Energy Management Case Study: Retro-Commissioning Service Cuts Energy Use

Two prominent grocery chains in the Upper Midwest are reducing their energy use and cutting energy cost by retro-commissioning their stores. The chains have done so with the help of SINGH360, a service provider that specializes in working with grocery chains, and the PowerScout 24 power meter.

The retro-commissioning process identifies opportunities to improve energy efficiency for stores that have been in operation for several years. The process is valuable because such stores tend to become less energy efficient with time, says Abtar Singh, president of SINGH360.

Strack and Van Til, a 37-store chain in Indiana and Illinois, recently hired SINGH360 to retro-commission 16 locations. As part of that process, the company upgraded system controllers to the latest software version. They put the energy-management system (or EMS) for each store on a network so that they can check and manage them remotely. They also implemented a system to control store lighting on an Energy Management System.

“In the last four months we’ve seen savings of 8% to 12% on average,” says Don Erminger, director of energy and maintenance. “Before the project, we expected a payback of two years. But after our first four months, we now think we’ll achieve full payback in 12 to 14 months. That’s twice as fast as we first projected, thanks to opportunities SINGH360 identified.”

Coborn’s, a 54-store chain headquartered in St. Cloud, Minnesota and operating in six states across the Midwest, recently retro-commissioned its first store. In addition to reducing energy costs and improving environmental sustainability, the company also benefited from addressing many maintenance issues, says Chris Braun, refrigeration project manager.

With the opportunities SINGH360 identified, plus a 75% utility incentive from Dakota Electric, the company expects payback in less than six months, Braun says. The project also identified added capital projects that could cut the company’s energy use by 20% to 25% during retro-commissioning, he says.

Such utility rebates often make retro-commissioning even more attractive.

Xcel Energy (http://www.xcelenergy.com/), an electric and natural gas utility that serves customers in eight states, provides attractive incentives for its customers. “Recommissioning can be a good way for supermarkets to save energy,” said Renae Wrich, Xcel Energy recommissioning program manager in Minnesota. “As an incentive for supermarkets to take action, we offer rebates to subsidize the cost of identifying and implementing energy-saving HVAC and refrigeration projects,” She said. Xcel offers recommissioning rebates in Colorado and Minnesota.

SINGH360’s retro-commissioning process is especially tailored to the needs of supermarkets, says Abtar Singh, president.

“We always involve a three-person team. They include a commissioning engineer, a refrigeration technician, and an electrician. They use a mobile app we developed to make the process thorough and consistent.

A DENT PowerScout 24 was used to submeter the mains, lighting, HVAC, refrigeration compressors, and condensers. The submetered data helped in three ways during the retro-commissioning:

  1. To quantify energy savings achieved during retro-commissioning
  2. To identify anomalies and help determine that lighting and HVAC were operating on the proper schedule
  3. To find optimum operating control parameters for the refrigeration system using the metered data

“The building owner uses that same data to protect their savings by continuous monitoring,” says Singh. “We selected the PowerScout because it provides easy installation and provides a rich set of data, such as voltage, current, and power factor.”

Each store takes about three weeks to recommission, Singh says. “First we dial in remotely to analyze the store’s energy management system (EMS). We prepare a game plan. Then our team spends a week in the store diagnosing and fixing problems. While we’re on site, we also fine-tune the EMS.”

“Then we further adjust the EMS remotely and monitor its performance to verify the changes are producing their intended effects,” Singh says.

“We create an issue list so the store owner can hire a refrigeration contractor to fix any problems that go beyond the solutions we provide. We also identify additional energy projects and initiatives that can further reduce energy consumption.

“Finally, we issue a commissioning report. The report summarizes the work we’ve done. It identifies and recommends new opportunities for savings. And it forecasts likely savings from the recommended projects.”

About SINGH360 Inc.

SINGH360 (www.singh360.com) specializes in facility management. The principals have worked with the supermarket industry for 20 years, providing objective counsel that helps operators find and implement the best solutions to energy and maintenance challenges. The company’s solutions often incorporate the latest technologies. Services range from building-envelope assessments to complete design of mechanical and electrical systems (including HVAC, lighting and refrigeration systems) for new and existing buildings. The company help organizations set priorities for efficiency projects based on sustainability goals, speed of payback, and the return on investment. For more information, contact Abtar Singh, abtar@singh360.com or 651-605-1093.