1. Reporting assessment of uncertainty
The National Greenhouse and Energy Reporting Regulations 2008 (NGER Regulations) require a registered corporation which has operational control over one or more facilities which emit more than 25 kilotonnes of CO2-e from the combustion of an energy type, or from a source other than fuel combustion, to calculate and report an estimate of statistical uncertainty. The registered corporation must report:
- an estimate of uncertainty associated with an estimate of total scope 1 emissions from the combustion of each fuel type at each facility where the total emissions from the combustion of the fuel type passes the 25 kilotonne CO2-e threshold, and/or
- an estimate of uncertainty associated with an estimate of total scope 1 emissions from each source of emissions at each facility where the total emissions from the source pass the 25 kilotonne CO2-e threshold.
Uncertainty is to be reported as a percentage value at a 95 per cent confidence level.
The uncertainty associated with scope 1 emissions estimates is to be calculated in accordance with the rules set out in Chapter 8 of the National Greenhouse and Energy Reporting (Measurement) Determination 2008, including in accordance with the ‘Greenhouse Gas Protocol guidance on uncertainty assessment in GHG inventories and calculating statistical parameter uncertainty (September 2003)’, as applicable.
An estimate of uncertainty associated with estimates of scope 1 emissions from the combustion of each fuel type at a facility and an estimate of uncertainty associated with scope 1 emissions arising from each source (other than fuel combustion) at a facility must be reported as a single aggregated value.
2. Auto-calculate
This button will automatically calculate and populate the uncertainty associated with all sources or fuel types listed on the page where Method 1 has been used to estimate emissions of all greenhouse gases for the source or combustion of the fuel type at a facility.
Checked boxes within the ‘Auto-calculate value’ column indicate which values will be automatically calculated when the ‘Auto-calculate’ option is used. You can uncheck the boxes to prevent automatic calculation for those sources and fuel types.
Click on the icon in the ‘User Input’ column to manually input the uncertainty value for that particular fuel type or source. This option must be used where a higher order method was used to estimate emissions of one or more greenhouse gases for the source or combustion of the fuel type at a facility. This option can also be used to amend an auto-calculated value.
3. Export as CSV
The reporter can estimate the uncertainty associated with each fuel type or each energy source by using the online Uncertainty Calculator available on the Clean Energy Regulator website.
To assist with the use of this calculator, fuel type and emissions source data can be exported as a CSV file by clicking the ‘Export as CSV’ button in the top right corner of the screen. The data can then be copied into the 'Uncertainty Calculator' to calculate an estimate of uncertainty. Further guidance on the use of the Uncertainty Calculator can be found on the Clean Energy Regulator website.