The May 2026 issue of Future Energy Journal brings together cutting-edge research exploring both technological innovations and global energy transitions. This issue highlights advancements in combustion optimization through piston geometry design in dual-fuel engines, alongside investigations into ammonia as a viable hydrogen carrier under varying combustion conditions. Complementing these studies are detailed numerical analyses of enhanced heat transfer using nanofluids and complex geometries, offering insights into more efficient thermal systems. On a broader scale, the issue also examines the geopolitical expansion of BRICS and its implications for renewable energy adoption, with a particular focus on hydrogen energy, reflecting the growing intersection of policy, sustainability, and engineering.