On the shoulders of giants: Life cycle based ecodesign applied in wind energy technologies

This PhD thesis aims at environmental management in the rapidly growing wind energy sector. The objective was pursued within the applied setting of a leading wind energy company Siemens Wind Power (SWP) which operates at all points in the value chain of wind energy technologies. Life cycle assessments (LCA) were performed for four representative European wind energy plants covering onshore and offshore markets and two power generator technologies (direct drive and geared). The assessed functional unit was the supply of 1 kWh to the grid. The systems were set to include all components from the power station up to the grid. The boundaries included all life cycle stages, from extraction of raw materials to their end of life (EoL). The results showed that the energy payback time – the time it takes for a plant to generate as much energy as is used during its lifecycle - is less than one year for all plants. The greenhouse gas emissions were found to be under 7 and 11 g CO2-eq/kWh for onshore and offshore plants respectively. Impacts from offshore plants are higher due to more impact dense infrastructure (more metals); and more fuel needed for installation and maintenance. In both markets larger turbines with advanced generator technology performed better. For all plants, most of the induced environmental impacts are due to the use of materials in the infrastructure (>70% contribution to climate change). The negative impact of materials can be offset (~ 20-30% for climate change) through material recycling at the EoL due to avoided production of primary materials. Beyond climate change, focus should be placed on human toxicity and respiratory health risks from inorganic particles. The EoL being the most uncertain part of the system needs to be seen in the context of future wind energy demand. The projected growth of global wind energy (cumulative capacity growing from ~0.4 TW in 2014 to ~1.7 TW in 2050) implies a huge material demand to support a future low carbon economy. This calls for recycling maximisation particularly for disused infrastructure such as offshore cabling, and via rethinking of product design to make use of recovered materials in new product development. It is essential that environmental burdens from recycling, do not offset the benefits from avoided primary production. The LCA results provided a scientific basis for ecodesign. They facilitated environmental target setting in all organisational and functional levels from high level strategic planning down to management and monitoring of individual facilities. LCA was aligned with the formal product development process within SWP and the results were related to stakeholders dealing with design, manufacturing, service and supply chain aspects. The analysis revealed that it is relevant to extend environmental initiatives across value chains. Manufacturing processes within the SWP boundaries were found to contribute less than 1% to the climate change impact from the life cycle. This calls for dialogue, collaboration and innovation across organisations e.g. through data sharing and increased transparency. Ecodesign activities were also tested in a context of social practice. An iterative ecodesign process based on participatory methods took place over four years and five iterations. Outcomes showed how LCA results can be used to build awareness, motivate discussion and eventual environmental action. Ecodesign implementation was facilitated via ensuring leadership commitment, provision of environmental information, formalised processes, stakeholder involvement to ensure feeling of ownership, and clear communication based on successful ecodesign cases. Throughout the period the rate of requests for assistance in target setting and for additional LCAs was increased. This indicates a gathering momentum in environmental management.