Biomass is essentially burning wood products of various types to produce heat in a boiler which is then transferred to a conventional hydraulic heating system for space heating, hot water or for commercial heating purposes (drying etc.). Its renewable credentials come from the fact that wood can be sourced from managed woodlands and forests where rotation and management of the trees results in a continuous, carbon neutral supply (i.e. the amount of carbon they absorb in their lifetime is equal to that they emit when they are burnt).
There are 3 types of Biomass heaters available depending on the type of fuel they burn:
Log gasification boilers
The type and size of boiler that may suit each particular project will depend on each projects circumstances, how much involvement they wish to have in the heating process and the space the have to accommodate the plant required.
All the above types are eligible for the RHI and all function as a normal boiler would, providing heat by burning the wood which is then transferred via a heat exchanger to a water-based hydraulic system which is then usually pumped around a radiator/UFH circuit and/or Hot Water cylinder.
If you have applied in the past with no success you may be accepted now as the qualifying criteria was changed dramatically at the beginning of the year (2017) to help more households pass for free funding.