On announcing the breakthrough Dr. Marvin Adams deputy administrator for defense programs at the US National Nuclear Security Administration said that the laboratory's lasers had input 2.05 megajoules (MJ) of energy to the target, which had then produced 3.15 MJ of fusion energy output.Prof Jeremy P. Chittenden, professor of plasma physics and co-director of the Centre for Inertial Fusion Studies at Imperial College London called it "a true breakthrough moment" which proves 'the 'holy grail' of fusion, can indeed be achieved".Prof Gianluca Gregori, Professor of Physics at the University of Oxford said: "Today's success rests upon the work done by many scientists in the US, UK and around the world.On the question of how long before we could see fusion being used in power stations, LLNL Director Dr. Kim Budil said there were still significant hurdles but that: "with concerted efforts and investment, a few decades of research on the underlying technologies could put us in a position to build a power plant".The experiment was only able to produce enough energy to boil about 15-20 kettles and required billions of dollars of investment."