Pellet stoves have an aura of mystery surrounding them. There's quite a bit of buzz about them, but accurate information is hard to obtain, and apparently conflicting claims abound. I set out a few years back, not to write a book, but to buy a pellet stove for my home. As I probed deeper, my fascination with this astonishing technology grew until I concluded that pellet stoves are what other heating systems want to be when they grow up. Nearly all conventional heating systems today are centered on post-Civil War technology. The modern pellet stove is truly the only 21st Century heat source in...