Decarbonizing Italy’s smaller islands through the introduction of local renewable energy sources has been an integral part of energy transition policies for several years. However, while the direction for improving the sustainability of these islands is clear and widely shared, identifying truly applicable solutions on the ground is often complex due to the specific peculiarities and challenges that characterize these systems.
For this reason, the activities described in this report aim to provide a concrete example of decision support for identifying efficient and practically applicable solutions for the energy transition, taking into account the real needs, constraints, and issues faced by stakeholders on the ground.
To achieve this goal, a close and intense collaboration was initiated with the electric company of the island of Ustica, to assess the effectiveness of different concrete and realistic planning interventions, based on detailed data on the island’s water-energy system and the main constraints related to the current operation of the power system. The O2WEnS modeling tool (developed in the previous year) was used to analyze different interventions, including:

1) An increase in photovoltaic generation,
2) The introduction of electrochemical storage,
3) The use of the desalination plant as an unconventional storage technology.

The results obtained for the specific case study analyzed show that an increase in photovoltaic generation can lead to significant reductions in CO2 emissions (up to 20%) and costs (up to 10%). More efficient management of the diesel plant and the inclusion of electrochemical storage serving the plant can reduce fuel consumption and operating and maintenance costs. Finally, dynamic and coordinated management of the desalination plant can lead to substantial benefits in terms of system flexibility, potentially avoiding the need for electrochemical storage.
More generally, the results demonstrate that, in systems such as smaller islands where potable water must be produced by desalination plants, an integrated management of the water-energy system is essential for achieving high levels of economic and environmental sustainability.