Innovation dynamics and technological maturity in the fusion sector: An assessment of fusion projects

Nuclear fusion is envisioned for near-term energy generation deployment, with projected timelines for commercial deployment of fusion expected for the 2030s. Previous research has been limited to either economic or technological maturity assessments of the sector. To address this gap, we design a novel framework that evaluates fusion projects across the most common reactor types and derives the trajectories of technological and economic maturity. We adopt a multiple-case study design to compare innovation dynamics of large-scale public research organizations and privately financed new ventures. The results reveal a systemic asymmetry: Publicly funded organizations represent advanced technological achievements, having established their scientific foundations through decades of incremental and iterative research. Their levels of technological and economic maturity are relatively aligned but they remain in the early phases of innovation. In contrast, private actors pursue a leapfrogging strategy and aim to transition directly from basic research to commercialization, thereby bypassing the incremental validation stages. While economic progress mirrors the commercialization phase, it is decoupled from equivalent technological progress. Rather than emerging from validated achievements, it is propelled by projected outcomes that circumvent the protracted and risk-intensive validation processes. While fusion energy is frequently portrayed as being on the verge of commercialization, this analysis shows that no project fulfils the technical and economic criteria necessary to demonstrate a functioning reactor for energy generation. These findings challenge dominant narratives and underscore the systemic risk of building political decisions on unproven technological foundations, highlighting the need for integrated, evidence-based strategies to guide policy and investments. • Development of novel framework to assess innovation dynamics in fusion projects. • Multiple case study of public & private fusion projects across main technology lines. • Economic and technological progress in private projects are decoupled. • Private firms pursue technological leapfrogging to achieve ambitious timelines. • Economic momentum of private firm is based on projections, not proven technologies.