I had never heard of the term but like you looked it up on line. It is indeed a compost based unit and you replace the compost fairly regularly to keep the heat levels up in your home. The unit I saw was about 5 feet around and 2 feet wide, it could produce 90,000 btu per hour. The web site claimed that an average house in a northern climate [ Think Chicago ] looses about 45,00 btu per hour, so you were adding 45,000 btu to your house every hour. It was a very lengthy article and frankly I did not read the whole thing , I am a functional illiterate after all,
The advantage they were claiming was no fire, no chimney, no heat loss out the chimney, no fossil fuel. I did not read what they did with the gas that is produced by the compost , but it seemed that the system worked. Here is a link.
http://mb-soft.com/public3/globalzl.htmlMaybe someone who can read better than I can will take the time to read the whole article and tell me about it.
Never doubt that a small group of dedicated people can change the world, indeed it is the only thing that ever has.