A steam-driven power plant comprising: a low pressure drum of a heat recovery steam generator as a steam source providing steam at a desired pressure; a steam turbine including a low pressure section and an intermediate pressure section, the steam turbine operably connected to the steam source; a steam conduit extending from the steam source to convey the steam from the steam source to the steam turbine; a low pressure admission conduit connected to the steam conduit and configured to convey steam from the steam conduit to an entrance of the low pressure section; an intermediate pressure drum of the heat recovery steam generator producing steam to be introduced to the steam turbine at an entrance of the intermediate pressure section; an intermediate pressure admission conduit extending from the low pressure admission conduit and configured to convey at least portion of the steam from the steam conduit to one of a number of different points located along the intermediate pressure section substantially between the intermediate pressure section entrance and an intermediate pressure section exit; and one or more valves disposed between the steam source and the steam turbine to control a flow of steam from the steam source through the low pressure admission conduit and/or the intermediate pressure admission conduit; the plant further comprising a controller operably connected to the one or more valves (42,46); wherein the controller is configured to open and/or close the one or more valves (42,46) to convey steam to a selected one of the number of different points located along the intermediate pressure section depending on a power operating level of the power plant. a low pressure drum of a heat recovery steam generator as a steam source providing steam at a desired pressure; a steam turbine including a low pressure section and an intermediate pressure section, the steam turbine operably connected to the steam source; a steam conduit extending from the steam source to convey the steam from the steam source to the steam turbine; a low pressure admission conduit connected to the steam conduit and configured to convey steam from the steam conduit to an entrance of the low pressure section; an intermediate pressure drum of the heat recovery steam generator producing steam to be introduced to the steam turbine at an entrance of the intermediate pressure section; an intermediate pressure admission conduit extending from the low pressure admission conduit and configured to convey at least portion of the steam from the steam conduit to one of a number of different points located along the intermediate pressure section substantially between the intermediate pressure section entrance and an intermediate pressure section exit; and one or more valves disposed between the steam source and the steam turbine to control a flow of steam from the steam source through the low pressure admission conduit and/or the intermediate pressure admission conduit; the plant further comprising a controller operably connected to the one or more valves (42,46); wherein the controller is configured to open and/or close the one or more valves (42,46) to convey steam to a selected one of the number of different points located along the intermediate pressure section depending on a power operating level of the power plant.