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March 16, 2023

Thermal Energy Refrigeration

With two awards from NSF’s Small Business Innovation Research program, engineers have developed and brought to market a cold thermal storage system that is impacting the food supply in developing countries.

Credit: U.S. National Science Foundation


Refrigeration is essential to preserving the freshness of foods. In rural areas of developing countries, electricity may only be available for a few hours a day, if at all. How could food spoilage be reduced? Is there a way to reduce reliance on fossil energy when options are limited? We'll explore the future of refrigeration in the U.S. National Science Foundation's "Discovery Files."

In developing countries electrical grids are not nearly as robust as we are accustomed to. To maintain a quality food supply, access to a refrigerated supply chain is a must.

With a NSF Small Business Innovation Research grant, Promethean Power Systems developed a thermal energy battery that stores energy in the form of ice. The ice pack freezes in 5 hours as grid electricity is available and melts to release the energy when needed to cool perishable products thereby preserving their freshness when grid electricity is not available.

With a Phase II award, they commercialized a new type of industrial refrigerator powered by the thermal battery. The systems are now in villages across Bangladesh, Sri Lanka and India, the largest producer and consumer of milk in the world, where nearly 400 million people depend on it for their daily protein.

With access to steady refrigeration, the farmers have a much-needed boost in income. Eliminating the use of diesel generators and huge amounts of perishable food lost to spoilage.

This technology is being adapted to solar energy sources and being developed towards increasing the energy efficiency of refrigeration appliances back home, including air conditioning in commercial buildings.

To hear more science and engineering news, including the researchers making it, subscribe to "NSF's Discovery Files" podcast.


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