Dairy Potential

Solar thermal applications in milk production and processing

By Jaideep N. Malaviya, Project Head, Solar Payback, India

With an annual production of 176.4 million tonnes, India is the world’s largest producer of milk and milk products. There are over 1,200 large, medium and small dairy industries across the country, which require significant amounts of energy for processing milk and milk products. In a dairy, primary energy sources such as furnace oil are used to generate steam, which in turn is used for heating applications like pasteurisation, evaporation and drying.

Typical dairy plants meet about 70 per cent of their energy requirements through thermal energy and the remaining 30 per cent is consumed as electricity. Nearly 30 per cent of the overall production cost is spent on the purchase of furnace oil and electricity, which is quite substantial.

Solar thermal applications

An Indo-German collaborative project “Solar Payback”, executed for the German Solar Association and funded by the International Climate Initiative, aims to promote solar heat for industrial processes (SHIP). It identifies dairy as the sector with the highest potential for solar thermal applications, amongst other process heat industries. In addition, India is the world’s third fastest growing SHIP market after Poland and Denmark, as per the International Energy Agency’s Solar Heating and Cooling 2018 report. The National Dairy Development Board (NDDB), a national institution to support policies for the growth of farmers, has already implemented 15 pilot SHIP projects in the country that are showing promising results. These results should be quantified and a suitable policy framework established to attract maximum dairy processing units in India.


For accelerating the use of solar thermal for dairy processing in India, a working committee should be constituted comprising officials from the NDDB, the Ministry of New and Renewable Energy, the Solar Thermal Federation of India, renowned dairy consultants and IIT-Bombay. The existing 15 installations should be studied to identify the grey areas that can be addressed, and the heat consumption pattern of a sample of large, medium and small dairies should be analysed to identify the optimum required solar thermal capacity. To understand the heat demand and annual heat output patterns, potential regions should be mapped to determine the direct normal irradiation (DNI) at different geographic locations.

In addition, a detailed real-time financial feasibility analysis should be conducted to justify the need for fiscal incentives for solar thermal, and all subsidies should be linked to performance. The energy service company concept can also be explored to reduce the burden on dairies as they will not have to invest upfront in costly solar thermal apparatus. In addition, mass awareness activities should be carried out for financial institutions on the economics of solar thermal heating in dairy processing to convince them to extend accessible finance. To this end, multilateral agencies need to be identified that can provide funds to financial institutions under various climate change-related programmes. The Department of Animal Husbandry, Dairying and Fisheries, and the Ministry of Food Processing Industries should be involved in organising workshops. Market demand should be created through policies mandating the use of a certain percentage of solar thermal energy. Finally, owing to the intermittent nature of sunlight, there is a serious need for research and development to produce cheaper energy storage solutions and facilitate demand-supply management.


Owing to the large production of milk and processed milk products, dairies consume a huge amount of fuel to meet their heat requirements. To decarbonise this energy-intensive process, a safe and achievable target of 10 per cent solar thermal use should be set. For this purpose, strict quality compliance is a must for solar thermal systems so that they perform as claimed and use only the best components. In addition, accurate DNI data has to be made available for every region of the country. Finally, if the right policy framework is in place with accessible finance, India has the potential to become a global leader in the use of solar thermal for dairy processing.

To decarbonise the energy-intensive process in the dairy industry, a target of 10 per cent solar thermal use should be set.


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