I'm skeptical that a small in-home generator of any type could compete with the efficiency of a commercial power plant, even if that plant burns natural gas. A

I'm skeptical that a small in-home generator of any type could compete with the efficiency of a commercial power plant, even if that plant burns natural gas. A small local generator will certainly be behind what a big commercial generator will do, but if the waste heat is also being harnessed ("Combined Heat and Power," or CHP), combined efficiencies of 60%-80% are possible. Commercial electrical generation is typically around 40% efficient, so CHP really can offer very big benefits. Of course, there's nothing fundamentally efficient about a single family living in a huge mansion with a 10KW energy demand and a big heated swimming pool. I would have guessed these things would be most attractive to hotels, universities, airports, truck stops, apartments and condos, and other institutional-scale places that have a significant round-the-clock demand for electricity and hot water. I wonder what it says about the device and the market that they're planning to sell to well-heeled homeowners first.