This paper is a first attempt to evaluate a refrigeration with cogeneration system focusing on a 915 kW genset/90 ton aqua-ammonia absorption system capable of supplying refrigeration, e.g. for cold storage warehouses for food conservation in the Northern Brazilian autonomous grid. The first and second law joined formulation, i.e. exergy, is used in order to determine irreversibilities and to address the exergetic and monetary costs of the system.