I found this link additional link. It has a few diagrams.
http://world.honda.com/news/2001/p010830.html
For sound output they says it's comparable to a typical air conditioner
compressor, whatever that is. Probably about 46db.
They also have a air conditioning unit that uses the same engine...
http://world.honda.com/news/1998/p980312.html
This little cogen system would compliment my 400 watt PV array, battery bank
and inverter quite nicely. My best power collection day was 24 amp hours at
50v. A 1kw
cogen running full time would double that electrical power and produce hot
water as well.
I already use a EU3000 generator with my system for periodic charging. I
just happen to be in need of a hot water heater.
The only thing I have seen is that they were testing them in Japan, and
nothing that says they have actually been selling them, or what the price
might be.
I'd seriously consider buying one of these if I could find one for sale.