Firm Imports Column
Column Type = Text
A value or Time Series vector, input in MW, specifying the pattern of imports into the pool which can be credited as a firm resource. As such, these values will affect Pool Commitment levels, reserve margin calculations and Planning Reserve Margin targets for long-term studies.
Firm Imports can affect unit commitment when using pool commitment. Pool commitment is used either when reliability-based commitment is selected thorough the Pool Commit switch in the Operating Pools table, or on the first day of a dynamic commitment run in order to bootstrap a reasonable commitment pattern. This variable does not impact economic dispatch or economic imports/exports.
For reserve margin accounting purposes, specified imports and exports are treated as a resource per NERC definition:
Reserve Margin = (Capacity + Firm Imports – Firm Exports) / (Peak Demand) – 1.
For long-term studies, this column is used in conjunction with the Use Reserve Margin Capacity Targets option located in the Long-Term folder of Simulation Options. This value will be used to define the Planning Reserve Margin target for the overall pool; zonal Planning Reserve Margins will also be met. This provides the ability to specify minimum targets at the zone level, and a potentially higher level at the pool level, letting the model decide where to build additional units above zone minimums. This holds true for both zones that are members of a multiple-zone pool, and those that are not. There is no attempt to aggregate zone level imports/exports up to pool level imports/exports.
The default is zero if the column is missing, unless the pool is comprised of a single zone, in which case the zonal value will be used.
See the Knowledge Base article Long-Term Studies Using Reserve Margins for more information.
Firm Imports Column
