A Fine-Tuned System and Digital Compressors Bring Cool Chunk of Change to One Supermarket

When Renteknik Group — experts in energy optimization and management — was tapped to help a southwestern Ontario grocery store take advantage of the Independent Electricity System Operator’s (IESO) saveONenergy incentive program, they engaged Emerson Climate Technologies for real-world ways to improve efficiencies in the store’s legacy refrigeration system. The store utilized low- and medium-temperature parallel rack systems running on 10 Copeland™ semi-hermetic compressors.

Measurement and Verification Program

First, Renteknik fine-tuned the existing system by optimizing every set point in the supermarket, cleaning condensers and replacing any damaged components. They performed these basic energy efficiency measures (EEM) for 11 months while closely monitoring system performance through their real-time ClimaCheck online portal.

Result: 18 percent reduction in energy costs

Next, Renteknik then replaced two weaker compressors — one low-temperature and one medium-temperature — with Copeland Discus™ digital compressors because of their ability to retrofit refrigeration systems with precise variable-capacity, load-matching capabilities. Before engaging their full digital potential, Renteknik measured the improvements to the system with the compressors alone (without engaging their variable capacity capabilities).

Result: 4 percent energy improvement

Lastly, they engaged the new compressors’ digital retrofit capabilities. In this configuration, the digital compressor serves as the lead compressor in the parallel rack.

Result: 12 percent savings from ongoing energy efficiency and reduced compressor cycling

The Payback

After three months, Renteknik verified a 122,965 kWh reduction in annual energy consumption (a 16 percent reduction in energy costs) and an annual savings of $17,215. In addition, this reduction translated into an incentive payout of $12,297 (at the saveONenergy incentive rate of $0.10 per kWh). With the projected annual savings of $17,215, the simple payback without incentives is just under a year and a half (including Renteknik’s consulting and measurement and verification program costs). The additional saveONenergy incentives cut the return on investment time in half. Because of the success of this trial, the supermarket will upgrade their system with a Copeland Discus™ digital compressor whenever one needs to be replaced.

This blog is a summary of the article A Cool Chunk of Change from our recent edition of E360 Outlook. Click here to read it in its entirety and learn more about how a digital compressor retrofit help reduce energy costs.