# What greenhouse gas saving must the biomass we burn show before CBAM lets us count it as zero?

Canonical: https://senseible.earth/answers/cbam-biomass-ghg-saving-threshold-by-start-date

Solid and gaseous biomass must beat a fossil comparator by a set percentage. For use starting after 20 November 2023 the Commission's guidance says 80%. Plants of 10 MW or more that started between 2021 and 20 November 2023 need 70% until 2029 and 80% from 2030. Older plants have a later 80% date.

## How the test works

1. Work out the emissions of the biomass from cultivation, land-use change, processing, transport and use, less any credit for soil carbon, capture or replacement.
2. Compare them with the fossil fuel comparator: saving = (comparator minus biomass emissions) divided by comparator.
3. If the saving is above the threshold for your start date, the biomass fraction is counted as zero. If not, treat the fuel as fossil.

## Thresholds in the Commission's Table 4-6

Start of operation means the first use of biomass. The 2023 amendment of the Renewable Energy Directive brought plants that used biomass before 2021 into the test as well. Where Table 4-6 shows a dash for a period, it lists no threshold in that column.

- Start of operation after 20 November 2023: 80% for biomass fuels in general.
- Between 1 January 2021 and 20 November 2023: installations of 10 MW or more, 70% until 31 December 2029 and 80% from 1 January 2030. Gaseous biomass in installations of 10 MW or less, 70% for the first 15 years and 80% after that.
- Before 1 January 2021: 80% after 15 years of operation, and not earlier than 1 January 2026 nor later than 31 December 2029, for installations of 10 MW or more and for gaseous biomass of 10 MW or less.

## The comparators

- Useful heat and cooling: 80 g CO2e per MJ of heat.
- Electricity: 183 g CO2e per MJ of electricity.
- For heat that cannot be metered, assume a heat generation efficiency of 90% unless you can show a better figure.

## Who does the sums

Normally a certification scheme or a proof of sustainability supplies the figures. You calculate it yourself only where no such proof exists. Use the newer global warming potentials for N2O and CH4 that the Commission points to: 265 and 28.

## What Senseible does here

Senseible reads your fuel, power and steam bills into verified emission records, so the monthly fuel quantities behind a monitoring plan are ready to hand to your verifier. Verified here means rule checks passed against the evidence. It is not third-party assurance, and a CBAM verifier still signs the report.

- [Biomass fuel in CBAM: proof to zero-rate it](https://senseible.earth/answers/cbam-biomass-fuel-zero-rating-proof)
- [CBAM Suite](https://senseible.earth/cbam-suite)

Sources: [European Commission, CBAM Guidance No. 3, calculation of embedded emissions](https://taxation-customs.ec.europa.eu/document/download/29b9eec7-1a4b-4eb6-ab85-96a0c9e35fd0_en?filename=Guidance%20No.%203%20-%20CBAM%20methods%20for%20the%20calculation%20of%20emissions%20embedded%20in%20goods.pdf)

Last reviewed 2026-11-04. The Commission's guidance notes the Renewable Energy Directive may be updated. Re-check Table 4-6 before each reporting year.