Increasing global warming and the resulting climatic changes are likely to advance the weather-related risks that are facing many different human and natural systems. In the attempt to cushion these effects, mitigation strategies that rely on low cost weather driven variable renewable energy technologies are gaining ground, and installed renewable energy generation capacities are increasing significantly. We present a study on, to what extend the weather is changing in a way that also directly impacts the best system design decisions for weather-driven sustainable energy systems. The latest generation of IPCC???s climate projections, RCP2.6, RCP4.5 and RCP8.5, have been used to represent a broad range of climate outcomes during the 21st century.