LT Plan Attributes Reference

This page documents the PLEXOS LT Plan attributes and their default values, validation rules, and descriptions.

To look at the open access PLEXOS documentation, go to PLEXOS LT Plan Index.

Use this reference when setting configuration values through PlexosDB attributes, for example with add_attribute, get_attribute, and list_attributes.

LT Plan Attributes

Name	Units	Default Value	Validation Rule	Description
Allow Capacity Sharing	Yes/No	0	In (0,-1)	If regions/zones can share capacity reserves to meet requirements.
Always Annualize Build Cost	-	0	In (0,-1)	If Build Cost is always annualized even when an option retires inside the horizon.
At a Time	-	0	>= 0	Number of years solved in each step of LT Plan.
Block Count	-	12	>= 1	Number of load duration curve blocks in each day/week/month.
Bridge Constraints	Yes/No	-1	In (0,-1)	If LT Plan should bridge (decompose) constraints for subsequent simulation phases.
Bridge Storage	Yes/No	-1	In (0,-1)	If LT Plan should bridge (decompose) storage for subsequent simulation phases.
Capacity Payments Enabled	Yes/No	0	In (0,-1)	If payments are made for generation capacity.
Chronology	-	2	In (2,3,4)	Type of chronology used.
Co-optimize Unit Commitment	Yes/No	0	In (0,-1)	If unit commitment is co-optimized rather than sequentially optimized with expansion.
Compute Multi-area Reliability Indices	Yes/No	0	In (0,-1)	Master switch for computation of reliability indices LOLP, LOLE, etc across multiple areas.
Compute Reliability Indices	Yes/No	0	In (0,-1)	Master switch for computation of reliability indices LOLP, LOLE, etc.
Decomposition	-	1	>= 1	Reduce the number of simulated periods by this factor in the first pass of a two-pass decomposition.
Depreciation Method	-	0	In (0,1,2)	Depreciation method for computing annuities.
Discount Period Type	-	4	In (1,2,3,4,6,7)	A unique discount factor and expansion decisions will be computed for each of these periods.
Discount Rate	%	0	>= 0	Discount rate.
End Effects Method	-	1	In (0,1)	Method used to account for end of horizon effects.
Inflation Rate	%	0		Inflation rate used in depreciation calculations.
Integerization Horizon	yr	-1	>= -1	Number of years over which the expansion decisions are integerized.
Last Block Count	-	0	>= 0	Number of load duration curve blocks in the last load duration curve of the horizon, or zero if same as Block Count.
LDC Pin Bottom	-	-1	>= -1	Number of points at the bottom of the LDC that are pinned and cannot be aggregated into blocks.
LDC Pin Top	-	-1	>= -1	Number of points at the top of the LDC that are pinned and cannot be aggregated into blocks.
LDC Slicing Method	-	0	In (0,1)	Method used to slice the LDC into blocks.
LDC Type	-	3	In (1,2,3,4,7)	One LDC is created for each period of this type in horizon.
LDC Weight a	-	0		LDC weighting polynomial function ‘a’ parameter.
LDC Weight b	-	1		LDC weighting polynomial function ‘b’ parameter.
LDC Weight c	-	0		LDC weighting polynomial function ‘c’ parameter.
LDC Weight d	-	0		LDC weighting polynomial function ‘d’ parameter.
Limit Capital Cost Perpetuity by Economic Life	-	-1	In (0,-1)	With perpetuity end effect, if annuity calculation should extend beyond the end of the horizon up to the Economic Life.
Maintenance Rate Output Basis	-	0	In (0,1)	Basis for Maintenance Rate (%) Output due to Maintenance Sculpting.
Maintenance Sculpting	Yes/No	0	In (0,-1)	If LT Plan should sculpt maintenance derating according to the inverse of load.
Optimality	-	2	In (0,1,2)	LT Plan integerization scheme.
Optimize Expansion	Yes/No	-1	In (0,-1)	If expansion is optimized by this simulation phase.
Outage Increment	MW	10	>= 1	Generator outage bin size in convolution.
Overlap	-	0	>= -1	Number of years overlap between steps where -1 invokes Rolling Horizon.
Pricing Method	-	0	In (0,1)	Type of generator pricing used in LT Plan.
Reduced Sample Count	-	4	>= 1	Statistically reduce the Sample Type periods to at most this number of samples each year.
Reduction Relative Accuracy	-	1	Between 0 And 1	Stop sample reduction when the accuracy of the reduced sample set reaches this level.
Sample Type	-	2	In (1,2,3,4)	For Chronology = Sampled, take this type of sample.
Sample Year Count	-	0	>= 0	For Chronology = Sampled, first select this many years then sample within only those years.
Sampled Block Count	-	0	>= 0	Number of blocks modeled in each sample period (day/week) where zero means the original number of intervals.
Sampled Shallow Storage Cutoff	h	0	>= 0	For Chronology = Sampled and Sampled Shallow Storage Treatment = Custom, maximum storage duration in hours for shallow storage formulation.
Sampled Shallow Storage Treatment	-	1	In (1,2,3)	For Chronology = Sampled, method used for formulating low duration storages and batteries.
Sampling Interval	-	4	In (-1,2,3,4,7)	For Chronology = Sampled, take Sample Type samples in each of these intervals of time.
Solution Count	-	1	>= 1	Maximum number of solutions produced in the solution hierarchy.
Solution Quality	%	0	Between 0 And 100	Continue producing solutions up to Solution Count or when Solution Quality falls to this level.
Start Cost Amortization Period	h	0	>= 0	Number of hours over which generator start costs are amortized.
Stochastic Method	-	0	In (0,1,2,3)	Stochastic optimization method for LT Plan.
Storage Formulate Head Effects	Yes/No	-1	In (0,-1)	If storage head effects should be formulated in LT Plan.
Storage Restart	Yes/No	0	In (0,-1)	If recycled storage should restart from their initial volume at the start of each capacity optimization period.
Tax Rate	%	0		Tax rate used to compute tax credits.
Use Effective Load Approach	Yes/No	0	In (0,-1)	If LT Plan uses the effective load approach.
Write Expansion Plan Text Files	Yes/No	0	In (0,-1)	If expansion plans should be written to text files.