It’s not officially confirmed yet. But there is much to suggest that researchers in the US are making a breakthrough in fusion power. For the first time in a controlled fusion, more energy is extracted than was put into it. The professional world is impressed – but there are also reminders.
Energy is mankind’s biggest problem. You can’t do without it, but things aren’t going so well with it either: After all, the massive use of fossil fuels has set climate change in motion with uncertain consequences. A message from the USA comes at just the right time: At the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory in California, researchers are said to have succeeded for the first time in controlled nuclear fusion to generate more energy than they put into it. The solution to the energy problem?
According to a Financial Times report, 2.1 megajoules of laser energy were used to ignite a fusion reaction that released 2.5 megajoules. The newspaper refers to two unnamed employees of the institute. The US Department of Energy has scheduled a press conference for Tuesday to present a “major scientific breakthrough”.
The reactions in the professional world have so far been positive – even if reference is made to the major hurdles that still stand in the way of nuclear fusion as a usable source of energy. According to the Science Media Center (SMC), Jeremy Chittenden, Professor of Plasma Physics at Imperial College London, calls the report a “real breakthrough that is incredibly exciting” – provided it is confirmed that the experiment released more energy than was used for the experiment Generation of the plasma was required. “It proves that the long awaited goal, the ‘holy grail’ of fusion, can indeed be achieved,” said Chittenden.
In order to be able to use fusion as an energy source, however, the energy yield must be increased even further, says Chittenden. “Also, before we can realistically turn this into a power plant, we need to find a way to reproduce the same effect much more frequently and much cheaper.”
But there are cautions: “While this is good news, this result is still a long way from the actual energy gain required to generate electricity,” Tony Roulstone, Lecturer in Nuclear Energy at the University of Cambridge, told SMC to consider. This is because 500 megajoules of energy had to be fed into the lasers for the experiment. “So even though they got 2.5 megajoules out, that’s still far less than the energy they used for the lasers in the first place,” Roulstone said.
In other words, according to Roulstone: “The energy output, mainly in the form of thermal energy, was still only 0.5 percent of the input.” However, a technical goal for fusion would be to recover much of the energy used in the process and achieve an energy gain twice the energy required for the lasers. While the outcome of the NIF is a “scientific success,” it is still a long way from delivering useful, abundant, clean energy.
If results from California prove true, it would mark a “remarkable point in human history,” Mark Wenman, senior lecturer in nuclear materials at Imperial College London, told the SMC. This could even “herald an era of green, safe and essentially inexhaustible energy in a compact form without long-lived nuclear waste”. In his opinion, the possible success at the NIF should also contribute to “more funds flowing into nuclear fusion research and the point in time at which we can connect a fusion power plant to the power grid is getting a little closer”.
“These are great results, for which we would like to congratulate our colleagues at NIF,” said Sibylle Günter, Scientific Director of the Max Planck Institute for Plasma Physics (IPP), when asked by ntv.de. “For the first time, more energy was released by fusion reactions than the laser irradiated.” However, the efficiency of the lasers in converting electrical energy into laser energy was not taken into account when calculating the energy gain.
However, according to Günter, the technology used in California is probably too inefficient for a power plant because the fuel has to be irradiated directly. “In addition, you would have to ignite such a pellet in a power plant at least ten times per second. These and many other technological questions still have to be clarified before one can think about building a power plant.”
