Development of sustainable ORC applications in the tertiary sector: a case study in the Mediterranean climate

In recent decades, climate change strong advancement has led many countries, especially the most developed ones, to a greater sense of environmental responsibility. On a global, European and national level, adaptation/mitigation strategies and actions aimed at improving energy-environmental sustainability and resilience in the tertiary sectors have been increasingly intensified. In this sector, therefore, plays a fundamental role the integration/introduction of technologies able to operate an efficient conversion of energy, such as indeed Organic Rankine Cycle (ORC) plant, other than renewable energy sources, in order to reduce both energy consumption and pollutant emissions. Within this scenario, the aim of this work is to investigate the potential application of a cogeneration ORC system powered by solar collector and geothermal sources, by evaluating its energy, environmental and economic advantages and limitations. To this purpose a case study involving the coverage of the energy needs of a hotel located in Catania (Southern Italy) has been simulated and analyzed. The outcomes put in evidence the importance of the operative conditions in optimizing the productivity of an ORC plant, especially when associated with renewable energy sources, although at the moment investment and supply costs are still quite high.