Industrial enterprises are increasingly driven to tap the potentials of energy efficiency in existing and future production sites. The challenge is to identify cost-efficient levers for a low energy demand in the linked energy system of production machines and peripheral devices. Considering enabling technologies for energy efficiency and energy recovery in a cascaded energy network with energy storages this paper presents an approach towards energy and cost-efficient system configurations for production sites. An outlook will be given on the research center eta-factory for energy efficient factories at the PTW, TU Darmstadt.