This paper describes a steam distribution system in which steam is generated by waste heat boilers, and by the exothermic reaction of a chemical process. The steam is distributed at four different pressures through a combination of control valves and a turbo-alternator. The steam load on each of the four pressure headers is dependent on the operating modes of two chemical plants; and can vary in magnitude from a situation of steam demand, to one of surplus steam. As part of an energy conservation programme, the distribution of steam has been optimised to provide the maximum possible utilisation of the turbo-alternator for all operating modes, consistent with chemical plant operation. An additional improvement in electrical power generation of 0.25 MW was obtained by the application of a computer to the optimising loops.