Life cycle assessment of large structure mechanical endurance tests - Identifying hotspots and reduction potentials

Mechanical endurance testing of large structures is usually conducted over several months, demanding a substantial amount of electricity, labor, and materials. In this research a life cycle assessment is conducted for a representative testing project of a wind turbine pitch bearing system. A second system is modelled to assess the testing facility as an organization, including the processes corresponding to the operation of the offices. Both models follow a cradle-to-grave system boundary in an attributional approach. The life cycle impact assessment is performed using ReCiPe 2016 (H). indicate that the mechanical endurance testing projects are responsible for most of the emissions of the organization across all impact categories, accounting for over 85% of the impacts in 17 of the 18 categories. The testing project accounted for 453 ton of CO 2-eq (GWP100) respectively 89 % of the annual operation of the testing facility. Steel supply for machine elements manufacturing, electricity supply to the testing facility and transportation logistic have been identified as the processes with the highest environmental impacts contributions and therefore, represent the processes where highest potential for impact mitigation exists. Shifting to a renewable electricity supply shows the highest impact reducing GHG emissions around 37% from the testing facility. The use of electric arc furnace steel in the manufacturing of the machine elements that are directly commissioned by the testing facility, and an alternative transportation logistic which reduces the distance travelled by road and uses water transportation, when possible, also present high potential to reduce the emission of the testing projects. Reductions of 9% (43 ton of CO 2-eq ) and 7% (33 ton of CO 2-eq ) in the GWP100 indicator are observed respectively.