Processing plants are usually concentrated in industrial areas or cities. Carbon footprints of such areas tend to be very high and improvements in energy efficiency is becoming increasingly important. However, energy integration across such cities is a largely unexplored research area. This project develops a new approach to enable multi-level screening for energy integration across plants in industrial cities. The approach enables the identification of energy targets which allow the engineer to quickly assess the potential for energy savings through recovery. The approach further enables energy recovery systems design to achieve these targets. The focus in the development of the approach has been on overcoming the many operating issues that pose obstacles for implementation of heat integration across plants in practice.