Conclusions — with personal reflections.

Global warming necessitates a replacement of traditional technologies based on fossil fuels. The number of options is rather limited. Renewable energies will play a dominant role in this process. Whereas biomass and hydro-electricity are limited, wind and photovoltaic power (PV) can be upscaled to large capacities. The technical side of CO₂-free technologies has been covered in the bulk of these proceedings. In this paper, we concentrate on the main characteristics of an electricity system based mostly on wind and PV power and the consequences of integrating intermittent technologies. Most practical examples are taken from Germany. The question whether nuclear power can be considered as clean electricity source supplementing renewable energies will be discussed. Nuclear power will still play a role in 2050 and beyond in and outside of Europe. [ABSTRACT FROM AUTHOR]