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AUCTION_TRANCHE

AUCTION_TRANCHE supports the Settlement Residue Auction, by holding the default definitions for the percentage number of units allocated and dates applicable to each tranche for a specified auction quarter. This information provides the basis for setting up contracts for individual tranches.

AUCTION_TRANCHE is public data, and is available to all participants.

Source

Updates are quarterly from SRA team via SRIS interface.

Volume

AUCTION_TRANCHE contains a maximum of 100 records per year.

Column Schema

CONTRACTYEAR

SRA Contracted Year

SQL Type: NUMBER(4,0) Polars Type: pl.UInt16

This column is mandatory, and a primary key.

Example: 2032

QUARTER

SRA Contracted Quarter

SQL Type: NUMBER(1,0) Polars Type: pl.Int8

This column is mandatory, and a primary key.

Example: 4

TRANCHE

Label identifying the arbitrary segmented share of the Interconnector flow

SQL Type: NUMBER(2,0) Polars Type: pl.Int8

This column is mandatory, and a primary key.

Examples: 1, 12

VERSIONNO

Version of data for other key data - a higher version for same key data will take precedence

SQL Type: NUMBER(3,0) Polars Type: pl.UInt16

This column is mandatory, and a primary key.

Example: 1

AUCTIONDATE

Default date of the auction

SQL Type: DATE Polars Type: pl.Date()

This column is not mandatory.

Example: 2029/12/17 00:00:00

Note that AEMO represents dates as datetimes with a midnight time component.

CHANGEDATE

Date of changing this record

SQL Type: DATE Polars Type: pl.Date()

This column is not mandatory.

Example: 2026/10/01 00:00:00

Note that AEMO represents dates as datetimes with a midnight time component.

CHANGEDBY

Name of person who changed this record

SQL Type: VARCHAR2(15) Polars Type: str

This column is not mandatory.

Example: SYSTEM

LASTCHANGED

Date and time record was last changed

For more information, see the dedicated documentation page.

SQL Type: DATE Polars Type: pl.Datetime()

This column is not mandatory.

Example: 2026/10/01 00:00:00

NOTIFYDATE

Default date participants notified of details

SQL Type: DATE Polars Type: pl.Date()

This column is not mandatory.

Example: 2029/12/03 00:00:00

Note that AEMO represents dates as datetimes with a midnight time component.

UNITALLOCATION

Percentage of units allocated to the tranche

SQL Type: NUMBER(18,8) Polars Type: pl.Float64

This column is not mandatory.

Example: 8.33333333

New Data Timing

Updated quarterly

Code Examples

Polars

Casting is enums, categoricals etc is not essential, but may speed up parsing. Swapping int for pl.UInt16, pl.Int32 would also speed up parsing. However some of the datatypes are inferred, so they may be wrong.

This code deduplicates for you. Deduplication is normally only required across multiple months.

This code assumes that all columns are present, which may not be true for older files.

import polars as pl
import polars.selectors as cs

# e.g. "2029/03/15 00:05:00"
dt_s_fmt = "%Y/%m/%d %H:%M:%S"

# Dates are represented as datetimes at midnight

d_fmt = "%Y/%m/%d 00:00:00"

csv_paths = ["SOMEFILE.CSV", "OTHERFILE.CSV"]

lf = (
    pl.concat(
        [
            pl.scan_csv(
                csv_path,  # must be unzipped beforehand
                skip_rows=1,  # skip the header
                infer_schema=False,  # much faster
            )
            .filter(cs.by_index(0) == "D")  # drop the footer
            .select(~cs.by_index(range(4)))  # drop metadata columns
            for csv_path in csv_paths
        ],
        how="diagonal_relaxed",
    )
    .with_columns(
        pl.col("LASTCHANGED").str.strptime(pl.Datetime, dt_s_fmt),
        pl.col("AUCTIONDATE", "CHANGEDATE", "NOTIFYDATE").str.strptime(pl.Date, d_fmt),
    )
    .cast(
        {
            "CONTRACTYEAR": int,  # or pl.UInt16
            "QUARTER": int,  # or pl.Int8
            "TRANCHE": int,  # or pl.Int8
            "VERSIONNO": int,  # or pl.UInt16
            "AUCTIONDATE": pl.Date(),
            "CHANGEDATE": pl.Date(),
            "CHANGEDBY": str,
            "NOTIFYDATE": pl.Date(),
            "UNITALLOCATION": pl.Float64,
        }
    )
    # Deduplicate
    # We want one row per ['CONTRACTYEAR', 'QUARTER', 'TRANCHE', 'VERSIONNO']
    # Tie-breaker: greatest value of ['LASTCHANGED']
    .sort(["LASTCHANGED"], descending=False)
    .unique(subset=["CONTRACTYEAR", "QUARTER", "TRANCHE", "VERSIONNO"], keep="last")
)

Nemosis

This table is not yet available in Nemosis.

Example File

From PUBLIC_ARCHIVE_AUCTION_TRANCHE_FILE01_202609010000.zip

CONTRACTYEARQUARTERVERSIONNOTRANCHEAUCTIONDATENOTIFYDATEUNITALLOCATIONCHANGEDATECHANGEDBYLASTCHANGED
20324192031/12/15 00:00:002031/12/01 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
203241102032/03/15 00:00:002032/03/01 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
203241112032/06/15 00:00:002032/06/01 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
203241122032/09/15 00:00:002032/09/01 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
20324122030/03/15 00:00:002030/03/01 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
20324112029/12/17 00:00:002029/12/03 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
20324132030/06/17 00:00:002030/06/03 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
20324182031/09/15 00:00:002031/09/01 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
20324142030/09/16 00:00:002030/09/02 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
20324162031/03/17 00:00:002031/03/03 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
20324152030/12/16 00:00:002030/12/02 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
...

CSETP.WORLDDVD_AUCTION_TRANCHEAEMOPUBLIC2026/10/0915:24:38001791523478344MONTHLY_ARCHIVE001791523478344
IIRAUCTION_CONFIGAUCTION_TRANCHE1CONTRACTYEARQUARTERVERSIONNOTRANCHEAUCTIONDATENOTIFYDATEUNITALLOCATIONCHANGEDATECHANGEDBYLASTCHANGED
DIRAUCTION_CONFIGAUCTION_TRANCHE120324192031/12/15 00:00:002031/12/01 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
DIRAUCTION_CONFIGAUCTION_TRANCHE1203241102032/03/15 00:00:002032/03/01 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
DIRAUCTION_CONFIGAUCTION_TRANCHE1203241112032/06/15 00:00:002032/06/01 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
DIRAUCTION_CONFIGAUCTION_TRANCHE1203241122032/09/15 00:00:002032/09/01 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
DIRAUCTION_CONFIGAUCTION_TRANCHE120324122030/03/15 00:00:002030/03/01 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
DIRAUCTION_CONFIGAUCTION_TRANCHE120324112029/12/17 00:00:002029/12/03 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
DIRAUCTION_CONFIGAUCTION_TRANCHE120324132030/06/17 00:00:002030/06/03 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
DIRAUCTION_CONFIGAUCTION_TRANCHE120324182031/09/15 00:00:002031/09/01 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
DIRAUCTION_CONFIGAUCTION_TRANCHE120324142030/09/16 00:00:002030/09/02 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
DIRAUCTION_CONFIGAUCTION_TRANCHE120324162031/03/17 00:00:002031/03/03 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
DIRAUCTION_CONFIGAUCTION_TRANCHE120324152030/12/16 00:00:002030/12/02 00:00:008.333333332026/10/01 00:00:00SYSTEM2026/10/01 00:00:00
...
CEND OF REPORT15

CONTRACTYEAR,QUARTER,VERSIONNO,TRANCHE,AUCTIONDATE,NOTIFYDATE,UNITALLOCATION,CHANGEDATE,CHANGEDBY,LASTCHANGED
2032,4,1,9,"2031/12/15 00:00:00","2031/12/01 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
2032,4,1,10,"2032/03/15 00:00:00","2032/03/01 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
2032,4,1,11,"2032/06/15 00:00:00","2032/06/01 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
2032,4,1,12,"2032/09/15 00:00:00","2032/09/01 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
2032,4,1,2,"2030/03/15 00:00:00","2030/03/01 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
2032,4,1,1,"2029/12/17 00:00:00","2029/12/03 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
2032,4,1,3,"2030/06/17 00:00:00","2030/06/03 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
2032,4,1,8,"2031/09/15 00:00:00","2031/09/01 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
2032,4,1,4,"2030/09/16 00:00:00","2030/09/02 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
2032,4,1,6,"2031/03/17 00:00:00","2031/03/03 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
2032,4,1,5,"2030/12/16 00:00:00","2030/12/02 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
...

C,SETP.WORLD,DVD_AUCTION_TRANCHE,AEMO,PUBLIC,2026/10/09,15:24:38,001791523478344,MONTHLY_ARCHIVE,001791523478344
I,IRAUCTION_CONFIG,AUCTION_TRANCHE,1,CONTRACTYEAR,QUARTER,VERSIONNO,TRANCHE,AUCTIONDATE,NOTIFYDATE,UNITALLOCATION,CHANGEDATE,CHANGEDBY,LASTCHANGED
D,IRAUCTION_CONFIG,AUCTION_TRANCHE,1,2032,4,1,9,"2031/12/15 00:00:00","2031/12/01 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
D,IRAUCTION_CONFIG,AUCTION_TRANCHE,1,2032,4,1,10,"2032/03/15 00:00:00","2032/03/01 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
D,IRAUCTION_CONFIG,AUCTION_TRANCHE,1,2032,4,1,11,"2032/06/15 00:00:00","2032/06/01 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
D,IRAUCTION_CONFIG,AUCTION_TRANCHE,1,2032,4,1,12,"2032/09/15 00:00:00","2032/09/01 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
D,IRAUCTION_CONFIG,AUCTION_TRANCHE,1,2032,4,1,2,"2030/03/15 00:00:00","2030/03/01 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
D,IRAUCTION_CONFIG,AUCTION_TRANCHE,1,2032,4,1,1,"2029/12/17 00:00:00","2029/12/03 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
D,IRAUCTION_CONFIG,AUCTION_TRANCHE,1,2032,4,1,3,"2030/06/17 00:00:00","2030/06/03 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
D,IRAUCTION_CONFIG,AUCTION_TRANCHE,1,2032,4,1,8,"2031/09/15 00:00:00","2031/09/01 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
D,IRAUCTION_CONFIG,AUCTION_TRANCHE,1,2032,4,1,4,"2030/09/16 00:00:00","2030/09/02 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
D,IRAUCTION_CONFIG,AUCTION_TRANCHE,1,2032,4,1,6,"2031/03/17 00:00:00","2031/03/03 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
D,IRAUCTION_CONFIG,AUCTION_TRANCHE,1,2032,4,1,5,"2030/12/16 00:00:00","2030/12/02 00:00:00",8.33333333,"2026/10/01 00:00:00",SYSTEM,"2026/10/01 00:00:00"
...
C,"END OF REPORT",15

Availability

Visibility: Public

This table is in the public monthly MMSDM archive.

I have collated the list of all those files into one place, in this CSV metadata file. (Columns year, month, url, compressed_size in bytes).

The earliest available data is month 1 of 2015. The most recent available data is month 9 of 2026.

Warning

There are some months with no files.

Data Size

Each year of data is approximately 7 KB when zipped, 69 KB as unzipped CSV.

Deduplication and PDR Loader Configuration

The primary keys are:

The transaction type is "INSERT-UPDATE", which means that you will likely see duplicate data with different values.

You should deduplicate by sorting based on LASTCHANGED, within each group of primary keys.

PDR Loader configuration is:

Report Name Report Subtype Version
IRAUCTION_CONFIG AUCTION_TRANCHE 1

This means that the CSV files start with metadata columns:

I,IRAUCTION_CONFIG,AUCTION_TRANCHE,1,...
D,IRAUCTION_CONFIG,AUCTION_TRANCHE,1,...

ROW_FILTER_TYPE is LASTCHANGED

Indexes

This page as JSON (schema documented here, but may change)

Download a JSON Schema specification for this table.

Official AEMO schema documentation

Other Information

Package: IRAUCTION