Originally Posted by unzippy
I take it you are using the heat from the charcoal to generate the steam?
Yep you would be able to use any fuel available be it wood, charcoal or briquettes.
All you need is water, and it does not have to be clean water since there is no contact between the exhaust steam and the meat. The pressure vessel holds about 2 liters of water that lasts about 3 hours, but if you need to keep the rotisserie going for longer than 3 hours you simply release the pressure by means of a valve open the pressure vessel up and fill it up again.
Some of the plans for the second generation is a much larger water tank, a larger steam engine and an adjustable heat shield to control the temperature that the meat sees, while still keeping the steam pipes nice and hot.