REA Kvarner: Turning Unije (Croatia) into an energy independent island

Read how REA Kvarner is helping Unije to become an energy independent island and a model for a number of similar small island communities in the Adriatic.

Unije, a small island in the Kvarner Bay, is on the path to becoming energy independent and a model for a number of similar small island communities in the Adriatic, contributing not only to their survival in terms of preventing the total depopulation but also to their socio-economic development.

The Island of Unije is one of the 1244 Croatian islands, with the area of 16,77 km² and is inhabited by 88 permanent residents, according to the 2011 Census. However, in the summer period, this number can increase up to ten times, leading to problems with water shortages, energy supply etc. In a study entitled “The Island of Unije: Energy Self-Sufficient Island“, prepared by REA Kvarner in cooperation with the University of Zagreb Faculty of Mechanical Engineering and Naval Architecture, different scenarios until 2020 and 2030 were examined, and concrete RES and EE measures proposed, leading to the start of “Unije – energy-independent island” project, initiated by the Primorje-Gorski Kotar County and coordinated by the Regional Energy Agency Kvarner.

The Agency :

  • Developed a conceptual design and selected a location for the construction of a photovoltaic power station (capacity of 1 MW)
  • Produced a study examining the connectivity of a power station (capacity of 1 MW) including a battery system (capacity of 1 MW) with an existing submarine electric power grid
  • Developed the main design and oversaw the construction of a desalination unit on the Unije Island; a project of introducing a rooftop photovoltaic system (capacity of 7kW) in order to supply the desalination unit was implemented subsequently
  • Implemented a project introducing an energy-efficient street LED lighting system.

Furthermore, within the H2020 project INSULAE, a battery storage system of 1MW will be hybridized with the PV plant with a twofold objective: to accommodate all the PV plant generation within Unije grid and to enable Unije to become in the long-term an energy buffer for the entire archipelago. It is expected that at the end of the project, Unije will achieve a 100% share of RES in the energy mix.

The aim of INSULAE is to foster the deployment of innovative solutions for the EU islands decarbonization by developing and demonstrating at three Lighthouse Islands (located in Croatia, in Denmark and in Portugal) a set of interventions linked to seven replicable use cases, whose results will validate an Investment Planning Tool (IPT). The interventions will prove the ability of the use cases to develop RES-based systems 40-70% cheaper than the diesel generation.

This Pilot Project, if successful, should also be replicated in a number of similar small island communities in the Adriatic. the Island of Unije would become the first energy self-sufficient island in Croatia and thus the best practice example and a model for all other small island communities, with a significant impact on their socio economic development.


Country :
Region :
Time frame :
2015 - 2023
Website :
Organisation Name Position Contact
REA Kvarner