Brown Coal (Lignite)

Brown coal is Australia’s paradox fuel: the lowest per-tonne emission factor of any coal in the National Greenhouse Accounts, yet the most emissions-intensive per unit of energy. That distinction matters when you build a Scope 1 inventory — and when someone tries to argue lignite is the “cleaner” option based on a per-tonne comparison.

The moisture-heavy lignite of Victoria’s Latrobe Valley holds barely a third of the energy of black coal, which is the only reason its per-tonne number looks modest. Here is the 2025–26 factor and how to apply it, with examples you can reproduce in a Scope 1 and 2 calculator.

Quick Verdict

Brown coal (lignite) has a combined Scope 1 emission factor of 93.82 kg CO₂-e per gigajoule under the NGA Factors 2025 — higher per unit of energy than any black coal. With an energy content of just 10.2 GJ per tonne, that translates to 956.96 kg of CO₂-equivalent per tonne combusted. The organisation operating the combustion plant reports these emissions under Scope 1. A separate upstream Scope 3 factor of 0.4 kg CO₂-e/GJ applies. Both values come from Table 4, published by DCCEEW for the 2025–26 reporting year.

How to Calculate Brown Coal Emissions

Emissions (t CO₂-e) = Quantity (t) × Energy content (10.2 GJ/t) × Emission factor (93.82 kg CO₂-e/GJ) ÷ 1,000

Worked Example 1: Generator parcel of 10,000 tonnes

A power station burns a 10,000-tonne parcel of brown coal. Using the tabled per-tonne factor:

10,000 t × 956.96 kg CO₂-e/t = 9,569,600 kg CO₂-e

9,569.6 tonnes CO₂-e (Scope 1)

Worked Example 2: Industrial user burning 500 tonnes

A manufacturer draws 500 tonnes of lignite for process heat.

500 t × 956.96 kg CO₂-e/t = 478,480 kg CO₂-e

478.48 tonnes CO₂-e (Scope 1)

Worked Example 3: Full NGA formula on 1,000 tonnes

Applying the formula end to end for a 1,000-tonne consumption:

1,000 t × 10.2 GJ/t = 10,200 GJ of energy

10,200 GJ × 93.82 kg CO₂-e/GJ = 956,964 kg CO₂-e

≈ 956.96 tonnes CO₂-e (Scope 1)

How Brown Coal Compares to Other Solid Fuels

NGER and AASB S2 Reporting

Brown coal combustion is a headline source under NGER: reporters above the thresholds must submit these emissions to the Clean Energy Regulator using current NGA Factors. The same Scope 1 tonnes flow into your AASB S2 disclosure, with the small upstream Scope 3 component (0.4 kg CO₂-e/GJ) captured separately in your Scope 3 inventory.