This article describes an integrated energy planning optimization case-study. Starting from an integrated urban energy planning practice based on the urban planning information, an optimization approach is implemented to support decisions on suitable energy structures. Based on a use-case, energy demand, renewable energy resources, energy policy and energy prices are analyzed and set as inputs of the optimization. The results are energy structures minimizing the cost for two separated zones. Meanwhile, under different scenarios, in terms of renewable ratio targets and thermal storage, comparison is made for illustrating economy differences. The optimization mentioned in the article is modelled as a Mixed-Integer Linear Programming problem, which can search the optimal solution with high efficiency among the possible system designs.