Facility Units

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

Input

Facility Units is the number of installed units at the 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 Operating Level apply to each unit thus there is no need to adjust other properties on the Facility 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 Production is assumed to be spread evenly across the Units Operating . However, when detailed unit commitment is modeled e.g. start up and shutdown, unit commitment is tracked unit-by-unit.

Table 1: Units Example

Facility	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

Output

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