How to measure emissions from Biomass

What counts as Biomass

Solid biomass — wood chips, wood pellets, wood logs, straw/grass and agricultural byproducts such as rice husk — combusted for heat or power in boilers or CHP plant that the organisation owns or controls. Excludes biomass combusted by a third-party energy services contractor unless the organisation controls that asset's operation.

Biomass is reported separately from other solid fuels because its combustion emissions are typically treated differently under biogenic CO2 accounting conventions, even though transport and processing emissions still count. This entry covers only combustion at sites you own or control; biomass grown or processed upstream by suppliers belongs in their inventories, not yours, though associated purchased-goods emissions may appear elsewhere in your Scope 3 if material. Keep wood-based fuels separate from packaging or construction timber, which are recorded as purchased goods rather than fuel.

What activity data you need

Collect the most specific physical unit available. Unit definitions are in Appendix I — Description of Units.

• kWh
• tonne

Which emission scope it falls under

Biomass activity data typically maps to Scope 1 and Scope 3 Category 3 under the GHG Protocol. Confirm organisational boundary and ownership before reporting.

Sub-types available in the platform

All 5 sub-types available in the platform.

• Agricultural byproducts: Rice hull / rice husk
• Grass / straw
• Wood chips
• Wood logs
• Wood pellets

Common questions

Is the CO2 from burning biomass reported as zero?

Biogenic CO2 from biomass combustion is often reported separately from fossil CO2 under GHG Protocol conventions, but you should still record and disclose the activity data and any associated non-CO2 gases — check your reporting framework's treatment before assuming a zero result.

How do I record biomass fuel that arrives with variable moisture content?

Use the tonnage on the delivery note as your activity data and note the moisture percentage from the supplier's certificate if provided; do not adjust the recorded weight yourself, as any conversion happens at the emission factor stage, not the activity data.

Does wood used in construction count here?

No — timber used as a building material is purchased-goods activity data (see Construction or Materials), not fuel. Only wood combusted for heat or power belongs in this Biomass entry.

What if our biomass boiler also burns some fossil fuel as a start-up source?

Record the fossil fuel (e.g. diesel or gas) tonnage/volume separately under the relevant fuel entry; keep the biomass tonnage isolated so your renewable energy reporting is not distorted by the fossil top-up.

Do biomass byproducts like ash disposal need recording here?

No — ash and other combustion residues are a waste stream; record their disposal under the relevant waste activity entry, not against biomass fuel input.