When dry biomass fuel such as wood is burned in any fire, the solid fuel must first be converted into its component combustible gases. When the making of those gases is separate from where the gases are combusted, the device is called a “gasifier” and the process is “gasification.” Large-system gasification has been in use for nearly two centuries, but the two forms of very small scale gasification (called “micro-gasification”) were not practical and commercially available until 2003 and 2006.