The systems and methods described herein reduce relatively high pressure supercritical CO2 to a relatively low-pressure supercritical CO2 using a first CO2 expansion system positioned upstream of the thermal input system. The relatively low-pressure supercritical CO2passes through the thermal input system and into a second CO2 expansion system. The first supercritical CO2 expansion system provides a first power output and/or the second CO2 expansion system provides a second power output. A CO2 compressor system converts the gaseous CO2 exiting the second CO2 expansion system to the relatively high-pressure supercritical CO2 , at least a portion of which is returned to the first CO2 expansion system.
Aaron M. McClung; Klaus Brun