By Susan Stewart, Organic Certification and Sustainability Coordinator

In the fiscal year 2010 (July 1, 2009–June 30, 2010), the Wedge used 1,149,600 kilowatt-hours (kWh) of electricity and 26,940 therms (THMs) of natural gas to operate the store. Compared with other grocery stores of this size, we consume a little less electricity than average. We are a bit on the high side of average for natural gas use due to our location in frigid Minnesota. In this first Sustainability Report, we disclose both our energy consumption and our practices for maintaining and replacing equipment.

The amount of energy used in our homes fluctuates, depending on behavior (and, of course, on weather). According to the US Energy Information Administration, in 2009 the average Minnesota household used about 800 kWh per month. Heat uses the most of a home's energy budget, followed by lighting and appliances, hot water heating, air conditioning and, finally, refrigeration. In the home, small modifications of habits can make a big collective impact on the amount of energy used, like turning off lights when leaving a room, reducing heat or air conditioning when leaving home for awhile, and shutting off electrical appliances and computers all the way to the source. Replacing energy guzzling equipment with newer, more efficient equipment will reduce energy use and costs also.

In a grocery store, refrigeration is the highest energy user. Food safety requires maintaining the right temperature for refrigerated items at all times. Most grocery refrigerators and freezers have glass doors, appropriately designed so that customers can decide on a product before opening the door.

Lighting is the next greatest energy user. In the Spring of 2009, the Wedge replaced the old ballast lights with new, more energy efficient lights that use sensors to detect natural light from the front windows, and adjust the strength of the lighting accordingly. We also changed the orientation of the fixtures, which reduced the number of lights ten percent.

Just like in our homes, the store has to use energy for heating and cooling the building and for running appliances and computers. The heating and cooling fluctuations are automated to keep customers and workers comfortable throughout the seasons. Solar panels on the south roof of our building are thermal solar heaters, used to heat water in the store so that we use less natural gas.

The cash register area of the store, fondly called The Front End, reduced its energy consumption by automating a computer turn-off switch for all the registers. Before the last worker leaves the co-op at closing, a final check is made to ensure that everything non-essential is shut off. For every kWh we consume, we generate $36.02 in sales, we use an average of 1.8 kWh per customer, and we use about 49 kWh per square foot of the building.

The Wedge is doing a fairly good job of keeping energy consumption to the minimum needed to run a good store. But improvement is always a goal. Reporting on our energy use is an element of helping us understand where improvements might be made. Our next Sustainability Report will compare our energy use from one year to the next, so that we can measure the effectiveness of changes in our behavior and learn what more we can do to be more energy efficient.