Private investment in fusion energy companies has increased dramatically, rising from $10 billion to $15 billion in recent months as investors bet on the technology's commercial potential.

Fusion energy, which has been described as perpetually "20 years away" for decades, involves fusing atomic nuclei to generate power in a process similar to what occurs in the sun. The technology promises a clean, steady source of electricity without carbon emissions.

The recent surge in private funding represents a significant shift in how fusion research is being financed, with investment coming from sources beyond traditional energy sector backers. This private capital is funding companies working to develop commercially viable fusion power plants.

However, questions remain about the economic viability of fusion power even if the technical challenges are overcome. A recent study suggests that fusion electricity may not become as affordable as other energy sources, despite the typical pattern of new technologies becoming cheaper over time.

The fusion industry faces the dual challenge of proving the technology can work at scale while also demonstrating it can compete economically with other clean energy sources like solar and wind power. Success would require companies to successfully build and operate commercial fusion plants, a goal that has remained elusive despite decades of research and development.