In terms of energy supply, the vast majority of populated islands depends on fossil fuels. These are normally not locally available on the islands. Because of the increasing profitability of renewable energies and a growing environmental awareness, more and more islands are breaking away from the conventional energy supply and are reinforcing the use of renewable energies. An energy supply system proven successful on one island could also be successfully implemented on another island. For this, the second island has to have similar conditions for the use of renewable energies. This study classifies the global islands with the use of cluster analysis. Input variables of the performed cluster analysis are climatic as well as physical and socio-economic parameters. In total 1087 islands are classified. Finally, ten main clusters of islands could be pointed out. These clusters contain regional and global spread groups of islands. The result offers the possibility to identify similar islands concerning the implementation of RES. Therefore, it supports the transfer of proven, well-working concepts and the direct adoption of these concepts by suitable islands. Furthermore, islands which have especially high potentials for the use of a specific renewable energy source can be easily recognized. (C) 2016 Elsevier Ltd. All rights reserved.