A turbine washing system having a water making apparatus at a turbine site having a turbine. The water making apparatus extracts water from air. A water delivery system delivers the extracted water from the water making apparatus to the turbine to clean the blades of the turbine while the turbine is on-line. A water feeder is provided for feeding the extracted water from the water making apparatus to the water delivery system.A method for cleaning turbines on-line comprises extracting water from air directly at a turbine site having a turbine and treating the air and the extracted water to obtain extremely clean water having a conductivity of less than 3. This extremely clean water is then fed to the turbine to clean the turbine blades while the turbine is on-line. Preferably the extremely clean water is fed through a deionizer before being fed to the turbine.