The summer of 2018 is bringing with it extreme weather events and a record-breaking global heatwave. Regions in Japan experienced temperatures as high as 104 degrees Fahrenheit, Sweden, Greece, and the western United States have been ravaged by wildfires, and even the Arctic Circle saw temperatures peak above 86 degrees.
By: Collin Coker, Viking Cold Solutions, Vice-President Sales & Marketing
This global heatwave is indicative of the increase in extreme weather events – such as hurricanes, wildfires, and flooding – caused by climate change. When considering the effects of extreme weather events on the food supply the focus is typically on the impact on crops. Resiliency further up the supply chain, however, is equally important.
Food stored in cold storage facilities such as grocery store walk-in freezers or low-temperature warehouses are put at risk when the energy supply is threatened by extreme weather events. In a heatwave, energy demand rises as households and businesses turn up their air conditioning and refrigeration, putting a considerable strain on the electrical grid and leading to power outages and blackouts. The resulting fluctuations in temperature inside the facility can lead to damaging processes known as micro-thawing and micro-freezing. When the temperature in a cold storage facility increases due to a power outage, some small elements of the frozen food will thaw. When the power comes back on and the temperature decreases again, the slow refreezing of these elements causes larger ice crystals form, which damages the cellular structure of the food and decreases its overall quality.
When the electrical grid is down due to storms, the impact on the food supply can be even greater. The powerful hurricanes that wreaked havoc on the Caribbean and coastal states in 2017 knocked out the electrical grid for days and weeks – and in some extreme cases, months – putting millions of dollars of food in cold storage at risk of spoiling. In the wake of a natural disaster, when many are without homes and reliant on emergency services for food and shelter, this loss of food further exacerbates a difficult and dangerous situation.
Building a food supply chain that can stand up to extreme weather events requires a resilient cold chain. Integral to building that resiliency is the ability to maintain stable temperatures without full-time reliance on the electrical grid. While there are technologies that can help, thermal energy storage (TES) is an extremely effective technology for building the resiliency of the cold chain, particularly in low-temperature freezers. A TES system from Viking Cold Solutions is easy to install and uses specially formulated phase change material (PCM) to absorb heat and maintain temperature stability three times longer during a loss of power. TES acts as a ‘thermal blanket,’ keeping food cool and absorbing heat during times without refrigeration. When there is an inconsistent energy supply, this can act as insurance against food loss and provide additional time for responding and restoring power.
This additional resiliency needed during power outages or equipment failures can also be used daily to shift the scheduled refrigeration system run time to lower energy costs. In daily operation, the intelligent controls leverage the existing refrigeration system to freeze the environmentally safe PCM during hours when energy costs are lower. During more expensive periods the refrigeration system is cycled off. The PCM absorbs up to 85 percent of all heat infiltration in the freezer while using less energy and lowering energy costs up to 35% percent. Reducing energy consumption is also important in the wake of a natural disaster when prices for goods such as fuel for back-up generators rise exponentially, or are difficult to source.
Our increasing global population demands a reliable and resilient food supply chain, especially as climate change creates more frequent and extreme weather events. Thermal energy storage is a key technology for building that resiliency by providing the multiple benefits of acting as a temperature buffer during mechanical or power failures, protecting the food supply, and helping the cold chain industry reduce its energy consumption and carbon footprint.
