Walmart Canada DC is model for energy conservation.
By Eric Kulisch
In November 2010, Walmart Canada opened a 400,000-square foot fresh food distribution center in Balzac, Alberta, that sets industry standards for sustainability.
The company says the $115 million facility, which services all 104 Walmart stores in Western Canada, is 60-percent more energy efficient than a traditional refrigerated warehouse.
Walmart showed off the ultra-modern facility during its annual global sustainability summit a year ago at corporate headquarters in Bentonville, Ark. A video and other material on the corporate Website describe its features.
The DC, which is operated by Supply Chain Management Inc., a subsidiary of Exel, the contract logistics arm in North America of Deutsche Post DHL, includes the company’s first hydrogen fuel cells to power the entire fleet of 71 forklifts. The use of hydrogen fuel cells instead of traditional lead acid batteries will reduce carbon dioxide emissions by 55 percent, saving 530 tons of carbon annually, or the equivalent of taking 101 passenger vehicles off the road per year, according to the company.
Two 30-kilowatt wind turbines on the property generate about 100,000 kilowatt-hours per year each, producing enough electricity to power 40 average-size Canadian homes per year. There are 16 solar thermal panels mounted on the facility that produce energy to heat water used in office and maintenance areas. The solar array produces a peak of more than 205 kilowatt-hours per day, or the equivalent of heating the water of 20 Canadian homes with 40-gallon tanks.
Custom-designed automatic doorways between refrigerated and freezer areas produce an airflow pattern that keeps different temperature air in respective zones, minimizing energy loss in refrigerated sections. Gaps between trucks and the dock doors have been lessened to reduce the loss of refrigerated air. The windows found in dock doors, which allow cooling loss, have been eliminated. Walmart also installed insulation in the floor levelers that bridge the gap between the truck and the dock floor. Electronic monitoring ensures that dock doors are not left open longer than necessary.
Walmart Canada’s DC has a smart refrigeration system which uses ammonia as a coolant instead of ozone-depleting freon. Designed with a demand-response capability, it is able to draw electricity during off-peak grid times. Walmart says the system is 33 percent more energy efficient than traditional freon systems. Waste heat from the system is also recycled and used to keep the subfloor frost free in the winter. The smart refrigeration system will help the company avoid an estimated $2 million in costs over five years.
Thermal imaging scanners are frequently used to test for, and plug, cooling leaks.
Overhead lighting is provided by light emitting diode (LED) bulbs. LED lights are 69 percent more energy efficient than incandescent bulbs. They are preferred for refrigerated environments because they produce less waste heat and can last up to 20 years. The use of LEDs in the perishables DC is projected to save more than 7 million kilowatt hours and $645,000 over five years.
In the warehouse, concrete slabs were poured in large sections, reducing cleaning requirements, chemical compound joint fillers and wear and tear on machinery. The floor also contains a reflective coating to improve reflective capacity by 80 percent, making the facility brighter and reducing lighting requirements.
Walmart says it expects to save an estimated $4.8 million in energy costs during the DC’s first five years in operation.
Charged up
