What can be done in existing retail home furnishings stores to move toward sustainability?
Illuminating Retail by Monte Lee
Retailers place great emphasis on sustainability in new construction projects. J C Penny Co., for example, opened its first LEED (Leadership in Energy and Environmental Design) certified store In August.1 It is designed to consume 41 percent less energy compared to a conventional store. Beyond lower operating costs, certified retailers like Penny, Office Depot, Walmart, and others, earn the loyalty of environmentally conscious shoppers. Sustainability is also an evaluation criterion on Wall Street and often a prerequisite for construction loans.
But what can be done in an existing store to move toward sustainability? Lighting is a relatively easy area to reduce operating costs and we have discussed that topic.2 But lowering operating costs is not the only objective of sustainable lighting. Lets take a look at what sustainable lighting is, whether LEDs are a magic solution, and what can be done to achieve sustainable lighting in existing buildings.
Sustainable Lighting Defined
Sustainable lighting is, "Lighting that meets the qualitative needs of the visual environment with the least impact on the physical environment.”3 It is really important to understand and to meet the criteria of both parts of the definition. We could turn the store lights off to reduce our impact on the environment, but that would not meet the visual needs of our customers.
The Visual Environment
The first goal of sustainable lighting, meeting the needs of the visual environment, may seem to be contrary to having the least impact on the physical environment. The fact is, providing quality light typically minimizes the amount of energy used. Innkeepers, for example, often buy the cheapest compact fluorescent in a lower wattage than actually required while thinking they will maximize savings. When we get to our room we find it necessary to turn on all the cheap lights to see what we are doing. The net result of the cheap approach is higher energy consumption with greater environmental impact.
Quality lighting is all about presenting color and detail at retail. Why else would grocers, including Walmart, put the most expensive light source in produce and bakery departments? Sales in those departments increase 85% with “good” light.
Why would auto parts stores buy the best fluorescent tubes rather than saving a buck? They know that quality lighting is important to the way customers perceive the store and its products.
LEDs or Solid State Lighting (SSL) like these from Philips are screw-in replacements that match the output of 45 and 50-watt halogen bulbs. Technological challenges stand in the way of more powerful SSLs to replace 75 and 90-watt halogens used by most furniture stores.
Pop, Sparkle & Texture
If color is the first requirement of retail lighting, then pop, sparkle and texture are next on the list. Accent lighting adds these elements of visual interest to the sales floor. Accent lighting helps the customer focus on what is important by making important items at least twice as bright as the background lighting. Accent lighting adds the sparkle to a diamond, a chandelier, or china place setting. Accent lighting also shows textures by creating shadows that provide depth and contrast to what we see.
Pop, sparkle and texture can only come from lights that are point sources. Bulbs that generate light along the surface of the bulb, like fluorescents, are called diffuse sources. The beauty of a diffuse light source is that it does not cast shadows. Fluorescent light is great for background or general lighting, but not good for accent lighting (as in track lighting) because of this shadow/texture issue.
The Physical Environment
The environmental issue for lighting isn’t the use of scarce resources to make lighting products, or even what goes to the landfill at the end of the product’s life. The real issue is the demand for electricity lighting creates. Generating electricity typically releases greenhouse gasses and mercury into the environment. Lighting products that reduce demand for electricity, are recyclable, or reduce the demand for additional products, move us toward sustainability.
Linear fluorescent products, like T8 lamps used in 2x4 fixtures, need about 30% less electricity than the products they replace. The lamps are 99% recyclable and their service life, how long they last, is commonly 10-12 years, so that fewer replacement products are required.
Compact fluorescent lamps that also contain mercury often go to the landfill but, because they use 75% less electricity than the incandescents they replace, the release of mercury into the environment is greatly reduced. We get 53% of our electricity from burning coal; coal naturally contains mercury and burning coal releases mercury.
Any amount of electricity saved, reduces our impact on the physical environment. Using efficient, incandescent lighting products can achieve a 30% reduction in electricity consumption, but still give us the pop, sparkle and texture that are seen as necessary by even the most strict lighting regulations. But what if there were a way to generate light with the energy savings and long life of a fluorescent, but without mercury? What if the source could also give us the pop we need to merchandise our stores? We have been hoping that LEDs would be the answer.
Compact fluorescent bulbs are the recent rage in lighting, but they were actually invented in the 1970s. At that time major lighting manufacturers didn’t want to invest in the technology necessary to bring a quality product to market. A lot of products that did get to market were junk that didn’t come on instantly, maintain light output, or even have good color. Those flaws retarded consumer acceptance of compact fluorescents for 30 years.
The lighting industry does not want to repeat that experience with “solid state lighting,” what you and I generally call LEDs. National standards for solid state lighting products were published about the same time, 2008, as the final standard for compact fluorescents. Products that meet requirements and have the ENERGY STAR label.
A light-emitting diode (LED) is not a “light bulb”, as we know it. LEDs are solid state devices, semiconductors (as in computer chips) that emit light. I can’t explain how it happens, but I know that the magic works. LEDs have been around since 1962 as indicators.4 Those are the tiny lights that flash on laptops and computers to let us know if data is processing.
The Technical Challenge
There is a big difference between an “indicator” and an “illuminator.” Getting a solid state device to become an illuminator is a serious technical challenge. The reality also is that red, green and blue SSL devices are pretty easy to build but getting white light in sufficient quantity is difficult. Good color rendering from white SSL devices is even more difficult. A blue-white light may be acceptable for utility LED flashlights but will not work in retail stores.
What humans prefer is a warmer tone that makes earth tones appear more natural.
Unfortunately with solid state lighting devices getting the warm tone is less efficient. An 11-watt SSL system can generate 560 lumens at 4,100 degrees on the Kelvin scale (cool) but only 410 lumens at 3,000 (warm). To encourage manufacturers to meet our needs, the U.S. Department of Energy is offering a cash reward, $5 million, for a solid state replacement for the 90-watt, PAR38 halogen. Not only cash, but government procurement and sponsorship by power generators nationwide go to the winner.5
The DOE estimates that approximately 141 million 90PAR38 lamps are installed in residential and commercial applications. If all 141 million reflector lamps were converted we could avoid 2.6 million metric tons of carbon emissions. So far the prize is unclaimed.
Are Solid State Lighting Systems Ready?
Did you notice that I slipped the term “systems” into the discussion? Solid state lighting requires a power supply to condition and regulate electrical input to the diode. In some linear systems a single power supply can drive an entire group of diodes. Solid state screw in lamps have a power supply that is built in, just like ballast in compact fluorescents.
The direct answer to the $64 question, “Are Solid State Lighting Systems Ready?” is, “Sometimes.”
SSL systems have replaced fluorescents in supermarket freezer cases, and we recently put SSL into ice cream cases at Friendly's Ice Cream Restaurants. Energy savings are good and the visual requirement is met. I was in an Olive Garden restaurant where SSL accent lights were used to highlight objects d’art on the walls. The lights were relatively close to the objects, so the visual effect worked for me.
As this article goes to press, Philips Lighting is introducing a line of PAR30 and PAR38 SSL systems that I tested as engineering samples. The products are acceptable replacements for 50PAR30 and 45PAR38, 25-degree floods as claimed by the manufacturer. The thought of using 1/4 of the electricity for the 45,000-hour service life of the light is very appealing. If you are using a 50PAR30 on your sales floor, you might be very satisfied with the new product.
My personal view is a 50PAR30 is about 2/3 of the minimum light required to meet the visual requirement for accent lighting. If my store were paying 28 cents per kilowatt-hour for electricity, I might find the 50-watt quite acceptable. The SSL device would be a blessing if I could save $39 per track head per year.
Working Toward Sustainable Lighting
The poster child for what not to do to achieve sustainable lighting is my local, High Point, Pier One. The store used to be all track (halogen) lighting, which was great for pop, sparkle and texture – what else is Pier One? But halogen lighting is energy intensive -- big electric bill, big environmental impact. Someone suggested the store should use 2x2 fluorescents and fluorescent “accent lights” in a new track grid. That lighting design uses the least efficient general lighting fixture, and the least effective accent light.
Lighting in the store does not meet the visual need, nor does it minimize the impact on the environment.
Lighting technologies are available today to help your store move toward sustainable lighting. Using the right linear fluorescent, compact fluorescent, infrared coated halogen, and SSL systems can meet your visual requirement and reduce the impact to our physical environment.6 Any step in the right direction will help the planet as well as your bottom line.
(1) The Leadership in Energy and Environmental Design (LEED) Green Building Rating System™ encourages sustainable green building practices. LEED is a third party certification program developed by the U.S. Green Building Council. LEED certification verifies that the building is operating exactly the way it was designed. For additional information see: www.usgbc.org
(2) Better Store Lighting at Lower Cost, Furniture World, Vol 135, No. 6, October 05, 2005, p. 4.
(3) International Association of Lighting Designers, Sustainability Committee, 2001.
(4) For a brief explanation of how diodes emit light see http://www1.eere.energy.gov/buildings/ssl/how.html
(5) The “L Prize” competition is designed to spur lighting manufacturers to develop solid-state lighting products to replace common light bulbs. See: U.S. Department of Energy, http://www.lightingprize.org/.
(6) A discussion of sustainability and specific actions is provided on the web site, www.servicelamp.com. Service Lamp also provides demonstrations and information in the NHFA Retailer Resource Center during the High Point Market.
Monte Lee is a Regional Manager for Service Lamp Corporation, a distributor of lighting products such as fixtures, bulbs, plus lighting consulting and design services for retailers. Inquiries on any aspect of furniture store lighting can be sent to Monte care if FURNITURE WORLD Magazine at firstname.lastname@example.org. See all of Monte Lee’s articles on store lighting posted to the www.furninfo.com website.