If businesses’ energy consumption stories were best-selling mysteries, it wouldn’t be difficult to figure out “whodunit,” because the terms “supply chain” and “carbon footprint” often seem to be synonymous. In fact, according to some estimates, transportation and logistics may account for up to 75 percent of most companies’ carbon emissions.
While it’s true that supply chains will always involve higher-than-average energy demands, that doesn’t mean your company can’t find multiple ways to “green” its logistics from end to end. And one good place to start is with your warehouses — or, more specifically, your warehouses’ carbon footprints.
What Goes Into a Warehouse Carbon Footprint Calculation?
To some people, the concept of a carbon footprint calculation requires no introduction. Simply put, it’s a way to measure the impact that a particular function, facility, or activity has on the environment so that a company, department, or individual can make better, more sustainable decisions.
In the case of warehouses, some of the key ingredients besides square footage, headcount, and total hours of operation include:
E-grid emissions: Here in the United States, all men may have been created equal — but all megawatt hours are not. Each of the 26 sub-regions within our country’s three power grids emits a different level of carbon dioxide — ranging from a high of more than 2,000 pounds per megawatt hour in Pennsylvania to a low of just over 819 pounds per megawatt hour in New York State. As a result, an electrical appliance or forklift operating at a facility in one area of the country is going to account for a considerably different level of greenhouse gas than that same appliance or forklift operating in another area.
Material-handling equipment: It’s not just about how many pieces of industrial equipment a facility uses. It’s also about whether those piece of equipment are forklift or pallet jacks; how they’re powered (propane or electricity); where they’re operated (in some e-grid sub-regions, propane and electric power sources are roughly equal, and in others, i.e., the higher power grid regions, propane is going to have the lower level of carbon emissions); and whether they’re sit-down or stand-up (the latter is generally more energy-efficient). Each piece of equipment’s wattage or gallons per mile/gallons per hour, whichever is applicable, is another important consideration.
Warehouse, office, and miscellaneous equipment: Plugging in key data about heat-shrink machines, conveyors, layer-picking devices, or other machines that might be in use on a warehouse floor may be the most important aspect of this particular category. However, it’s important not to forget that even small pieces of equipment operating in other areas of a facility, such as breakroom refrigerators and microwaves or office computers and printers, are carbon footprint contributors, too, even if they are fairly negligible ones.
Heating, cooling, and insulation: A simple assessment of a facility’s heating and cooling systems and their energy-efficiency ratings is merely the tip of the iceberg. A thorough assessment also must examine how many exposures a facility has to the outer environment — windows, truck doors, doors for personnel to travel in and out of — as well as what kinds of materials were used for a facility’s walls (and how thick they are), what types of roofing shingles have been used (and what their R factor is), and how many days per year each system is in use.
Lighting: In addition to tallying the number and wattage of fixtures used, companies also must distinguish between the type of lighting used — metal halide or fluorescent/incandescent (which is considerably more energy-efficient) — and factor in things like the hours these lights are used, and whether or not energy-saving devices like auto-sensors are in place. The importance of this particular category cannot be stressed enough, because it usually is the single largest contributor to a warehouse’s carbon footprint.
Waste: Unless a warehouse is actively participating in a recycling program, it could be sending tons of plastic, cardboard, and other waste to landfills each year — as much as one pound per 100 square feet of warehouse, according to The Rosenthal Group, a waste and recycling management firm — with an equally dramatic impact on the environment. Thus, it’s essential to record and capture what type of trash compactor a company is using (including the type and compaction ratio), the size of dumpsters it’s using in tons, and the frequency of how often its trash is collected.
Real-world, reliable references: When it comes to assigning the proper values or ratings to all of the aforementioned things, there are several highly helpful primary and secondary sources available. Some — including the Environmental Protection Agency, Department of Energy, National Institute of Standards and Technology, and National Oceanographic Data Center — are government agencies. Others, such as LEED and Energy Star, are private or government initiatives. Plus, there are many academic organizations, e.g., Utah State University’s Climate Center, and private companies that specialize in things like lighting design, roofing and climate control, etc. — specialties that could enable companies to drill down into certain areas of their calculations more quickly or thoroughly.
Next: How Can a Warehouse Carbon Footprint Calculation Be Used?