Wood (in either wood waste, chip or pellet format) is a cheap commodity. In addition to the cost savings on fuel, the Renewable Heat Incentive (RHI) has been introduced with the aim of making renewable heat a financially attractive investment. Paybacks vary from 5 to 15 years; with a subsidy lifeline of 20 years this can provide a worthwhile investment as well as a robust heating system.
Biomass district heating systems use a thermal store. The boiler heats the store, which in turn provides heat for 2 or more properties. This allows for more efficient use of the boiler and a more regulated peak heat load.