Why Demand Charges Hit Refrigerated Facilities So Hard

This is Charles, also known as Chuck, Tralka. I’m an electrical engineer and the founder of ZeroQuest, where we focus on energy optimization for grocery stores and cold storage facilities. 

In the previous video, we talked about why refrigerated facilities are energy outliers— why grocery stores and cold storage facilities consume more electricity, more consistently, than almost any other commercial building type. 

In this video, I want to explain how that constant, refrigeration-driven load translates into unexpectedly high electric bills. And in particular, I want to focus on one concept that drives a disproportionate share of cost for refrigerated facilities: demand charges. 

To understand demand charges, it helps to first understand how most people think electric bills work. Most operators assume their bill is based mainly on energy usage over time— kilowatt-hours consumed over the course of a month. 

But for many commercial and industrial customers, especially grocery stores and cold storage facilities, that’s only part of the story. 

A large portion of the bill is driven by demand charges. Demand charges are not based on how much energy you use overall. They are based on how much power you draw at one specific moment in time. 

More precisely, demand charges are typically calculated based on the single highest 15-minute average power draw during the entire billing cycle. 

Not the average day.
Not the busiest hour.
Just one 15-minute interval. 

That one interval can quietly determine a large portion of the electric bill for the entire month.  This billing structure is especially punishing for refrigerated facilities. 

Unlike office buildings or retail spaces with relatively predictable load patterns, refrigerated facilities rely on systems that cycle automatically based on temperature, pressure, and product load. 

Compressors stage on and off.  Condenser fans ramp up and down.
Defrost heaters activate on schedules that are often set years earlier and rarely revisited. 

Individually, each of these systems makes sense. But when several of them line up at the same time—even briefly—the result can be a sharp spike in electrical demand. 

What makes this even more challenging is when those spikes occur. 

In grocery stores and cold storage facilities, the highest demand event often does not occur during business hours. In fact, it frequently happens late at night or in the early morning hours. 

This might be during an overnight defrost cycle, or it might be during a compressor staging transition.  Or it might be when multiple refrigeration systems recover simultaneously after a load change. 

From an operational standpoint, nothing feels wrong.  The facility may be empty.  Staff may not even be on site. 

But that one short event—sometimes lasting only 15 minutes—can set the demand charge for the entire billing period. 

This is why demand charges in refrigerated facilities can represent thirty, forty, or even seventy percent of the total electric bill.  And it’s also why these costs are so difficult to manage. 

Most utility bills do not clearly show when the peak occurred.  They don’t explain what equipment was running at the time.  They simply report the result.  So operators are left with a higher-than-expected bill and no clear visibility into what
caused it. 

The key insight here is this: 

In refrigerated facilities, demand charges are not driven by average behavior. They are driven by short-duration, high-impact events that are largely invisible without interval data. 

This is why traditional energy efficiency efforts—focused only on average usage or equipment nameplate ratings—often fail to address the real cost drivers on the bill. 

Until you can see exactly when and why those peaks occur, demand charges remain a hidden and uncontrolled expense. 

In the next video, I’ll walk through the most common operational patterns that cause these overnight demand spikes in grocery stores and cold storage facilities—and which of those issues can often be addressed without major capital upgrades. 

This has been Charles Tralka, known to my friends as Chuck, for ZeroQuest Energy.