Marcus Eichhorn

Model-Based Estimation of Collision Risks of Predatory Birds with Wind Turbines

The expansion of renewable energies, such as wind power, is a promising way of mitigating climate change. Because of the risk of collision with rotor blades, wind turbines have negative effects on local bird populations, particularly on raptors such as the Red Kite (Milvus milvus). Appropriate assessment tools for these effects have been lacking. To close this gap, we have developed an agent-based, spatially explicit model that simulates the foraging behavior of the Red Kite around its aerie in a landscape consisting of different land-use types. We determined the collision risk of the Red Kite with the turbine as a function of the distance between the wind turbine and the aerie and other parameters. The impact function comprises the synergistic effects of species-specific foraging behavior and landscape structure. The collision risk declines exponentially with increasing distance. The strength of this decline depends on the raptors foraging behavior, its ability to avoid wind turbines, and the mean wind speed in the region. The collision risks, which are estimated by the simulation model, are in the range of values observed in the field. The derived impact function shows that the collision risk can be described as an aggregated function of distance between the wind turbine and the raptors aerie. This allows an easy and rapid assessment of the ecological impacts of (existing or planned) wind turbines in relation to their spatial location. Furthermore, it implies that minimum buffer zones for different landscapes can be determined in a defensible way. This modeling approach can be extended to other bird species with central-place foraging behavior. It provides a helpful tool for landscape planning aimed at minimizing the impacts of wind power on biodiversity.

Spatial Trade-Offs between Wind Power Production and Bird Collision Avoidance in Agricultural Landscapes

The expansion of renewable energy production is seen as an appropriate way to mitigate climate change. Renewable energies are not free of negative external effects on humans and the natural environment. We analyzed the conflict between wind power production and bird protection through the example of one of the most sensitive species, the red kite (Milvus milvus) in West Saxony, Germany. We investigated a large number of potential land use scenarios, defined by whether or not each potential site contained a wind turbine (WT). Based on meteorological and ornithological data, we evaluated the land use scenarios for their annual energy supply and impact on the red kite. We identified the efficient land use scenarios that maximized energy supply for a given ecological impact. Within the scope of our analysis, the current allocation of WTs in the study region was considered inefficient. The set of efficient scenarios allowed us to draw conclusions on the trade-offs involved. We developed an indicator that measures the severity of the conflict between wind power production and bird protection. Increasing the minimum distance of WTs to settlements beyond the legal requirements in order to minimize the impact on humans further intensifies the conflict. Our results can support planning authorities in their development of longterm regional plans by identifying areas that are most suitable for wind power production from an integrated point of view.

The Potential of Flexible Power Generation from Biomass: A Case Study for a German Region

Energy scenarios and roadmaps indicate that intermittent renewable energy sources such as wind power and solar photovoltaic (PV) will be crucial to the power supply in the future. However, this increases the demand for flexible power generation, particularly under conditions of insufficient wind and/or solar irradiation. Among the renewable energy sources, bioenergy offers multiple end-use in the form of power, fuel or heat. Biomass-based power combines the advantages of being renewable, exceptionally CO2 neutral and supporting demand-oriented production.

SECURING ENERGY SUPPLY AT THE REGIONAL LEVEL - THE CASE OF WIND FARMING IN GERMANY: A COMPARISON OF TWO CASE STUDIES FROM NORTH HESSE AND WEST SAXONY

Wind power is one way we can reduce our dependency on fossil fuel imports and mitigate climate change. However, wind power can play this important role only if sufficient space for wind farming is made available off-shore as well as on-shore including sites far away from the seashores. Against this background this paper presents a comparative analysis of two hinterland case studies from Germany. Applying GIS and official wind speed data we evaluate the effectiveness of designated wind farming areas in the regions of West Saxony and North Hesse in terms of their expected wind energy yields and potential for repowering. We show that, in this respect, the current spatial allocation for wind power generation in both study regions is not as effective as it could be, but for different reasons. We contrast this finding with an alternative proposal which not only meets the legal requirements for wind power generation but also yields better results in terms of expected energy output. This proposal takes into account the availability of different turbine types and a spatial re-allocation of wind farming areas within the study regions.