To save both money and energy from installing skylights in a retail environment, control is essential. Automatic photocontrols will ensure that stores are maximizing daylight, and there is a choice between switching and dimming controls. Heschong explains that switching is “simple and less expensive” and in general tends to result in higher energy savings, while dimming is “more subtle, more sophisticated, and more expensive.” She says switching is an attractive choice in retail because people move around while shopping, meaning their focus continuously is shifting and “they are less aware of discreet changes in light levels.”

Loveland explains that the relationship between the location of the skylights and the type of product being sold on the retail floor is important. He says he tends to generously skylight the non-internally lit shelving while keeping skylights out of refrigerated areas with internal illumination so the skylights do not compete with the electric lighting. Skylights typically are used to illuminate the general sales floor, but it varies from retailer to retailer. While PCC and Stop & Shop primarily have skylights in the general merchandise areas, Heschong says she knows retailers who employ different strategies, such as one in the Southwest who swears by providing daylight over the produce section. “Their comment to me was that the produce sells so quickly, having higher light levels or worrying about spoilage is a non-issue for them.” However, others avoid daylight over produce or flower displays because they worry the natural light will accelerate aging or blooming. Regardless of how many skylights are used or where they are located, “Make sure all sunlight is diffused,” Heschong says. “Unfiltered sunlight is not a good idea.”

As more supermarket chains across the country incorporate daylight into their stores, it appears to be a design strategy that will continue to be refined with time. And while the energy savings, customer satisfaction, and other benefits make the use of skylights in supermarkets worthwhile, Heschong says daylight also can be implemented as a creative design tool. “It is entirely possible to use daylighting as a strategic design element, to use it a little more artfully and as part of a visual merchandising strategy,” Heschong explains. “I see that as the next frontier of daylighting, is getting the architects, lighting designers, and interior designers to all understand that they can use daylighting as an aesthetic component of design.”

STORES | Albertsons, Boise, Idaho; Puget Consumer Cooperative Natural Markets, Seattle; Stop & Shop, Quincy, Massachusetts
RESEARCH TEAM | Heschong Mahone Group, Fair Oaks, California
DAYLIGHTING STRATEGIES | Photocontrols to measure daylight levels and automatically adjust electric light output; natural light via skylights

The use of skylights in supermarkets can result in substantial energy savings as photocontrols automatically adjust the electric lighting when adequate daylight is present. In stores such as Albertsons, skylights are an integral part of the lighting design and offer an ambient environment.The frozen foods section of a Food4Less store is shown illuminated by only daylight. Clerestory windows let in natural light and illuminate colored leaves hanging from the ceiling at the Redmond, Washington, PCC Natural Market location.The Redmond PCC store features 28 skylights that are specially glazed to block heat and diffuse the incoming daylight.Shoppers at an Albertsons store where illumination occurs by natural light via skylights with no electric lighting on.