In this issue

Big-box stores show sustainability is good business

Day-lighting and polished concrete floors in Wal-Mart's experimental Aurora, Colo., Superstore show that sustainable building is also attractive building. (Photo courtesy of National Renewable Energy Laboratory)

In the competitive world of "big-box" department stores, a new kind of competition is emerging, as industry giants strive to reduce their environmental footprint through the use of renewable energy and more efficient buildings and practices.

Wal-Mart Stores, Inc., which pioneered sustainable operations two years ago with experimental Supercenters in Aurora, Colo., and McKinney, Texas, recently announced that it would be adding solar arrays to 22 locations in California and Hawaii. About the same time, Kohl's Corporation unveiled its plans to convert 75 percent of its California stores to solar power.

Projects support business, state goals

Wal-Mart's project represents a major step toward the company's goal of powering its operations with 100-percent renewable energy. Total generation from the 22 facilities is estimated to be 20 million kilowatthours per year.

Kohl's is working closely with the state to help meet the California Solar Initiative goal to generate 3,000 MW of solar power by 2017. The first two California Kohl's will go solar this month, with the rest of the designated solar locations to be finalized by the end of 2008. When complete, the retailer's solar deployment alone will represent approximately 1 percent of California's 10-year objective.

Economics, as well as environmental concerns, motivated Wal-Mart's purchase. A press release about the project noted that the pilot stores would realize savings on their utility rates in addition to reducing greenhouse gas emissions by 6,500-10,000 metric tons per year. "These simplified solar-powered energy services will enable Wal-Mart to realize that environmental conservation can be enjoyed in accordance with the benefits of reduced as well as predictable long term energy pricing," said Jigar Shah, chief executive officer SunEdison.

The solar energy company is building all of Kohl's solar systems and will provide Wal-Mart with four systems in Hawaii and four in California. Wal-Mart is also working with BP Solar and SunPower. Each company will install seven systems in California.

Ron Judkoff, director of NREL's Buildings and Thermal Systems Center at the National Renewable Energy Laboratory, concurred with Shah that renewable energy, like energy efficiency, is a good investment. "Wal-Mart's decision to take advantage of the economic and environmental benefits of solar power and energy efficiency technologies is a great step in the right direction," he said. 

Lighting an early success

NREL is collecting data on Wal-Mart's Aurora store over a three-year period to evaluate the facility's 50 different sustainability measures and technologies. Although the project is only at the half-way mark, the data and anecdotal evidence so far are suggesting some lessons. "At this point, my main advice to other companies is that energy and water efficiency measures are economically attractive and should be pursued," said NREL Senior Engineer Michael Deru, who also works in the Buildings and Thermal Systems Center.

Lighting has emerged as one area in particular where a few changes can yield significant benefits for retailers. "We found that Wal-Mart's standard lighting design was already very good," noted Deru. "Some of the experimental systems didn't really improve on that performance."

Wal-Mart has been employing light harvesting techniques in its stores for about the last 10 years, acknowledged Spokesperson Bill Wertz. Skylights linked to automatic dimming systems light up the stores' main shopping areas. "Some of the tucked-away corners need electric lighting but the rest is natural daylight," he said.

Installing LED lights in refrigerator cases really paid off, said Wertz. "The lamps are less expensive to operate than fluorescent lights and they display merchandise better," he stated. "Wal-Mart is already putting LEDs in new stores and retrofitting existing facilities."

More measures show promise

Closed refrigerator cases are another measure that Wal-Mart is rolling out to some of its other stores. Open cases for refrigerated and frozen foods pour cold air into store aisles, requiring more energy to cool the case—and to warm the store in cold weather. While placing more products behind glass doors promises energy savings, store managers initially worried that customers might be put off. That was not the case, however, said Wertz. "The acceptance has been great. The products are just as visible and customers don't perceive the doors as a barrier."

Of the store's many "green" building features, two standouts are being adopted in the design of new Wal-Mart stores. The white roof reduces the building's cooling load, and the handsome, polished-concrete floors cut down on maintenance and the use of some cleaning products. Both features illustrate Deru's advice to keep design simple, showing that even low-tech, non-mechanical measures can save time, money and energy.

Generating your own energy is not the easiest way to go green as Wal-Mart's experience with wind turbines at the Aurora store proves. The turbine has broken down frequently, however, and the verdict is still out. "At this point we aren't ready to pursue installing our own individual turbines," Wertz said.

The solar pilot project will help the retailer determine if photovoltaics are a cost-effective way to reach its renewable energy goals. One lesson Wal-Mart has learned quickly is that there are many ways to increase a business's sustainability.

Businesses, customers, employees show interest

In a collaborative, rather than competitive, spirit, Wal-Mart is reaching out to other retailers to share lessons learned that could improve sustainability across the industry. The Aurora and McKinney experimental stores, and Wal-Mart’s High Efficiency stores in Kansas City, Mo. and Rockton, Ill. offer tours to interested professionals.

The experimental stores have generated a lot of interest from several different areas, Deru observed. "At NREL, we have received several inquiries and provided tours from several Federal and local government agencies," he said.

Retailers who would like to learn more about Wal-Mart's other sustainability efforts—to reduce waste and to sell environmentally-friendly products—can contact Tara Raddohl or David Tovar.

It isn't only employees from other companies and industries that are interested in Wal-Mart's experiment, Wertz said. "Our own associates are very enthusiastic about sustainability, and they are proud to be working at the experimental store."

Customer feedback has been very positive, too, Wertz added. It seems that goodwill increases as a company's environmental footprint gets smaller. "Businesses should not underestimate the potential image benefits in evaluating efficiency and renewable energy projects," Deru asserted.

That is another lesson that doesn't have to wait for the final report. As Wal-Mart CEO Lee Scott told USA Today, "We set out to do (sustainability) as an obligation, a good-works effort, but we discovered the truth: The real reason to do this is for the business itself."