Green and Air-Dried Wood

Not all wood fuel arrives kiln-dried. Forestry residues, arborist chip and freshly milled offcuts often go into the boiler green or merely air-seasoned — and the NGA Factors give that wetter fuel its own line, with its own energy content and its own per-tonne factor for your Scope 1 inventory.

The distinction matters for accuracy, not just neatness: use the dry wood factor on green fuel and you overstate emissions per tonne by more than 50 per cent. Here is the 2025–26 factor with worked examples you can verify in a Scope 1 and 2 calculator.

Quick Verdict

Green and air-dried wood carries a combined Scope 1 emission factor of 1.2 kg CO₂-e per gigajoule under the NGA Factors 2025 — identical per unit of energy to dry wood. Its higher moisture means an energy content of just 10.4 GJ per tonne, so each tonne combusted produces 12.48 kg of CO₂-equivalent. As a biomass fuel, its CO₂ is biogenic and zero-rated; the reportable factor covers methane and nitrous oxide only. The organisation operating the combustion equipment reports these emissions under Scope 1. Values come from Table 4, published by DCCEEW for the 2025–26 reporting year.

How to Calculate Green and Air-Dried Wood Emissions

Emissions (t CO₂-e) = Quantity (t) × Energy content (10.4 GJ/t) × Emission factor (1.2 kg CO₂-e/GJ) ÷ 1,000

Worked Example 1: Green residues programme burning 3,000 tonnes

A forestry operation burns 3,000 tonnes of green harvest residues for process heat. Using the per-tonne factor:

3,000 t × 12.48 kg CO₂-e/t = 37,440 kg CO₂-e

37.44 tonnes CO₂-e (Scope 1)

Worked Example 2: Seasonal boiler fuel of 200 tonnes

A horticultural facility burns 200 tonnes of air-dried wood over winter.

200 t × 10.4 GJ/t = 2,080 GJ of energy

2,080 GJ × 1.2 kg CO₂-e/GJ = 2,496 kg CO₂-e

2.5 tonnes CO₂-e (Scope 1)

Worked Example 3: Energy-based records of 5,000 GJ

A site meters its biomass energy and records 5,000 GJ from green wood.

5,000 GJ × 1.2 kg CO₂-e/GJ = 6,000 kg CO₂-e

6 tonnes CO₂-e (Scope 1)

How Green and Air-Dried Wood Compares to Other Solid Fuels

NGER and AASB S2 Reporting

Biomass combustion is reportable under NGER: facilities above the thresholds report the CH₄ and N₂O to the Clean Energy Regulator using this Table 4 factor, with biogenic CO₂ disclosed separately outside the total. The same figures flow into your AASB S2 climate disclosure, so keep moisture classifications and weighbridge records audit-ready.