Promethean Power Systems, which makes a milk chiller recently introduced in rural parts of India, is planning to expand distribution to Bangladesh, Pakistan and Sri Lanka over the next few months. Co-founder Sam White said his company hopes to have 500 units in the field by the end of the year.
Thanks to a thermal battery filled with phase change material, the chiller needs only intermittent electricity to quickly chill raw milk to a temperature that arrests bacterial growth. That's a potential game-changer for developing countries, where many dairy farmers don't have access to reliable electricity.
Boston-based Promethean manufactures the device, and the PCM, in Pune, India. White declined to identify the composition of the PCM, but a U.S. patent application for the device describes a salt hydrate with a melting point of -2º Celsius and a latent heat of fusion of 290 J/g. A nucleating agent is added to reduce the effect of supercooling.
The tech blog Gizmodo featured a Doc North video of the product over the weekend: