Pellet Stoves Inserts - Convert Your Drafty Fireplace Into an Efficient Heating Source Pellet stoves are either free-standing heat sources or fireplace inserts that fit into your existing fireplace. They are highly efficient and can burn compressed pellets made from wood byproducts, such as sawdust. They are also deemed "green" https://www.fireplacesandstove.com/categories/pellet-stoves/2