A research plan is proposed which will result in a thorough evaluation of absorption power cycles and a methodology for designing optimum power cycles. The research will specifically focus on power cycles operating with low temperature heat sources, such as solar or geothermal energy, or the energy rejected from higher temperature cycles. The utility of the universal efficiency concept, as a model leading to economically sound power cycle designs, will first be evaluated. According to the universal efficiency concept, the maximum power of simple cycles subject to heat transfer irreversibilities may be explicitly determined. The effect of additional thermodynamic irreversibilities on the efficiency at maximum power will be examined with the intent to develop a realistic goal for the efficiency of well-designed power cycles. A detailed evaluation of several absorption power cycles will be made by comparing their first and operating costs with those of conventional power cycles. Particular attention will be paid to absorption power cycles in which energy transfers to and from the cycle involve streams having finite thermal capacitance rates. The comparisons will include a consideration of realistic parasitic losses. It is clear that heat exchange is of primary importance in the design of optimized cycles. Heat exchanger network synthesis methods will be used to identify improved power cycles designs and to establish a general methodology for designing these cycles.