The cohort effect in solar energy and nuclear power: unveiling collective agency in energy transitions

How does the collective agency of multiple individual actors shape energy transitions? This paper engages with the many, varying careers of petroleum chemists, engineers and (geo)physicists who got involved in the development of alternative energy sources during the second half of the Twentieth century. In this period alternatives to oil, such as nuclear and solar power, were developed, often with the aid of many actors with roots in the already established oil regime. To preserve the agency of these many individual actors within the broader framework of energy transitions offered by the Multi-Level Perspective (MLP), this paper argues for the inclusion of (generational) cohort theory from the social sciences. Using cohort theory helps us better understand the agency the multi-facetted careers of the studied (oil) actors, often leading them through the revolving door between the political landscape, the existing oil regime, and the new technological niches of solar and nuclear energy.