The surge in large load growth across the Midwest presents MISO with both an enormous opportunity and a critical test. As energy demand accelerates, the region’s ability to attract and support these facilities will depend on whether MISO can modernize its interconnection processes to match the speed and scale of business need while maintaining the reliability the region requires.
The region’s energy needs demand that MISO include clean energy technologies to support rapid load growth. The fact is that clean energy offers the lowest-cost, fastest-to-market solution to meet rapidly increasing energy demand while reducing consumer costs and driving economic growth.
MISO’s initial zero-injection generator interconnection agreement (ZGIA) represents a workable clarification of existing practice that formalizes arrangements, as already applied to three facilities in MISO South. Limiting large load solutions only to zero-injection scenarios misses the mark and can create a myriad of challenges now and in the future.
Clean Grid Alliance offered a transparent solution to align generator and load interconnection processes at MISO’s Planning Subcommittee in August 2024, more than a year before MISO unveiled this initial zero-injection clarification. (See MISO Floats ‘Zero Injection’ Agreements to Bring Co-located Gen Online and Questions Abound over MISO Idea for Zero-injection Agreements.)
CGA emphasized the need for better information sharing between processes that currently operate in isolation despite significantly impacting each other in planning models. Generator interconnection nominally aligns with MISO’s 18-month MTEP process but recently has been taking up to five years, a misalignment that creates inefficiencies preventing project development and driving up costs unnecessarily.
Beyond Zero-injection: Leveraging Clean Energy Solutions
MISO should expand its initial ZGIA concept to leverage a larger toolkit of clean energy technologies that can facilitate rapid large load integration while maintaining grid reliability. Three technologies are of significant importance: battery storage, renewable energy paired with storage (hybrid projects) and high-voltage direct current (HVDC) transmission.
Battery Storage as Reliability Solution
Four-hour battery storage is ready to enter MISO markets. Storage responds instantaneously to variations in large loads, including sudden trips offline. This rapid response capability could prevent cascading blackouts in the event a large load suddenly disconnects, offering a reliability benefit that will become increasingly important as large load projects proliferate. Meanwhile, CGA and its members are working on market entry paths for longer-duration storage to complement and extend the benefits of four-hour batteries.
Yet MISO uniquely assesses storage for transmission service during charging, a barrier that no other RTO imposes and that directly delays the deployment needed for large load reliability. MISO should align its rules with its peers and accelerate integration of storage resources already queued in substantial quantities by more realistically modeling the reliability attributes of batteries.
By treating storage as an asset instead of a liability, MISO’s interconnection queue could unleash utility-scale batteries and their grid benefits within approximately 18 months or faster with other improvements to provide flexible capacity while longer-term transmission infrastructure comes online. (See MISO Members Push for Modernized Storage Rules.)
Renewable Energy with Storage Co-location
Co-locating storage with renewable energy maximizes use of existing transmission capacity and improves reliability. Providing grid support with this configuration will allow MISO to integrate even more unprecedented amounts of new demand in a short period of time.
Additionally, MISO should prioritize efforts to refine interconnection rules that allow renewables, storage and HVDC to enter the market with limited operations rather than waiting years for upgrades to allow full operations. This enables needed resources to come online faster while maintaining reliability. MISO must do this in a way that ensures expedited interconnection rules don’t inadvertently favor any one technology or hinder the traditional interconnection queue. Open access policies foster resource expansion and competition that keeps lights on and costs down for all consumers.
HVDC Transmission for Interregional Solutions
While HVDC represents a longer-term solution than storage or hybrid deployment, it offers critical strategic benefits that will expand siting opportunities for data centers for better fiber connectivity, cooling infrastructure or other business reasons by delivering available generation when and where it’s needed.
This matters because a single HVDC line delivers gigawatts of capacity equivalent to multiple large power plants without requiring new local thermal generation, fuel supply chains or emissions, all while allowing the grid to be “bigger than the weather” for better reliability and affordability.
The Path Forward
MISO’s zero-injection clarification represents a constructive first step, and we appreciate MISO’s commitment to expanding the current rules to address today’s complex challenges. After all, the alternative is a patchwork of narrow solutions that fail to capture the full economic and reliability value these technologies offer.
The scale and diversity of load growth projected in MISO demands more ambitious solutions and innovation. By expanding interconnection options to fully leverage battery storage, hybrid renewable energy and HVDC transmission, MISO can turn the large load challenge into an opportunity for grid modernization that benefits all customers now and for generations to come. MISO has a historic opportunity to lead in integrating large loads reliably and cost-effectively. The region’s economic growth depends on seizing it.
MISO has the tools and the moment to lead. Clean Grid Alliance stands ready to work with MISO and all stakeholders to turn today’s large load challenge into tomorrow’s competitive advantage. The Midwest’s energy and economic futures depend on getting this right.
David Sapper, vice president of transmission and markets for the Clean Grid Alliance, has been involved in the wholesale electricity industry for nearly 30 years.
