ENERGY SAVING BY ESCO (ENERGY SERVICE COMPANY) PROJECT IN JAPANESE HOSPITAL

This paper describes a study starting from an analysis of typical energy demand profiles in a hospital setting followed by the case study of a cogeneration system (CGS) by an ESCO (Energy Service Company) project. The concept is a future autonomous system for the combined generation of electrical, heating and cooling energy in the hospital. The driving cogeneration units are two high-efficiency gas engines; this is used to produce the electrical and heat energy. Gas engine is used as a driving unit because of high needs for electrical and heating energy. The natural gas-fuelled reciprocating engine is used to generate 735kW of power. In our case electrical energy will be used only in the Hospital. A deficit in electricity can be also purchased from the public network. The generated steam will be used to drive three steam-fired absorption chillers and delivered to individual consumers of heat. This system is capable of doing simultaneous heating and cooling. No obstacles were recognized for the technical feasibility of CGS. The average ratio between electric and thermal load in the Hospital is suitable to make CGS system operate. An analysis performed for a non-optimized CGS system predicted a large potential for energy savings.