The present invention discloses systems and methods for converting heat from external heat source streams or from solar energy derived from a solar collector subsystem. The systems and methods comprise a thermodynamic cycle including three internal subcycles. Two of the subcycles combine to power a higher pressures turbine and third or main cycle powers a lower pressure turbine. One of the cycles increases the flow rate of a richer working solution stream powering the lower pressure turbine. Another one of the cycles is a leaner working solution cycle, which provides increased flow rate for leaner working solution stream going into the higher pressure turbine.