With numerous breakthroughs recently, the race is on to prove the viability of nuclear fusion power, which could provide a nearly-limitless source of clean energy.

ITER, a $22 billion international megaproject in the south of France, is the best-funded endeavor. It's nearing completion on construction of the world's largest fusion reactor, with the goal of being the first to generate more energy than it consumes. But in recent years, the private fusion industry has also boomed, funded by venture capitalists and billionaire investors. And these start-ups have aggressive timelines, with some aiming to commercialize fusion power within the decade.

The latest to make headlines is Commonwealth Fusion Systems, an MIT-spinoff company that has built the most powerful fusion magnet in the world, capable of generating a stronger magnetic field than ITER in a much smaller space.

Lawrence Livermore National Laboratory also recently made news, as it got closer to producing net energy than ever before, using 192 huge lasers to generate 70% as much energy as went into the reaction.

But reaching net energy is just the beginning. Given the low price of fossil fuels and the high upfront costs associated with building fusion reactors, it's not yet clear how fusion would move from proof of concept to commercialization, and we're still likely many decades away from generating enough electricity from fusion to power cities and industry.

But this year, we've moved a little closer to replicating the power of the sun here on Earth.

Watch the video to learn more.