Life-Cycle Assessment of a Multi-Megawatt Airborne Wind Energy System

Abstract

A key motivation for airborne wind energy is its potential to reduce the amount of material required for the generation of renewable energy. On the other hand, the materials used for airborne systems’ components are generally linked to higher environmental impacts. This study presents comparative life-cycle analyses for future multi-megawatt airborne wind energy systems and conventional wind turbines, with both technologies operating in the same farm configuration and under matching environmental conditions. The analyses quantify the global warming potential and cumulative energy demand of the emerging and established wind energy technologies. The cumulative energy demand is subsequently also used to determine the energy payback time and the energy return on investment. The selected airborne wind energy system is based on the design of Ampyx Power, using a fixed-wing aircraft that is tethered to a generator on the ground. The conventional wind turbine is primarily based on the NREL 5 MW reference turbine. The results confirm that an airborne wind energy system uses significantly less material and generates electricity at notably lower impacts than the conventional wind turbine. Furthermore, the impacts of the wind turbine depend strongly on the local environmental conditions, while the impacts of the airborne wind energy system show only a minimal dependency. Airborne wind energy is most advantageous for operation at unfavourable environmental conditions for conventional systems, where the turbines require a large hub height.