Associated Wholesale Grocers

Fast Facts

Industry: Food Storage
Location: Nashville, TN
Program: TVA-Enel X Demand Response
Power Distributor: Nashville Electric Service
DR Strategy: Curtailment Only
Primary Curtailment Strategy: Refrigeration set point adjustments
Annual Payments: Approximately $25,000

The Big Picture

Associated Wholesale Grocers (AWG) in Nashville serves as a hub for grocery storage and distribution to its more than 300 co-op members, including Apple Markets, Piggly Wiggly, HG Hill, and more. AWG covers a wide territory that stretches throughout the South and Midwest. The AWG facility is enormous, including more than 500,000 square feet of dry storage and 250,000 square feet of refrigerated storage. Many items can withstand only a minor temperature variation, so AWG monitors its storage facilities carefully.

AWG is a major energy consumer, using more than 1 million kWh per month— resulting in a $1.4 million annual energy bill. In 2007, AWG’s local electric utility, Nashville Electric Service (NES), made demand response available to AWG. Established by the Tennessee Valley Authority (TVA) and offered by NES, AWG enrolled in the TVA-Enel X Demand Response (DR) program to reduce its energy costs, help protect its operation and the surrounding community from rising energy costs, and help maintain a stable grid. During DR dispatches, AWG curtails more than 850 kW by reducing its lighting and raising the temperature set points in its cold storage areas.

These changes result in consistent energy reductions and annual payments of more than $25,000 for AWG. As a co-op, AWG must cut costs whenever possible, and the DR program enables significant savings and other benefits.

Cooling Down Energy Costs

At first, Associated Wholesale Grocers leaders assumed that it would be impossible for the organization to participate in demand response. “We heard about DR back in 2004 and liked the idea a lot,” recalls Benny Phillips, facilities manager at AWG’s Nashville division. “But it just seemed too risky, since we were storing very temperature-sensitive items, such as bananas.”

But the more Phillips and others looked into their use of energy, the more flexibility they found. They analyzed temperature readings and found that refrigerated storage areas could hold their temperatures for hours longer than initially seemed possible. They found that they could shut off the electricity to refrigeration units during off-cycles, saving energy costs without affecting operation. They also began charging the batteries for their forklifts during off-peak times. And they completed a major lighting retrofit that saved the company money and helped modernize its infrastructure. All of these efforts are part of the company’s commitment to “going green”—adjusting its way of doing business to reduce environmental impact and increase sustainability. AWG sees this commitment as crucial to the future success of the company.

In the summer of 2007, AWG participated in a demand response pilot program offered by its utility, Nashville Electric Service, and sponsored by TVA. During dispatches, AWG moved temperature set points by approximately 3 degrees in its extensive cold storage area. AWG found that it was able to reduce its energy use significantly without affecting its operation or the quality of the diverse goods it warehouses for its co-op members.

During a DR dispatch, AWG receives notification from Enel X via phone and email, and has 30 minutes to respond. In its machine room, AWG facilities personnel shut off evaporators and compressors associated with the refrigeration area and begin monitoring these areas throughout the duration of a dispatch, which can last from 2 to 8 hours.

“For us, DR has turned out to be really easy,” says Phillips. “We simply make some adjustments, monitor carefully during the dispatch, and reset our refrigeration settings when it’s over. We’ve found that we’re able to make changes without any effect on the items we store—and we can put everything back to normal in minutes.”

AWG’s 150 employees are informed of dispatches, which are largely invisible to staff members, though some may notice that refrigeration fans aren’t operating. “Everyone at AWG is very pleased to help out and to be part of the DR program,” says Phillips. “We want to be part of the energy solution, not part of the problem.”

The Results

AWG’s initial target energy reduction was 700 kW, but the company ended up going well above this amount. On average, AWG provides approximately 850 kW in energy reductions during DR dispatches. The pilot earned AWG $25,000 in payments. But the savings have helped AWG learn more about ways to achieve efficiency in other areas as well. “We’re saving at least $70,000 a year from off-cycle energy reductions and other curtailment changes,” says Phillips. “And we’re constantly looking for new ways to save. Demand response makes a big difference to our bottom line. As a co-op, the more we save, the more we can pass along these savings to our members.”

The Benefits

The biggest benefit that the DR program brings to AWG is a positive financial impact. AWG sees DR as a way of earning money without making major changes or putting its produce and other stored commodities at risk. “My boss is ecstatic,” says Phillips. “Any time you can save some dollars, we’re all for it.” The money earned from DR goes directly into the general facilities fund, and helps pay for other cost-saving changes.

But the benefits of Enel X go beyond the bottom line, and include a range of more qualitative—but equally powerful—benefits.

Simple Implementation

“Working with Enel X was a real pleasure,” says Phillips. “They did a great job during the whole implementation process. They worked with our people. They didn’t rush. And they kept our comfort level extremely high.”

Clear Communication

AWG receives clear, prompt communication from Enel X, including timely notification of dispatches. “They give us plenty of advance warning so we can do everything we need to do to ensure quality and lower risk,” says Philips. “We’re in touch via phone and email, and Enel X’s commitment to communication really makes a difference.”

Increased Collaboration with NES

During the DR process, AWG collaborated with its local energy provider, Nashville Electric Service. “NES has given us a great opportunity by making DR available,” says Phillips. “This has helped us build a stronger relationship with NES. They see that we’re willing to help out our community in any way possible. And they’re more forthcoming about ways that they can help us reduce our energy costs. This better relationship is a real plus for us.”

A Community Commitment

AWG is located in the middle of a largely residential area, and is the largest user of electricity in its community. “We feel strongly about not sucking up so much juice,” says Phillips. “With DR, we’re able to protect our company, but also help the community keep rates down.”

Using Software to Find New Savings

Much of AWG’s energy use is flexible. For example, it can charge the batteries for its forklifts almost any time. With Enel X's energy intelligence software, AWG can see the peaks and valleys of its energy use, and choose to time energy-intensive activities during periods when the rates are lower. “Enel X's software is a really useful tool,” says Phillips. “Even if no one is here on site, we can see trends in energy use and get information that helps us trim our energy bills even more. I feel certain we’ll be using it more and more in the future.”

The Future

Phillips continues to look for new ways to boost energy savings and overall efficiency. Under this program, AWG estimates its future payments to be over $25,000 per year.

Phillips is also spreading the word about the DR program to other AWG facilities. “I’m definitely advising them to sign up for demand response if it’s available in their area,” he says. “It’s money in their pocket. And DR is easy to implement, thanks to Enel X.”

Associated Wholesale Grocers is just one of the many innovative organizations that benefit from demand response. To find out more contact your local distributor or email