ABSTRACT Combustion turbines (CTs) are increasingly used for electric power generation in combined heat & power (CHP) applications, including those in the district energy arena. CTs exhibit an inherent loss in power output as ambient air temperature rises, at precisely those times when power is most in demand and most highly valued. This article presents the concepts, and the benefits, of cooling the inlet air entering CTs during times of high ambient air temperature. Various technologies are reviewed that can be and have been employed to achieve CT inlet air cooling (CTIAC). Comparisons are drawn between the technologies, and the advantages and disadvantages of the various techniques are described. Actual examples are presented of CTIAC in district energy applications, illustrating the various technologies. CTIAC can typically achieve a CT power output improvement of 20 to 30 percent, as well as an efficiency improvement of 5 percent. CTIAC unit capital costs are often roughly half those of equivalent simple cycle CTs. Further enhanced cost benefits are described that are achievable when CTIAC is coupled with district cooling systems. CTIAC is projected to be of increasing value in future deregulated electric power environments.