We ' re already at the point of running reactors for much longer , 29 hours being the current record . Reactors don ' t need to be run for long to provide data . They don ' t rebuild the reactors , they analyze the fucktons of data they took . And then they try for longer and longer burns . You don ' t seem to understand just how complex Fusion reactors actually are , compared to other types of energy , Fission in particular . Fusion is a lot more difficult to pull off than originally thought , that ' s why we still have a grand total of one reactor that could produce more energy than it consumes , the JT 60 in Japan , if it were to be run on Deuterium and Tritium . DEMO would produce power by 2048 , but ITER , and thus DEMO , aren ' t the only game in town . Other , less efficient reactors are in development , such as the reactors being built by MSWR , which are smaller , simpler , but produce less energy Q 8 , rather than the Q 25 of DEMO , and will be available much sooner . But ITER is as Tokamak reactor , only one type of Fusion reactor . There are others , such as Stellarators , which can be smaller than Tokamaks for the same output , and can run continuously , whereas Tokamaks have to be powered down periodically . There are also pulsed reactors , like the ones MSNW and Helion Energy build . Helion is actually developing a 50 MW reactor , and aim to complete it in 2019 . There ' s also things like the Polywell , and Lockheed Martin claim to be developing a powerproducing reactor , too . So , whereas Tokamaks may well be another 2030 years away before they produce power , Fusion doesn ' t depend solely on Tokamaks .