The paper presents steam turbine power, energy and exergy efficiencies and losses analysis during
steam extractions opening/closing. The analyzed steam turbine can be used in steam power plant
or in the marine steam propulsion system (low-power steam turbine). Steam extractions opening
and closing can have a notable influence on various turbine operating parameters, what is currently
purely exploited in the literature. Turbine developed power during steam extractions opening/closing
is direct proportional to turbine energy and exergy losses and reverse proportional to turbine exergy
efficiencies. Turbine energy efficiency is not affected by steam extractions opening/closing. Considering
all the combinations of turbine steam extractions opening/closing, it is obtained that the range of
real developed power is between 30612.91 kW and 34289.14 kW, while the range of turbine exergy
efficiencies is between 85.65% and 86.08%. The range of turbine energy power losses in all possible
observed combinations is between 5401.78 kW and 6050.30 kW, while the range of exergy destruction
is between 4949.44 kW and 5746.81 kW.