Something that Zues mentioned to me the other week on our way to play Bridge was a technology called
Micro-CHP (Combined Heat & Power). (Wikipedia entry) Apparently it is a small natural gas generator used to generate electricity. Ok, nothing spectacular there, right? Well, a natural by-product of generators is heat. So, what do they do with the heat? Use it to heat your house.
Marathon Engine is one supplier Some data cites it as being over 90% efficient. The downside?
*) It's kinda pricey. Between $8k and $20k, depending on what size you get.
*) It only makes power when it makes heat. So, while this is very useful in someplace that stays cold a long time (like the Great North [NY included]), someplace like Florida it's probably not so useful.
The simplest application I can see for it is to generate the power operate the blower that moves the heat throughout the house. Or figure out how to have the bleed air heat water in your tank.
Anyway, thought I'd mention it here in case anyone was interested.