A waste heat recovery system includes a heat recovery cycle system coupled to at least two separate heat sources having different temperatures. The heat recovery cycle system is coupled to a first heat source and at least one second heat source. The heat recovery cycle system is configured to circulate a working fluid. The at least one second heat source includes a lower temperature heat source than the first heat source. The working fluid is circulatable in heat exchange relationship through a first heat exchange unit, a second heat exchange unit for heating the working fluid in the heat recovery cycle system. The first heat exchange unit is coupled to the at least one second heat source to heat at least a portion of a cooled stream of working fluid to a substantially higher temperature.