The future of clean energy? How nuclear fusion works

The Department of Energy announced a scientific breakthrough in nuclear fusion this week, marking a major step toward developing a new, sustainable form of energy that releases virtually no carbon dioxide or other types of air pollution.

Here's a look at exactly how that reaction works according to the U.S. Department of Energy and the Lawrence Livermore National Laboratory:

The reaction itself was done on Dec. 5 at the National Ignition Facility, the world's largest laser system at the Lawrence Livermore National Laboratory. Scientists at the lab successfully generated a fusion reaction between two hydrogen atoms and maintained that reaction in a controlled setting, marking the potential to use such reactions to generate huge amounts of energy without burning fuels.

The experiment pointed 192 lasers at a container holding a small pellet of fuel the size of a peppercorn, specifically made up of deuterium and tritium – both isotopes of hydrogen.

Those lasers generated 2.05 megajoules of energy within that container that hit the fuel pellet and ignited the reaction, briefly heating it to over 3 million degrees Celsius - creating the conditions of a star – and generating 3.15 megajoules of energy.

That increase is why the experiment is being called such a success because by generating more energy than they put in it proves the potential that this kind of reaction could be a source of power someday, if they can scale it up and make it more efficient outside of a lab setting.

The announcement could mark a major step in creating a form of energy that would not release the gases that are warming the planet and contributing to climate change, but is still decades away from being ready for large-scale application.