Refrigeration Battery Could Lower Supermarket Energy Use By 40 Percent

The capacity to deliver continuous electricity for refrigeration is one of the central planks of the modern-day food distribution system.

Using fossil fuel-generated energy to refrigerate and freeze foods around the clock produces a lot of pollution – carbon and greenhouse gas emissions that are warming the global climate, as well as emissions of a range of potentially toxic chemicals that deplete the ozone layer and wind up in our waterways and soil.

Enter Berkeley, California-based Axiom Energy and its Refrigeration Battery: a water- and ice-based backup cooling system designed for use in large supermarkets and food distribution facilities. The system is now available in California, Axiom announced last week.

The system offers “behind the meter," or customer-sited, energy storage -- enabling supermarkets and food distributors to store energy at night when demand and utility rates are low and use it for cooling and refrigeration during peak daytime hours when rates are high. This affords these businesses substantial cost savings and hence high returns of investment, Axiom says. Along with the financial gains come substantial health and environmental benefits.

Lowering supermarket electricity bills and helping address climate change

Following through on President Obama's Climate Action Plan, the U.S. Department of Energy in February 2014 issued new energy efficiency standards for commercial refrigeration equipment. Over the ensuing 30 years, DOE projects the new standards will reduce carbon pollution by 142 million tons – the equivalent of generating electricity for 14.3 million U.S. homes – while also saving businesses as much as $11.7 billion on energy bills.

Large commercial refrigerators commonly used in grocery stores can consume up to 17,000 kilowatt-hours of energy per year. A large commercial freezer can use up to 38,000 kWh, according to the DOE. Axiom points out that refrigeration costs make up over 50 percent of a typical supermarket's electricity bill. With the capacity to store energy for 6 to 12 hours, its Refrigeration Battery can “shave” peak electricity demand at supermarkets and large food distributors by as much 40 percent,” the company claims.

The winner of the Venture Capitalists Choice award at the 2014 Cleantech Open Accelerator, Axiom says its battery “solves a major technical problem that businesses with high refrigeration loads have to been unable to address until now: the inability to actively manage unintelligent refrigeration systems.” By installing the Refrigeration Battery, supermarkets and food distributors can essentially transform “their refrigeration systems into large-scale, cloud-connected, smart energy storage resources.”

“Supermarkets and cold-storage facilities must keep perishable food at a constant temperature around the clock, which means they must run power-hungry refrigeration equipment even when electricity prices skyrocket during the peak hours of the afternoon. Until now, this has been a huge, unavoidable cost that erodes their razor-thin profit margins — that’s where we come in,” Amrit Robbins, Axiom Energy's president, stated.

Axiom's Refrigeration Battery

The Refrigeration Battery stores energy for later use in refrigeration by freezing a tank of water “with common additives at night when electricity is inexpensive,” Axiom explains. The energy storage system can then be discharged during peak periods of electricity demand in the afternoon. This enables supermarkets and food distributors to turn off their refrigeration systems' compressors and condensers.

With a lifespan that at 30 years – many times that for traditional batteries – and an installed cost that Axiom asserts is significantly lower than any alternatives available, the company is keen to prove the Refrigeration Battery's touted benefits in the market, Robbins added. “We believe we are the only viable energy storage solution for facilities that depend on refrigeration."

In addition, Axiom has worked to ensure that its battery “is a non-invasive, 'plug-and-play' retrofit that doesn’t require modifications to existing refrigeration systems.” This is a big factor in driving down the system's total cost of ownership, resulting in a short payback period and the ability to roll out the battery across multiple sites in short order, according to Axiom.

Axiom highlights the Refrigeration Battery's key attributes in a press release:

• Shifts peak usage to off-peak hours;


• Provides backup cooling during power outages to prevent food spoilage;


• It's an easy retrofit that uses existing refrigeration equipment;


• Much less expensive than competing solutions.

“The refrigeration industry has been trying to solve the problem of ever-increasing refrigeration energy costs for a long time,” said Pete Cuneo, national facility systems manager for a major supermarket chain.

“It looks like Axiom Exergy has finally cracked the nut and potentially even solved a bigger problem — low-cost backup cooling. The Refrigeration Battery represents a major advancement in an industry that hasn't changed much in decades."

*Image credits: 1) Energy.gov; 2) Axiom Energy