rocket stoves can be very efficient for home use. the designes allow for alot of retention and burn more of the gasses in the wood.
a copper pipe coil can be placed in the exhaust to heat water fast.
https://www.facebook.com/groups/502734133080025/ FB group for rocket stoves, lots of good content.
i have seen some compressed air burning systems hooked up to a engine turbo for power generation ( uses too much wood )
garbage burning stirling engines made from 45 gal drums could be designed.