Education for sustainable development (ESD) has the potential to stimulate and promote both the goals of quality early childhood education (ECE) and sustainable development at the local level. Especially since the UN Decade of Education for Sustainable Development 2005–2014 (UN DESD) (UNESCO, 2005), efforts have been made to integrate ECE into the ESD discourse in Germany. This paper traces the subsequent changes in educational practice in preschools and outlines the strategies and measures employed to this end. The Kindergarten and Energy (KIEN) project “Preschools and the Energy Transition: Development of Model Educational Practice, Staff Qualification and Municipal Integration” has shown how collaboration amongst preschools and municipal partners (including parents) can be developed to help meet these two goals. Ten case studies in the KIEN project illustrated that, when supported by ESD professional development activities and by practitioners with expertise on sustainability issues, preschool teaching staff can be qualified and motivated to act as “change agents” for sustainable development. The implementation of the UNESCO Global Action Programme (GAP) (UNESCO, 2014) in Germany has offered a framework to help ensure that ESD not only depended on individual promoters and projects, but was also structurally anchored. The KIEN project demonstrated that preschools can become a place of learning about sustainable development in the community for children and adults alike. An important implication of the KIEN project was that ESD should be integral to education policy-making at a municipal level, and specifically, in the area of early childhood education.