One approach which is illustrated by several example files is by having different plant equipment operation schemes (and associated plant equipment list) for on peak and off peak period. If others know a better approach, please chime in. The example below is from VAVSingleDuctReheat.idf.
Schedule:Compact,
On Peak, !- Name
Fraction, !- Schedule Type Limits Name
Through: 12/31, !- Field 1
For: Alldays, !- Field 2
Until: 9:00,0.00, !- Field 3
Until: 18:00,1.00, !- Field 5
Until: 24:00,0.00; !- Field 7
Schedule:Compact,
Off Peak, !- Name
Fraction, !- Schedule Type Limits Name
Through: 12/31, !- Field 1
For: Alldays, !- Field 2
Until: 9:00,1.00, !- Field 3
Until: 18:00,0.00, !- Field 5
Until: 24:00,1.00; !- Field 7
PlantEquipmentOperationSchemes,
CW Loop Operation, !- Name
PlantEquipmentOperation:CoolingLoad, !- Control Scheme 1 Object Type
Peak Operation, !- Control Scheme 1 Name
On Peak, !- Control Scheme 1 Schedule Name
PlantEquipmentOperation:CoolingLoad, !- Control Scheme 2 Object Type
Off Peak Operation, !- Control Scheme 2 Name
Off Peak; !- Control Scheme 2 Schedule Name
PlantEquipmentOperation:CoolingLoad,
Peak Operation, !- Name
0, !- Load Range 1 Lower Limit {W}
70000, !- Load Range 1 Upper Limit {W}
Chiller Plant, !- Range 1 Equipment List Name
70000, !- Load Range 2 Lower Limit {W}
245000, !- Load Range 2 Upper Limit {W}
Chiller Plant and Purchased, !- Range 2 Equipment List Name
245000, !- Load Range 3 Lower Limit {W}
500000, !- Load Range 3 Upper Limit {W}
Purchased Only; !- Range 3 Equipment List Name
PlantEquipmentOperation:CoolingLoad,
Off Peak Operation, !- Name
0, !- Load Range 1 Lower Limit {W}
900000, !- Load Range 1 Upper Limit {W}
All Chillers; !- Range 1 Equipment List Name
PlantEquipmentList,
Chiller Plant, !- Name
Chiller:ConstantCOP, !- Equipment 1 Object Type
Little Chiller; !- Equipment 1 Name
PlantEquipmentList,
Chiller Plant and Purchased, !- Name
Chiller:Electric, !- Equipment 1 Object Type
Big Chiller, !- Equipment 1 Name
DistrictCooling, !- Equipment 2 Object Type
Purchased Cooling; !- Equipment 2 Name
PlantEquipmentList,
Purchased Only, !- Name
DistrictCooling, !- Equipment 1 Object Type
Purchased Cooling; !- Equipment 1 Name
PlantEquipmentList,
All Chillers, !- Name
Chiller:Electric, !- Equipment 1 Object Type
Big Chiller, !- Equipment 1 Name
Chiller:ConstantCOP, !- Equipment 2 Object Type
Little Chiller; !- Equipment 2 Name
(Note: There are example files which have same control scheme name "Peak Operation" for both 'On Peak' and 'Off Peak' schedule. I am not sure whether this is as intended or a defect in exmaple files. HeatRecoveryElectricChiller.idf, CoolingTower.idf etc. to name a few but I am sure there are more such files. Posted another question on UnmetHours which highlights the above issue.)