Solar energy is in the focus of the whole m on. So is the role of cities and public governments in creating an urban future m is sustainable. This volume highlights the role of solar energy and other solar-related energy technologies for a sustainable low-carbon energy system and, above all, for cities and city regions in the SUD. The articles refer to solar power generation technologies, smart urban planning concepts, and the development of solar energy generation technologies. as well as, 'passive solar building design approaches.