Optimization of the energy performance of the system: trade-off between environmental and economic objectives

A valuable mean to increase the energy performance of building systems can be found in a system designed to allow the operator to choose between multiple energy sources. These systems can be referred to as multi-energy systems and recently a wide interest was put on this topic at both district and building level. Since multi-energy systems use non conventional aggregation of energy sources, new energy converters, unusual system layouts, it is of the foremost importance to provide modelling and optimization procedures for those systems. In this paper, various objective functions based on a set of economic, energy and environmental criteria are defined and analyzed on a case study as a function of the customer, the energy costs, the pollutants emissions and the legislative requirements showing that there is generally a trade-off between environmental and economic objectives.