A comparison of product-based energy intensity metrics for cheese and whey processing

• Product-based energy intensity (PEI) metrics for cheese processing are determined.
• A process-by-process method (PBP) to estimate energy use is presented.
• Three energy allocation methods on a mass and solids basis are compared.
• For energy benchmarking programs, the choice of PEI basis is critical.
• The PBP method on a mass basis is a better indication of the actual energy used.

Dairy processing is one of the most energy intensive sectors within the food processing industry. Accordingly, reducing energy use and energy-related air emissions is of critical importance to improve its economic and environmental performance. This paper focuses on product-based energy intensity (PEI) metrics for improving the energy efficiency of dairy processing by presenting a process-by-process (PBP) method to determine PEIs in a multi-product system, with a focus on U.S. dairy processing operations. This method is compared with two alternative methods in the case of a cheese and whey processing system. For all three methods, energy use is allocated on a mass and solids basis. The results show that the PEI values depend highly on the choice of method. In the case of an energy benchmarking program relying on the PBP method, the choice of PEI basis has an impact on the allowances permitted for each plant and should be chosen carefully.