I have a kohler 14 kw which runs on propain.  It was expensive, but I am 
on oxygen at night as well as a c p a p machine, and I really can't be 
without power.  I have the automatic transfer box.  If power is off for 
about 3 seconds it cranks up and transfers power.  When power comes back, 
it waits 20 minutes to make sure and then switches back to utility and 
runs for five more minutes to cool down.  THe who thing is microprocessor 
controlled, you can set voltage and so forth.  Of corse, nothing talks. 
I've been very pleased with it.
73
Butch
WA0VJR
Node 3148
Wallace, ks.