Generator Units

Units:	-
Mode:	Input/Output
Multi-band:	False
Default Value:	0
Validation Rule:	≥0
Key Property:	Yes
Description:	Number of installed units
Detail:

Input

Generator Units is the number of installed units at the generation facility. This can simply indicate the existence (1) or not (0) of a single unit, or the presence of multiple units. For multi-unit facilities the units are treated identically and properties such as Max Capacity apply to each unit thus there is no need to adjust other properties on the generator when the number of units changes. The number of units can change via input at any time during the simulation horizon and there is no limit to the number of units.

The number of units can increase in LT Plan according to Max Units Built and reduced by Max Units Retired. Units can automatically retire if the Technical Life property is set.

There is a performance advantage in modeling using multi-unit facilities because Generation is assumed to be spread evenly across the Units Generating . However, when detailed unit commitment is modeled e.g. start up and shutdown, unit commitment is tracked unit-by-unit.

Table 1: Units Example

Generator	Property	Value	Units	Date From
NEW	Units	1	-	1/01/2006
NEW	Units	2	-	1/01/2007
RETIRING	Units	1	-
RETIRING	Units	0	-	1/01/2010

Note:

• Power Station objects group like generators together into multi-unit generators automatically creating a single Generator object with properties equal to the weighted-average value of the original objects.
• The Fixed Load property is a value (required Generation) across all units in aggregated, unless the facility is an expansion candidate, in which case Fixed Load is per unit.

Output

As output, Units reports the net of existing units and those built or retired in LT Plan thus: