Opportunities for the energy efficiency improvement in the dairy food sector. The case study of portuguese traditional cheese industries.

Worldwide, cheese is a major dairy food product with great nutritional value and organoleptic characteristics. Over 20.4 million metric tons of cheese were produced worldwide in 2012 (80 thousand tons in Portugal). This paper characterizes the production process and the energy consumption of traditional cheese industry in Portugal (31 companies) and discusses the average specific energy consumption (SEC). Data collection was conducted via survey to obtain information about the facilities, the production process, quantities of raw materials, characteristics of cooling systems, and energy consumption. The average value of this indicator for this sample was 0.152 kWh/l.RM (handmade type) to 0.283 kWh/l.RM (industrial type). Electricity consumption is about 63% of the total energy consumption, mainly due to the energy supply of the refrigeration systems. The potential of energy saving was estimated at 20.8% (handmade type) and 19.4% (industrial type).