Method and arrangement for augmenting the power output and the efficiency in a gas turbine plant, as well as a gas turbine plant

The method involves injecting a liquid into the induction air (2) of a compressor (10) in the gas turbine system (1). The liquid contains a substance for preventing surface tension. The surface tension prevention substance is a corrosion-inhibitor or contains a corrosion-inhibiting additive. Independent claims are also included for the following: (A) an arrangement for increasing power and efficiency in a gas turbine system (B) and a gas turbine system.