The Scenario Analyser
Purpose
To examine the sensitivity surrounding any given Dispatch Factor.
The output of a dispatch calculation is entirely dependent on the values of the input data. For any one dispatch calculation some of the input data could have a wide range of values without affecting the end result. For other data items even a fractional change in input value could effect wide reaching changes in the output data. Using EMarketOffer in Scenario Analyser Mode you can examine the sensitivity of any Dispatch Factor within a single dispatch in the Presentation Interface.
NOTE: You can analyse Scenarios created from either Market or Forecast Data Source, however results will not be useful in cases where historical Offers are unavailable in the Market data.
Marginal Analysis
Purpose
To examine the sensitivity around individual Dispatch Factors using a marginal analysis technique similar to that used for calculating Nodal Prices in the Market.
Marginal Analysis mode allows you to investigate the impact of small changes to the inputs of the dispatch problem. The inputs which may affect dispatch are:
- Nodal Demand
- Offer Prices and Quantities (energy and reserves)
- The limits of various Constraints such as Circuit Capacities and Group Constraints.
- The setting of a number of Reserves-related parameters
Not all of these input values will have an impact on the dispatch solution. Those that do have an impact include:
- Demand values
- Offer quantities for Units on the margin (i.e. Units with Offer tranches which have been partially dispatched)
- Offer Prices for marginal tranches
- Limits for Circuit and Group Constraints which are constrained.
Marginal analysis is conducted by changing the value of a selected value by a small amount, re-dispatching and comparing the new dispatch figures to the original ones. Differences in the 'before' and ' after' dispatch results are highlighted on the map and in the Main Window Information Grids.