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Researchers just discovered a massive 'jacuzzi bubbling with almost pure hydrogen' — a lucrative source of clean energy
(www.businessinsider.com)
This is a most excellent place for technology news and articles.
If you come at it from the angle of the equipment used to capture it having a carbon footprint, then that should also apply to equipment doing electrolysis.
That said, what is the level of environmental footprint we're talking about in comparison to electrolysis? We don't know yet, because it's not clear this new source can be economically tapped, but we'll see.