The Myth vs. Reality of Energy Savings
On many occasions, I have heard from people responsible for 24/7 operations — typically, convenience stores and restaurants — that energy management systems (EMS) do not make sense for them because there are no real opportunities for savings in a facility open for business all the time.
In fact, based on the number of times we have heard this, it would appear to be the conventional wisdom. But closer examination suggests this may be more of a common misperception than a common truth.
Consider the following four opportunities for savings in a facility open 24/7.
It is true that a major part of EMS savings in facilities that have standard open and close hours comes from adjusting the settings during the hours the facility is closed. However, there are also savings available from enforcement of company policies around HVAC settings that aim to balance customer comfort with energy spend.
Programmable thermostats do not accomplish this objective because there is no guarantee that the local staff will maintain the programmed settings; we have seen huge variations that can have a large impact on costs. As many operators have learned, even locking thermostats away does not eliminate the tendency for local staff to override the settings on a fairly regular basis.
Moreover, being open 24/7 doesn’t mean you need the same target temperature 24/7. The target temp may vary based on a variety of factors, such as time of day (fewer customers may enable you to skew the comfort/cost balance slightly) and season (perceptions of hot/cold vary by season).
Remote-controlled thermostats as part of an EMS, with flexible local lockouts that can maintain company policies and the type of “micro-targeting” described above, can have a surprisingly significant impact on energy costs.
"OFF HOURS" USAGE
Yes, it’s true that everything cannot be turned off at a standard closing hour in a 24/7 facility. But that does not mean everything needs to be on all the time.
For example, for a foodservice operation with multiple hot plates, griddles or other such equipment, it is likely not necessary to have all of them on during early morning hours or other low traffic periods during the day. In some cases, there may be services not provided at all after a certain time of day, so there are likely opportunities to turn things off, even in a 24/7 operation.
On multiple occasions, we have seen everything running all night at convenience store car washes that stop taking cars after 8 p.m. The unnecessary energy spend in these cases can be very significant.
Lighting is an area where the savings potential is clearly reduced dramatically in a 24/7 environment, but even here, savings are possible. There is no reason for outdoor lighting to be on during daylight hours, but we have often seen outdoor lights left on 24/7, or lights turned on at 6 a.m. instead of 6 p.m. due to a programming error with a mechanical lighting control system.
Even indoors, there may be areas where lights do not need to be on all the time; a storage area is one example, and the aforementioned car wash another. But this is, by no means, an exhaustive list.
In some situations, a motion sensor or a light sensor may be all you need to address these situations. In other cases, an EMS that controls the lights may be cost-effective.
In almost all cases, replacing older bulbs and lighting fixtures with state-of-the-art LEDs makes a lot of sense, especially in the many parts of the country where utility rebates are available to make these investments extremely cost-effective.
Malfunctioning equipment can end up using lots of extra energy. In fact, increased energy use itself is a symptom of equipment problems that can end up costing even more in repair and maintenance costs.
This is certainly true of major equipment such as HVAC and refrigeration, where overloaded compressors will result in greater energy spend than necessary, as will units that are short cycling. However, problems that can lead to significant energy expense occur in other equipment as well.
We recently came across a situation where a conveyer toaster was drawing an excessive amount of energy even when it was not in use — to the tune of $100 wasted per month, or more than $1,000 per year in wasted energy if not identified. Without the proper monitoring, many of these problems will never be caught until the equipment fails.
Some newer EMS effectively integrate monitoring, analytics and diagnostics to look for and highlight these types of issues. In addition to the value of catching equipment problems before the equipment fails, the energy savings of these diagnostics alone may pay for the EMS.
It is generally, although not universally, true that energy savings opportunities are inversely related to operating hours — the shorter the hours, the greater the savings potential because of the possibility of unnecessary consumption during off hours. But that relationship does not mean the savings potential goes to zero in a facility that never closes.
In fact, the savings potential in a 24/7 environment is very real and can be very meaningful. What is needed are the right set of tools, such as an effective EMS, and the right set of creative approaches to yield significant cost savings in a 24/7 operation.
Editor's note: The opinions expressed in this column are the author's and do not necessarily reflect the views of Convenience Store News.