The Hong Kong Government intends to reduce greenhouse gases emissions from power stations through widening application of the more energy efficient water-cooled air-conditioning systems (WACS) in buildings. Consideration is being given to the development of centralized, district wide systems for supplying seawater for once-through condenser cooling (the CPSSCC scheme), or for make-up of water losses at cooling towers (the CPSSCT scheme) such that buildings that are restricted to using air-cooled air-conditioning systems (AACS) may adopt or convert to WACS. Development of district cooling systems (DCS) for supplying chilled water to buildings is another feasible option. This paper describes a study into the energy benefits of implementing these schemes in Hong Kong. Application of the analysis method to a territory-wide study for Hong Kong showed that these schemes were all technically feasible and economically viable. It was estimated that compared with all buildings using AACS, the economic saving that could be realized through implementing these schemes in large scale an around 6% for the CPSSCC scheme, 2-3% for the CPSSCT scheme and 20-23% for the DCS scheme. (C) 2001 Elsevier Science B.V. All rights reserved.