A method and apparatus for selecting optimal operating conditions of a genset is disclosed. The genset includes an engine coupled to an electrical power generator, the genset having a plurality of operating points each including an engine speed value and a generator electrical power output value, and having a plurality of cost values associated with operating the genset at respective operating points. The method involves selecting a set of operating points from the plurality of operating points such that a sum of cost values associated with operating points in the set is minimized and such that the engine speed and generator electrical power output values of the operating points in the set increase or decrease monotonically.