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SET_ANCILLARY_SUMMARY

SET_ANCILLARY_SUMMARY summarises payments for all Ancillary Services to participants on the basis of regions and trading intervals.

SET_ANCILLARY_SUMMARY data is available to all participants.

Volume

Approximately 30, 000 per week.

Column Schema

PAYMENTTYPE

Payment type identifier (e.g. COMPENSATION)

SQL Type: VARCHAR2(20) Polars Type: pl.Categorical

This column is mandatory, and a primary key.

Example: AVAILABILITY

PERIODID

Trading interval

SQL Type: NUMBER(3,0) Polars Type: pl.Int16

This column is mandatory, and a primary key.

Examples: 1, 288

REGIONID

Region Identifier

For more information, see the dedicated documentation page.

The SQL type is VARCHAR2(10). This is actually a factor/enum, with values:

  • QLD1

  • VIC1

  • TAS1

  • NSW1

  • SA1

  • SNOWY1

This column is mandatory, and a primary key.

SERVICE

Ancillary service identifier (e.g. REACTIVE_POWER)

SQL Type: VARCHAR2(20) Polars Type: pl.Categorical

This column is mandatory, and a primary key.

Example: RESTART

SETTLEMENTDATE

Settlement Date

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

This column is mandatory, and a primary key.

Example: 2026/08/31 00:00:00

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

VERSIONNO

Settlement Run No

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

This column is mandatory, and a primary key.

Example: 1

LASTCHANGED

Last date and time record changed

For more information, see the dedicated documentation page.

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

This column is not mandatory.

Example: 2026/09/01 01:12:12

PAYMENTAMOUNT

The NEM ancillary summary regional payment amount ($)

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

This column is not mandatory.

Examples: 30.63333333, 128.36666666

New Data Timing

After posting of a billing run

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("SETTLEMENTDATE").str.strptime(pl.Date, d_fmt),
    )
    .cast(
        {
            "PAYMENTTYPE": pl.Categorical,
            "PERIODID": int,  # or pl.Int16
            "REGIONID": pl.Enum(["QLD1", "VIC1", "TAS1", "NSW1", "SA1", "SNOWY1"]),
            "SERVICE": pl.Categorical,
            "SETTLEMENTDATE": pl.Date(),
            "VERSIONNO": int,  # or pl.UInt16
            "PAYMENTAMOUNT": pl.Float64,
        }
    )
    # Deduplicate
    # We want one row per ['PAYMENTTYPE', 'PERIODID', 'REGIONID', 'SERVICE', 'SETTLEMENTDATE', 'VERSIONNO']
    # Tie-breaker: greatest value of ['LASTCHANGED']
    .sort(["LASTCHANGED"], descending=False)
    .unique(
        subset=[
            "PAYMENTTYPE",
            "PERIODID",
            "REGIONID",
            "SERVICE",
            "SETTLEMENTDATE",
            "VERSIONNO",
        ],
        keep="last",
    )
)

Nemosis

This table is not yet available in Nemosis.

Example File

From PUBLIC_ARCHIVE_SET_ANCILLARY_SUMMARY_FILE01_202609010000.zip

SETTLEMENTDATEVERSIONNOSERVICEPAYMENTTYPEREGIONIDPERIODIDPAYMENTAMOUNTLASTCHANGED
2026/08/31 00:00:001RESTARTAVAILABILITYNSW11128.366666662026/09/01 01:12:12
2026/08/31 00:00:001RESTARTAVAILABILITYNSW12128.366666662026/09/01 01:12:12
2026/08/31 00:00:001RESTARTAVAILABILITYNSW13128.366666662026/09/01 01:12:12
2026/08/31 00:00:001RESTARTAVAILABILITYNSW14128.366666662026/09/01 01:12:12
2026/08/31 00:00:001RESTARTAVAILABILITYNSW15128.366666662026/09/01 01:12:12
2026/08/31 00:00:001RESTARTAVAILABILITYNSW16128.366666662026/09/01 01:12:12
2026/08/31 00:00:001RESTARTAVAILABILITYNSW17128.366666662026/09/01 01:12:12
2026/08/31 00:00:001RESTARTAVAILABILITYNSW18128.366666662026/09/01 01:12:12
2026/08/31 00:00:001RESTARTAVAILABILITYNSW19128.366666662026/09/01 01:12:12
2026/08/31 00:00:001RESTARTAVAILABILITYNSW110128.366666662026/09/01 01:12:12
2026/08/31 00:00:001RESTARTAVAILABILITYNSW111128.366666662026/09/01 01:12:12
...

CSETP.WORLDDVD_SET_ANCILLARY_SUMMARYAEMOPUBLIC2026/10/0916:30:38001791527438700MONTHLY_ARCHIVE001791527438700
ISETTLEMENTSANCILLARY_SUMMARY5SETTLEMENTDATEVERSIONNOSERVICEPAYMENTTYPEREGIONIDPERIODIDPAYMENTAMOUNTLASTCHANGED
DSETTLEMENTSANCILLARY_SUMMARY52026/08/31 00:00:001RESTARTAVAILABILITYNSW11128.366666662026/09/01 01:12:12
DSETTLEMENTSANCILLARY_SUMMARY52026/08/31 00:00:001RESTARTAVAILABILITYNSW12128.366666662026/09/01 01:12:12
DSETTLEMENTSANCILLARY_SUMMARY52026/08/31 00:00:001RESTARTAVAILABILITYNSW13128.366666662026/09/01 01:12:12
DSETTLEMENTSANCILLARY_SUMMARY52026/08/31 00:00:001RESTARTAVAILABILITYNSW14128.366666662026/09/01 01:12:12
DSETTLEMENTSANCILLARY_SUMMARY52026/08/31 00:00:001RESTARTAVAILABILITYNSW15128.366666662026/09/01 01:12:12
DSETTLEMENTSANCILLARY_SUMMARY52026/08/31 00:00:001RESTARTAVAILABILITYNSW16128.366666662026/09/01 01:12:12
DSETTLEMENTSANCILLARY_SUMMARY52026/08/31 00:00:001RESTARTAVAILABILITYNSW17128.366666662026/09/01 01:12:12
DSETTLEMENTSANCILLARY_SUMMARY52026/08/31 00:00:001RESTARTAVAILABILITYNSW18128.366666662026/09/01 01:12:12
DSETTLEMENTSANCILLARY_SUMMARY52026/08/31 00:00:001RESTARTAVAILABILITYNSW19128.366666662026/09/01 01:12:12
DSETTLEMENTSANCILLARY_SUMMARY52026/08/31 00:00:001RESTARTAVAILABILITYNSW110128.366666662026/09/01 01:12:12
DSETTLEMENTSANCILLARY_SUMMARY52026/08/31 00:00:001RESTARTAVAILABILITYNSW111128.366666662026/09/01 01:12:12
...
CEND OF REPORT1003

SETTLEMENTDATE,VERSIONNO,SERVICE,PAYMENTTYPE,REGIONID,PERIODID,PAYMENTAMOUNT,LASTCHANGED
"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,1,128.36666666,"2026/09/01 01:12:12"
"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,2,128.36666666,"2026/09/01 01:12:12"
"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,3,128.36666666,"2026/09/01 01:12:12"
"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,4,128.36666666,"2026/09/01 01:12:12"
"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,5,128.36666666,"2026/09/01 01:12:12"
"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,6,128.36666666,"2026/09/01 01:12:12"
"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,7,128.36666666,"2026/09/01 01:12:12"
"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,8,128.36666666,"2026/09/01 01:12:12"
"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,9,128.36666666,"2026/09/01 01:12:12"
"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,10,128.36666666,"2026/09/01 01:12:12"
"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,11,128.36666666,"2026/09/01 01:12:12"
...

C,SETP.WORLD,DVD_SET_ANCILLARY_SUMMARY,AEMO,PUBLIC,2026/10/09,16:30:38,001791527438700,MONTHLY_ARCHIVE,001791527438700
I,SETTLEMENTS,ANCILLARY_SUMMARY,5,SETTLEMENTDATE,VERSIONNO,SERVICE,PAYMENTTYPE,REGIONID,PERIODID,PAYMENTAMOUNT,LASTCHANGED
D,SETTLEMENTS,ANCILLARY_SUMMARY,5,"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,1,128.36666666,"2026/09/01 01:12:12"
D,SETTLEMENTS,ANCILLARY_SUMMARY,5,"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,2,128.36666666,"2026/09/01 01:12:12"
D,SETTLEMENTS,ANCILLARY_SUMMARY,5,"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,3,128.36666666,"2026/09/01 01:12:12"
D,SETTLEMENTS,ANCILLARY_SUMMARY,5,"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,4,128.36666666,"2026/09/01 01:12:12"
D,SETTLEMENTS,ANCILLARY_SUMMARY,5,"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,5,128.36666666,"2026/09/01 01:12:12"
D,SETTLEMENTS,ANCILLARY_SUMMARY,5,"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,6,128.36666666,"2026/09/01 01:12:12"
D,SETTLEMENTS,ANCILLARY_SUMMARY,5,"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,7,128.36666666,"2026/09/01 01:12:12"
D,SETTLEMENTS,ANCILLARY_SUMMARY,5,"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,8,128.36666666,"2026/09/01 01:12:12"
D,SETTLEMENTS,ANCILLARY_SUMMARY,5,"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,9,128.36666666,"2026/09/01 01:12:12"
D,SETTLEMENTS,ANCILLARY_SUMMARY,5,"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,10,128.36666666,"2026/09/01 01:12:12"
D,SETTLEMENTS,ANCILLARY_SUMMARY,5,"2026/08/31 00:00:00",1,RESTART,AVAILABILITY,NSW1,11,128.36666666,"2026/09/01 01:12:12"
...
C,"END OF REPORT",1003

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 24 MB when zipped, 243 MB as unzipped CSV.

Deduplication and PDR Loader Configuration

The primary keys are:

The transaction type is "insert", which means that you will usually not see duplicate data. If you do, you can deduplicate based on the primary keys, without sorting first. Rows from different files with the same primary keys should have the same values.

PDR Loader configuration is:

Report Name Report Subtype Version
SETTLEMENTS ANCILLARY_SUMMARY 5

This means that the CSV files start with metadata columns:

I,SETTLEMENTS,ANCILLARY_SUMMARY,5,...
D,SETTLEMENTS,ANCILLARY_SUMMARY,5,...

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: SETTLEMENT_DATA