The system building perspective for building sustainable system configurations using the German energy transition as an example

An increasing number of countries employ net-zero decarbonization targets in their climate policies, which requires decarbonizing socio-technical systems like the energy system by mid-century. While there is a high level of agreement about net-zero targets, there remains great uncertainty as to how to meet them. At the same time, the challenges of building a new system that fulfils systemic targets such as net-zero are insufficiently reflected on in the sustainability transitions literature. With the help of a literature review building on theories of socio-technical transitions, this paper introduces system building dimensions that account for the difficulties of net-zero transitions. We identify four such dimensions: (1) competing potential system configurations with different sustainability implications; (2) a broad range of complementary system elements needed; (3) lock-ins and path dependencies in the system building process; and (4) the politics of system building. We offer the German energy transition as an empirical case study to illustrate the relevance of these system building dimensions. Like other countries, Germany agreed in reaching net-zero greenhouse gas emissions by mid-century, which requires decarbonizing the energy system. Despite the agreement of net-zero goals, it is uncertain of how to achieve net-zero. We propose four system building challenges that account for the difficulties of achieving net-zero: (i) competing potential system configurations with different sustainability implications; (ii) a broad range of complementary system elements needed; (iii) lock-ins and path dependencies in the system building process; and (iv) the politics of system building. We use examples from the German energy transition to illustrate the relevance of these system building dimensions. Graphical Abstract