In the United States, approximately one third of the energy end-use is from the industry, which makes the industrial sector ranked the number one in terms of energy consumption. Energy efficiency in the industrial processes can reduce the energy demand as well as greenhouse gas emission, which is the most concerned topic in the global warming debate. In fact, the improvement of energy efficiency and an intelligent linkage of the energy consumer, distribution, storage, and energy supply is the key to lower the energy consumption in industrial approaches. In this paper, the research is focused on the study of these combinations leading to a "smart grid" in the industry via a plastic factory case study. In order to obtain flexibility of the energy supply, the electrical heating method is changed to thermal oil heating in the production machines. The reconstruction of moulding machines from electric to oil heating and the thermal grids in the plastics factory enhances the use of heat generated by a CHP unit. In addition, by changing the refrigeration supply from a compression to an absorption chiller, the use of the heat is increased even further. By the case study presented, the primary energy demand is lowered by up to 40 percent. The simulation shows the energy savings potential for a manufacturing company located in Germany and the USA.