Feasibility of polygeneration in energy supply systems for health-care facilities under the Italian climate and boundary conditions

This article investigates the opportunities of a multi-energy system in a hospital facility under the Italian climate and boundary conditions. One of the benchmarks for tertiary buildings constructed by the U.S. DOE (Department of Energy) to be used in association with the energy simulation software EnergyPlus was taken as a reference hospital. After importing that benchmark under the Italian climatic conditions (in the Turin, Florence and Naples locations) and determining the energy needs for heating energy, cooling energy and electricity, several polygeneration alternatives were presented. The reference configuration of the benchmark case study is based on a one-energy rationale (one energy carrier for each load), while the polygeneration alternatives (cogeneration, trigeneration and renewable) are based on a multi-energy rationale (variable energy carriers used in several converters to cover the same load with the maximum efficiency and reliability). By means of a multi-energy systems modeling framework, the scenarios that are most efficient or profitable were determined. Results show that renewable energy is far from covering the whole energy demand of a hospital, and that – given the actual Italian primary energy weighting factor for electricity, that is the amount of source energy required for the production of one unit of electricity in Italy – trigeneration can be feasible only from an economic point of view, and not from an energy point of view.