Yes Sparky, that little 4" thing would be tough!
It will be interesting to see what a finished unit looks like. Real world...if that thing in his hand could power my house, and the $$$ was reasonable, I'm on the waiting list for one.
Heck, where does the gas piping go? Where's the power connections?
TBC
The little stack is just the membrane and anode/cathode... See the websites for pictures of what the completed system looks like. In its current size, I think it's only realistic for commercial users. The 60 minutes video takes a peek inside one, and probably provides the best size comparison than the promotion material.