As reported on the selected basis
107.6
t CO₂-e — 39,600 L, hours-based estimate
Hours-based estimate — PCAF option and score not assigned
Worked example
Asset emissions, explained.
Explore how asset identity, utilisation and finance structure influence an emissions estimate. Adjust a worked example, then follow the evidence behind it.
336-class hydraulic excavator · NGER emission factors · PCAF attribution
Open the interactive example01 — Asset identification
Asset identification and specification
The machine modelled here is a 336-class tracked hydraulic excavator. Category 13 and Category 15 reporting requires an identified asset: serial number, hour meter reading, location, and ownership or finance status. Identification is also the first variable in the PCAF data quality score, applied at stage 06.
Plate 01 — General arrangement37,600 kg · 336-class tracked excavator
- Operating weight
- 37,600 kg
- Engine
- C9.3B 9.3 L displacement
- Net power, ISO 9249
- 232 kW at 1,800 rpm
- Bore × stroke
- 115 × 149 mm
- Fuel tank
- 600 L
- Hydraulic system
- 373 L, 161 L tank
- Implement flow
- 558 L/min, 2 × 279
- Implement pressure
- 35,000 kPa maximum
Model inputs
Operating assumptions
Identification, activity-data basis, utilisation and duty state drive every figure below. The emission factors are fixed by the NGER determination and are not adjustable.
1,800 illustrative machine hours
02 — Fuel delivery
Fuel delivery and the point of measurement
Diesel passes from the tank through a water separator and filtration to the transfer pump, is raised to injection pressure by the high-pressure pump, and is distributed by the common rail to the injectors. Unburnt fuel returns to the tank on the low-pressure return line.
Fuel is the only carbon-bearing input to the machine. Activity data for Scope 1 reporting is therefore collected on this path: bowser meter, tank reconciliation, fuel card, or the ECU’s cumulative fuel counter.
Assurance is applied to the record and to the allocation, not to the volume alone: the source document, the period it covers, and the basis on which the volume is assigned to this asset rather than another.
Plate 02 — Fuel system22 L/h at medium duty
- 1 Tank · 600 L
- 2 Water separator
- 3 Primary filter
- 4 Transfer pump
- 5 Secondary filter
- 6 High-pressure pump
- 7 Common rail and injectors
03 — Combustion
Compression ignition cycle
Bore 115 mm, stroke 149 mm, displacement 9.3 L, rated speed 1,800 rpm. Air is drawn in and compressed to auto-ignition temperature. Diesel is injected near top dead centre through a multi-hole nozzle and ignites without a spark. Combustion products are expelled on the exhaust stroke.
Carbon present in the fuel is oxidised to CO₂. Scope 1 emissions therefore scale with the volume of fuel consumed. Engine hours, output and utilisation are proxies for that volume, not substitutes for it.
Plate 03 — Cylinder section39,600 L estimated fuel per year
- 1 Injector · multi-hole nozzle
- 2 Intake valve
- 3 Exhaust valve
- 4 Piston · re-entrant bowl
- 5 Connecting rod
- 6 Crankshaft throw
04 — Duty and consumption
Duty state and fuel consumption
The engine drives two pumps delivering a combined 558 L/min to the implement circuit at a maximum pressure of 35,000 kPa. Fuel consumption varies with load: idle, tramming, trenching and mass excavation draw materially different power for the same metered hour.
A statistical estimate applies one assumed utilisation and one class-average rate to every machine. An hours-based estimate applies the selected illustrative hours and duty rate. Neither is a fuel measurement; their difference can run in either direction.
Set the activity basis to statistics and move the duty control between Light and Heavy: the statistical estimate holds at 41,600 L while the hours-based estimate moves, so the difference changes sign.
Plate 04 — Fuel consumption by duty stateMedium selected · book rate 26 L/h
05 — Aftertreatment
Exhaust aftertreatment and reported CO₂
A diesel oxidation catalyst oxidises carbon monoxide and unburnt hydrocarbons. A diesel particulate filter retains particulate matter in plugged wall-flow channels. Urea solution is dosed into the exhaust stream and selective catalytic reduction converts NOₓ to nitrogen and water.
No stage of the aftertreatment system removes CO₂. Reported Scope 1 CO₂-e is unaffected by aftertreatment specification.
Australia does not regulate pollutant emissions from non-road diesel engines. DCCEEW consulted on regulation in May 2023. Aftertreatment fitment consequently varies between machines of the same model on Australian sites, affecting reported NOₓ and particulate matter but not CO₂-e.
Plate 05 — Aftertreatment train107.6 t CO₂-e passes through unchanged
- 1 Turbocharger
- 2 Diesel oxidation catalyst · CO and HC oxidised
- 3 Diesel particulate filter · PM retained
- 4 Urea dosing and mixer
- 5 SCR catalyst · NOₓ reduced
- 6 Exhaust stack
06 — Data quality
Evidence sets the data quality tier
PCAF Table 5.6-1 is a reference for motor vehicle loans, including yellow equipment. Its options depend on asset identity and activity evidence. This example derives fuel from illustrative machine hours and an indicative rate, so that result is not assigned a PCAF option or score.
Read the top two reference rows across: when make and model are unknown, selecting machine hours does not improve the shown score. In client work, fuel records, machine identity and the chosen method must be reviewed together.
Illustrative hours × indicative duty rate; fuel is estimated, not measured — PCAF option and score not assigned
Plate 06 — PCAF Table 5.6-1Hours-based estimate · score not assigned
Regional statistics
Local statistics
Primary fuel / distance
Unidentified
53b
53b
53b
Type only
43a
43a
43a
Make and model
32b
22a
11a/1b
07 — Emissions calculation
Fuel volume to tonnes CO₂-e
Under the NGER (Measurement) Determination, fuel volume is converted to energy using the energy content factor for diesel oil, then to emissions using the applicable emission factor. The combined factor is approximately 2.7 kg CO₂-e per litre. The conversion is fixed; the litre figure in the first box is set by the identification and activity basis selected above.
Activity
39,600
litres per year
Hours-based estimate, 1,800 h × 22 L/h — PCAF score not assigned
× Energy content
38.6
GJ per kL
NGER Schedule 1, diesel oil
× Emission factor
70.4
kg CO₂-e per GJ
NGER Schedule 1, Part 4
= Scope 1
107.6
tonnes CO₂-e
≈ 2.7 kg CO₂-e per litre
Hours-based estimate, same machine
107.6
t CO₂-e — 39,600 L at 22 L/h × 1,800 h
No difference between the selected estimates; neither is measured fuel.
08 — Product structure and attribution
One machine. Four compliant disclosures.
The reported category and quantity depend on the finance product written over the asset. The PCAF standard does not address lease classification for equipment; the GHG Protocol table places downstream leased assets in Category 13. The classification is a disclosed judgement for the reporting entity, made whether or not it is written down.
$310,000
$520,000
The attribution trap
Where the denominator is unknown, the standard directs a conservative approach: assume 100% attribution
Attribution factor
0.60
outstanding ÷ value at origination
Asset Scope 1
107.6
t CO₂-e per year, as reported
Category 15
64.2
t CO₂-e disclosed by the reporting entity
Emissions intensity
59.8
t CO₂-e per 1,000 hours, reported basis
Attribution moves inversely with the value at origination. A value 20% too high reduces the calculated figure by about 16.7%; a value 20% too low increases it by 25%, with the other inputs held constant. When the value is unknown, PCAF directs 100% attribution; compare that assumption with the entered-value result rather than treating it as a maximum.
09 — The evidence line
Every figure above resolves to one row
The deliverable is this row, per asset: identification, activity source, method, factors and their version, a score where supported, and whether the figure is measured or estimated. It is the row an assurer opens first, and the row a spend-based method cannot produce.
| Asset | Identification | Activity data | Method | Factors, versioned | Scope 1 | Attribution | Attributed | Basis |
|---|---|---|---|---|---|---|---|---|
| 336-class hydraulic excavator | Make and model | 1,800 illustrative machine hours | Hours-based estimate · PCAF score not assigned | 38.6 GJ/kL · 70.4 kg CO₂-e/GJ · NGER Sch 1, 2024 | 107.6 t | Category 15 · 0.60 | 64.2 t | Estimated |
One asset is shown. An engagement runs the same stages — identify, establish utilisation, attribute, evidence — across every exposure in the extract. Each asset carries this row; the portfolio can carry a weighted average score where supported, the percentage of gross exposure measured, and an improvement queue ranking the assets where evidence work moves the score furthest.
Basis of preparation
Sources and limitations
Machine specification
- Manufacturer’s published technical specification for the 336 hydraulic excavator: C9.3B engine, 232 kW net (ISO 9249) at 1,800 rpm, 9.3 L displacement, bore 115 mm × stroke 149 mm, 37,600 kg operating weight, 600 L fuel tank, 558 L/min implement flow at 35,000 kPa.
- All drawings are illustrative technical schematics. They are not dimensionally scaled and are not manufacturer drawings.
Method registry
- Energy content 38.6 GJ/kL and emission factor 70.4 kg CO₂-e/GJ: NGER (Measurement) Determination Schedule 1 — diesel oil, transport energy purposes, 2024 compilation. The stationary energy row differs; which row applies is a scoping determination for the reporting entity and is disclosed with the output.
- Data quality reference: PCAF Financed Emissions Standard Part A, third edition, Table 5.6-1 — motor vehicle loans, including yellow equipment. This illustrative hours × rate estimate is not assigned a PCAF option or score; a client method requires evidence review.
- Lease classification: GHG Protocol Corporate Value Chain (Scope 3) Standard, Appendix A, Table A.2.
Regulatory position
- Australia does not regulate pollutant emissions from non-road diesel engines. DCCEEW consulted on regulation in May 2023.
- PCAF data quality scores run from 1 (highest quality) to 5 (sector or portfolio average).
Modelled inputs
- Burn rates by duty state, annual hours, outstanding balances and asset values are indicative and user-adjustable. The statistical estimate is modelled as 1,600 h × 26 L/h. These demonstrate the method; they are not a measurement of any particular asset.
- Assera does not provide independent audit or assurance, or certify PCAF compliance.
Asset-level evidence