Growing Greener: Let There Be Light! (Or, How My Condo Association Saved $2,000 on Electricity)
Advances in lighting can save energy and money at your home, in the workplace and along our city streets.
There aren't a lot of ways to help the environment that are cheap and easy. But we found one. It came at a particularly dull moment in the condo meeting, as we reviewed the “financials.” Charts showed how much we had spent this year compared to what we spent on the same things last year. But as we turned a page in the report, a murmur of surprise ran through the room.
“How come there’s this big difference in what we spent on electricity? How come the cost went down? By two thousand dollars!”
The answer was: lighting. It turns out the drop in electricity was because we changed our outdoor lights and stairway lights to ones that are turned on by motion sensors when someone appears who needs lighting.
Instead of the lights being on all night, we are now just lighting where and when someone needs it. A math nerd in the group did some fast calculations: “We’re saving 26 percent!”
And there are some other advantages to the motion sensor lights: we are not only saving money but also energy (less fossil fuel is being burned to make our lights go on). We have leveraged that energy gain by switching to compact fluorescent lights (we got them free when we got our free energy audit through Mass Save).
At the same time we replaced very bright "jail yard lights" with lights that provide more even lighting. The new lights cut down on the glare that had been coming in some people’s condo windows. They also don’t create deep dark shadows the way the very bright lights did, so they actually make the area outside our home more clearly lit and safer overall.
Finally, by choosing outdoor fixtures that aim the light where people want to see – on the ground and at people height instead of in all directions -- we are decreasing the amount of light pollution we are throwing up into Boston’s night sky.
Hey, we cut our budget and made the world a better place just by putting our lighting where we need it!
Street lamps are changing too
It turns out that the city of Boston has been doing the same thing. For the sake of public safety as well as reduced costs and environmental benefits (win – win – win) the city has taken on the job of converting its stable of 64,000 street lights from mercury and sodium vapor lamps to much more efficient LEDs that are aimed at the areas they are supposed to light.
In a bold, multi-year initiative that started in 2010, the city will have converted more than a third of the street lights to LEDs by the end of this year, bringing savings to almost three million tax dollars a year. The Mass Department of Energy loves the energy savings of the program (in fact they gave the city their Leading By Example award last year). Late-night dogwalkers love the clearer, more even light quality. Star-gazers sigh and say well, at least the new streetlight has a flat, cobrahead fixture that aims the lights where we need them, instead of the old lights that intensified light pollution.
Shorter days, more efficient lighting
Maybe one reason for my concern with light comes from our seasonal dip into darkness, emphasized by the sudden loss of an hour of daylight this weekend. When our family lived in Germany, this was the time of year for St. Martin’s Day (Nov. 11). I remember children parading in the dark with little hand-made paper lanterns through the narrow streets of the Old Town, singing songs about the light from the sun and moon and the stars.
Germany is further north than we are, and the days seemed much shorter and darker at this time of year (every afternoon the children played soccer in the dark behind our building). Unlike the pre-Halloween Lantern Parade around Jamaica Pond, the St. Martin’s Day Lantern Parade felt to me like an adaptation of some dark-time pagan rite meant to remember the sunlight and plead for its return. (The upside of St. Martin’s Day was the excuse to enjoy traditional roast goose with red cabbage. And dumplings... Comfort food for dark days.)
Last weekend my physicist husband, always a lover of hard data, picked up a copy of Cooler Smarter: Practical Steps for Low-Carbon Living from the Union of Concerned Scientists. The easy-to-read graphs show that lighting is the largest component of home electricity use, usually between 10 and 15 percent. The fastest way to cut lighting energy is converting to compact fluorescent bulbs – or better, LED lighting, but installing motion sensors, especially for outdoor lighting, or occupancy/vacancy sensors can push the savings further.
New construction gives you lighting options
Of course if you are starting a new building, there are lots of ways of designing energy efficient lighting. And now that more people are paying attention to the issue, those alternatives are evolving at lightning speed. We can see it in the design of green buildings in our corner of Boston.
I remember being wowed by the lighting design of the Boston Nature Center when it was first opened in 2002. Built in collaboration with the city of Boston, this first green municipal building on the other side of Forest Hills Cemetery modeled cutting edge energy efficiency. (Since then the Boston Nature Center has continued to tweak its eco-friendly design, adding large-scale solar arrays, dual-flush toilets, and a green roof.)
In that original design, windows were planned to maximize the amount of natural light entering the building so that only a minimal amount of artificial light would be necessary. Rooms were equipped with photocell sensors which dim or raise interior lighting depending on the amount of natural light entering the space. Cool!
How smart to focus not just on more efficient light fixtures, but on using free natural light. Okay, natural daylight is not entirely free, because you have to plan for ways of blocking the heat that comes with the light in summer, but it’s still making use of an existing resource, and one that may have special benefits for us humans!
Staples' Roslindale store is a model of (lighting) efficiency
When Staples opened its Roslindale store in 2009, lighting was one of the key factors in winning the building super-green LEED certification at the Gold level. (LEED is a voluntary green building rating system. It stands for Leadership in Energy and Environmental Design, and it is the recognized standard for buildings that are efficient, cost-effective, and good for occupants and the environment.)
The Roslindale store uses 50 percent of the energy such a facility would be expected to consume, and the majority of the savings are the result of efficient lighting. In the words of the certification, there is “an innovative skylight system that directs sunlight into the store using mirror and lens assemblies. Windows are tinted to eliminate excessive heat gain but to allow for maximum levels of natural daylight.”
There are actually 39 roof skylights providing natural light for the store! Which seriously reduces the need for artificial lighting during the day.
Meanwhile lots of folks are tinkering with the lighting in existing structures, adding skylights, solar tubes, and maybe exploring hybrid solar lighting (I love the web video of those snaky fiber thingies of sunlight!).
Arboretum takes advantage of latest lighting techniques
Putting the light where you need it continues to be a useful focus,whether it is a question of just where to install kitchen task lights or how to provide the best lighting for the 48 researchers and assistants at the Arnold Arboretum’s latest addition, the Weld Hill Research Building.
Weld Hill is another example of a LEED Gold building. Buildings can win LEED certification by amassing points in a number of different areas. The Arboretum got a lot of points by figuring out how to maintain the landscape without using any potable water, by on-site soil management and erosion control -- but I mean it is an Arboretum so you kind of expect that they will know about landscaping.
But Julie Warsowe, who runs the Arboretum’s visitor education program, says that the comment she hears most often from people who work at the Weld Hill building is that they love the lighting. It could be because each researcher gets to decide when and where and how much lighting. According to Harvard’s description of the lighting controls, “Each space has overhead lighting controlled by multiple switches/zones and each desk has either under-counter task lights or desk lamps for multiple lighting levels based on different needs. The project’s lighting design allows occupants to adjust the lighting to suit their individual preferences, which not only increases occupant productivity and comfort, but also decreases energy use.”
There are also thirty-three individual occupancy/vacancy sensors to shut off the lights and save energy when nobody is in the room. And, as we would expect, lights installed near the windows are controlled by photo-sensors, dimming lights and saving energy when there is enough natural daylight. The building runs on 30 percent less energy than such a facility would be expected to use with conventional lighting.
In these dark times, folks in our corner of Boston are beginning to see the light!