Moving the system boundaries in decarbonization of large islands

During the last few years, the majority of the EU Governments are implementing suitable energy policies, promoting a transition toward full decarbonized sustainable energy systems by 2050. This paper focuses on creating comprehensive decarbonization scenarios for the island systems, using EnergyPLAN software. The island of Sardinia, Italy, was selected as a case study. The presented method uses scenario approach and seeks to push the boundary of the island energy system and use the locally available resources to partially supply the maritime transport connecting the island to the mainland. The reference model was validated using the data provided by EDGAR and IEA for 2017. The Business as Usual Scenario and High Renewable Scenario by 2030 and 2050 were modelled. The latter considers the conversion of the Sardinia energy system into a smart, highly efficient and integrated system. For the power system, improvements are made by the installation of small decentralized renewable systems, mainly including photovoltaic and wind technologies, and increase of storage technologies use. Thermal demand is reduced by building energy refurbishment actions, including the envelope insulation and use of heat pumps. For the transport sector, raise of the share of electrical vehicles is expected, as well as the possibility to introduce biofuels in both maritime and road transport sectors. Results clearly show that carbon neutrality by 2050 is a reasonable target in different decarbonization scenarios. The study also provides useful suggestions to be implemented in order to achieve this goal.