I've been following Rossi for a number of years. He pops up every once and a while, makes huge promises and then falls off the radar for a while.
I'd love it if he had legit working LENR (low energy nuclear reaction) tech, but so far it looks like the game he's playing is to drum up a lot of investor money and keep 'developing' shit forever.
LENR is one of the most promising techs out there, and it's the only fusion tech that would scale down small enough and be safe enough for people to run in their homes, cars, etc... thing is, while you can patent a LENR device, you can't patent the low energy nuclear reaction itself because it's a force of nature. Just like you can't patent fission or electricity.
So, whenever these things get released or commercialized, there's going to be a mad rush of companies reverse engineering and building their own versions. Rossi, if he is legit and if he gets to market first, he could make some fast money before the flood. Although, I think he's probably raking in a pretty penny in investor money with the press he's getting.
I honestly doubt his ability to get to market at all, since by listening to his past promises, he should have been to market several years ago.