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Loblaws’ cool moves

The new location will include cutting edge refrigeration, lighting and heating technologies. The store will also be part of Loblaw’s Demand Response Program agreement with the Ontario Power Authority (OPA).

Innovative heat exchange

Loblaw Companies Limited (Loblaw) is Canada’s largest food distributor, with operations across the country. It’s also one of the largest private sector employers in Canada, with 139,000 employees. As a grocery retailer, Loblaw incurs substantial costs to maintain its stores. One of the largest costs is energy. As of late 2007, the company was consuming 3.2 Terawatt hours of electricity annually in Canada — 1.3 Terawatt hours in Ontario alone.

With such a substantial electricity requirement, energy efficiency has to be top-of-mind.

Approximately 50 per cent of the total energy consumption of a Loblaw supermarket goes toward operating the refrigerated systems. Space heating also accounts for around 11 per cent of total usage.

A supermarket’s refrigeration system is generally designed as an autonomous system for producing cold; the bulk of the heat extracted from the system is released into the air outside the building. Yet, this heat can be captured to heat the building and provide hot water. This is something that Loblaw has introduced at a number of its stores, including the Scarborough Loblaw Superstore.

“Through the use of plate-to-plate heat exchangers, we are able to effectively capture all of the heat that is being rejected by the refrigeration plant and circulate it via a fluid loop to support heating the store,” says Elizabeth Margles, Vice-President of Public Affairs at Loblaw. “It’s a very simple concept but there are some technical barriers around it. However, we’ve been able to overcome these obstacles and incorporate this system in a number of projects.”

Refrigerant upgrades

Supermarkets also generally use a substantial quantity of synthetic refrigerant, which is circulated through the stores’ display cases in copper pipe under high pressure and fluctuating temperatures. This can be a source of significant leakage.  Conservative estimates suggest an annual leak rate of 10 per cent in a typical supermarket. Some put the total at closer to 30 per cent. These refrigerants, when leaked, contribute to harmful greenhouse gas (GHG) emissions — 1,500 to 3,000 times more damaging as compared to an equivalent mass of CO2.

Loblaw has equipped its new Scarborough Loblaw Superstore with innovative technology that reduces both energy consumption and the risk of harmful GHG emissions.

The refrigeration system at this Loblaw location is composed of a low-temperature system for frozen foods and a medium-temperature system for fresh produce.

Both systems use the refrigerant R507. The difference that’s being made at the Scarborough Loblaw Superstore site is that the refrigerant will not be circulated throughout the store. Instead, it will be confined to the mechanical room and cold distribution will be managed via two secondary loops with environmentally less harmful fluids: propylene glycol for medium temperatures and CO2 for low temperatures.

“We have about 60 of these medium-temperature systems installed across the country,” says Margles. “To my knowledge, we are the North American leader in the use of such systems. And we do it for a couple of strategic reasons: to reduce the refrigerant charge in our stores, due to the GHG emissions concerns of leakage; and because it preserves fresh product better, keeping it from getting dry.”

 This is similar to a demonstration project Loblaw ran in its Repentigny, Quebec store. “We used a secondary fluid in that low-temp system, but it’s not a product that we could replicate because of the fluid’s corrosive nature,” notes Margles. “This is what led us to the idea of using CO2 — the same CO2 that’s used in soft drinks.”

The use of CO2 will reduce the use of R507 substantially — from an average of about 3,600 pounds in a standard store, to only 350 pounds at the Scarborough Loblaw Superstore. That’s about a 90-per-cent reduction.

Natural Resources Canada has acted as a partner with Loblaw in introducing these innovations, through the support of their Technology Early Action Measure (TEAM) Program and supported by the CANMET Energy Technology Centre – Varennes.

Lighting and sensors

Another technology that the Scarborough Loblaw Superstore site is introducing is LED lighting in the door cases of the frozen food aisle. In addition, sensors are to be used, so that when a customer is detected in the aisle, the sensors turn the lights on. When they leave, the lights go out.

“The benefit is twofold — the energy required to run the lights is reduced and the energy required by the refrigeration plant to remove the heat produced by the lights while they are on is also diminished.” says Margles.

Demand response leadership

Innovative technology is excellent, but sometimes it’s simply effective management practices that make a big difference in energy efficiency. One of the ways in which Loblaw has been tackling this challenge and promoting energy efficiency at the same time is through participation in the OPA’s Demand Response Program (DRP).

This program was first introduced in June 2005. The DRP is an initiative to reduce peak demand in the province. It is playing an important role in addressing the future electricity supply in Ontario.

The program encourages short-term demand response capacity in response to the Independent Electricity System Operator’s (IESO) Three-Hour Ahead Pre-Dispatch price signal in the electricity market. Basically, if the price of electricity hits a certain threshold due to supply demand, the systems in a building are automatically cut back — store lighting may be dimmed, task lighting reduced, air conditioning set back, parking lot lighting cut by a certain percentage, etc.

The voluntary program allows participants to receive compensation for curtailing the electricity demand of their business.

Customer awareness

The Loblaw Demand Response Project is a 10-megawatt demand reduction initiative. The project consists of the installation of intelligent controllers at over 100 Loblaw-owned grocery stores across Ontario, including Scarborough Town Centre. Each one of these controllers has the ability to accept instructions from a central command authority and control pre-specified loads in the stores.

The loads are primarily lighting and air conditioning. The server in the central command authority monitors the hourly electricity prices posted by the IESO and reacts at a pre-defined threshold.

The server automatically executes a demand response control strategy and sends the necessary instructions to controllers located at each store. The controllers then instruct the building automation system to take appropriate control actions to reduce the loads.

“We have over 100 stores that are already operating within the DRP, and have plans to roll this out in all of our corporate stores in Ontario,” says Margles.

According to Margles, the load reductions are not disruptive for shoppers. In fact, shoppers have praised store managers for taking the energy-saving initiative.

“Control happens on multiple levels,” explains Margles. “Initially, for instance, lighting will be reduced in our parking lots. This isn’t usually noticed by customers. It’s only at about a fourth-level requirement that customers may notice a reduction in lighting in the store.”

Margles points to the several benefits the program provides for the company — a reduction in utility costs, a way in which to increase public awareness of the electricity market and a reduction in the emissions associated with electricity generation.

These won’t be the last innovations by Loblaw. Many more store retrofits are still to come, and the exploration of new technologies will continue. For instance, with the amount of roof space the company has under management, Margles believes photo voltaics are a natural consideration.

“The OPA standard offer for PV generation is a good one,” she notes. 

The key for the company is to use its resources as effectively as possible.