A thermo-economical assessment of solar-based low-grade heat applied to the meat and dairy industries in Brazil

Abstract

Solar heating for industrial processes (SHIP) is a promising alternative for heat generation worldwide, especially in industries where low-temperature heat is required. However, despite the large importance of the food industry in Brazil’s gross domestic product, SHIP technology is still incipient. Among the reasons, one can mention high installation costs and the fact that many industries in Brazil already use affordable biomass as fuel for heat generation. Therefore, this work carries out a nationwide study of the technical and economic applicability of SHIP for hot water production in the Brazilian food industry, assessing the influence of several variables on SHIP systems profitability, such as the location of the food processing plant, the amount of heat it consumes, the size of the SHIP system installed for this plant, the costs of the solar heating system and of the replaced fuel. Results show that SHIP can be a profitable alternative to natural gas in any part of Brazil but can only compete with firewood in very specific locations, at very specific conditions. For instance, costs reductions around 20% for small SHIP systems allow them to compete with firewood for heat generation, while larger reductions (i.e., similar to 40%) would be beneficial for larger SHIP systems even when firewood costs are below 16 USD/MWh.