Nearly 40 countries are engaged in nuclear fusion programmes with investment now exceeding $10bn (€8.6bn) and more than 160 fusion devices operational, under construction or planned, ranging from pilot plants to larger facilities, the International Atomic Energy Agency (IAEA) has said.

The figures are in the agency’s World Fusion Outlook 2025, which highlights how fusion energy is entering a new phase of implementation as it becomes a cornerstone of national energy strategies and industrial planning.

Launching the publication at the second ministerial meeting of the World Fusion Energy Group and the 30th IAEA Fusion Energy Conference in Chengdu, China, IAEA director-general Rafael Grossi said the fusion energy landscape continues to develop at “an extraordinary pace”.