An exergetic analysis was performed for a 116-MW gas-turbine power plant. Mass and energy conservation laws were applied to each component of the system. Quantitative exergy balance for each component and for the whole system was considered. In this study, the exergy of a material stream is decomposed into thermal, mechanical and chemical exergy and an entropy-production flow. The effect of a change in the inlet turbine temperature on the exergetic efficiency and exergy destruction in the plant was evaluated. The crucial dependency of the exergetic efficiency and the exergy destruction on the change in the turbine inlet temperature was confirmed.