This Ancillary Max Contribution column specifies the maximum contribution in MW that a given resource can make to the Ancillary Products in which it participates. If this field is not populated, Aurora will limit the ancillary contribution based upon the value of [Product Time Length]*[Unit Ramp Rate in MW/Min]. The maximum of this calculation and the Max Operating Reserve input will be used for the upper bound.

Note that for Commitment Units which are offline, the Ancillary Max Offline Contribution is used to limit the ancillary contribution instead of this column.

When the resource participates in more than one ancillary product, the entry should be a comma-delimited list with the same products entered in the same order as in the Ancillary Services input column for that resource. If an entry is found for at least one product but not for all products in which the unit participates, the entry for the last product specified will be used for all unspecified products.

Optional Transmission Flow Limit

This value can also reference the transmission flow between two zones such that the ancillary contribution will not be greater than the single directional flow between those two zones. To enter this kind of limit, the value should be of the form “ZoneIDFrom_ZoneIDTo”. For example, an input of “1_2” would tell Aurora that the ancillary contribution for the given resource to the product in question must be less than or equal to the transmission flow from zone 1 to zone 2 in each hour. When this kind of constraint is specified, Aurora also limits the resource ancillary contribution based on the unit Ramp Rate and the product Time Length.

 NOTE: Specify inputs for any time period (annually, monthly, weekly, hourly, or sub-hourly). For information on specifying a variable's time series, see Entering a Time Series.