Optimizing the In-House Power-Plant Usage of Industrial Users for Case of Changing Energy Purchase Prices

The paper dwells upon optimizing the use of in-house generating capacities by large and energy-intensive industrial enterprises (steelworks in particular) in the context of constantly changing external energy source pricing. The distinctive feature of such power plants consists in the combined use of multiple energy resources, both purchased and in-house, the range of which depends on the company's process. Costs as a function of electrical load (the techno-economic characteristics) of such facilities are complex and have discontinuity points. It is proposed to use a method based on discrete dynamic programming and fuzzy sets to optimize power use in the light of such distinct features. Setting the techno-economic characteristics of units as fuzzy-variable functions reduces the computational intensity, which is a feature of the proposed method. The developed method has been implemented as a computer program. Changes in the prices of purchased energy sources, as well as their effects on the optimal capacity structure of an industrial enterprise have been analyzed for an industrial location featuring a major enterprise, around which a company town is formed.