Energy-intensive industries are facing new challenges due to the advancing energy transition and the legal requirements regarding the achievement of climate targets. They have to take a closer look at their use of energy in terms of efficiency and develop measures to achieve the specified greenhouse gas reduction targets. The energy flow analysis used in this work is an instrument through which the energy efficiency of the processes can be observed and subsequently improved. With the help of this analysis, the energy flows can be influenced technically, economically and ecologically through the implementation and execution of energy management. In this paper, special attention is paid to the technical optimisation potential. In the theoretical part, the background of the data collection and analysis methods used, as well as the technologies dealt with, are presented. The data required for the practical part was collected, processed and evaluated. In the process, problems arose with data availability and data quality, the solution of which was costly and took a lot of time. Based on the processed data, an energy flow analysis was carried out. This resulted in optimisation proposals in the form of heat pump implementations for the use of waste heat from refrigeration plants and the installation of a photovoltaic system to reduce secondary energy consumption. The results of the calculations carried out for these optimisation proposals provide information on the possible potential for reducing both greenhouse gas emissions and the amount of electrical energy drawn from the power grid. The results of the energy flow analysis also showed where there are additional opportunities for optimisation, for which, however, a lot of data is missing at the moment or the available data is not recorded in sufficient detail. For future improvements, data collection can be carried out for the most promising areas with the highest optimisation potential. In addition, efficiency improvement measures can be implemented, which ultimately contributes to achieving the legal and internal climate targets by the years 2050 and 2040.