Keeping milk cool
To reduce production cost for farmers and effectively use the electricity available, two techies have built a machine to refrigerate milk without power, writes Sneha Bhattacharjee
India is the world’s largest producer of milk with an output of 165 million tonnes in 2016-17. Most of the milk comes from rural areas where dairy farming is not easy. Unreliable and erratic electricity supply results in least 3 per cent of the milk being wasted.
This is because milk needs to be cooled at source in order to increase its shelf life, which dairy farmers are not able to do easily. To provide refrigeration, milk producers have to depend on diesel generators that make the cooling process expensive. To reduce the production cost for farmers, and to effectively use the electricity already available, two former techies decided to develop a cooling technology that would help keep milk cool even without power.
Founded in 2015, Inficold is a bulk milk cooling venture started by Nitin Goel and Himanshu Pokharna, who had worked with Intel in developing electronic cooling systems for computers. Their venture uses solar power to provide refrigeration for milk. While Goel's background in thermal science made him associate with thermal energy storage at the outset, the idea of using solar power for refrigeration came to them when the two were working on a solar power project in India. It made them realise the potential solar energy has, if it could be stored for use later, to light up areas without power, or prone to power outages.
So, how does the cooling system work? In Goel’s words, they tap power using solar as well as grid electricity, then convert it into ice which can be stored and used at a later stage. It provides round-the-clock cooling with just 7 hours of grid/solar power. It is different form other cooling systems in two ways: Inficold’s system is not only using power produced from solar or grid, it is also making a refrigeration system that comes with world’s first retro-fittable cooling system. That is, one can easily fit it into the milk coolers. “The thermal storage methodology used by most companies is primitive especially in the way they extract electricity from ice,” says Goel, adding that is precisely what Inficold is trying to break.
“A farmer not only saves on the cost of diesel generator but is also giving a thought to the environment,” he adds. The two ways by which most farmers use cooling agents are either diesel generators or lead acid batteries. While the previous one harms the environment and at the same time, makes a farmer spend almost three times his actual milk cooling cost, the latter has a short life and needs to be replaced frequently. In comparison, the hardware of the ice coolers used by Inficold, Goel says, can last up to 20 years. “Milk cooling is typically done in the morning and evening hours. When there is a power cut during milk cooling period, these milk coolers require electricity to generate cooling. A milk cooler's operational cost is 10-12 paisa/litre with grid electricity and 120-140 paisa/litre with diesel generator,” he adds.
The company's thermal storage units are currently operational in milk cooperatives and large private dairies in Punjab, Haryana, Uttar Pradesh, Gujarat, Tamil Nadu and North East India. “We are working closely with the National Institute of Solar Energy (NISE), an autonomous research institute of Ministry of New and Renewable Energy for solar integration of milk cooler,” says Goel. The company has already had seven installations, with the oldest one being operational since March last year. They work with Farmer Producer Organisations to provide their facility to farmers. This low-cost technology has brought the team multiple awards.
In March 2017, the company collaborated with the NISE to help make integrated cooling system powered by solar energy for state level horticultural and agricultural departments. Goel feels this area needs this invention dearly if farmers are looking to export their produce. The current challenges posing this sector are that whatever a farmer produces has to be sold immediately because of a lack of storage facilities. Further, most cold storage facilities are used by large farmers, while the small farmers are left with no option but to sell their produce immediately. According to Goel, this situation is further aggravated by the lack of acceptance of newer technologies and risk-taking abilities of Indian farmers. This holds true for the dairy industry as well. But Goel is happy to note the small changes in the way the states are coming together to use this environment-friendly, as well as effective mode of cooling agent.