Teens Win 2025 Earth Prize For Refrigerator That Runs on Salt

From India comes the story of three teen inventors who were looking to improve rural healthcare by creating a portable fridge that needed no electricity or coolant fluids.

Digital mock-up of a Thermavault

The result of their endeavours is a small, salt-cooled fridge that cools down passively as the salts dissolve in water - without needing a power outlet or a battery. The teenage trio - Dhruv Chaudhary, Mithran Ladhania, and Mridul Jain - are all children of physicians or medical field workers in the state of Indore and became aware of how difficult it was to keep Covid-19 vaccines viable en route to rural villages in tropical heat, and wanted to create a better, portable solution to keeping medical supplies cool.

Calling their subsequent invention “a fridge to bridge the world,” the Thermavault can use different combinations of salts to keep the contents at temperatures just above freezing or below it. Some vaccines require regular kitchen fridge temps, while others, or even transplant organs, need to be kept below freezing, meaning this versatility is a big advantage for the product’s overall market demand.

From left to right: Chaudhary, Ladhania and Jain

Designing a prototype, the teens have already tested it in local hospitals, and are in the process of assembling another 200 for the purpose of testing them in 120 hospitals around Indore to produce the best possible scope of use and utility data for a product launch.

Their ingenuity and imagination won them the 2025 Earth Prize, which came with a $12,500 reward needed for this mass testing phase.

Jain said they're planning to use the prize money to pursue a Performance, Quality and Safety certification through the World Health Organization so they can pitch it to Gavi, an international alliance that distributes vaccines.

Source