Besseau, Romain; Perez-Lopez, Paula; Blanc, Isabelle

This research work aims at assessing environmental impacts of prospective energy scenarios for isolated territories. Life Cycle Analysis is a relevant tool to support decision making. Many LCA of energy scenarios exist but often rely on generic data not adapted to specific prospective context. We developed a methodological approach to assess prospective footprint of energy scenarios based on LCA for isolated territories. This approach brings innovation at two levels. The first one relies on the adaptation of life cycle inventories (LCI) to prospective and local contexts. In the case of electrically non-interconnected energy scenarios with high share of weather-dependent renewable energy, storage may be needed to locally ensure the temporal energy balance production-consumption. If storage needs are already known, environmental impacts of energy scenario can be assessed thanks to customized LCI. The second one relies on the coupling of production and consumption hourly time-series to assess storage needs. This second level of innovation paves the way to the generation of a high number of energy scenarios integrating the constraint of the temporal production-consumption adequation. Finally, this work provides, for a specific prospective context, a multicriteria LCA of energy scenarios and of energy systems part of scenarios. Its application to French islands highlights the dominant contribution of fossil energy sources to environmental impacts. Renewable energy is not burden-free but its impact can be contained, even when accounting for storage needs. Special attention must be paid to land use (related to biomass and photovoltaic energy-PV), to mineral resources depletion (related to PV, wind turbines and batteries) highlighting the necessity of recycling on the long run, and to pollutants emitted by biomass combustion. Outcomes of this study provide food for thought in the perspective of future revisions of territorial energy planning.