Author: Tobias Schmid, Forschungsstelle für Energiewirtschaft e.V. (as of June 2017)
For grid operators, it is necessary to spatially localize the future development of renewable energies as precisely as possible. This enables early and forward-looking planning of grid expansion. The FfE wind scenario tool WiSTl enables plant-specific expansion scenarios for wind turbines, taking into account different land suitability, potential yield and the repowering potential of existing wind farms.
Excluded areas and available areas
Available areas are all areas that are basically suitable as a site for a wind turbine. Thus, only sites in special protection areas (including nature conservation areas, flora-fauna-habitat protection areas, national parks) or near settlement areas are excluded.
Devaluation
In addition to areas that are not suitable as a site for wind turbines, sites with limited usability are also recorded. Areas with limited usability deposited in the model are:
- Landscape conservation areas
- Nature parks
- Forest areas
Sites in these areas are less suitable for wind turbines and are assigned lower development probabilities under the model presented here.
Potential Full Load Hours
In order to calculate the potential yield or full load hours for the sites, the model uses Weibull digital data on wind frequencies.
WiSTl
WiSTl models a facility-specific expansion of wind turbines on the available land. Starting from sites with high potential full load hours, wind farms and individual turbines are built - taking into account necessary distances between wind turbines.
Repowering
Repowering is modeled in four steps using WiSTl. First, the turbine locations of existing wind farms are recorded, then the wind farm is described as a polygon. This polygon is provided to WiSTl as an area to be built on. WiSTl builds a new wind farm in the area.
Visualization of the results
For each question a suitable visualization of the results has to be chosen. In the following, a very small-scale visualization with individual plants, a visualization of the power density for a larger region and a visualization of the installed power in Germany as a kernel-density map are presented.
Outlook
WiSTl is already used by many distribution grid operators in the context of target grid planning. In the 2025 grid development plan, wind power development scenarios are modeled for transmission system operators. The wind scenarios are supplemented by another model. This describes the development of PV capacity per municipality based on historical development and future influencing variables. In summary, this results in a valid database for describing the future expansion of renewable energies in the highest spatial resolution.
