How Are Scope 2 Indirect Emissions (Energy Consumption) Calculated?

Scope 2 emissions are greenhouse gas emissions from external sources that an organisation does not own directly but from which it purchases energy (usually electricity, heating or cooling). These emissions arise from energy generation and depend on the energy supplier's activities.

Steps for calculating Scope 2 emissions

1. Determining energy consumption

• The first step is to determine the total electricity, heating or cooling energy used by the organisation. This data can usually be obtained from energy bills or from the energy provider.

  • Electricity consumption: Measured in kWh (kilowatt-hours).

  • Heating or cooling energy: May be measured in MWh (megawatt-hours) or another energy unit.

2. Determining emission factors

• Emission factors indicate the quantity of greenhouse gases emitted per unit of energy consumed (usually in kg CO₂e/kWh or kg CO₂e/MWh). They are obtained from national grid data or from the energy supplier.

• Emission factors vary according to the source from which the energy is generated. For example (approximate values):

  • Electricity (high carbon intensity, generated from coal): 0.9 kg CO₂/kWh

  • Electricity (generated from natural gas): 0.4 kg CO₂/kWh

  • Electricity (renewable energy, e.g. hydropower): 0 kg CO₂/kWh (may be a very low value when the life cycle is taken into account)

3. Calculation formula

The following formula is used to calculate Scope 2 emissions:

Emissions (kg CO₂e) = Energy consumption (kWh) × Emission factor (kg CO₂e/kWh)

4. Calculating total emissions

• Separate calculations can be made for different energy sources (electricity, heating, cooling), and these values together make up total Scope 2 emissions.

Example calculation

An office consumes 100,000 kWh of electricity a year, and the electricity it is supplied with is generated from natural gas. In this case, the emission factor for gas-fired electricity is 0.4 kg CO₂/kWh.

Data:

• Electricity consumption: 100,000 kWh

• Emission factor (gas-fired electricity): 0.4 kg CO₂/kWh

Calculation:

Emissions = 100,000 kWh × 0.4 kg CO₂/kWh = 40,000 kg CO₂

The office's Scope 2 emissions will therefore be 40,000 kg CO₂ (40 tonnes of CO₂).

Two methods for calculating Scope 2 emissions

The GHG Protocol requires Scope 2 emissions to be reported under both methods:

1. Location-based approach:

• This approach uses the average emission factor of the electricity grid in the region where consumption takes place. In other words, the overall generation mix of the grid is taken into account, regardless of which supplier the company has contracted with.

2. Market-based approach:

• This approach is based on the contracts the company enters into when buying energy and the certificates it holds. If the company buys electricity backed by renewable energy guarantees of origin (such as YEK-G in Türkiye or I-RECs internationally) or through direct renewable energy contracts, lower emission factors can be used.

In summary

Scope 2 emissions, the indirect greenhouse gas emissions arising from an organisation's energy consumption, are calculated using energy consumption data and emission factors. These calculations are important for organisations to optimise their energy use and move towards more sustainable energy sources.