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Project Cost

GIPS displays the estimated cost for the project size. This is reflected in both the Constraints and POI tables.

Cost columns in the Constraints table​

  • Line Length — the length of the branch constraint, in US miles. Transformers do not have a length, so this cell will be empty with a note telling you why.
  • Cost — the aggregate of the "Pre-Existing Cost" and "Incremental Cost" columns, in millions of dollars.
  • Pre-Existing Cost — the cost, in millions of dollars, to upgrade the line. GIPS considers the possibility of upgrading a line before calculating the cost of installing a new line. If the project is big enough, it is possible to incur both a pre-existing and an incremental cost.
  • Incremental Cost — the cost, in millions of dollars, of installing a new piece of equipment, either a line or transformer.

Totals in the POI table​

The total cost is displayed in the POI table on a per-POI basis: the "Cost" column is the sum of all the "Cost" columns for that POI's constraints. The same holds for the POI's "Pre-Existing Cost" and "Incremental Cost" columns and their respective columns in the Constraints table.

Ignore POI Impact​

Not all upgrades are the same, and sometimes it is acceptable not to incur an incremental cost if the project size is small enough. This is controlled via a percentage of the TrLim in the setting entitled "Ignore POI Impact".

Setting this and specifying the percentage instructs GIPS to use each constraint's effective TrLim — the greater of its TrLim and the MW available at the specified impact percentage — and to not incur a pre-existing (upgrade) cost while the project size is less than that effective TrLim. The TrLim column of the constraints table displays this effective value, and each POI's TrLim is the smallest effective TrLim among its constraints.

Example

A constraints table may show a pre-existing cost even though the project size is 0 MW — that constraint is already overloaded and needs to be upgraded before doing anything. Enabling "Ignore POI Impact" changes the cost to 0 in the constraints table and the POI table. Once the project size exceeds a constraint's effective TrLim, costs start to be incurred.