Walmart Experimental Store Performance Stories: Preprint

Walmart opened two experimental stores--one in Colorado and one in Texas--in 2005 to serve as test beds for several advanced building systems. Each embodied more than 50 experiments covering materials, water systems, energy systems, and renewable energy production. Walmart worked for three years with the National Renewable Energy Laboratory for the Colorado Store and Oak Ridge National Laboratory for the Texas store to monitor, analyze, and report on their performance. HVAC experiments included waste oil boilers, a microturbine/absorption chiller combined heat and power system, evaporative cooling, and a transpired solar collector. The refrigeration systems integrated a medium-temperature secondary loop, evaporatively cooled condenser, doors on medium-temperature cases, and light-emitting diodes on cases. Experiments in the lighting systems included a redesigned roof for clerestory daylighting and T-5 fluorescent lamps. Three photovoltaic systems for a total of 135 kW and a 50-kW wind turbine are also included. The energy system performance was compared to the measured performance of a prototypical Walmart store and to other benchmarks.