OFFERAGCDATA

OFFERAGCDATA shows availability reoffers of Automatic Generation Control.

OFFERAGCDATA data is confidential to the relevant participant.

Source

OFFERAGCDATA updates as reoffers submitted.

Tip

1 second, 6 second, 5 minute, 60 second and regulation refer to types of FCAS markets.

Column Schema

CONTRACTID

Contract Identifier

SQL Type: VARCHAR2(10) Polars Type: pl.Categorical

This column is mandatory, and a primary key.

EFFECTIVEDATE

Market date of offer

Warning

Despite what the name suggests, this is a datetime, not a date.

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

This column is mandatory, and a primary key.

Example: 2026/01/20 00:05:00

PERIODID

Market day trading interval number

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

This column is mandatory, and a primary key.

VERSIONNO

Version no of record

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

This column is mandatory, and a primary key.

AGCDOWN

AGC Ramp Rate Down. This is used by SPD.

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

This column is not mandatory.

AGCUP

AGC Ramp Rate Up. This is used by SPD.

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

This column is not mandatory.

AUTHORISEDBY

Authorised by

SQL Type: VARCHAR2(15) Polars Type: str

This column is not mandatory.

AUTHORISEDDATE

Authorised date

Warning

Despite what the name suggests, this is a datetime, not a date.

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

This column is not mandatory.

Example: 2026/01/20 00:05:00

AVAILABILITY

Availability flag (0 or 1)

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

This column is not mandatory.

FILENAME

Name of reoffer file

SQL Type: VARCHAR2(40) Polars Type: str

This column is not mandatory.

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: 2026/01/20 00:05:00

LOWERLIMIT

Lower control limit MW. This is used by SPD.

SQL Type: NUMBER(4,0) Polars Type: pl.Int16

This column is not mandatory.

UPPERLIMIT

Upper control limit. This is used by SPD.

SQL Type: NUMBER(4,0) Polars Type: pl.Int16

This column is not mandatory.

New Data Timing

On participant Automatic Generation Control (AGC) reoffers submission

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"

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("EFFECTIVEDATE", "AUTHORISEDDATE", "LASTCHANGED").str.strptime(
            pl.Datetime, dt_s_fmt
        ),
    )
    # Polars can't cast string straight to bool. Need to go via something else.
    .cast({"AVAILABILITY": pl.UInt8})
    .cast(
        {
            "CONTRACTID": pl.Categorical,
            "PERIODID": int,  # or pl.Int16
            "VERSIONNO": int,  # or pl.UInt16
            "AGCDOWN": int,  # or pl.Int16
            "AGCUP": int,  # or pl.Int16
            "AUTHORISEDBY": str,
            "AVAILABILITY": pl.Boolean,
            "FILENAME": str,
            "LOWERLIMIT": int,  # or pl.Int16
            "UPPERLIMIT": int,  # or pl.Int16
        }
    )
    # Deduplicate
    # We want one row per ['CONTRACTID', 'EFFECTIVEDATE', 'PERIODID', 'VERSIONNO']
    # Tie-breaker: greatest value of ['LASTCHANGED']
    .sort(["LASTCHANGED"], descending=False)
    .unique(
        subset=["CONTRACTID", "EFFECTIVEDATE", "PERIODID", "VERSIONNO"], keep="last"
    )
)

Nemosis

This table is not yet available in Nemosis.

Availability

Visibility: Private

This table is not available in the public monthly MMSDM archive. Is is only available to registered market participants over FTP inside a VPN.

Deduplication and PDR Loader Configuration

The primary keys are:

• CONTRACTID

• EFFECTIVEDATE

• PERIODID

• VERSIONNO

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
ASOFFER	OFFERAGCDATA	1

This means that the CSV files start with metadata columns:

I,ASOFFER,OFFERAGCDATA,1,...
D,ASOFFER,OFFERAGCDATA,1,...

Indexes

There is more than one index.

Index 1:

• LASTCHANGED

Index 2:

• CONTRACTID

Links

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: ASOFFER

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