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Emissions Calculation

Objective

In this step, you'll learn how to calculate your greenhouse gas emissions using the activity data you've collected and appropriate emission factors. By the end of this step, you will understand the fundamental calculation methodology, know how to select the right emission factors, and be able to perform calculations for different emission sources using Carbon GPT.

Understanding the Basic Calculation Formula

The basic formula for calculating GHG emissions is:

Emissions = Activity Data × Emission Factor

Where:

  • Activity Data: Quantitative measure of activity that results in emissions (e.g., liters of fuel consumed, kWh of electricity used)
  • Emission Factor: Factor that converts activity data into emissions (e.g., kgCO2e per liter of fuel, kgCO2e per kWh)

For example, if your organization consumed 10,000 kWh of electricity, and the emission factor for your electricity grid is 0.5 kgCO2e/kWh, your emissions would be: 10,000 kWh × 0.5 kgCO2e/kWh = 5,000 kgCO2e

Emission Factors

What Are Emission Factors?

Emission factors are values that represent the amount of greenhouse gases emitted per unit of activity. They are typically expressed in terms of carbon dioxide equivalent (CO2e), which accounts for the global warming potential of different greenhouse gases.

Types of Emission Factors

  • Location-Based Factors: Based on average emissions intensity of the grid where electricity is consumed
  • Market-Based Factors: Reflect contractual instruments like Renewable Energy Certificates (RECs)
  • Supplier-Specific Factors: Provided by specific suppliers for their products or services
  • Industry-Average Factors: Represent typical emissions for a particular industry or process
  • Life-Cycle Factors: Account for emissions across the entire life cycle of a product or service

Selecting Appropriate Emission Factors

When selecting emission factors, consider:

  • Geographical Relevance: Use factors specific to your region when available
  • Temporal Relevance: Use the most recent factors available
  • Specificity: Use the most specific factors available for your activities
  • Consistency: Use consistent sources of emission factors across calculations
  • Transparency: Document the source and vintage of all emission factors used

Calculation Methodologies by Scope

Scope 1 Calculations

Stationary Combustion

Emissions = Fuel Quantity × Fuel-Specific Emission Factor

Example: Natural gas combustion

  • Activity data: 1,000 m³ of natural gas
  • Emission factor: 2.02 kgCO2e/m³
  • Calculation: 1,000 m³ × 2.02 kgCO2e/m³ = 2,020 kgCO2e

Mobile Combustion

Emissions = Fuel Quantity × Fuel-Specific Emission Factor

Example: Diesel consumption in company vehicles

  • Activity data: 500 liters of diesel
  • Emission factor: 2.68 kgCO2e/liter
  • Calculation: 500 liters × 2.68 kgCO2e/liter = 1,340 kgCO2e

Fugitive Emissions

Emissions = Refrigerant Leakage × Global Warming Potential

Example: R-410A refrigerant leakage

  • Activity data: 2 kg of R-410A leaked
  • Global Warming Potential: 2,088
  • Calculation: 2 kg × 2,088 = 4,176 kgCO2e

Scope 2 Calculations

Purchased Electricity (Location-Based)

Emissions = Electricity Consumption × Grid Emission Factor

Example: Office electricity consumption

  • Activity data: 25,000 kWh
  • Grid emission factor: 0.42 kgCO2e/kWh
  • Calculation: 25,000 kWh × 0.42 kgCO2e/kWh = 10,500 kgCO2e

Purchased Electricity (Market-Based)

Emissions = (Electricity Consumption - Renewable Energy Purchases) × Grid Emission Factor

Example: Office electricity with renewable energy certificates

  • Activity data: 25,000 kWh total, 10,000 kWh covered by RECs
  • Grid emission factor: 0.42 kgCO2e/kWh
  • Calculation: (25,000 kWh - 10,000 kWh) × 0.42 kgCO2e/kWh = 6,300 kgCO2e

Scope 3 Calculations

Business Travel

Emissions = Distance Traveled × Transport Mode Emission Factor

Example: Air travel

  • Activity data: 10,000 passenger-kilometers in economy class
  • Emission factor: 0.082 kgCO2e/passenger-kilometer
  • Calculation: 10,000 passenger-kilometers × 0.082 kgCO2e/passenger-kilometer = 820 kgCO2e

Purchased Goods and Services

Emissions = Quantity of Good/Service × Emission Factor

Example: Paper purchases

  • Activity data: 500 kg of office paper
  • Emission factor: 3.0 kgCO2e/kg
  • Calculation: 500 kg × 3.0 kgCO2e/kg = 1,500 kgCO2e

Creating Emission Activities

In this step, you will create specific emission activities based on the emission sources identified earlier. These activities are the basis for calculating your emissions accurately. Carbon GPT provides two approaches to set up these emission activities:

  • Using Emission Source Templates: Emission Sources function as templates for your recurring Emission Activities. Predefining your Emission Sources will simplify your Emission Activities process tremendously and also reduce room for error. Typically, the Emission Sources will be set up by your sustainability team or consultants who understand the subject matter, while the data entry can be done by admin staff that just need to provide the Activity value.
  • Custom Emission Activities: For one-off Emission Activities, you may not have Emission Sources set up as templates. You may also create Emission Activities to keep track of the emissions from these one-off activities. This may include capital investment, one-off purchases.

There are 3 methods of creating Emission Activities for your organization:

  • Single Record: Create individual emission entries using the 'Create' feature.
  • Bulk Import: Use Excel templates to easily import multiple records in one go, streamlining the data entry process.
  • Data Request: Send data requests to your internal or external stakeholders to provide the necessary activity data, ensuring completeness and collaboration.

Setting Periodic Tracking SOPs

To maintain consistency and ensure ongoing accuracy, it is crucial to set up periodic Standard Operating Procedures (SOPs) for tracking emission activities. These SOPs can be set to track emissions on a monthly, quarterly, or yearly basis, depending on the level of detail and frequency of reporting required by your organization.

  • Monthly Tracking: Recommended for organizations needing regular updates to monitor progress closely or meet specific stakeholder requirements.
  • Quarterly Tracking: Useful for companies looking to balance reporting frequency with administrative ease, ensuring sufficient data granularity without excessive workload.
  • Yearly Tracking: Often used for regulatory or public reporting purposes, ensuring that all data is collated and verified at the end of each reporting year.

Setting up these SOPs in Carbon GPT will help streamline data collection, ensure accuracy, and support effective emission management over time.

Practical Implementation with Carbon GPT

Automated Calculations in Carbon GPT

Carbon GPT simplifies the calculation process by:

  • Providing Built-in Emission Factors: Access to regularly updated emission factors from reputable sources
  • Automating Calculations: Automatic application of appropriate emission factors to activity data
  • Supporting Multiple Methodologies: Flexibility to use different calculation approaches
  • Handling Unit Conversions: Automatic conversion between different units of measurement

Implementation Process

  • Input Activity Data

    • Enter collected data into the appropriate modules in Carbon GPT
    • Ensure correct units are specified for each data point

  • Select Emission Factors

    • Choose from Carbon GPT's database of emission factors
    • Import custom emission factors if needed for specific activities

  • Review Calculations

    • Examine preliminary results for any anomalies or unexpected values
    • Verify that calculations align with expected ranges

  • Document Methodology

    • Record calculation methodologies, emission factors, and assumptions
    • Maintain documentation for transparency and verification

Handling Special Cases

Biogenic Emissions

Biogenic CO2 emissions (from combustion of biomass) are reported separately from fossil fuel emissions. Carbon GPT allows you to:

  • Track biogenic emissions separately
  • Apply appropriate accounting methodologies
  • Report in line with GHG Protocol requirements

Renewable Energy

For organizations using renewable energy, Carbon GPT supports:

  • Dual reporting (location-based and market-based methods)
  • Tracking of renewable energy certificates and guarantees of origin
  • Proper accounting of zero-emission energy sources

Carbon Offsets and Removals

While offsets don't reduce your gross emissions, Carbon GPT allows you to:

  • Track purchased carbon offsets separately
  • Calculate net emissions after applying verified offsets
  • Maintain transparency in reporting gross and net figures

Case Study: Manufacturing Company Emissions Calculation

A manufacturing company needed to calculate emissions across multiple facilities. They used Carbon GPT to:

  • Organize Activity Data: Structured data by facility, emission source, and time period
  • Apply Appropriate Factors: Selected region-specific emission factors for electricity and fuels
  • Calculate Emissions: Automated calculations across all scopes
  • Analyze Results: Identified that natural gas heating (Scope 1) and purchased electricity (Scope 2) were the largest emission sources
  • Target Reductions: Focused efficiency efforts on the highest-emitting activities

Results:

  • Calculated total emissions of 12,500 tonnes CO2e
  • Identified that 65% of emissions came from just two processes
  • Developed targeted reduction strategies for high-impact areas
  • Established baseline for tracking future performance

Next Steps

  • Verify Calculations: Review all calculations for accuracy and completeness
  • Identify Hotspots: Analyze results to identify major emission sources
  • Document Methodology: Record all calculation methods and assumptions
  • Enter Your Historical Emission Activities: Enter your historical emission activities in Carbon GPT to start tracking your emissions
  • Create Tracking SOPs: Set up Standard Operating Procedures (SOPs) to ensure your emission data is updated regularly. This could be done monthly, quarterly, or yearly, depending on your reporting needs
  • Contact Support: For assistance in identifying emission sources, setting up emission factors, or tracking your historical data, contact the Carbon GPT sales team via sales@carbongpt.ai
  • Prepare for Reporting: Organize calculated emissions data for internal and external reporting