Repower It Right: Identification of low ecological risk-energy scenarios for second generation wind turbine placements

Background/Question/Methods

Wind is a spatially abundant renewable energy resource, but often associated with innumerable ecological impacts, including collisions, displacements, and destructions. Every year thousands of avian species are reportedly killed due to wind turbines in Germany. But, as one of the pioneer countries for wind power, harnessing wind since the early 80s, their best wind sites are often engaged by less efficient wind turbines, nearly completing the second half of their service lifetimes, making repowering the only obvious solution for capacity additions. Installing more efficient and technologically advanced wind turbines taking advantage of the existing grids and other infrastructure, would significantly increase electricity generation and contribute substantially towards the country’s renewable energy targets and its decarbonization goals. However, like the assessments of the ageing wind turbines were done prior to their installations for obeying siting rules, the repowered turbines also require fresh assessments to calculate the relative challenges to their predecessors. The study focused only on the northern states of Germany, contributing ∼85% towards its annual generation, estimating the risks for species of immediate concern, shortlisted from the historical list of detected collisions, along with those sensitive to disturbance and habitat change, and those undergoing rapid population declines, having localized populations.

Results/Conclusions

Individual species sensitivity indices were calculated and applied to their GIS maps of distribution, aggregating four vulnerability factors: Morphology (size, wingspan, wing loading), Flight (maneuverability, altitude, duration), Habitat (range, habitat use, preferences) and Conservation status (stock availability, adult survival rate, conservation status). Each factor was scored, between 1-5, with higher scores reflecting higher sensitivity. An overall GIS avian sensitivity calculator was developed, based on the sum of the indices of the inhabited species, grading the region into five risk categories: extremely high, high, medium, low, and negligible risk. 90% of the area under investigation was classified under medium-high risk categories, prominently present across the states of Nordrhein-Westfalen, Niedersachsen, Schleswig-Holstein and Brandenburg, Mecklenburg-Vorpommern, Sachsen-Anhalt respectively, with sparse distribution of very high risk (∼7%) prominent across the northeastern districts of Brandenburg as well as the northern districts of Mecklenburg-Vorpommern and Schleswig-Holstein, along with low to negligible risk (∼< 2%) restricted across the western and northern districts of Niedersachsen, and western districts of Schleswig-Holstein, being the only suitable regions for repowering, avoiding the demarcated highly sensitive regions within the neighboring states. Therefore, effectively identifying and minimizing wildlife impacts prior to development, providing authorities, investors, and stakeholders with information to avoid poor siting decisions.