The US is expected to announce a major breakthrough in fusion energy tomorrow.

The first nuclear fusion experiment to achieve a “net energy gain” has reportedly been carried out by scientists at the Lawrence Livermore National Library in California, according to the Financial Times.

This has been the holy grail of nuclear fusion research since the 1950s. No group so far has been able to produce more energy than is consumed by the reaction.

Sources familiar with the results of the research told the Financial Times that the reaction had produced 1.2 times as much energy as was put in at some point over the last two weeks.

Though the laboratory and US Energy Department declined to comment further on the preliminary data, it said a “successful” test was carried out at the National Ignition Facility.about:blank

US Energy Secretary Jennifer Granholm and under-secretary for nuclear security Jill Hruby are expected to announce “a major scientific breakthrough” at a press conference on Tuesday.

Why would a breakthrough in nuclear fusion be a ‘game changer’?

Around the world, huge amounts of money have been spent on trying to develop nuclear fusion into a viable alternative to other more polluting sources of energy.