Life cycle assessment of wind power: comprehensive results from a state-of-the-art approach

Abstract

The article presents the method and results of the life cycle assessments (LCAs) of the Vestas' 2-MW GridStreamer TM wind turbines and outlines the state-of-the-art approach adopted. For more than 10 years, Vestas has prepared LCAs of wind power. However, since 2010, a step change in comprehensiveness has been employed, for example, conducting the LCA to individually assess all components within a wind turbine (being composed of around 25,000 parts). Three LCAs have been conducted with the 2-MW GridStreamerTM turbines in accordance with ISO 14040/44 and critically reviewed by an expert. The goal was to evaluate potential environmental impacts and other non-impact indicators per kilowatt hour of electricity generated for a ‘typical’ 50-MW onshore wind plant. The LCAs assessed all life cycle stages and were built using GaBi DfX software. A significant quantity of primary data were gathered, for example, covering over 100 Vestas' sites for manufacturing, sales and servicing, as well as establishing turbine use-phase performance (i.e. electricity generation, servicing, etc.) based on over 20,000 monitored wind turbines around the world, covering around 20 % of the current worldwide installed capacity. The baseline results show that per kilowatt hour of electricity generated by the 2-MW GridStreamer™ turbines have the following baseline performance: ADP elements 0.44 to 0.58 mg Sb-e, ADP fossil 0.10 to 0.13 MJ; acidification potential 37 to 45 mg SO2-e, eutrophication potential 3.7 to 4.5 mg PO4-e, freshwater aquatic ecotoxicity 100 to 130 mg DCB-e, global warming potential 7 to 10 g CO2-e, human toxicity potential 1,150 to 1,400 mg DCB-e, marine aquatic ecotoxicity potential 1,100 to 1,300 g DCB-e, photochemical oxidant creation 4 to 5 mg ethene, terrestrial ecotoxicity potential 19 to 24 mg DCB-e, return-on energy 8 to 11 months and recyclability 81 to 85 % of turbine mass. Being equipped with extensive facts and comprehensive LCA models provides Vestas the basis to further integrate environmental considerations into product marketing, design and research, procurement and to deliver transparent information to stakeholders. Overall, the article presents a case study of the LCA approach used to assess the potential impacts of 2-MW GridStreamer™ turbines based upon comprehensive product knowledge and represents a state-of-the-art approach to LCA modelling of wind power. The article discusses further applications of LCA internally to direct product improvement and for external communications and also highlights the LCAs' aim to improve transparency and robustness of previous LCAs of wind power.