A Synergistic Future: Integrating Nuclear Fusion with Renewable Energy Systems for Global Energy Transition

The global energy transition, driven by the climate crisis, is increasingly dominated by variable renewable energy (VRE) sources, whose inherent intermittency presents a critical challenge to grid stability and necessitates the integration of firm, dispatchable, carbon-free power to ensure a reliable energy supply. This paper critically evaluates the potential role of nuclear fusion, not as a standalone baseload generator, but as a synergistic component within a VRE-dominated energy system, arguing that its viability is contingent upon a clear-eyed assessment of its benefits as a flexible energy hub against significant, newly quantified challenges in waste management, resource sustainability, and economic competitiveness. Through a systematic review and synthesis of recent literature spanning engineering, life-cycle assessment (LCA), materials science, and socio-economic analysis, we find that fusion demonstrates significant potential to provide firm power and high-quality process heat for integrated applications such as green hydrogen production, thereby enabling the decarbonization of hard-to-abate sectors. However, this potential is tempered by three critical findings: current reactor designs are projected to produce substantial volumes of Intermediate-Level Waste (ILW) requiring long-term geological disposal; global scalability may be limited by resource constraints, including competition for lithium with the battery industry and reliance on limited supplies of beryllium and helium; and fusion's projected high Levelized Cost of Energy (LCOE) is unlikely to be competitive with VREs for bulk electricity generation. We conclude that fusion's most plausible role is as a flexible partner to renewables, but its development requires a strategic pivot towards designing for load-following and hybrid applications, developing advanced materials to minimize long-lived waste, and engaging in transparent, life-cycle-informed assessments to ensure its path is aligned with the principles of a truly sustainable and equitable global energy future.