Stand-alone photovoltaic (PV) systems comprise one of the promising electrification solutions to cover the demand of remote consumers, especially when it is coupled with a storage solution that would both increase the productivity of power plants and reduce the areas dedicated to energy production. This paper presents a multi-objective design of weakly connected systems simultaneously minimizing the total levelized cost and the connection to the grid, while fulfilling a constraint of consumer satisfaction. For this task, a multi-objective code based on particle swarm optimization has been used to find the best combination of different energy devices. Both short and mid terms based on forecasts assumptions have been investigated. An application for the site of La Nouvelle in the French overseas island of La Reunion is proposed. It points up a strong cost advantage by using lead-acid (Pb-A) batteries in the short term and a mitigated solution for the mid term between Pb-A batteries and Gaseous hydrogen (GH2). These choices depend on the cost, the occupied area and the local pollution and, of course, legislation. (C) 2010 Elsevier Ltd. All rights reserved.