There's a serious hoax going around under the name Brilliant Light Power, which is basically this guy who is selling a free-energy device that electrolizes water, disposes of the oxygen, and does... something... to the hydrogen. He says it reduces the electron below the ground state, creating what he calls a "hydrino."
An example of this guy selling the idea.
He's spent 20 years being about 9 months away from selling it.
Among other psuedoscientific problems, they claim that the "reactor" works fine, but they are having trouble turning the heat output from it into usable energy. They want to use concentrated solar cells, but if it's putting out that much energy, a thermal engine would work just fine.
Kind of resembles some ads I've seen a while back about some bunch of stuff claiming to have found either a revolutionary power source that involves only sand or that the power source was sand grain sized. In the few looks at it that I did, I never saw any actual details about the power source, other than maybe outright claiming it to be as simple and as common as beach sand, seemingly implying that it IS sand. Of course though, I wasn't hearing/seeing of it elsewhere since finding a new power source would be big deal.
The founder of the Brilliant Light Power company very humbly self-published a book called The Grand Unified Theory of Classical Physics.
Let me guess, it's about the classical elements? You know, the main four, with metal sometimes included