Analysis of complementarities: Framework and examples from the energy transition

•We highlight the relevance of complementarities and their dynamics for socio-technical transitions.•We introduce a framework to systematically study complementarities.•We direct attention to the distinction of complementarities at the sector and technology level.•We illustrate our framework with examples from photovoltaics, wind power and alternative vehicles.•We present complementarity related bottlenecks and discuss strategies of how to address them.

Complementarities play a crucial role in socio-technical transitions as they accelerate technology development or decline. Missing complementary components in contrast may hamper the emergence of new technologies or negatively affect sector performance. In this paper, we introduce a conceptual framework to analyze complementarities and to understand their consequences for transitions. Our framework consists of four building blocks: i) different relationships, ii) different components, iii) different purposes and iv) complementarity dynamics. The latter two aspects go beyond existing concepts as they highlight the relative and dynamic nature of complementarities. We illustrate the applicability of the framework with examples from the ongoing energy transition. Finally, we discuss a series of complementarity bottlenecks and potential strategies by firms and policy makers of how to resolve these.