Promethean Power Systems is a small startup with a big dream: change lives of poor Indians villagers by helping them keep milk chilled. This simple thing could be a massive revolution for impoverished and isolated people in parts of India where you cannot rely on electric power. Each year in India $10 billion in agricultural produce is lost due to inadequate refrigeration.
The startup co-founders Sam White and Sorin Grama planned everything from a warehouse in Boston and after several trips to India came out with a solution. Initially, the two partners in the company wanted to build a solar-powered milk chiller, but that route was discounted in the end due to the technology proving too expensive, complicated and bulky to be used in Indian milk processing centers.
Having falling out of love with the idea of solar energy, White and Grama opted for a sort of large ‘thermal battery’ that can swiftly chill milk. This device was developed with Olin College through a National Science Foundation grant and has one very special feature: it can chill milk even when the grid is down, which in Indian villages is a common occurrence.
This can have a major impact in the way they operate, since local milk collection stations could work for longer hours, rather than urgently make the milk available in more centralized processing centers before is too late. Previously, failing to do so would mean the milk would be unfit for consumption.
In practical terms, the thermal battery stores and releases cold thermal energy. The battery acts like an electrical battery but rather than supplying an electrical current, it supplies a stream of cold fluid. This fluid can then be used to chill the food products, in this case milk, down to 4 degrees Celsius.
When the grid is not available it can run for several hours on a car battery, rendering dirty diesel generators obsolete. Although, this technology was designed specifically to fulfill a chosen application, it could be also used to make air conditioners more efficient or utilized for in-truck refrigeration in developing countries.
Leave a Comment