The large majority of the Coincident Peak Load Forecasts in MISO are opaque and not independtly verified by MISO. Under the present Planning Resource Auction (PRA) rules, Planning Reserve Margin Requirements are set equal to an LSE’s/EDC’s forecasted Coincident Peak Demand, including transmission losses, multiplied by one plus MISO’s Planning Reserve Margin. LSEs and EDCs provide the annual Coincident Peak Demand forecast, along with the LRZ peak demand data, to MISO. MISO then reviews a “sampling of submitted Demand forecast methodologies and inputs to ensure accurate and consistency, in accordance with the BPM for Resource Adequacy.” Module E-1, 69A.1.1. This “sampling” described in the Tariff has translated to a random sample of LSEs/EDCs where the focus is on the methodologies and inputs. No additional screens or validation processes are articulated in the Tariff.
While MISO does evaluate the Coincident Peak Demand forecasts of a random sample of EDCs, it does not dive into the details to verify the accuracy each load forecast. This results in an opaque process where stakeholders and MISO are not provided with a detailed understanding of the key drivers of the large majority of the load forecasts provided. The lack of transparency impacts market outcomes and near- and long-term assessments of the MISO region.
It is worth noting that the State Utility Forecasting Group at Purdue University provides an annual report on MISO Energy and Peak Demand Forecasting for System Planning. But, this independent forecast is not directly used in the PRA and provides Noncoincident Peak Demand values.