Storage Charge Records (SCRs) and Storage Discharge Records (SDRs)

Introduction

The issuance of Storage Charge Records (SCRs) and Storage Discharge Records (SDRs) is a fundamental process in the registry that ensures accurate tracking of energy entering and exiting a storage system. These records serve as the foundation for time-shifting energy attributes, allowing Granular Certificates (GCs) to be allocated to storage and later retrieved for use in 24/7 Carbon-Free Energy (CFE) strategies.

This section details the methodology for creating, validating, and issuing SCRs and SDRs in the registry. The FIFO allocation process and Storage Allocation Records (SARs) are covered in the following section.

Overview of Storage Records

Storage Charge Record (SCR)

An SCR is created whenever energy is charged into a registered storage device. It records the quantity of energy stored and the time of the charging event.

Each SCR contains:

  • Storage Asset ID – Unique identifier of the storage system.

  • Charging Timestamp (UTC) – Start and end time of the charging interval.

  • Charged Energy Volume (Wh) – The total energy absorbed by storage during the interval.

  • Charging Source – Whether the energy comes from:

    • A renewable GC-backed source (linked to a retired GC).

    • Grid electricity (if applicable).

  • Round-trip Efficiency Placeholder – The efficiency loss expected when the energy is later discharged.

  • SCR Status – Pending, Allocated, or Expired.

SCRs remain open and pending until they are linked to an SDR when the stored energy is discharged.

Storage Discharge Record (SDR)

An SDR is created whenever energy is released from a storage device. It records the quantity of energy discharged and the time of the event.

Each SDR contains:

  • Storage Asset ID – Unique identifier of the storage system.

  • Discharge Timestamp (UTC) – Start and end time of the discharge interval.

  • Discharged Energy Volume (Wh) – The total energy output from storage.

  • Discharge Destination – The final location of the energy:

    • Grid injection (for resale or reallocation).

    • Behind-the-meter consumption (onsite usage).

    • Direct delivery via PPA (contracted power delivery).

  • Reference to Corresponding SCR(s) – Links the discharged energy to its original stored source.

  • Storage Efficiency Factor – Adjusts for round-trip efficiency losses.

  • SDR Status – Pending, Allocated, or Expired.

SDRs remain pending until they are allocated to a Storage Allocation Record (SAR), at which point they can be used for SD-GC issuance.

Step-by-Step Issuance Process

Step 1: Receive Storage Meter Data

  • The storage facility submits interval-based metering data for charging and discharging events.

  • Meter data includes:

    • Timestamp of event

    • Energy volume charged/discharged (Wh)

    • Storage system ID and meter ID

    • Charging source or discharge destination

Step 2: Split Meter Data into Hourly Intervals

  • The registry follows the same hourly data-splitting methodology used for generation data.

  • If an event spans multiple hours, the energy is distributed proportionally based on the power profile.

Example of Splitting a Charging Event Across Two Hours

Original Charge Event
Split Hourly Intervals

17:30 - 19:15 (1,500 Wh)

17:30 - 18:00 → 500 Wh 18:00 - 19:00 → 800 Wh 19:00 - 19:15 → 200 Wh

  • A similar approach applies to discharge events, ensuring hourly granularity.

Step 3: Assign Attributes and Create SCR/SDR

Once the energy is split into hourly blocks, the system creates an SCR for charge events and an SDR for discharge events, assigning the appropriate metadata.

SCR Creation Example

Attribute
Example Value

Storage Asset ID

STG-001

Charging Timestamp

2025-04-03T14:00:00Z to 15:00:00Z

Charged Energy Volume

1,200 Wh

Charging Source

Renewable GC-backed

Reference to GCs

GC-4587 (canceled for storage)

SCR Status

Pending

SDR Creation Example

Attribute
Example Value

Storage Asset ID

STG-001

Discharge Timestamp

2025-04-05T18:00:00Z to 19:00:00Z

Discharged Energy Volume

1,080 Wh (accounting for 90% efficiency)

Discharge Destination

Grid injection

Reference to SCRs

SCR-9211 (charged energy source)

SDR Status

Pending

Step 4: Store and Display Records in Registry

  • SCRs and SDRs are stored in the registry ledger, maintaining a complete history of energy movement.

  • Users can view all available storage records on the Storage Projects Page.

  • Records remain pending until they are allocated to a Storage Allocation Record (SAR) in the FIFO matching process.

Compliance & Data Integrity

  • The registry automatically validates all incoming storage meter data.

  • SCRs and SDRs are immutably recorded in the ledger to prevent modification.

  • A FIFO allocation method is enforced to ensure:

    • Chronological consistency between SCRs and SDRs.

    • Preventing selective cherry-picking of storage events.

    • Accurate tracking of round-trip efficiency losses.

Summary of SCR & SDR Issuance Steps

Step
Action
Registry Interaction

1

Receive storage meter data

System ingests charging and discharging records

2

Split into hourly intervals

Data is proportionally allocated based on timestamps

3

Create SCRs & SDRs

Attributes are assigned and linked to storage assets

4

Store in Registry

Displayed on the Storage Projects Page

5

Allocate SCRs to SDRs

Process covered in the FIFO Allocation & SARs Section

Next Steps: Linking SCRs and SDRs

Once issued, SCRs and SDRs must be linked using the FIFO allocation method. This ensures a structured, chronological process for managing energy time-shifting. The next section details:

  • Storage Allocation Records (SARs)

  • FIFO allocation of SCRs to SDRs

  • Conversion of linked SARs into SD-GCs

PreviousStorage Charge Records (SCRs)NextStorage Discharge Granular Certificate (SD-GC) Issuance

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