Carbon Report Data
How to Choose Emission Factors for a Carbon Report
How businesses can choose emission factors for a carbon report, including matching factors to activity data, units, fuel type, electricity method, and reporting period.
Emission factors convert activity data into emissions. Choosing the right factor matters because the credibility of a carbon report depends on whether the factor matches the activity, unit, method, location, supplier, and reporting period being measured.
Match the factor to the activity
The first rule is simple: the factor should match the activity being measured. Electricity should use an electricity factor. Diesel should use a diesel factor. Petrol, LPG, natural gas, or other fuels should use factors that match those fuels.
Using a generic factor when a more specific one is available can make the report harder to explain.
Check the unit before calculating
A factor only works correctly when the unit matches the activity data. For example, a factor per liter should be multiplied by liters, while a factor per kg should be multiplied by kilograms.
If the unit does not match, convert the activity data or choose a factor that matches the unit being entered.
Choose an electricity factor that matches the method
Electricity factors should match the selected reporting method. A location-based calculation usually uses a grid factor, while market-based reporting may use supplier-specific or contractual data where appropriate.
The reporting method should be visible so reviewers understand how the Scope 2 result was produced.
Keep the source visible for review
A carbon report is easier to trust when the factor source is known and the factor is visible. This helps future reviewers understand the assumption behind the calculation.
If better factor data becomes available later, a visible factor makes it easier to update or compare reports.
Final takeaway
Choosing emission factors is about matching the factor to the activity, unit, method, and reporting context. Clear factors make carbon reports easier to review, explain, and improve.