Abstract: Systems and methods are provided for the recovery of mechanical power from heat energy sources via multiple heat exchangers and expanders receiving at least a portion of heat energy from a source. The distribution of heat energy from the source may be portioned, distributed, and communicated to the input of each of the heat exchangers so as to permit utilization of up to all available heat energy. In some embodiments, the system receives heat energy from more than one source at one or more temperatures. Mechanical energy from expansion of working fluid in the expanders may be communicated to other devices to perform useful work or operatively coupled to one or more generators to convert the mechanical energy into electrical energy.