Can you make electricity from the heat energy from a wood or pellet stove?
Yes, its called Combined Heat and Power (CHP) and is becoming increasingly popular with current fossil fuel issues. How much electricity you would generate from a home built system is uncertain, but you can certainly buy factory made CHP plants that run off wood/pellets and even straw bales. I recently saw a domestic unit serving 2 houses with a combined power output of 90kW, other sizes are available.
