Wal-Mart Stores Inc. will open its latest generation of energy-efficient test stores this week with a Las Vegas Supercenter that uses new cooling technology to cut overall energy use by up to 45%. The Las Vegas store builds on advances in earlier pilot stores that reduced energy use in areas including lighting, refrigeration, and water flow.
The previous pilot stores in the Midwest cut energy use up to 25% compared to a typical Supercenter built in 2005, the year Wal-Mart launched a broad environmental program to reduce energy use and packaging waste and to sell more sustainable products. Wal-Mart said the new Las Vegas store adds to those savings with a new cooling system based on water evaporation for total energy savings of between 35% and 45%.
The latest store is built specifically for the arid climate of Western states, where water evaporates faster than in the more-humid East. It uses rooftop cooling towers to chill water that then runs in conduits under the floor of the store. The radiant cooling from the floor replaces traditional electricity-powered air-conditioning. The store also incorporates innovations from the previous pilot stores that include recycling heat from refrigerators and combining low-power LED lights in freezer cases with sensors that turn off those lights when no customers are around.