Energy efficiency and environmental impacts of horizontal small wind turbines in Austria

Abstract

Small wind turbines (SWT) can contribute to the urgent need of transforming the energy system. Nevertheless, due to the heterogeneity of SWT technology, a high variety in environmental impacts of SWT exist. To evaluate whether the use of horizontal SWT can efficiently contribute to a renewable energy system, Life Cycle Assessments of two SWT, a commercial Schachner SW5 and a do-it yourself turbine in the Piggot Pig2F design, were conducted. The energy payback time was calculated using performance measurements from a rural and a suburban site in Austria. Results show that SWTs can reduce greenhouse gas emissions of the Austrian electricity production with calculated global warming potentials of 62gCO2eq/kWh (SW5) and 94gCO2eq/kWh (Pig2F) respectively. For both SWTs, the sub-system tower with foundation contributes about half to their overall global warming potential as well as to the cumulative energy demand. An improved shaping of SWT technology is therefore exemplified by both SWTs. The analysis shows that 19 out of 20 considered impact categories can be reduced by using secondary (recycled) or re-used steel, especially for the tower. The rural and suburban use of horizontal SWT can potentially contribute to reduce the environmental impacts of Austrian electricity production. Nevertheless, it becomes evident that a more sustainable shaping of SWT technology is highly recommendable.