Climate change affects regions differently and therefore also climate change effects on energy systems need to be analyzed region specific. The objective of the study presented is to show and analyze these effects on regional energy systems following a high spatial resolution approach. Three regional climate scenarios are downscaled to a 1 km resolution and error corrected for three different testing regions in Austria. These climate data are used to analyze effects of climate change on heating and cooling demand until the year 2050. Potentials of renewable energies such as solar thermal, photovoltaic, ambient heat and biomass are also examined. In the last process step the outcomes of the previous calculations are fed into two energy system models, where energy system optimizations are executed, which provide information concerning optimal setups and operations of future energy systems. Due to changing climate strong changes for the energy demand structure are noticed; lower heat demand in winter (between -7 and -15% until 2050) and - strongly differing between regions - higher cooling demand in summer (up to +355%). Optimization results show that the composition of energy supply carriers is barely affected by climate change, since other developments such as refurbishment actions, price developments and regional biomass availabilities are more influencing within this context.