Nutshells are natural bio-combustibles, which are not subject to any chemical process, but exclusively mechanical (they do not contain any chemical substances or additives). They are ecological combustibles with a calorific power around 4,2 KWh/Kg and, moreover, they have a particularly cheap price. Theirs very low level of moisture and high calorific power make them a great alternative to pellet in presence of a multi-fuel stove. Moreover, nutshells are perfectly functional in classical pellet stoves for companies and domestic heating. The main characteristics of nutshells are great thermal performance, local availability and considerable economic savings.