MISO Definitive Planning Phase assigns network upgrade cost estimates

MISO studies interconnection requests through an annual Definitive Planning Phase. Requests are grouped, studied together, and assigned network upgrade responsibility. Before that point, cost figures circulating around a project are estimates without study support.

The structural feature that matters is re-study. Cost allocation within a group depends on which projects remain. Each withdrawal reallocates upgrade costs among survivors, and each reallocation can move a project across its own investment threshold. A position that pencils at the first estimate may not pencil at the third.

MISO's footprint compounds this. It spans a long north-south geography with limited internal transfer capability, so upgrade sets identified in study frequently implicate facilities well away from the point of interconnection.

For a developer, the discipline is to treat the DPP estimate as the first credible number and everything earlier as a planning assumption. For a lender, the relevant document is the study report, not the interconnection request.

What to watch: whether MISO's expedited pathways for projects with demonstrated need change the composition of the standard cycle.