This paper is concerned with the feasibility study and evaluation of an energy savings opportunity in buildings energy management using co-generation coupling with thermal energy storage. Both the technical and economical feasibility is presented first for the co-generation and then compared with the co-generation using thermal energy storage. On-site cogeneration with double effect absorption chiller provides a potential of at least 13% peak demand reduction and about 16% savings in energy consumption. It provides an internal rate of return (IRR) greater than 21% but saving potential is limited by the low demand of co-generated chilled water within the community of the institution. Thermal energy storage coupling with co-generation offers a simple and economically more attractive approach for maximizing the utilization of cogenerated chilled water and shows 23% reduction in peak demand and 21% savings in energy consumption. It provides higher IRR, greater than 25%.