Skip to content

Ancillary Service Obligation

Ancillary Service Obligation

The purpose of this interface is to provide ancillary service obligation by service type for the requesting QSE. The request message would use the following message fields:

Message Element Value
Header/Verb get
Header/Noun ASObligations
Header/Source Market participant ID
Header/UserID ID of user
Request/MarketType DAM/SASM
Request/TradingDate Trading date
Request/ASType Optional: AS type
Request/Option Optional: SASM ID (required for SASM) Format: YYYYMMDDHHMMSS

If the AS type is not specified, all AS obligations will be returned. The corresponding response messages would use the following message fields:

Message Element Value
Header/Verb reply
Header/Noun ASObligations
Header/Source ERCOT
Reply/ReplyCode Reply code, success=OK, error=ERROR or FATAL
Reply/Error Error message, if error encountered
Payload/ ASObligations

Message Element Value
Header/Verb get
Header/Noun ASObligationsAdvisory
or
ASObligationsFinal
Header/Source Market participant ID
Header/UserID ID of user
Request/MarketType DAM
Request/TradingDate Trading date
Request/ASType Optional: AS type

The Advisory AS Obligations will be available by 06:00 am of the day ahead market. The Final AS Obligations will be available after DAM is published. If the AS type is not specified, all AS obligations will be returned. The corresponding response messages would use the following message fields:

Message Element Value
Header/Verb reply
Header/Noun ASObligationsAdvisory or ASObligationsFinal
Header/Source ERCOT
Reply/ReplyCode Reply code, success=OK, error=ERROR or FATAL
Reply/Error Error message, if error encountered
Payload/ ASObligations

The structure of the ASObligations payload is described by the following diagram. The values of ‘value1’ would represent the MW obligation:

ASObligations Structure

ASObligation Structure

ASObligation Structure RTC+B

The following table describes the items in the ASObligation payload.

Element Datatype Description Values
startTime dateTime Start time for bid Valid start hour boundary for trade date
endTime dateTime End time for bid Valid end hour boundary for trade date
TmPoint/time dateTime Absolute time for start of interval Valid time within trading date
TmPoint/ending dateTime Absolute time for end of interval Valid time within trading date
TmPoint/value1 float Megawatts Can be up to 5 points after the decimal
asType string Ancillary service type ECRS
Non-Spin
Reg-Down
Reg-Up
RRS
qse string Valid QSE
marketType string Market type DAM

The following is an XML example:

<ns1:ASObligations xmlns:ns0="http://www.ercot.com/schema/2007-05/nodal/eip/il"
    xmlns:ns1="http://www.ercot.com/schema/2007-06/nodal/ews">
    <ns1:ASObligation>
        <ns1:startTime>2023-04-18T00:00:00-05:00</ns1:startTime>
        <ns1:endTime>2023-04-18T01:00:00-05:00</ns1:endTime>
        <ns1:TmPoint>
            <ns1:time>2023-04-18T00:00:00-05:00</ns1:time>
            <ns1:ending>2023-04-18T01:00:00-05:00</ns1:ending>
            <ns1:value1>112.2</ns1:value1>
        </ns1:TmPoint>
        <ns1:asType>ECRS</ns1:asType>
        <ns1:qse>QSAMP</ns1:qse>
        <ns1:marketType>DAM</ns1:marketType>
    </ns1:ASObligation>
    <ns1:ASObligation>
        <ns1:startTime>2023-04-18T00:00:00-05:00</ns1:startTime>
        <ns1:endTime>2023-04-18T01:00:00-05:00</ns1:endTime>
        <ns1:TmPoint>
            <ns1:time>2023-04-18T00:00:00-05:00</ns1:time>
            <ns1:ending>2023-04-18T01:00:00-05:00</ns1:ending>
            <ns1:value1>169.3</ns1:value1>
        </ns1:TmPoint>
        <ns1:asType>Non-Spin</ns1:asType>
        <ns1:qse>QSAMP</ns1:qse>
        <ns1:marketType>DAM</ns1:marketType>
    </ns1:ASObligation>
    <ns1:ASObligation>
        <ns1:startTime>2023-04-18T00:00:00-05:00</ns1:startTime>
        <ns1:endTime>2023-04-18T01:00:00-05:00</ns1:endTime>
        <ns1:TmPoint>
            <ns1:time>2023-04-18T00:00:00-05:00</ns1:time>
            <ns1:ending>2023-04-18T01:00:00-05:00</ns1:ending>
            <ns1:value1>66.1</ns1:value1>
        </ns1:TmPoint>
        <ns1:asType>Reg-Down</ns1:asType>
        <ns1:qse>QSAMP</ns1:qse>
        <ns1:marketType>DAM</ns1:marketType>
    </ns1:ASObligation>
    <ns1:ASObligation>
        <ns1:startTime>2023-04-18T00:00:00-05:00</ns1:startTime>
        <ns1:endTime>2023-04-18T01:00:00-05:00</ns1:endTime>
        <ns1:TmPoint>
            <ns1:time>2023-04-18T00:00:00-05:00</ns1:time>
            <ns1:ending>2023-04-18T01:00:00-05:00</ns1:ending>
            <ns1:value1>40.6</ns1:value1>
        </ns1:TmPoint>
        <ns1:asType>Reg-Up</ns1:asType>
        <ns1:qse>QSAMP</ns1:qse>
        <ns1:marketType>DAM</ns1:marketType>
    </ns1:ASObligation>
    <ns1:ASObligation>
        <ns1:startTime>2023-04-18T00:00:00-05:00</ns1:startTime>
        <ns1:endTime>2023-04-18T01:00:00-05:00</ns1:endTime>
        <ns1:TmPoint>
            <ns1:time>2023-04-18T00:00:00-05:00</ns1:time>
            <ns1:ending>2023-04-18T01:00:00-05:00</ns1:ending>
            <ns1:value1>446.7</ns1:value1>
        </ns1:TmPoint>
        <ns1:asType>RRS</ns1:asType>
        <ns1:qse>QSAMP</ns1:qse>
        <ns1:marketType>DAM</ns1:marketType>
    </ns1:ASObligation>
</ns1:ASObligations>