Fuel records for equipment emissions calculations

Activity records and calculation inputs

Equipment emissions calculations depend on the activity being measured and the factor applied to it. GHG Protocol explains that emission factors relate an amount of activity, such as fuel consumed, to greenhouse gas emissions. The practical task is to establish which machine the activity belongs to, which period it covers and how the record was obtained.

Start with a machine identifier that can be reconciled to the asset register. A fuel-card number, telematics identifier or tank issue record may use a different naming system. Preserve the mapping between those records, including any unmatched transactions, rather than relying on a description that could apply to several machines.

Sources: GHG Protocol: Calculation Tools FAQ

Australian factor sources

For an Australian fleet estimate, record the factor publication and edition used as well as the fuel quantity. The Department of Climate Change, Energy, the Environment and Water publishes National Greenhouse Accounts Factors each year to support emissions estimates. Its guidance distinguishes those estimates from reporting under the National Greenhouse and Energy Reporting Act, for which the NGA Factors must not be used to meet reporting requirements.

The 2026 NGA Factors distinguish fuel used for stationary energy from transport applications. Identify the activity and applicable method before choosing a factor; the word diesel alone is not a complete selection rule. Keep litres and kilolitres explicit when reconciling fuel-card exports, bulk-tank issues and telematics records. The recommendations here concern evidence preparation; they do not change the factors in Assera’s published example model.

Sources: DCCEEW: National Greenhouse Accounts Factors; DCCEEW: National Greenhouse Accounts Factors 2026

Fuel consumption and fuel purchases

Fuel purchased for a site is not automatically fuel consumed by one machine in the reporting period. Shared tanks, deliveries near the period boundary, transfers and stock changes can affect the allocation. A practical evidence review records how those items were treated and which records remain missing.

Where machine-level records exist, retain the original units, timestamps and source files. Check for duplicate transactions and overlapping exports before aggregating them. Do not silently replace a missing month with zero consumption: zero activity and unavailable data describe different situations.

Operating-hour estimates

When direct fuel records are unavailable, an agreed method may estimate consumption from operating hours and a fuel-use rate. The rate is an assumption that needs a source and an explanation of its relevance to the machine’s work. An engine-hour total does not by itself show how much time was spent idling, travelling or operating under load.

Keep measured fuel and estimated fuel in separate fields. This lets a reviewer identify which part of the result comes from records and which part depends on an assumption. A later fuel record can then replace the estimate without losing the history of the calculation.

Calculation evidence schedule

Our recommended schedule keeps the source record beside each material calculation input. The applicable reporting method determines the factors and boundary; the schedule makes those decisions inspectable.

• Machine identifier, reporting period and activity-data source.
• Fuel type, quantity and units, with allocation or estimation steps where used.
• Factor source, edition, units and reason for selecting it for the equipment and activity.
• Unit conversions, calculation steps and the unrounded result.
• Missing records, assumptions, exclusions and actions to improve the next reporting period.

Equipment and reporting-entity boundaries

A machine’s calculated emissions and the amount attributed to a reporting entity are separate steps. Finance and lease records, the entity’s reporting boundary and the applicable method need their own review. Do not assume that a fuel calculation alone determines a lender’s or lessor’s reported amount.

Assera brings together asset records, valuations, emissions calculations and supporting documentation for banks and auditors to review. The auditor undertakes the independent assurance engagement. The emissions model on this site demonstrates the calculation sequence and identifies its assumptions; engagement-specific reporting requires an agreed method and evidence.

Sources: Assera: Equipment emissions model; Assera: Methodology