwood works directly with vendors like Sylvania and GE to address lighting needs, but Halliday also attends industry trade shows to find out what’s new and exciting. Lightfair 2011 is coming to Philadelphia next May, and Halliday will be there doing research. “We’re looking for more CFLs that have dimmable capability built right into the bulb,” he says. “I’m also in the market for outdoor floods with heavy glass.”

To bring its energy conservation efforts full circle, Longwood Gardens recycles spent bulbs, including fluorescents. “We want to go above and beyond,” Halliday says. “and we’re always looking at new technology. A solar photovoltaic plan is already underway.”

Visit Light Fair to learn about Lightfair International 2011. For information about Longwood’s solar energy plans, click here.