Lack of refrigeration in rural India is leading to millions of tonnes of fresh produce going to waste every year. India is the largest producer and consumer of milk in the world; 130 million tons of milk is produced annually by rural farmers in India, yet a significant proportion of this is lost due to non-existent cooling systems in small villages and farms. Lack of a reliable electricity supply is one of the biggest challenges in India. Around 400 million people are without access to a reliable power supply, reported the Guardian in July.
Recently, a group of young entrepreneurs of the start-up enterprise “promethean power systems” tried to solve this problem by developing a new thermal battery, which led to the creation of a “rapid milk chiller” (RMC). The RMC is now being deployed in the agricultural areas of Maharashtra, West Bengal and Tamil Nadu. It uses a thermal energy battery pack that charges on solar power and, when available, on grid electricity. The loaded battery provides cold storage around the clock regardless of unreliable access to electricity. The Rapid Milk Chiller can thus close the cold-chain from the small producers to the dairy.
This project was named one of seven “invention ambassadors” by “Powering Agriculture”, a new programme that highlights the value of technology-driven solutions to global problems. Powering Agriculture is being supported by international donor agencies like US-AID, Germany’s Ministry for Economic Cooperation and Development (BMZ), SIDA (Sweden) and private enterprises, and it is co-sponsored by AAAS – a US-based scientific society.
The two founders of Promethean Power Systems, Sorin Grama from USA and currently living in Mumbai, India and Sam White from the USA, initially intended to sell solar power concentrators to generate electricity in clinics and schools in villages without a dependable source of electricity. But the villages couldn’t find a use for the expensive technology, so Grama and White turned their attention to the country’s dairy industry, which is dominated by farmers with a only a few cows who depend on rickshaws, bikes, or their own feet to transport the warm milk on the first leg of its long journey from farm to local village collection centre to the dairy plant.
The rapid milk chiller is a dome-shaped machine that couples to a thermal energy battery to cool milk from 35°Celsius down to 4°Celsius. The rapid milk chiller cools the milk by means of a heat exchange with cold fluid inside the dome. When electrical power is not available, the rapid milk chiller can cool up to 500 litres of milk using only the thermal energy stored in the battery.
Dairy plants install the chiller-battery pairs in village collection centres. Thus villagers can keep their milk fresh for up to two days. Dairy trucks don’t have to make daily rounds and no longer need to transport milk from a village collection centre to a separate chilling centre. The dairy plants can also extend their reach to more isolated villages with rapid milk chillers.
So far, Promethean Power has sold 60 chiller-battery pairs to dairy processing facilities since the first one was installed three years ago. The company plans to produce more chiller-battery pairs as demand rises, and it intends to apply its technology to cool vegetables and other perishable food items.