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A Comprehensive Environmental Commitment
The management of Shaw's Supermarkets has long realized that energy savings cut pollution, while adding to the bottom line. Shaw's worked hard with utilities and others to improve its energy efficiency throughout the 1990's. Building on the success of initial investments, the company broadened its focus to include waste minimization and pollution reduction in all areas of its operations.
In fact, Shaw's has quietly become one of the most compelling environmental success stories in the Northeast.
Shaw's is involved in a wide array of energy efficiency and environmental programs, including recycling and waste minimization, the replacement of ozone-depleting refrigerants, and fuel-saving modifications to its truck fleet.
The two projects described here include Shaw's computerized energy monitoring and reporting system, and its advanced lighting system improvement program.
Few if any supermarkets in the U.S. have saved as much energy through advanced energy monitoring systems as Shaw's has. In 1997, the company began to develop an energy sub-metering and monitoring. Until then, the only way Shaw's could find energy waste was via broad trends on monthly "whole house" bills, making it difficult to pinpoint inefficiencies. It also was difficult to enlist the help of maintenance staff, since managers had little information to offer them.
By installing state-of-the-art sub-metering equipment capable of monitoring up to 16 electrical circuits per store, Shaw's now has a toolkit that saves time, energy and maintenance costs. Predicted use is modeled using historical data, taking into account weather information for the particular time of year, and retail volume data for the time of day. Based on daily monitoring data, store managers flag periods during which energy consumption is higher than expected.
For example, the system helped the company identify and correct control failures and lighting system overrides that previously would have gone undetected. These actions have generated savings estimated at between one and two million kilowatt-hours a year.
"With this system," explains Kathy Loftus, Shaw's Energy & Regulatory Affairs Manager, "we are able to diagnose a problem quickly, and either make a correction remotely through the energy management software, have store management take care of it, or dispatch maintenance personnel with a graphical representation of the problem."
The load profiles facilitate energy-saving strategies like improved refrigeration systems, more aggressive controls for anti-sweat heaters1 and air conditioning systems, and custom lighting schedules. The company can also test equipment manufacturers' of energy efficiency claims and use that information to design systems even more efficiently.
Here are a few examples of anomalies that it has identified:
All told, Shaw's new energy monitoring systems reduce electricity use by 23 million kilowatt-hours a year, while avoiding nearly 17,500 tons of CO2, as well as 71 tons of SO2 and 24 tons of NOx.2
In addition to energy monitoring, Shaw's has taken the relatively simple step of changing thermostat setpoints. By allowing stores to remain slightly warmer in summer and slightly cooler in winter, the company saves additional energy. The energy monitoring system quickly alerts store managers in the event of overcooling or overheating.
Financial Payoff
As originally authorized by management, the sub-metering and monitoring project for 110 stores carried a price tag of slightly over $2 million, an internal rate of return of 27 percent and a simple payback3 of about four years. It was assumed that about 5 percent of the total cost would be provided by utility companies in the form of end-use energy efficiency program rebates. In the end, the project cost was lower - a bit less than $2 million - because the company negotiated a lower installation price, with utilities contributing incentive payments that were three times greater than originally estimated. In the end, incentives accounted for more than 17 percent of the total project cost, and lowered the simple payback to just over two years.
Lighting retrofits are very attractive investments for Shaw's. They can cut electricity use in half. To date, the company has spent more than $4 million on them at 60 stores, for a per-store cost of about $65,000.
Shaw's has been retrofitting lighting systems since 1991, when it took advantage of existing utility incentive programs to convert several back room and perimeter area systems. At the time, sales area lighting consisted of metal halide fixtures, thought to be the most efficient option. Since 1996, however, the company has designed and retrofitted its continuous rows of uniform fluorescent fixtures with highly efficient T-8 lamps and electronic ballasts.
The company also installed efficient lamps in its refrigerated cases after the ballasts were improved to work well in cold environments. In addition to lowering lighting use, this cut refrigeration loads by reducing the amount of heat generated inside the cases. Finally, Shaw's has installed state-of-the-art lighting in its distribution centers, including "hi/lo dimming" systems that automatically lower lighting levels when aisles are empty.
Financial Payoff
Shaw's has consistently found that lighting investments pay for themselves in three to four years, offering internal rates of return of up to 30 percent. Utility incentives have helped with up-front costs, while making for more attractive rates of return. In some cases, they have reduced payback to less than three years.
Shaw's estimates that it is saving roughly 20 million kilowatt-hours per year as a result of the lighting retrofits it has done. These savings avoid more than 15,000 tons of CO2, 62 tons of SO2 and 21 tons of NOx each year.
The chart below illustrates the results of a lighting retrofit in one Shaw's supermarkets. The red peaks on the bars during the early weeks of the retrofit record electricity use by the construction crews that performed the work overnight, when fewer lights normally are on. Beginning the week of May 17, the store's daily electricity use fell by an average of nearly 50 percent.
Energy Savings = Environmental Savings
Looking at Shaw's energy monitoring systems and lighting retrofits together, the company is reducing CO2 emissions by more than 32,500 tons per year. This is similar to a cut in oil consumption of nearly 60,000 barrels per year or the removal of over 4,500 typical passenger cars from the road. The company also has reduced SO2 emissions by nearly 133 tons, and NOx emissions by some 45 tons.
Initially, the lighting retrofits offered paybacks of two to three years, and more rebate dollars were available from utilities. This made retrofits particularly attractive business decisions. Due to the success of these programs and Shaw's environmental commitment, the company has continued the retrofits, and designed high-efficiency lighting into new stores, even when rebates have been lower and the economics less compelling. At a time when competitive pressures force retailers to spend more on sales-generating measures, Shaw's continues to see considerable benefit in earmarking capital for energy efficiency and environmental investments.
Encouraged by these impressive results, Shaw's is going beyond electricity savings. The company has initiated a program to modernize its vehicle fleet. It is focusing on achieving more efficient engine ratings and better aerodynamics, and installing electronic speed limit controls. About 20 new trucks are purchased each year, and a number of existing trucks retired. As a result, the Shaw's fleet annually achieves an increase in overall efficiency of about 0.2 mile/gallon. The company estimates that to date it has gotten an additional 17 million miles out of its fleet for the same amount of fuel.
To reduce miles traveled by its vehicles, Shaw's is reviewing driving patterns and working on network optimization. It also has a tire-recapping program, and has voluntarily discontinued use of the ozone-depleting refrigerant R-12 by replacing or converting 95 percent of its refrigerated trailers with newer units that use HCFCs.
Inside it's stores, Shaw's has been working with architectural and engineering firms to incorporate daylighting technology, more sophisticated air conditioning controls, solar-powered condenser systems and sustainable construction practices into its buildings. In addition, the company continues to investigate the use of natural gas microturbines to offset peak electricity requirements, and renewable resources to meet some of its energy needs.
1 Anti-sweat heaters are electric heaters that prevent condensation from forming in specific areas of refrigerated cases.
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The retail grocery business is highly energy intensive. Grocery stores are huge spaces that must be heated, cooled and lighted around the clock. The storage and display of frozen and refrigerated foods creates large cooling loads, even in winter, and the transportation of food from distribution centers to stores puts a fleet of large trucks in motion around the clock. In other words, behind every grocery store lies a great deal of energy consumption.
