Diagnostic Marginal Unit
| Units: | Yes/No |
| Default Value: | False (0) |
| Validation Rule: | False (0) or True (-1) |
| Description: | Execute region marginal unit diagnostic (this is an active diagnostic) |
| Detail: |
The Marginal Unit Diagnostic calculates the marginal unit for each Region in the system or for the whole system. This is calculated by performing a sensitivity analysis on regional load or system load for all periods in the simulation.
Marginal Unit Transmission Detail flag sets the units report level. Note that currently, Fixed shift factor OPF method does not support Regional setting in Marginal Unit Transmission Detail.
Note:
- In regional reporting, Region can be excluded from this diagnostic with the Region Include in Marginal Unit flag.
- Possible marginal units can be Generator, Purchaser,Physical Contract or Market.
The various steps that are involved in creating this diagnostic are as follows (for regional report):
- Freeze certain decision variables (i.e. pumps, hydro's and the unit commitment), as we do not want these values to change during the sensitivity analysis
- Optimize this problem so that we have a 'base' solution.
- Get the current region's Load and increment this by the Marginal Unit Increment at the Reference Node
- Optimize this problem
- Retrieve the list of possible marginal objects across the system whose Generation/Load changed in response to the change in Load
- Reset the Load for the Region
- Print out the report for this Region
- Go back to step (3) using the next Region in the system or until all Regions have been analyzed
The marginal unit diagnostic in no way modifies the solution values i.e. the solution database does not include any results from this diagnostic. The following table (Table 1) describes the values that are reported in the Marginal diagnostic.
Table 1 - Marginal Unit Diagnostic Property Description
| Property Reported | Description |
|---|---|
| Year / Month / Day / Hour / Minute | The time and date of the period reported |
| Sample | The sample number that is being reported |
| Region Name* | The name of the region which the sensitivity analysis is being performed on |
| Region Shadow Price* | The locational marginal price (LMP) of the reference node (Node Price) |
| Uplift* | The uplift for the region (Region Uplift) |
| Region Price* | The price of the reported region (Region Price) |
| Marginal Region | The name of the region which the marginal generator belongs to |
| Marginal Change | The change in the marginal generators generation in response to a one MW increase in region load. It is most commonly one but values other than unity indicate other marginal generators have increased or decreased their generation due to constraints. |
| Marginal Generator | The name of the marginal generator for the analysed region. If no marginal object can meet the demand sensitivity, USE will be reported |
| Marginal Market | The name of the marginal market for the analysed region. If no marginal object can meet the demand sensitivity, USE will be reported |
| Marginal Purchaser | The name of the marginal purchaser for the analysed region. If no marginal object can meet the demand sensitivity, USE will be reported |
| Marginal Generation Physical Contract | The name of the marginal generation physical contract for the analysed region. If no marginal object can meet the demand sensitivity, USE will be reported |
| Marginal Load Physical Contract | The name of the marginal load physical contract for the analysed region. If no marginal object can meet the demand sensitivity, USE will be reported |
| SRMC/Price | The Marginal Generator SRMC or Market/Purchaser/Physical Contract Price |
| Load | The Region Load (excluding any increases performed by the diagnostic report) |
| Imports | The imports to the region (Region Imports) |
| Exports | The exports from the region (Region Exports) |
| Net Load | This is the Region Load + Region Net Interchange |
| Heat Rate | The marginal Generator Heat Rate |
| Hydro Generation | The sum of all generation by the hydro generators in the region |
| Pump Generation | The sum of all generation by the pump generators in the region |
| Pump Load | The sum of all load for the pump generators in the region (Generator Pump Load) |
| Maintenance Outage | The sum of all generator maintenance outages in that region (Generator Maintenance) |
| Forced Outage | The sum of all generator forced outages in that region (Generator Forced Outage) |
| Fuel | The name of the fuel that the marginal generator is generating with. If there are no fuels then the name will reported as "None". |
| Fuel Price | The price of the fuel being used by the marginal generator (Generator Fuel Price) |
| VOM Charge | The marginal Generator VOM Charge |
| Wheeling Charge* | This is calculated by: Shadow Price - Marginal Generators SRMC - ∑x (Emission (x) SRMC - Marginal Generator. SRMC where 'n' is the total number of emissions belonging to the marginal generator. |
| Unserved Energy | This is the unserved energy in the region (Region Unserved Energy) |
| Dump Energy | This is the dump energy in the region (Region Dump Energy) |
| Emission Rate | This is the marginal generators incremental emission production value (Production Rate) |
| Emission Cost | This is the marginal generators incremental emission cost. This is calculated by the following: Emission SRMC - Generator SRMC |
* items are for regional report only.