GRID-C key to success of SPP’s Consolidated Planning Progress

After approving SPP’s innovative Consolidated Planning Process (CPP), members of the Federal Energy Regulatory Commission (FERC) praised the measure as ushering in a streamlined way to add more capacity to the grid.

FERC urged other Regional Transmission Organizations (RTOs) to follow SPP’s lead.

As is evident by the name, the CPP consolidates transmission planning and generation interconnection (GI) studies into one process.

In a concurrence to the FERC Order, issued in March, Commissioner Judy Chang wrote to “commend SPP on taking a bold step to address the needs of its system.”

But the most important ingredient of the CPP may just be GRID-C.

So, what is GRID-C?

It stands for Generalized Rates for Interconnection Development-Contribution. It’s how the CPP provides cost certainty to generators who are evaluating the potential commercial viability of connecting to the SPP grid.

GRID-C helps create a first-of-its kind blueprint for keeping the regional grid reliable and affordable.

The first CPP window for new project applications was opened in April, which is an important initial step toward a more coordinated planning process.  

The new process is designed to give generation developers earlier and clearer information about transmission costs, while helping SPP better align generator interconnection studies with long-range transmission planning.

Today, developers often receive updated cost information late in the generator interconnection process, which can create uncertainty, delay project decisions, and complicate how future generation is reflected in the Integrated Transmission Plan (ITP).

CPP addresses that challenge by combining generator interconnection and transmission planning evaluations into one coordinated process.

A key component of that framework is GRID-C, which establishes how generation customers contribute to transmission upgrades needed to support new resources.

GRID-C is intended to create a more equitable cost-sharing approach. Rather than placing a disproportionate burden on the first project that triggers a needed upgrade, the framework spreads responsibility more appropriately among generation customers that use and benefit from the transmission system.

The SPP Markets and Operations Policy Committee (MOPC) is expected to take up the 2026 ITP and CPP transition study portfolio at its October meeting.

This will be another key step in advancing CPP implementation and will allow the publishing of the GRID-C rates.

FERC Commissioner David Rosner in his concurrence saw the value of the cost model.

“CPP represents the innovation that America needs to facilitate cost-effective transmission buildout and generator interconnection, reduce costs, and enhance system reliability,” Rosner wrote.