BRE DG532/2 PDF

Introduction

Biomass energy is generated from burning biomass fuel (sometimes abbreviated to wood fuel) that is derived from recently living organisms to produce usable heat. They differ markedly from fossil fuels such as gas, heating oil and coal, in that they do not require millions of years of processing within the earth before they can be used. This results in a short cycle from living organism to usable product, allowing for a sustainable supply where it is possible to match the rate of consumption to the rate of production. Biomass can be of animal or plant origin, but in the context of MCS and the built environment, the biomass fuel is typically derived from wood or cereal.

The carbon neutral status of biomass fuel is the subject of debate. The carbon contained within a biomass fuel has only recently been drawn from the atmosphere, and so any CO₂ released during its combustion is not considered as a contributor to atmospheric levels. However, CO₂ is generated during processing and transport of these fuels. This should be considered when assessing their impact. The amount of this CO₂

will be dependent on the type of biomass being produced as well as the location of the harvesting of the biomass relative to the location of the system in which it is to be burned.

Typically, wood fuel used in those installations falling within the scope of MCS will be in one of three forms: logs, wood chip and pellets; the amount of carbon emitted during processing is different in each case.