Trading period  Zone  Constraint name  Type  Limit (MW)  Shadow price ($/MWh)  

13  CNI  FK_HLY2201 HLY5_CTRLMAX  MnCnst  348.000  2.39  


28  USI  COL_HOR3.1__COL_HOR2.1__COL_HOR2__COL__LN  BrCnst  34.620  24.81  

Trading period start  Trading period  Zone  Constraint name  Type  Factor  Component  MW  Limit (MW)  Shadow price ($/MWh) 

21/10/2019 06:00:00  13  CNI  FK_HLY2201 HLY5_CTRLMAX  MnCnst  1.00000  HLY2201 HLY5 [ENOF]  348.00000  348.0000000000  2.3862000000 
21/10/2019 13:30:00  28  USI  COL_HOR3.1__COL_HOR2.1__COL_HOR2__COL__LN  BrCnst  1.00100  COL_HOR2.1  17.04200  34.6200000000  24.8137000000 
21/10/2019 13:30:00  28  USI  COL_HOR3.1__COL_HOR2.1__COL_HOR2__COL__LN  BrCnst  1.03000  COL_HOR3.1  17.04900  34.6200000000  24.8137000000 
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Binding transmission and market node constraints in the SPD solution for final pricing are described in this report. The technical parameters for each constraint are presented.
Constraints in the SPD model fall into one of three categories:
Only the instances of the above constraints that are binding in the SPD solution for final pricing are presented in this report. A constraint is determined to be binding if its associated shadow price is positive. On any given day, there may well be no binding constraints of any or all of the three constraint types. Binding branch limits are quite rare.
Limit (MW) denotes the megawatt value of the transfer capacity parameter for branch constraints and branch limits, and the generating machine limit net of the frequency keeping requirement in the case of market node constraints (i.e. the righthand side of the constraint).
Shadow price ($/MWh) is a measure of the cost to the system of a binding constraint. Conversely, a constraint that is not binding will have a zero shadow price and imposes no cost on the system. More technically, the shadow price represents the decrease (increase) in the SPD objective function value that would be associated with a 1 MW increase (decrease) in the limit of the constraint. Shading is set between zero (white), $100 (yellow), and $200 (red) on the shadow price as a visual cue indicating the severity of boundedness. Historically, approximately 80% of all binding constraints have a shadow price of less than $200/MWh.
The components that the constraint is composed of (i.e. the lefthand side) can be viewed by clicking on the plus sign at the left to expand the row:
The sum (over all components) of the factor multiplied by the MW for each component will equal the limit or righthand side parameter for a constraint that is binding.
If a branch or branch limit constraint spans two zones, the constraint will appear in the report twice; once for each zone.
Downloading the report as a CSV or PDF does not capture the components of the constraints. To obtain all details of binding constraints, including its components, and to select binding constraints for more than a single day, please use the underlying data report (icon at upper right of screen).
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