US scientists, not satisfied with just one groundbreaking achievement, have now managed to repeat a fusion ignition breakthrough for the second time since December 2022, according to a statement by the Lawrence Livermore National Laboratory. This near-limitless, safe, clean source of energy is now closer to becoming a reality.

The latest experiment, which took place on July 30, 2023, at the California-based lab, produced a higher energy yield than the previous breakthrough, although final results are still being analyzed. Fusion has long been hailed as the answer to Earth's energy conundrum, powering the sun and stars, and if the technology can be scaled up, it has the potential to produce abundant clean energy.

This comes after the first historic net energy gain in a fusion experiment using lasers back in December 2022, in which the output energy (3.15 megajoules) exceeded the laser energy used to drive the reaction (2.05 megajoules), The Guardian reported. The US Department of Energy called this a "major scientific breakthrough decades in the making" that will have enormous implications for future advancements in national defense and clean power.

The fusion process involves combining light elements like hydrogen to form heavier elements, releasing a massive burst of energy. Fusion fuel, composed of heavy forms of hydrogen (deuterium and tritium), can produce energy equivalent to 10 million kilograms of fossil fuel from just one kilogram of fusion fuel, according to NBC Bay Area.