Posters

Abstract

The progression of climate change emphasizes the importance of renewable energy like wind energy. The question of the impact of climate change on the energy yield of wind farms during their operating period was increasingly raised at various conferences and industry meetings, since this is usually neglected in the preparation of wind and yield assessments. To consider climate change, its impacts on the yield-relevant quantities and thus on the future yield of wind farms are estimated using various climate scenarios. The estimation is based on a coupling of an ensemble of regional climate projections from CORDEX with the CFD-model FITNAH-3D, that has been operated exclusively by GEO-NET for decades and is continuously developed to meet the requirements in the field of wind energy. Within the CORDEX initiative, regional climate models are driven by global climate models, which provide forecasts for future climate changes.  Site-specific changes between CORDEX-data from a reference and a future period assuming a constant bias are determined for high-altitude wind statistics, temperature, pressure, and relative humidity, respectively, as these quantities are yield-relevant and used for the calculation of the energy yields. The change signals are applied to the current yield relevant parameters to calculate modified energy yields.   The method was applied to an exemplary German site. A change in annual energy production ranging between -2.9 % and 8.5 % was found. Assuming that the medium RCP4.5 scenario is the most probable, a slight increase of 0.93 % can be expected for the energy yield. The in-depth analysis of the yield-relevant parameters was recently extended from Germany to Europe. Here, we investigated the changes in high altitude wind speed, wind direction and extreme wind. Derivations between the model combinations of the CORDEX data, e.g. due to model uncertainties, are considered via an uncertainty measure based on the 15th and 85th percentiles and a significance measure for the results giving the fractions of ensemble members that agree on the projected trend. The presented method is a tool for a forecast of the influence of climate change on the yield-relevant meteorological variables and thus on the energy yield of wind farms. Since climate change is usually neglected in the preparation of wind and yield assessments, the method is an important contribution to industry knowledge. CORDEX data is available worldwide, hence this method can be used worldwide for wind energy assessments. It was found that the use of the change signal of the CORDEX data between two periods enables statements about the impact of climate change on wind energy yield relevant parameters, but climate variability as a possible cause of the analysis results cannot be ignored. Model uncertainties are described via uncertainty measures. A possible uncertainty due to inconsistent land use data in the CORDEX data is reduced considering foreseeable changes in land use and orography in FITNAH-3D.