Promethean’s milk chiller technology has been deployed by established players like Amul in Maharashtra, Hatsun Agro in Tamil Nadu, Mother Dairy in UP and Heritage Foods in Vizag.
Khanderao Nimbhorkar, a 45-year-old dairy farmer from Ahmednagar district’s Hattalkhindi village, is brimming with confidence and excitement. His dairy farming activities now fetch him a tidy sum of Rs 20,000 per month. Coming this far would not have been possible for Nimbhorkar without the help of Pune-based refrigeration solution provider Promethean Power systems. Co-founded by Boston-based entrepreneurs Sorin Grama and Sam White, the company has come up with a socially- relevant invention to strengthen the weakest link in the chain of dairy farming: milk collection.
As the largest milk producer and consumer in the world, India has earned the sobriquet of the oyster of the global dairy industry. It accounts for 18 percent of global milk production in the world. Rural India churns out 102 million gallons of milk every year, generating employment for over 75 million dairy farmers.
Crying over sp(o)ilt milk
Milk procurement is a time-bound exercise. The milk produced by dairy farmers is aggregated and transported to dairies via small, village-based collection centers. Transporting the produce to the processing centers of different dairies without refrigeration can be challenging.
The operations of the dairy industry are ruled by the clock. “Dairies have a very time- specific operation: they collect milk early in the morning from 7AM-9AM and early in the evening around 6PM-8PM. The milk must be refrigerated within a few hours of milking. You need power at that time to chill the milk quickly before it spoils,” Jiten Ghelani, CEO, Promethean Power Systems.
Dairy farming is heavily dependent on refrigeration. But most villages are reeling under an acute power shortage which has has sapped the momentum of dairy farming. With intermittent power supply and frequent power cuts keeping milk fresh becomes either very difficult or very costly or both. If the milk gets spoiled before reaching the dairy, the farmer is not paid. This in turns deals a debilitating blow to the income of farmers. Not surprising then, the dairy farming industry trips on power pangs.
The dairies are at crossroads. “Of the roughly 130 million tons of milk produced by India each year, millions of tons go to waste or reach the market as low-quality dairy products that pose health hazards,” shares Ghelani. To find a way out of the impasse, dairies have to spend big money on diesel generators for providing refrigeration.
Don’t have a cow!
Sorin Grama and Sam White while on a market evaluation trip to India discovered that the dairy farming sector in rural India was plagued by the issue of milk-refrigeration.The duo realized the possibilities of tapping into the power grid when it was on and storing energy to keep milk cold. The company launched a manufacturing and testing facility in India in 2013 to commercialize its thermal energy storage-based approach.
Promethean Power’s milk-chiller technology uses an innovative thermal battery that saves cold energy instead of electricity. “The machine has three components – the thermal energy storage battery, the compressor and a plate heat exchanger. Our thermal battery is not a battery in the traditional sense, but a tank that contains two types of materials: a phase-changing material (PCM) that freezes and liquefies inside a series of tubes, submerged in a heat-transfer fluid (HTF) that never freezes. The battery is charged by the refrigeration compressor when grid power is available. The milk is poured either on a 3-foot high, stainless steel heat exchanger that instantly chills milk or in an active storage tank that gradually chills milk,” explains Prakash Ratha, Head of Product & Technology, Promethean Power Systems.
In the battery’s charging process, using grid electricity, the HTF is cooled by the compressor to a temperature that allows the PCM inside the tubes to freeze, and therefore absorb huge amounts of thermal energy. The thermal energy later released from the melting PCM, as it changes from solid to liquid, is captured by the HTF and circulated around the custom heat exchanger. Cold energy is essentially stored in the battery and released to cool and preserve milk.
In the Rapid Chilling mode, milk is poured over the cylindrical heat exchanger and collected in a basin at the bottom. By the time the milk drips from the top of the cylinder to its basin, it receives a “thermal shock” that instantly cools it from 35 to 4 degrees Celsius reducing chances of bacterial growth.
“When power comes on – it could be any time of the day or the night – we run a refrigeration compressor, which basically makes ice. When the power goes out the ice is still there, it doesn't melt immediately, it stores substantial cold energy for a while,” explains Ratha.
The thermal battery provides backup energy just like a mobile power bank. It takes about four hours to fully charge and the system and can be used to cool up to 1,000 liters of raw milk per day. Chilled milk is stored inside an insulated tank for pick-up by dairies. “A standard 1000 liter solution is priced at Rs 5 lacs. Promethean’s systems are set up by dairies in village level collection centers, where farmers can bring milk within half an hour after milking a cow,” he adds.
Taking the milky way to prosperity
Word is spreading about the transformative impact of milk chiller technology. And the industry biggies are taking note. Promethean’s milk chiller technology has been deployed by established players like Amul in Maharashtra, Hatsun Agro in Tamil Nadu, Mother Dairy in UP and Heritage Foods in Vizag. The dairies in Andhra Pradesh and Tamil Nadu also use the product extensively.
The company has 25 installations in Bangladesh for the world’s largest NGO, BRAC. It has also installed a trial unit in Sri Lanka. The company has now sold over 500 milk chilling units to its dairy partners in India, Sri Lanka and Bangladesh - all of them in villages. Promethean has a working solution in the food segment as well. Online retailer Green Tokri uses Promethean’s system for refrigerating vegetables and fruits.
Milking the growing demand
The technology solution has resulted in cost-effectiveness and enhancement of productivity. “For a 1000 liter system, the chilling cost with diesel is four times that of chilling with electricity. So the use of diesel generators for refrigeration becomes a cost-prohibitive option for dairies, and there are additional challenges of pilferage and diesel handling,” cautions Jofi Joseph, Director- Sales & Marketing, Promethean Power Systems.
“In addition to quality improvement, the volume of milk collection also increases by 30-40 % when a village-level chilling center is installed because the collection process becomes more streamlined,” says Joseph. Over the years, milk generation in these villages has increased. The farmers are doing a brisk business. Dairies have reduced their opex and carbon footprint.
The company is brimming with plans to expand its outreach. On being asked about future plans, Joseph explains “We consistently seek feedback from all stakeholders on what more we can do to increase the efficiency and effectiveness of the village level milk collection process”
Basis feedback received so far, Promethean is in the process of developing milk chillers of 500 liters/day capacity to enable dairies to go into smaller villages. The company is also working on a monitoring system so that the dairies can track in real time all the critical parameters of the milk chillers installed in remote villages.
Equipped with Promethean’s solution, dairies can do away with expensive diesel generators. The reduced opex encourages the dairies to spread their reach to nondescript villages dotting India’s rural landscape. Dairies can now procure milk from remote villages that didn’t have collection routes before.
Little wonder then, dairy farmers are a happy lot.