This chapter deals with some major methods and guidelines for the efficient integration of energy during the conceptual process design. The central idea is that the energetic performance of a unit depends not only on its design as a stand-alone equipment, but above all on how taking advantage from the interactions with other units. The optimal behaviour of a unit operation can be formalised by the concept of appropriate placement. A first section is devoted to heat and power integration, including recent developments in the field of environmental friendly refrigerants. Important issues are industrial refrigeration, combined heat and power and waste heat recovery. Energy saving in distillation, a major utility consumer in industry, handles optimal distribution of energy, heat pumping, as well as heat-integrated and -coupled columns. The heat integration of chemical reactors is a key issue for the optimal management of energy. The last section addresses the structure of the utility system, as well as an introduction in site integration.