One of the most important conclusions of the energy integration techniques is that energy efficiency can only be analyzed with respect to the pinch point location of the system. Therefore, the problem boundaries cannot be limited to the chemical process level but should be extended at the site scale level. In this paper, we discuss how to adapt the pinch based techniques in order to solve the industrial site integration. In the proposed approach, each process requirement is defined by its respective hot and cold composite curves that become hot and cold streams for the site scale problem. The use of mathematical programming techniques allows us to target the minimum cost of energy requirement (MCER) of the total site, including the integration of the combined production of heat and power by the steam network. The illustrative example shows an energy saving of 35% of the total site energy consumption with a very small pay back time.