To support their technology, factories use eat and power. Inputs may be produced internally or purchased in the market. To produce inputs internally, factories use the TPC, i.e. an energy system consisting of a steam boiler and a purely condensing turbine. Factories may also use an energy system consisting of a steam boiler and a turbine with steam extraction (TSE). Using a steady-state, bottom-up approach in a network of energy modules and mixed integer linear programming (MILP), we derive the cost-region diagrams for both the TPC and TSE. These diagrams provide the plant operator with guidance for optimum resource utilization which results in a cost saving of 71.8%.