Just like your Spotify playlist, you never want to leave out the “oldies but goodies” — in the case of renewable energy, that’s hydropower and geothermal. The first hydropower dam was operational in 1882, while the first geothermal power plant came online in 1904.

What if we could harness the reaction at the core of the sun to generate power? For decades, scientists have been trying to do just that: create a fusion generator that could supply the world with unlimited clean electricity from hydrogen molecules found in seawater.