Power plant methods and apparatus

A system comprising:

• a gas turbine system including a gas turbine;
• a boiler system including a boiler, said boiler including a first gas turbine flue gas input and a second gas turbine flue gas input, the first gas turbine flue gas input being one of:
• i) a gas turbine flue gas boiler hopper input of said boiler,
• ii) a gas turbine flue gas burner air supply duct input which supplies air to a burner of said boiler, or
• iii) a gas turbine flue gas mill air supply duct input which is included as part of a mill air supply duct which supplies air to a mill which provides fuel to said boiler, the second gas turbine flue gas input being one of:
• i) a boiler hopper input of said boiler,
• ii) a burner air supply duct which supplies air to a burner of said boiler, or
• iii) a mill air supply duct which supplies air to a mill which provides fuel to said boiler, said second gas turbine flue gas input being different from said first gas turbine flue gas input;
• a fan which supplies air which is mixed with gas turbine flue gas prior to the gas turbine flue gas reaching the boiler;
• an oxygen sensor that measures an oxygen level in flue gas output by the boiler;
• a first damper used to control a supply of gas turbine flue gas to the first gas turbine flue gas input;
• a controller coupled to the oxygen sensor, said fan, and said first damper;
• wherein said controller controls during a first mode of operation during which said boiler is active and said gas turbine is active:
• (i) the supply of gas turbine flue gas to the first gas turbine flue gas input of said boiler system, and
• (ii) a supply of gas turbine flue gas to the second gas turbine flue gas input of said boiler system;
• and
• wherein said controlling, during said first mode of operation, the supply of gas turbine flue gas to the first gas turbine flue gas input of said boiler system includes controlling said first damper used to control the supply of gas turbine flue gas to the first gas turbine flue gas input to be in an open position and throughput of the fan which supplies air which is mixed with gas turbine flue gas prior to the gas turbine flue gas reaching the boiler.