Techno-economic and environmental assessment of energy vectors in decarbonization of energy islands

Abstract

Decarbonization and transformation of the power system go beyond integrating large shares of variable distributed energy sources; it implies understanding the increasing flexibility needs of the power system and breaking barriers in the process of transforming passive users to active participants in future low carbon energy systems. Unlocking the potential of final users and transforming them into distributed flexibility providers requires harmonization of operation through new models such as the association in energy communities. Multi-vector energy communities (MEC) can provide further flexibility options, enable integration of local energy generation and empower energy islands to increase self-sufficiency and resilience to external impacts. In line with this, the paper develops a unified mixed-integer linear programming (MILP) model of a MEC and rigorously assesses techno-economic performances of different combinations of energy sources, vectors and consumers. That way, the potential of different MECs for providing flexibility and increasing the utilization of electricity production from local renewable energy sources is assessed. Based on the results of the MILP models, the paper further proposes novel indicators for estimation of the techno-economic and environmental potential of different multi-energy vectors in decarbonization of energy islands. Case study analysis comprises of eight scenarios with different MEC’s setups with realistic data from island Ærø in Denmark and island Vis in Croatia, capturing also geographical specificities. The results show significant differences across different MEC set-ups as well as between the geographical locations, and some of the results that can be highlighted are: demand responsive electric heat pumps and use of battery energy storage systems provide stand-out energy potency and can ensure self-sufficiency with smallest capacity of electricity production from local renewable energy sources, but comes with a growing costs for the increase of storage capacity; use of imported natural gas as a transition fuel could be affordable solution but does not lead to fulfilment of self-sufficiency or environmental goals; hydrogen energy vector has significant potential, especially in cases where seasonal energy storage is needed but the costs are still a main barrier; correlation of production and consumption patterns in island Ærø in Denmark favor wind energy, while the increased capacity and production from solar plants is more favorable in island Vis in Croatia.