Considering biodiversity targets and landscape aesthetics in 100%-renewable-energy scenarios for Germany

One goal of the German government is a full transition towards a sustainable energy supply (UBA 2010). This goal is in many ways contrary to the implementation of the National Strategy on Biological Diversity (BMUB 2007). Development trajectories for expanding renewable energy production while minimizing conflicts with nature conservation still remain unclear. While some sensitive areas are already excluded from the allocation of energy farms in current practice, there are still potential conflicts with biodiversity targets (BMUB 2015). Furthermore, landscape aesthetics is often not or insufficiently taken into account, especially in large scale plans. However, expected impacts on landscape aesthetic quality (LAQ) often trigger public resistance (DANIEL et al. 2012). The scenario technique can be used to explore potential development trajectories by analyzing energy supply and impacts, under certain assumptions.

The objective of this contribution is to explore potential energy supply in scenarios that respect the Biodiversity Strategy, with or without consideration of impacts on LAQ. The main focus for energy production lies on the expansion of wind power, which is promoted in the current political discourse in Germany. However, assumptions for energy production from other sources are taken into account. Results of the energy yield calculation will be compared with Germany’s predicted energy demand in 2050.

First we calculate potential wind energy production considering only areas outside legally binding exclusion zones and of minor sensitivity with regard to biodiversity targets. The energy potential is calculated based on the performance curve and hub height of most likely to be installed wind energy plants and the average wind speed, considering all non-excluded sites to be fully covered with wind energy plants. The demand-supply comparison will show whether a full transition is possible under consideration of biodiversity targets, or whether compromises are necessary.

We then analyze the impact of this first scenario on LAQ. The assessment method uses landscape diversity, naturalness, and uniqueness as main indicators and is applied both to the status quo and the scenario (cf. HERMES et al. in prep.). For comparing the results we use graphs showing changes in the overall distribution of LAQ scores, as well as maps of where changes happen and how strong the impacts are.

Last, we calculate energy yield of a scenario where areas of high aesthetic quality are excluded from energy production as well. A demand-supply comparison will again show, if a full transition is possible under the given assumptions, or if trade-offs are to be expected.

Finally, we discuss our results in the light of the current discourse on energy production, and draw conclusions for further development of respective plans and programs, which must not only take into account the combination of different energy sources, but also future developments on the demand side.