Optimal energy supply structures for industrial sites in different countries considering energy transitions: A cheese factory case study

Abstract

This present study focuses on analysing the most efficient utility energy supply structure in terms of primary energy efficiency, carbon emissions and energy costs. In the German dairy industry, separate conversion with gas fired steam boiler, and cooling with ammonia chillers are the-state-of-the-art technologies. It is attractive due to its robustness and low investment costs. But given the ongoing energy transition to renewable energy, opportunities to reduce emissions will become increasingly important. There are other energy supply options, such as Combined Heat and Power (CHP) and Heat Pumps (HP), that if implemented need to compete against the conventional energy supply systems. One option is CHP to provide cogenerated electricity and heat while cooling remains supplied by ammonia chillers. In countries with high electricity Grid Emissions Factors (GEF) such as Germany and the USA, the use of decentralised CHP results in savings of primary energy and emissions. However, this option is less attractive for countries with low GEF such as France and Norway, and for places like Germany where the energy transition lowering its GEF by 50 % in 2030. In these cases, HP solutions provide the lowest emissions and highest primary energy efficiency.