Sustainability assessment of wind turbines using fuzzy logic

Renewable energy systems provide opportunities for developing methods to evaluate their sustainability claims, inclusive of their life cycles, and to rank them based on their broader impact. In this paper, a fuzzy-logic-based method is proposed to evaluate and rank wind turbines as sustainable systems handling wind energy, in terms of renewability and environmental friendliness. Implementation of the proposed method is demonstrated in two steps: First, major factors defining life cycle and sustainability characteristics of wind turbines are identified. These factors are: Capital Cost, Greenhouse Gas Emission, and wind turbine Energy Efficiency. Nevertheless, the method allows expansion to include other factors, which may later be deemed as critical to the evaluation process. Second, a fuzzy-logic-based model is built and tested using hypothetical data to prove the concept. As a result, the relatively best sustainability is decided on a single dimension scale. The proposed method produced reliable results in terms of ordinally ranking the sustainability of wind turbines, but with interdependencies based on the entire group of wind turbine cases being examined. The proposed method formulates a satisfactory stepping stone on the way to establish a unified method and process to rank wind turbines based on sustainability.