Neutralizing Charging Impact

Neutralizing the carbon impact of charging an energy storage system is a crucial step in ensuring that the operation does not result in a net increase in greenhouse gas emissions.

This section outlines the methodology for neutralizing the induced emissions from charging by matching charging hours with Power Emissions Certificates (PECs) and demonstrates compliance with the EnergyTag Standard. It also explains how to ensure that the overall operation leads to a net reduction in emissions, even if not all induced emissions are fully offset by PECs, provided that the avoided emissions during discharge exceed the remaining induced emissions.

Key Considerations

• Environmental Integrity: The methodology ensures that energy storage operations contribute to overall emissions reductions, upholding environmental integrity.

• Flexibility: By allowing for partial neutralization, the methodology accommodates operational and market realities while still achieving sustainability objectives.

• Alignment with Standards: This approach aligns with the principles of the GHGP Scope 2 Guidance and the EnergyTag Standard, supporting accurate and transparent carbon accounting.

Hourly Matching with PECs

Process of Matching Charging Hours with PECs

To neutralize the induced emissions from charging, energy storage operators must match each hour of charging activity with an equivalent amount of PECs. This process involves the following steps:

1. Identify Charging Hours:

   • Use the hourly charging data collected during the data collection phase.

   • Determine the total energy consumed (in MWh) for each charging hour.

2. Acquire PECs for Charging Hours:

   • Source PECs: Obtain PECs that correspond to the same balance authority area as the energy storage project.

   • Match Energy Volumes: Ensure that the amount of PECs (in MWh) equals the energy consumed during each charging hour.

3. Retire PECs Corresponding to Charging Hours:

   • Retirement Process: Officially retire the PECs used to neutralize charging emissions to prevent double counting.

   • Documentation: Record the serial numbers and details of retired PECs for verification purposes.

4. Maintain Hourly Alignment:

   • Temporal Matching: The PECs must correspond to the exact hours of charging, maintaining precise hourly alignment.

   • EnergyTag Compliance: Ensure that the PECs include hourly timestamps in accordance with the EnergyTag Standard.

Compliance with the EnergyTag Standard

The EnergyTag Standard establishes guidelines for creating and tracking Granular Certificates (GCs) on an hourly basis, enabling 24/7 carbon-free energy matching. Compliance with this standard requires:

• Hourly Granularity:

  • PECs must represent energy generated during the same hours as the charging activity.

  • This granularity ensures accurate matching of energy consumption and generation.

• Location Specificity:

  • PECs should be sourced from generation facilities within the same balance authority area.

  • This alignment accounts for regional grid conditions and emissions profiles.

• Verification and Traceability:

  • Detailed records of PEC acquisition and retirement must be maintained.

  • This transparency supports verification by the PEC Registry and stakeholders.

By adhering to the EnergyTag Standard, energy storage operators contribute to the development of a more precise and transparent renewable energy market, facilitating the achievement of 24/7 carbon-free energy goals.

Ensuring No Net Increase in Emissions

Demonstrating that Induced Emissions are Offset

The goal of neutralizing charging impact is to ensure that the induced emissions from charging do not result in a net increase in overall emissions. This is achieved by:

Calculating Remaining Induced Emissions:

• After PEC Neutralization: Subtract the emissions avoided by the retired PECs from the total induced emissions during charging.

• Formula:

$$Remaining Induced Emissions=Total Induced Emissions−PEC Avoided Emissions$$

Assessing Discharge Avoided Emissions:

• Calculate Avoided Emissions: Determine the emissions avoided during the discharging phase by applying the Marginal Emissions Rates (MER) to the energy discharged.

• Formula:

$$Avoided Emissions During Discharge=Discharging Energy×Discharging MER$$

Comparing Emissions:

• Net Emissions Impact: Evaluate whether the avoided emissions during discharge exceed the remaining induced emissions after PEC neutralization.

• Condition for No Net Increase:

$$Discharge Avoided Emissions ≥Remaining Induced Emissions$$

• If the condition is met, the operation does not result in a net increase in emissions.

Partial Neutralization of Induced Emissions

It is recognized that fully neutralizing all induced emissions through PECs may not always be necessary or practical. The methodology allows for scenarios where:

• Partial Neutralization: Only a portion of the induced emissions is offset by the retired PECs.

• Discharge Emissions Offset: The remaining induced emissions are effectively offset by the higher avoided emissions achieved during discharging.

Justification

• Maximizing Emissions Reduction: The primary objective is to ensure that the overall operation leads to a net reduction in emissions.

• Efficient Resource Utilization: Allowing for partial neutralization enables more flexibility and cost-effectiveness while still achieving environmental goals.

Example Scenario

• Total Induced Emissions During Charging: $1,000 tCO₂$
• Emissions Offset by Retired PECs: $900 tCO₂$
• Remaining Induced Emissions: $1,000 tCO₂ - 900 tCO₂ = 100 tCO₂$
• Avoided Emissions During Discharge: $1,500 tCO₂$
• Net Emissions Reduction: $1,500 tCO₂ (avoided) - 100 tCO₂ (remaining induced) = 1,400 tCO₂ net reduction$

In this example, even though not all induced emissions are neutralized by PECs, the significant avoided emissions during discharge result in a substantial net reduction in emissions.

Compliance and Verification

To ensure compliance with this approach:

1. Detailed Documentation:

   • Emissions Calculations: Provide comprehensive calculations for induced emissions, emissions offset by PECs, and avoided emissions during discharge.

   • PEC Retirement Records: Document the details of PECs retired for neutralization.

2. Verification by PEC Registry:

   • Review of Calculations: The PEC Registry will verify that the methodology has been correctly applied.

   • Assessment of Net Emissions Impact: Confirm that the avoided emissions during discharge exceed any remaining induced emissions.

3. Transparency:

   • Reporting: Clearly report the net emissions impact in the Project Impact Report.

   • Traceability: Maintain records that allow stakeholders to trace the calculations and verify the environmental benefits.