Our definition of biomass encompasses the combustion of biomass to generate energy.
Fuels may range from Wood Logs, Woodchip (Willow,Miscanthus etc), to Wood Pellets. There are some more exotic biomass fuels such as kernels etc. In all cases a well-designed solution is required which allows the biomass boiler to operate as part of a system, whether that is to run a CHP engine in the industrial-scale plants or to provide heating water at the domestic scale.
Correct sizing of the boiler and the downstream systems to match the load is crucial, biomass often being best deployed to meet baseload only.