How close is nuclear fusion power?

Caption notes

Sabine Hossenfelder examines the energy gain Q in fusion publicity, distinguishing energy delivered to the plasma from consumption by the entire facility. Heat must also pass through an imperfect conversion to electricity. Reports about ITER, JET and NIF from the time of the video illustrate why a local energy ratio cannot by itself answer whether a plant supplies net electricity to the grid. This guide retains that accounting distinction without presenting the video’s estimates or schedules as current measurements, or adopting its speculation about researchers’ motives.