India Hits Criticality on 500 MWe Reactor, US Fusion Gains 4.13x, Solar Cells Reach 34% Efficiency

India achieved first criticality on its 500 MWe Prototype Fast Breeder Reactor on April 6, 2026, advancing fast nuclear energy. US fusion systems hit 8.6 megajoules output from 2.08 MJ input for a 4.13 gain record in April 2025. Tandem perovskite-silicon solar cells exceed 34% efficiency versus 24% for commercial silicon panels.