Why has one of the world’s richest men been putting his money where his mouth is when it comes to natural hydrogen?

Microsoft founder Bill Gates has called it one of the three key breakthroughs humanity can make to meet burgeoning clean energy needs.

In a new Gates Notes video on YouTube, Gates talks up the potential of natural hydrogen.

Noting it was formed underground by geo-chemical reactions, he says: "If we can locate, extract and manage it at scale, hydrogen will supply a significant new source of clean energy."

Gates, through Breakthrough Energy Ventures, has tipped tens of millions of US dollars into funding hydrogen research, mainly through US-based Koloma and French company Mantle8.

"By 2050 we’ll need nearly three times as much of it (energy) as we use today," he says in the video.

He names three technologies, gold hydrogen being one, that "will help make affordable, reliable, clean electricity possible".

His thoughts can be found here.