We just released a heat engine for generating electricity.
We make a wood burning fire box for it but would love to see some folks retro fit the engine into their wood stove for a true Combined Heat and Power Appliance.
The engine is a stirling engine and runs off of externally applied heat (~400F). Heat can be from wood, natural gas, solar, bio-waste, or waste heat to name a few.
The output of the engine can be configured to between 100 Watts to 1000 Watts dependent upon the temperature and pressure that you run it at.
You can see some of the development at volodesigns-sterlingproject.blogspot.com or visit www.seftonmotors.com
We're hopping this can have an impact on the improving the use application of wood stoves for getting off the grid.