by Marc Sandofsky, contributing editor
Oil prices are at an all-time high and show no signs of pulling back. Generally, that means natural gas and electricity prices will follow suit. Unfortunately, unless you are among those who had the foresight to lock in energy prices in advance, there is little you can do on short notice to reduce your costs other than to use less energy. In an industry that prides itself on its ability to control its energy costs, that may be easier said than done.
Reflecting back on the California power shortages of 2001, the major California supermarket chains agreed to voluntarily reduce their electric power consumption by 10% when a Stage I Emergency was declared.
To accomplish this, they lowered store lighting by up to 50%, restricted the use of equipment such as battery chargers and electric appliances, and reduced air conditioning use by raising temperature set points. Refrigerated case temperatures, in deference to food safety, remained unchanged. Supermarkets reported that customers seldom complained about the changes, and many stores maintained the setback conditions even when there was no emergency.
The point is not that, in response to skyrocketing energy prices, supermarkets should revert to a crisis mode. Rather, perhaps it is time to evaluate the necessity of continuing certain policies that have led to increased energy use over the years.
For instance, while most supermarkets install reach-in doors on frozen food cases, medium temperature cases remain open. The blame for this has been placed on merchandising people who, it is said, feel that reach-in doors inhibit sales. While the economics of this position might have made sense when kWh costs were 7 cents, do they still hold true at 15 to 20 cents/kWh? Speaking of reach in doors, Bruce Malwitz of Phoenix, AZ-based Door Miser claims that the vast majority of all centralized anti-sweat heater controls are placed into bypass shortly after installation.
"The first time a service person is called to correct a door fogging problem, he places the control into bypass and leaves it there," says Malwitz. Understandably, his solution is to use a distributed control like Door Miser.
The actual percentage of anti-sweat heater controls that are in bypass is open to debate, but it wouldn't cost much to make certain yours are still in operation. Furthermore, those stores that are lacking anti-sweat heater controls might want to consider them, as the typical payback in this high-energy cost environment is one year or less.
Head pressure settings are also worth checking. We know that as head pressures are lowered, energy use decreases. However, head pressures are often raised in response to temporary problems, and remain that way until a store is re-commissioned. A little labor spent checking these settings could save a great deal of energy.
Another technology worth looking into is the ConsERV energy recovery ventilator by Dais Analytic of Odessa, FL. It is an air-to-air heat exchanger that uses exhaust air to pre-condition makeup air by reclaiming sensible and latent energy. One major chain completed a test on the ConsERV system last year, and has begun specifying it on their new stores.
In summary, the response to rising energy prices need not be grudging acceptance. An aggressive, calculated response may offset the rising prices while helping to improve overall store operations.
Marc Sandofsky, contributing editor, at firstname.lastname@example.org or call 508/653-3494.