Cold storage operators face challenges from globalization, tight margins, and rising energy costs. After personnel, energy is their second highest operating expense. To maintain stable temperatures 24 hours a day and protect their inventory of frozen food requires massive amounts of energy to run refrigeration equipment nearly non-stop. These facilities have the highest energy demand of any industrial category and are the third highest commercial energy consuming category per cubic foot, consuming over $30 billion USD of power every year.
This high energy demand and need for continuous run time have significant impacts on a cold storage facility’s energy costs. Utilities generally charge operators in three ways (Video: Utility Bill Explanation). First are overall consumption charges. This straight forward calculation is simply the number of kilowatt hours (kWh) of electricity a facility uses multiplied by its kilowatt hour rate. Second is transmission & distribution charges that help cover the costs of the infrastructure that delivers energy to the facility. The last, and often most misunderstood charge, is the peak period (or peak demand) charge. Each utility determines the peak period for its customers and these periods range anywhere from two to more than 12 hours. During this window of time, the highest amount of energy a customer consumes is measured to determine the peak period rate. This rate, which is much higher than the kWh rate, is then multiplied by all the kWh used during the designated peak period.
In the U.S. alone, the cold storage industry has over 2,200 frozen food warehouses ranging from 10,000-200,000+ square feet, 40,000 supermarkets and over 620,000 restaurants with walk-in freezers from 150-1,500+ square feet. Each of these facilities face energy challenges, and for many years cold storage operators have added incremental improvements such as more efficient lighting systems or better insulation technology to create slight reductions in their energy costs.
Clearly, the real energy consumption comes from the continuously running refrigeration systems. And because peak period demand charges can account for more than 70% of the total energy costs in cold storage, it is critical to minimize run-time during these hours. Until recently there was not a solution that could make significant reductions in energy consumption and provide the flexibility to shift this energy usage to outside of high-priced peak periods.
Now Thermal Energy Storage (TES) technology from Viking Cold Solutions can reduce peak period consumption by up to 90% and reduce energy costs by up to 35% while improving temperature stability in the freezers and maximizing the efficiencies of the refrigeration equipment. TES leverages the heat transference properties of phase change materials (PCM), intelligent controls, and 24/7 monitoring & reporting software to reduce consumption and shift the refrigeration electricity load.
During off-peak hours, the facility’s existing refrigeration equipment freezes the non-toxic, environmentally-safe PCM. During peak hours, operators can dramatically reduce mechanical run time of the costly, grid-dependent refrigeration systems while the PCM absorbs and stores 85% of all heat infiltration in the freezer, maintains temperature stability to ensure food quality and safety and helps avoid 90% of the expensive demand-based energy usage (Video: See How TES Works).
Additionally, when the refrigeration systems do run, they are able to run fully-loaded at times with lower ambient temperatures – which is how and when they run most efficiently. This along with the PCM’s ability to easily release thermal energy allows for the stored heat to be removed using less energy (White Paper: Refrigeration Benefits of Thermal Energy Storage).
The TES systems are non-mechanical, easily installed in existing facilities or during new construction projects, and last more than 20 years. They integrate easily with existing refrigeration, control, and racking systems, and do not reduce any storage space in the facilities.
These thermal energy storage systems are installed inside numerous facilities and in multiple countries, saving operators thousands of dollars each month. Soon, TES will be a standard technology in all cold-storage freezers. Those forward-looking cold storage operators who implement proven TES technology now will lead the way with greater refrigeration efficiencies and immediately improved bottom line results.