After five fruitless attempts to agree on joint transmission projects across their seams, MISO and SPP will use what they call a “blended joint model” in parallel with existing SPP and MISO regional models.
The RTOs’ staffers told stakeholders during a Sept. 9 Interregional Planning Stakeholder Advisory Committee meeting that their coordinated system plan (CSP) study, required every two years by a joint operating agreement, will identify near-term upgrades that “incrementally enhance” transfer capability and produce multiple benefits across the two grids. The study will include reliability, economic, and transfer analysis using forward-looking models and assumptions (10- and/or 20-year models), they said.
“The hope is that we have some mutually beneficial projects that we can both agree to recommend approval and ultimately share costs and construct,” SPP’s Clint Savoy said. “That’s the way the current process works today, or that’s the way it’s envisioned in the JOA.”
Five previous studies have failed to produce any joint projects over differences in allocating costs. That led the RTOs to try a different approach with the Joint Targeted Interconnection Queue project, which identified a $1.86 billion portfolio of five projects that could support up to 28 GW of interconnecting generation on both sides of the seam. The Department of Energy last year awarded the portfolio $464 million under its Grid Resilience and Innovation Partnerships program. (See DOE Announces $3.46B for Grid Resilience, Improvement Projects.)
Under the blended model, MISO will use its 2023 Long-Range Transmission Planning reliability and economic model sets and SPP will run the 2025 Integrated Transmission Planning’s same model sets. Staff will use three of four base seasonal models (winter peak, summer peak, average load and light load).
The RTOs both want a multi-benefit style project type and cost allocation to draw on a broader set of benefits for project recommendations, they said. Savoy said FERC Order 1920, which requires transmission-planning regions use at least a 20-year horizon, has provided something of a guidepost for the RTOs to follow.
“We hope this new approach will let us look into additional drivers for projects other than just economic or reliability benefits, if you will, maybe consider different assumptions as we are developing, the list of needs that we want to fix,” he said. “And so what we hope is a better outcome to look more proactively, maybe have a broader set of issues that we’re looking for or benefits to consider, rather than just the traditional economic reliability and public policy.”
The two staffs will continue to develop the study’s scope, incorporating stakeholder feedback, and share it with stakeholders when complete later this year. The 2024 CSP will run through 2025.
The RTOs will have to file a waiver request with FERC requesting permission to use the blended study process. They said they will partner with states and stakeholders to identify and file any needed changes to their JOA and tariffs.
