ER26-3552-000 · 2026-09-11 · Organization of MISO States, Inc.
Motion for Acceptance of Late-Filed Comments and Comments in Conditional Support of the Organization of MISO States, Inc. re Midcontinent Independent System Operator, Inc.’s proposed tariff revisions
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UNITED STATES OF AMERICA
BEFORE THE
FEDERAL ENERGY REGULATORY COMMISSION
)
Midcontinent Independent System
)
Docket No. ER26-3552-000
Operator, Inc.
)
)
MOTION FOR ACCEPTANCE OF LATE-FILED COMMENTS AND
COMMENTS IN CONDITIONAL SUPPORT OF
THE ORGANIZATION OF MISO STATES, INC.
The Organization of MISO States, Inc. (“OMS”) submits this Notice of Intervention and
Conditional Comments in Support in response to proposed tariff revisions filed by the
Midcontinent Independent System Operator, Inc. (“MISO”) with the Federal Energy Regulatory
Commission (“Commission”) in the above-captioned proceeding.1 On August 18, 2026, MISO
filed proposed revisions to its Open Access Transmission, Energy, and Operating Reserves
Markets Tariff (“Tariff”) to establish a Zero Injection Generator Interconnection Agreement
(“ZGIA”), associated study process and operational requirements, and market and resource
adequacy rules to accommodate Zero-Injection Generation Resources (“ZG Resource”) that intend
to serve load interconnecting at the same substation as the Generating Facility. OMS cautiously
supports the ZGIA proposal but highlights several critical reliability and resource adequacy
concerns for the Commission’s consideration.
I.
MOTION FOR ACCEPTANCE OF LATE-FILED COMMENTS
Pursuant to Rule 212 of the Commission’s Rules of Practice and Procedure, OMS
respectfully requests that the Commission accept these late-filed comments.2 On September 8,
1 Midcontinent Indep. System Operator, Inc., Zero Injection Generator Interconnection Agreement, Docket No.
ER26-3552 (August 18, 2026) (“ZGIA Filing”).
2 18 C.F.R § 385.212.
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2026, OMS timely filed a doc-less Notice of Intervention in this proceeding.3 Due to the need to
coordinate the perspectives of several OMS members and allow for sufficient review, it was
determined that additional time was necessary to conduct a vote on the comments.
OMS offers the following comments to aid the Commission in its decision-making process.
The Commission may allow an untimely response when there is no showing of undue prejudice or
delay. Through these brief comments, OMS does not seek to disrupt or delay the proceeding. OMS
believes these comments will assist the Commission in its deliberations and improve overall
understanding by offering the important perspectives of state regulators. Therefore, good cause
exists to grant this Motion. OMS respectfully requests that the Commission grant this Motion and
accept OMS’s comments.
II. COMMENTS
Over the course of the year, MISO and its stakeholders have worked to develop an
interconnection and study process that facilitates the expedited integration of large loads and
proximately located generation while maintaining system reliability and protecting customers from
unnecessary costs. As recognized by the Commission in its Show Cause Order, rapidly increasing
demand from data centers and other large loads presents new challenges for transmission planning,
generator interconnection, resource adequacy, and reliable system operations.4
OMS conditionally supports MISO’s Zero Injection Generator Interconnection Agreement
(“ZGIA”) framework as a potential tool for addressing these challenges. However, MISO’s ZGIA
framework should be implemented only with appropriate safeguards to ensure that expedited
interconnection does not create increased reliability risks, preferential treatment, or costs shifted
3 Notice of Intervention of the Organization of MISO States, Inc., Docket No. ER26-3552 (Sept. 8, 2026).
4 Midcontinent Independent System Operator, Inc., Order Instituting Proceeding Under Section 206 of the Federal
Power Act, 195 FERC ¶ 61,212 (2026) (“Show Cause Order”).
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to existing customers. Furthermore, nothing in the ZGIA Filing shall supplant state and local rules
regarding generation and load application, approval, and interconnection processes.
OMS’s position has evolved through substantial review of MISO’s ZGIA proposal and
draft tariff provisions. In March 2026, OMS identified significant questions concerning reliability,
multiple points of interconnection, cost allocation, resource adequacy, market participation, and
circumstances in which associated generation does not materialize. In June, OMS recommended
that additional time was needed to resolve outstanding issues before MISO filed its proposal. In
July, after MISO delayed its filing, OMS continued to identify unresolved resource adequacy
issues described in subsection E. below.
OMS appreciates MISO’s subsequent efforts to further develop the proposal. Nevertheless,
the Commission should evaluate ZGIA as a comprehensive package involving both generation and
load, rather than as a generator interconnection mechanism considered in isolation. The
Commission should also direct MISO to work with stakeholders on the development of Business
Practice Manual rules to remedy the remaining reliability and resource adequacy issues presented
by ZGIA.
A. OMS Supports ZGIA as a Potential Tool to Interconnect Large Loads, Subject to
Appropriate Safeguards.
MISO began developing the ZGIA framework with the recognition that co-located
arrangements were necessary to quickly integrate large loads and their associated generation while
shielding existing customers from any resulting costs.5 The ZGIA framework is further premised
on the understanding that a generator that serves a co-located load and is prohibited from injecting
beyond the interconnecting substation may not present the same transmission impacts as a
5 Interconnection of Large Loads to the Interstate Transmission Sys., Advanced Notice of Proposed Rulemaking,
Docket No. RM26-4-000 (Oct. 27, 2025).
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conventional generating facility seeking firm interconnection service. As such, a properly designed
ZGIA process could reduce unnecessary network upgrades, improve utilization of existing
infrastructure, and facilitate timely development of generation and large loads.
OMS recognizes the potential value of ZGIA and the importance of practical pathways for
large load integration. The Commission’s Show Cause Order demonstrates that existing processes
may need to evolve to accommodate rapidly changing demand. MISO’s ZGIA Filing likewise
explains that ZGIA is intended to provide a defined interconnection and study process for
generation serving load at the same substation and voltage level while prohibiting injection onto
the broader transmission system. Therefore, OMS does not oppose the ZGIA Filing.
While OMS does not oppose the ZGIA Filing, the Commission should determine whether
the proposed ZGIA framework adequately protects the reliability and economic interests of
existing customers and whether the treatment of ZGIA resources is consistent with MISO’s
broader resource adequacy, market, transmission planning, and transmission service constructs.
OMS recommends that the Commission approve ZGIA only if those protections are clear and
enforceable.
B. Reliability Protections Must Be Fundamental to the ZGIA Framework.
The defining characteristic of ZGIA is the prohibition on injection beyond the
interconnecting substation. That limitation must be treated as a reliability requirement, not merely
a contractual condition. OMS remains concerned that financial penalties alone may not adequately
protect against inadvertent injection, no matter how momentary or transitory. Relevant
transmission system conditions should be studied prior to ZGIA execution rather than relying
solely on post-event penalties.
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MISO appears to appreciate the importance of this distinction as its ZGIA Filing requires
detailed modeling of the generator, associated load, and protection facilities as well as proposed
operating requirements necessary to prevent injections beyond the interconnecting substation.
OMS remains concerned, however, that MISO has deferred establishing an explicit definition of
the appropriate Transient Tolerance Window to the development of its Business Practice Manual.6
It is paramount that the studies and the Transient Tolerance Window be developed and conducted
with sufficient rigor to ensure that ZG Resources do not cause adverse impacts to system reliability.
OMS recommends that the Commission ensure those operating requirements are
sufficiently specific, enforceable, and capable of physically or operationally preventing prohibited
injection. Depending on the facility, such mechanisms could include physical controls, generator
drawback controls, remedial action schemes, or other technologies and operating requirements
MISO determines are necessary. OMS also recommends that the ZGIA study process evaluate
both sides of the generation-load relationship, including but not limited to:
• the ZGIA generator tripping offline;
• the associated load tripping offline;
• the associated load rapidly reducing and increasing output;
• the generator being required to rapidly reduce output following a load reduction;
• simultaneous or correlated outages of the generator and load; and
• circumstances in which the generator and load do not behave as assumed in the
interconnection study.
6 ZGIA Filing, Prepared Direct Testimony of Marc Keyser, at 25-26; Per MISO’s proposed Tariff revision,
Transient Tolerance Window shall mean the period of time after a reduction or loss of load by the ZG Associated
Load by the end of which window the Generating Facility with ZG Interconnection Service must have reduced its
injections to an amount not greater than the Load of the ZG Associated Load. The Transient Tolerance Window
shall be no greater than 20 seconds, and is further described by the Business Practices Manual for Large Load. The
Transient Tolerance Window will be subject to Transmission Owner local planning criteria.
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These scenarios are important because a large load that suddenly disappears can leave generation
temporarily without its expected sink. Conversely, a generator outage can cause a large load to
rely immediately on the broader network for support.
OMS therefore recommends that the Commission consider whether MISO’s ZGIA study
procedures adequately evaluate these operating conditions, including dynamic and stability
considerations where appropriate. MISO’s ZGIA Filing should also establish detailed metering,
telemetry, modeling, communications, and operating requirements to ensure that MISO and the
applicable Transmission Owner have adequate visibility into both the ZGIA generator and
associated load.
C. The Initial ZGIA Framework Should Be Limited to Generation and Load at the
Same Substation and Voltage Level.
OMS continues to support a narrowly defined ZGIA framework. MISO’s ZGIA Filing
limits ZG Interconnection Service to generation and associated load located at the same substation
and voltage level. MISO explains that this can include configurations in which the generation and
load have separate points of interconnection or withdrawal at a common substation, provided the
required limitations on injection are maintained. 7 OMS supports this narrow approach and
recommends that the Commission retain the common-substation limitation.
OMS recognizes that MISO considered both a strict same-POI approach and broader
electrically proximate configurations (e.g., campus approach). MISO rejected the latter for this
proposal because of unresolved reliability, transmission service, and jurisdictional issues but
intends to address electrically proximate configurations through its forthcoming Large Load
Addition Resource Study (“LARS”) process. OMS agrees that those broader configurations should
7 ZGIA Filing at 7.
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not be incorporated into ZGIA. Expanding the framework beyond a common substation could
introduce additional reliability, transmission service, cost allocation, market, and jurisdictional
questions. As such, OMS recommends that the Commission accept the common-substation and
voltage-level limitation as the appropriate scope of ZGIA.
D. MISO Must Prevent Cost Shifting When the Associated Generation or Load Does
Not Materialize.
A central benefit of ZGIA is the ability to avoid or reduce network upgrades that otherwise
could be required if associated load were evaluated without the ZG generation. That benefit
depends upon the continued existence and operation of the generation relied upon in the load study.
OMS supports MISO’s requirements for an agreement between the generator and associated load
demonstrating that the full output of the generating facility is intended to serve the associated load,
with an expected period of at least five years.8 MISO explains that this requirement is intended to
prevent speculative requests and provide sufficient certainty for MISO to rely on the generation as
an alternative mitigation in transmission-service studies.9
MISO also recognizes that if the generating facility ceases to serve the associated load,
MISO may need to restudy the load’s transmission impacts and potentially delay or suspend
service while an alternative mitigation is identified. Those provisions are important, but MISO’s
Tariff should go further by establishing clear responsibility for resulting costs. If network upgrades
subsequently become necessary because generation that supported the original study assumptions
does not materialize or ceases to operate, the costs of that incremental need should not
automatically shift to existing transmission customers.
8 Id. at 32.
9 Id.
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To prevent such occurrences, the Commission should require MISO to establish in its
Tariff or BPMs:
•
clear notification requirements;
•
defined triggers for restudy;
•
procedures for identifying previously avoided or deferred upgrades;
•
mechanisms for tracing subsequent upgrades to assumptions underlying the original ZGIA
approval;
•
appropriate cost responsibility for the customer or customers whose circumstances caused
the additional need; and
•
protections against socializing costs that would not otherwise have been incurred.
These provisions are particularly important because MISO’s proposal relies on the ZG Resource
as an alternative mitigation in studying the associated load.
E. Resource Adequacy Treatment Must Be Complete, Transparent, and Consistent
with Physical Capability.
OMS continues to have significant concerns regarding the treatment of ZGIA resources in
MISO’s Resource Adequacy (“RA”) construct. The fact that a ZG Resource cannot inject beyond
the interconnecting substation does not mean that it has no relevance to regional reliability.
Similarly, associated load cannot be treated as though it has disappeared simply because it is served
in part or in whole by on-site generation.
OMS recognizes that MISO’s filing proposes specific RA treatment. In particular, MISO
proposes to cap Seasonal Accredited Capacity (“SAC”) for a ZG Resource based on the applicable
portion of the Coincident Peak Demand forecast attributable to the ZG Associated Load, less SAC
assigned to that load, with an adjustment for avoided transmission losses.10 MISO also proposes
10 Id., Proposed Tariff Redlines, Seasonal Accredited Capacity of Capacity Resources, 43.0.0, i., 1.
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limits on ZG Resource participation in the Planning Resource Auction and would not permit
uncleared Zonal Resource Credits to be used for replacement.
The Commission should ensure that MISO has demonstrated these provisions operate
consistently across the entire RA construct and accurately reflect the physical reliability
contribution of the paired generation and load. To that end, OMS requests that MISO explain in a
compliance filing, subsequent BPM rules, or a workshop how ZGIA resources and associated loads
will be represented in:
•
the LOLE model, including CIL, CEL, LCR calculations;
•
UCAP calculations;
•
SAC calculations;
•
PRM requirements;
•
the Planning Resource Auction;
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must-offer requirements;
•
transmission outage scenarios;
•
generator outage scenarios;
•
load outage and load-reduction scenarios; and
•
PRMR allocation framework(s).
Of particular concern is whether different ZGIA-specific limitations produce inconsistent
outcomes among the various components of the RA construct. For example, OMS has identified a
potential mismatch if a ZG Resource’s availability is reduced because its associated load decreases,
but there is not a mechanism for such reductions to be accounted for or modeled in the LOLE
study. Consequently, resource class-level results in the LOLE study may over-estimate resource
performance. Although ZG Resources would have SAC constrained by the associated load’s
Coincident Peak Demand forecast, that cap takes place outside of the LOLE study. Without
addressing limitations, it appears possible that MISO could produce study results that suggest a
fleet of resources that appears capable of satisfying the PRM in one component of the RA construct
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but is unable to provide the corresponding reliability contribution under other ZGIA-specific
limitations.
MISO should demonstrate that its methodology avoids such inconsistencies. The
Commission also should require MISO to explain how ZGIA treatment will interact with
forthcoming changes to DLOL and PRMR allocation. Tariff provisions tied too specifically to the
current Coincident Peak Demand construct could become inconsistent with MISO’s future RA
framework. OMS therefore recommends that ZGIA Tariff language or BPM rules provide
sufficient flexibility to remain consistent with subsequent Commission-approved RA reforms
while preserving the fundamental principle that accreditation must reflect the physical capability
and reliability contribution of the resource.
F. ZGIA Should Provide a Clear Transition Path Without Circumventing the DPP.
OMS recognizes that MISO’s proposal expressly permits a ZG Resource to pursue another
form of interconnection service separately, including full integration and injection rights through
Network Resource Interconnection Service (“NRIS”) through MISO’s Definitive Planning
Process (“DPP”), with the subsequently effective service superseding ZG Interconnection Service.
OMS supports providing a clear transition path for a ZGIA resource that later seeks injection rights.
That transition, however, must not allow a ZGIA resource to circumvent or obtain an advantage
over interconnection customers already participating in the DPP queue. MISO should clearly
specify how such transitions will be sequenced, how queue position and study impacts will be
determined, and how transmission capability reserved or relied upon under ZGIA will be treated
when the resource seeks broader injection rights.
MISO characterizes ZGIA as a permanent feature in its Tariff rather than a temporary
program. Meanwhile, MISO and stakeholders are also developing separate processes for broader
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electrically proximate configurations (e.g., LARS). The Commission should focus on preventing
ZGIA from becoming a mechanism for indefinite avoidance of the standard DPP interconnection
process and should continue to hold MISO accountable for improving the processing of its
standard generator interconnection queue.
G. OMS Supports Transparency and Meaningful State and Stakeholder Oversight.
The rapid development of large-load projects creates significant implications for state
regulatory commissions, load-serving entities, transmission owners, existing customers, and other
market participants. The ZGIA framework should therefore provide sufficient transparency for
regulators and stakeholders to understand:
•
the amount and characteristics of load relying on ZG Resources;
•
the amount and characteristics of associated generation;
•
the status of ZGIA projects;
•
material changes to ZGIA arrangements;
•
withdrawals or failures to materialize;
•
restudies and resulting network upgrades;
•
the treatment of ZG Resources in RA and markets; and
•
the reliability assumptions underlying ZGIA approvals.
This information is important not only for MISO’s operations and planning functions, but also for
state regulatory processes, including integrated resource planning, certificates of public
convenience and necessity, procurement proceedings, and other state proceedings concerning the
adequacy, cost, and reliability of electric service.
OMS is particularly concerned that a framework designed to accelerate large-load
development should not impair states’ ability to evaluate the costs and risks associated with serving
those loads. In its ZGIA Filing, MISO recognizes that ZGIA does not establish new transmission
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service rules and that additional large-load proposals will address other issues raised by the
Commission.
H. ZGIA Should Complement, Not Displace, Broader Transmission and Large-Load
Reforms.
OMS supports ZGIA as one tool within MISO’s broader response to large load growth.
ZGIA should not, however, substitute for: cost-effective transmission expansion and regional
planning when objective and broadly distributed benefits clearly outweigh costs; improvements to
MISO’s generator and load interconnection processes; or development of appropriate large-load
transmission service.
MISO describes ZGIA as the first in a series of proposed solutions developed through the
stakeholder-led Large Load Working Group and identifies LARS as a forthcoming process for
addressing electrically proximate generation and load that do not satisfy the narrower ZGIA
requirements.11 The underlying growth in demand will continue to affect regional transmission
planning, resource adequacy, and system operations even when some large loads are paired with
generation behind the meter or at a common substation.
Consistent with OMS’s support for MISO and the MISO Transmission Owners’ abeyance
request, the Commission should therefore evaluate ZGIA as one component of a broader,
comprehensive framework for large load integration rather than as a standalone solution.12 That
framework should address the broader concerns identified in the Commission’s Show Cause Order,
including reliable and transparent transmission planning, meaningful consideration of alternative
11 Id. at 7.
12 Answer in Support of the Motion to Hold Proceeding in Abeyance of MISO and the MISO Transmission Owners
of OMS, Docket No. EL26-70-000 (August 7, 2026).
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solutions, protection of existing customers from inappropriate cost shifting, and consideration of
reliability impacts associated with uncertain or delayed load development.
The Commission should also make clear that consideration of the ZGIA Filing does not
resolve these broader issues or otherwise limit the scope of its inquiry. Since MISO intends its
stakeholder process and subsequent 205 filings to address the Commission’s concerns regarding
large load interconnection, the Commission should evaluate the ZGIA Filing together with other
reforms developed during that process only after a complete record is developed whether the
resulting framework adequately addresses the concerns identified in the Show Cause Order.
III. CONCLUSION
OMS appreciates MISO’s efforts to develop a practical mechanism for facilitating the
timely integration of large loads and associated generation. OMS agrees that a well-designed ZGIA
framework can provide meaningful benefits by allowing generation that is dedicated to serving an
associated load to be evaluated in a manner consistent with its limited transmission-system impact.
OMS’s support, however, is conditioned on maintaining the fundamental principles of reliability,
cost causation, transparency, and equitable treatment of customers and market participants as
detailed above.
OMS submits this Answer because a majority of OMS members support this filing. This
should not be construed to mean that all OMS members agree with all comments herein. Individual
OMS members reserve the right to file separate comments. In recognition of such, the following
members voted in support of this filing:
Arkansas Public Service Commission
Illinois Commerce Commission
Iowa Utilities Commission
Indiana Utility Regulatory Commission
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Kentucky Public Service Commission
Louisiana Public Service Commission
Michigan Public Service Commission
Minnesota Public Utilities Commission
Mississippi Public Service Commission
Missouri Public Service Commission
New Orleans City Council
North Dakota Public Service Commission
South Dakota Public Utilities Commission
Public Service Commission of Wisconsin
Public Utility Commission of Texas
The Manitoba Public Utilities Board and the Montana Public Service Commission did not
participate in the vote on this filing.
Respectfully submitted,
/s/ Brad J. Pope
/s/ Tricia DeBleeckere
Brad Pope
Tricia DeBleeckere
Legal and Regulatory Director
Executive Director
Organization of MISO States
Organization of MISO States
811 E. Washington Ave., Suite 400
811 E. Washington Avenue, Ste. 400
Madison, WI 53703
Madison, WI 53703
brad@misostates.org
tricia@misostates.org
Dated: September 11, 2026PDF page 15
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CERTIFICATE OF SERVICE
I certify that I have served the preceding document upon each person designated on the official
service list prepared by the Secretary for this proceeding in accordance with the requirements of
Rule 2010 of the Commission’s Rules of Practice and Procedure. 18 C.F.R. § 385.2010.
/s/ Brad J. Pope
Brad Pope
Director of Legal & Regulatory Affairs
Organization of MISO States
811 E. Washington Avenue, Suite 400
Madison, WI 53703
brad@misostates.org
Dated: September 11, 2026