A method of generating power, the method comprising: combusting a carbonaceous fuel in a combustor with oxygen in the presence of a pressurized working fluid stream formed of essentially pure CO 2 to provide a heated combustor exhaust stream comprising one or more combustion products; expanding the heated combustor exhaust stream in a turbine to generate the power and form a turbine exhaust stream; withdrawing heat from the turbine exhaust stream in a heat exchanger to form a cooled turbine exhaust stream; purifying the cooled turbine exhaust stream in a separator by separating one or more of the combustion products from the turbine exhaust stream to form a stream of essentially pure CO 2; pressurizing the stream of essentially pure CO 2 to form the pressurized working fluid stream formed of essentially pure CO 2; adding the heat withdrawn from the turbine exhaust stream to the pressurized working fluid stream formed of essentially pure CO 2 by passing the pressurized working fluid stream formed of essentially pure CO 2 through the heat exchanger; further heating the pressurized working fluid stream formed of essentially pure CO 2 with available solar heating; and passing the pressurized working fluid stream formed of essentially pure CO 2 to the combustor; wherein the amount of carbonaceous fuel and oxygen provided to the combustor is controlled such that heat of combustion in the combustor is inversely related to heat available from the solar heating for heating the pressurized working fluid stream formed of essentially pure CO 2, wherein the amount of heat available from the solar heating varies by greater than 10% over a single solar cycle, and wherein the amount of carbonaceous fuel and oxygen provided to the combustor is controlled such that the temperature of the heated combustor exhaust stream comprising one or more combustion products passed to the turbine varies by less than 10% over the single solar cycle. combusting a carbonaceous fuel in a combustor with oxygen in the presence of a pressurized working fluid stream formed of essentially pure CO 2 to provide a heated combustor exhaust stream comprising one or more combustion products; expanding the heated combustor exhaust stream in a turbine to generate the power and form a turbine exhaust stream; withdrawing heat from the turbine exhaust stream in a heat exchanger to form a cooled turbine exhaust stream; purifying the cooled turbine exhaust stream in a separator by separating one or more of the combustion products from the turbine exhaust stream to form a stream of essentially pure CO 2; pressurizing the stream of essentially pure CO 2 to form the pressurized working fluid stream formed of essentially pure CO 2; adding the heat withdrawn from the turbine exhaust stream to the pressurized working fluid stream formed of essentially pure CO 2 by passing the pressurized working fluid stream formed of essentially pure CO 2 through the heat exchanger; further heating the pressurized working fluid stream formed of essentially pure CO 2 with available solar heating; and passing the pressurized working fluid stream formed of essentially pure CO 2 to the combustor; wherein the amount of carbonaceous fuel and oxygen provided to the combustor is controlled such that heat of combustion in the combustor is inversely related to heat available from the solar heating for heating the pressurized working fluid stream formed of essentially pure CO 2, wherein the amount of heat available from the solar heating varies by greater than 10% over a single solar cycle, and wherein the amount of carbonaceous fuel and oxygen provided to the combustor is controlled such that the temperature of the heated combustor exhaust stream comprising one or more combustion products passed to the turbine varies by less than 10% over the single solar cycle.