Wondering how to report greenhouse gas emissions by scope in Mestro? This article explains the GHG scope framework and how different energy sources map to each scope.

What do we mean by emissions in different scopes?

When reporting sustainability data, emissions are divided into scopes depending on where they occur in the value chain. This approach was developed as part of the Green House Gas Initiative and is used in reporting standards such as GRI and ESRS.

• Scope 1: Direct emissions — Greenhouse gases produced by sources owned or controlled by the organisation, e.g. combustion of fuels in boilers or company-owned vehicles.
• Scope 2: Indirect emissions from purchased energy — Emissions from energy purchased by the organisation, such as electricity or district heating. Reducing energy consumption or switching to renewables reduces scope 2 emissions.
• Scope 3: Other indirect emissions — All other emissions outside the organisation's direct control, such as transport of goods, waste, and the energy use of tenants. Scope 3 is typically the largest part of an organisation's emissions profile.

What is scope 1 for one organisation may be scope 3 for another. For example, a tenant's energy use falls in the tenant's scope 2 and the property owner's scope 3.

CO2 or CO2e?

Under the GHG protocol, all emissions should be reported in carbon dioxide equivalents (CO2e). This unit converts different greenhouse gases into the equivalent amount of CO2 based on their global warming potential. Emission factors from energy companies are usually expressed in CO2e — always verify you are reporting consistently.

Emissions from different energy sources

Fossil fuels (coal, oil, natural gas) generate significant greenhouse gas emissions across their entire lifecycle. Renewable sources (solar, wind) have substantially lower emissions, though lifecycle impacts from manufacturing and disposal should be considered for scope 3. Carbon-free sources (nuclear, hydro) have minimal direct emissions. Biofuels (e.g. wood pellets) still generate emissions — CH4 and N2O are reported in scope 2, while the CO2 portion of combustion is reported outside the scopes according to the GHG protocol.

Which scope does energy use fall under?

• Grid electricity or district heating — combustion emissions go to scope 2; production and transport of fuel go to scope 3.
• On-site produced energy (e.g. pellet boiler, solar) — combustion goes to scope 1; fuel production and transport go to scope 3.
• Tenants' energy — goes into the property owner's scope 3 and the tenant's scope 2.

Emission factors

An emission factor expresses the amount of greenhouse gases (CO2e) released per unit of energy (e.g. g CO2e/kWh). In Mestro, emission factors are entered in this unit. To capture all emissions correctly, each factor is split by scope — one part for scope 2 (combustion) and one for scope 3 (fuel production and transport).

Market based and location based for electricity

Under the GHG protocol and ESRS, electricity use must be reported twice: market based (emissions from the electricity you purchased — e.g. 0g CO2e if you buy 100% renewable) and location based (emissions from the actual electricity mix in the grid your property is connected to).

Financial or operational control? Tag correctly!

There are two methods for reporting emissions linked to energy use: operational control (based on who uses the energy) and financial control (based on who pays). ESRS requires operational control reporting. In Mestro, meters can be tagged as property energy or tenant energy under meter settings — this lets you filter emissions by category in the reports.

Common questions

• What is CO2e reporting?
• What are GHG scopes 1, 2, and 3?
• How do I report greenhouse gas emissions in Mestro?
• What is the difference between CO2 and CO2e?
• How do I report scope 3 emissions?