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Three Part Supply Offer (TPO)

Three-Part Supply Offer (TPO)

The following diagram defines the structure of a Three-Part Supply Offer that could be included within a BidSet, using the ThreePartOffer tag. This is one of the more complex structures as it involves startup costs, minimum generation costs, and price curves. The PriceCurve is defined by CIM directly as a subclass of CurveSchedule.

ThreePartOffer Structure

The error tag is used to return one or more errors that may be the consequence of the failure of business or syntax validation rules for each type of bid/offer/trade/schedule. The EnergyOfferCurve element is based upon a PriceCurve type. Within PriceCurve, the values of 'xvalue' are used to identify the quantity in MW, and the values of 'y1value' are used to define the price in \$/MWh. The number of points in each PriceCurve is limited to 10. Where more than one PriceCurve is supplied for a bid/offer/trade, the start and end times must not overlap. The incExcFlag is to indicate whether the capacity of the ThreePartOffer is inclusive of the capacity bid in the AS market. The reason code is typically used for adjustments. The structure of a PriceCurve type is detailed in the following diagram:

PriceCurve Structure

PriceCurve Structure

The following diagrams describe the structures used for FIP/FOP, startup costs and minimum generation costs within the ThreePartOffer message. Note that if more than one StartupCost or MinimumEnergy is provided, there must not be overlapping start and end times. That is to say that more than one StartupCost or more than one MinimumEnergy can be specified within the day, provided that the time intervals for each instance are distinct.

FipFop, Startup Cost and MinimumEnergy Structure

On submission, the following table describes the items used for a ThreePartOffer. Please note that fields that are used as 'keys' to identify a bid/offer/trade/schedule (see section 2.3.3) are identified by 'K'. Required fields are identified by 'Y', option fields are identified by 'N'. There are some exception cases where identified key fields are identified as not being required (e.g. expirationTime), and are notated as 'K, N'.

Element Req? Datatype Description Values
startTime N dateTime Start time for bid Valid start hour boundary for trade date
endTime N dateTime End time for bid Valid end hour boundary for trade date
externalId N string External ID QSE supplied
resource K string Resource Valid resource name
combinedCycle N string Combined cycle to which resource is associated NULL or Valid plant name if unit is part of a combined cycle
expirationTime Y dateTime Time of offer expiration Valid time within trade date adjustment period
EocFipFop/startTime Y dateTime Start time for Energy Offer Curve Valid hour boundary within the trade date
EocFipFop/endTime Y dateTime End time for Energy Offer Curve Valid hour boundary within the trade date
EocFipFop/fipPercent Y decimal Fuel index price percent for Energy Offer Curve >= 0, \<= 100
EocFipFop/fopPercent Y decimal Fuel oil price percent for Energy Offer Curve >= 0, \<= 100
SuMeFipFop/startTime N dateTime Start time for Startup Minimum Energy Valid hour boundary within the trade date
SuMeFipFop/endTime N dateTime End time for Startup Minimum Energy Valid hour boundary within the trade date
SuMeFipFop/fipPercent N decimal Fuel index price percent for Startup Minimum Energy >= 0, \<= 100
SuMeFipFop/fopPercent N decimal Fuel oil price percent for Startup Minimum Energy >= 0, \<= 100
Note: SuMeFipFop element is required when StartUpCost and MinimumEnergy are present.
StartupCost/startTime N dateTime Start time for startup costs Valid hour boundary within the trade date
StartupCost/endTime N dateTime End time for startup costs Valid hour boundary within the trade date
StartupCost/hot N decimal Hot startup cost >= 0
StartupCost/intermediate N decimal Intermediate startup cost >= 0
StartupCost/cold N decimal Cold startup cost >= 0
MinimumEnergy/startTime N dateTime Start time for minimum energy costs Valid hour boundary within the trade date
MinimumEnergy/endTime N dateTime End time for energy costs Valid hour boundary within the trade date
MinimumEnergy/cost N decimal Minimum energy cost >= 0
EnergyOfferCurve/startTime Y dateTime Start time for curve Valid hour boundary within the trade date
EnergyOfferCurve/endTime Y dateTime End time for curve Valid hour boundary within the trade date
EnergyOfferCurve/curveStyle N string Not used
EnergyOfferCurve/CurveData/xvalue Y float Megawatts Quantity in MW
EnergyOfferCurve/CurveData/y1value Y float \$/MWh Price in \$/MWh
EnergyOfferCurve/incExcFlag Y string Identifies whether or not an AS offer is linked to this offer. INC or EXC. Default should be INC, where it is linked to an ASOffer
EnergyOfferCurve/reason Y string Reason for adjustment OUT
FUEL
DSCM
OTHR
EnergyOfferCurve/reasonText N string Text field used when reason is OTHR. ReasonText will be required with RTC+B implementation if the EnergyOfferCurve is submitted after the end of the Adjustment Period. Freeform text limited to 128 characters. Alphanumeric with spaces only (no special characters).

Note

There should minimally be a StartupCost, MinimumEnergy or PriceCurve specified for a Three Part Offer.

The following is an XML example of a Three Part Offer:

<BidSet xmlns="http://www.ercot.com/schema/2007-06/nodal/ews" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.ercot.com/schema/2007-06/nodal/ews ErcotTransactions.xsd">
    <tradingDate>2008-01-01</tradingDate>
    <ThreePartOffer>
        <startTime>2008-01-01T00:00:00-05:00</startTime>
        <endTime>2008-01-02T00:00:00-05:00</endTime>
        <marketType>DAM</marketType>
        <expirationTime>2008-01-02T00:00:00-05:00</expirationTime>
        <resource>Resource1</resource>
        <EocFipFop>
            <startTime>2008-01-01T00:00:00-05:00</startTime>
            <endTime>2008-01-02T00:00:00-05:00</endTime>
            <fipPercent>20</fipPercent>
            <fopPercent>80</fopPercent>
        </EocFipFop>
        <SuMeFipFop>
            <startTime>2008-01-01T00:00:00-05:00</startTime>
            <endTime>2008-01-02T00:00:00-05:00</endTime>
            <fipPercent>20</fipPercent>
            <fopPercent>80</fopPercent>
        </SuMeFipFop>
        <StartupCost>
            <startTime>2008-01-01T00:00:00-05:00</startTime>
            <endTime>2008-01-02T00:00:00-05:00</endTime>
            <hot>7</hot>
            <intermediate>5</intermediate>
            <cold>3</cold>
        </StartupCost>
        <MinimumEnergy>
            <startTime>2008-01-01T00:00:00-05:00</startTime>
            <endTime>2008-01-02T00:00:00-05:00</endTime>
            <cost>5</cost>
        </MinimumEnergy>
        <EnergyOfferCurve>
            <startTime>2008-01-01T00:00:00-05:00</startTime>
            <endTime>2008-01-02T00:00:00-05:00</endTime>
            <CurveData>
                <xvalue>3.1</xvalue>
                <y1value>3.1</y1value>
            </CurveData>
            <incExcFlag>INC</incExcFlag>
            <reason>OTHR</reason>
            <reasonText>reason 123a</reasonText>
        </EnergyOfferCurve>
    </ThreePartOffer>
</BidSet>

And the corresponding response:

<ns1:BidSet xmlns:ns1="http://www.ercot.com/schema/2007-06/nodal/ews">
    <ns1:tradingDate>2008-06-15</ns1:tradingDate>
    <ns1:ThreePartOffer>
        <ns1:mRID>QSE1.20080615.TPO.Resource1</ns1:mRID>
        <ns1:externalId/>
        <ns1:status>ACCEPTED</ns1:status>
        <ns1:error>
            <ns1:severity>INFORMATIVE</ns1:severity>
            <ns1:text>Successfully Cancelled the Output Schedule</ns1:text>
        </ns1:error>
        <ns1:error>
            <ns1:severity>INFORMATIVE</ns1:severity>
            <ns1:text>Successfully processed the ERCOT Three Part Offer.</ns1:text>
        </ns1:error>
    </ns1:ThreePartOffer>
</ns1:BidSet>