Design of a Solar Pond as an Energy Storage System for the Pasteurization process in Dairy Industry

The usage of solar energy started from the ancient time. After a remarkable increase in oil prices, various countries started extensive research and development in utilization of a solar energy. There are various methods to store this solar energy and solar pond is one of them. Solar ponds are nothing but pools of salt water which store solar energy. Salt water naturally forms a salient gradient in which low salinity water floats on high salinity water. High salinity water does not mix readily with the low salinity water above it. When bottom part of a pool is heated, convection occurs separately in two layers which results in a decrease in the heat loss. This phenomenon allows the high salinity water to increase the temperature of the water up to 90 C. In a dairy industry, the pasteurization process plays a crucial role. Pasteurization is a process which kills microbes and bacteria in food and beverages. This process was invented by French Scientist, Louis Pasteur in 1864. In this process food or beverage is heated at an appropriate temperature and held at that temperature for a certain time and then cooled. As the output temperature from solar ponds can be up to 80 C (176 F), the energy from a solar pond can be used for the pasteurization method in a dairy industry. In a dairy industry where daily production of milk is around 85000 liters, required pond area is 2172 m2. If an existing coal or a natural gas boiler system is replaced with a solar pond as an energy storage, 160 tons and 90 tons of carbon dioxide emissions can be reduced respectively per month.