ER26-3650-000 · 2026-08-28 · Midcontinent Independent System Operator, Inc.

Tab C - Testimony of BeiBei Li.pdf

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UNITED STATES OF AMERICA 
BEFORE THE 
FEDERAL ENERGY REGULATORY COMMISSION 
 
 
 
Midcontinent Independent   
 
 
) 
 
Docket No. ER26-___-000 
  System Operator, Inc. 
  
 
 
) 
 
 
 
PREPARED DIRECT TESTIMONY OF 
BEIBEI LI 
SENIOR MANAGER OF STRATEGIC ASSESSMENT

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I. 
PROFESSIONAL BACKGROUND AND QUALIFICATIONS 
1 
Q. 
PLEASE STATE YOUR NAME, BUSINESS ADDRESS, AND RELATIONSHIP TO 
2 
THE MIDCONTINENT INDEPENDENT SYSTEM OPERATOR, INC.  
3 
A. 
My name is Beibei Li.  I am the Senior Manager of Strategic Assessment for the 
4 
Midcontinent Independent System Operator, Inc. (“MISO”).  My business address is 720 
5 
City Center Drive, Carmel, Indiana 46032. 
6 
Q. 
PLEASE 
DESCRIBE 
YOUR 
EDUCATION 
AND 
PROFESSIONAL 
7 
BACKGROUND. 
8 
A. 
I hold Bachelor’s degrees in both Electrical and Computer Engineering and Political 
9 
Science from Purdue University.  I also hold a Master’s Degree in Electrical and Computer 
10 
Engineering from Purdue University and an Executive MBA from the University of 
11 
Chicago Booth School of Business.  I began my career with MISO in 2008 as an Outage 
12 
Coordination Engineer before progressing to Operations Engineer, Market Design 
13 
Advisory, and Manager of Economic and Policy Planning, before assuming my current 
14 
role of Senior Manager of Strategic Assessment.   
15 
Q. 
PLEASE DESCRIBE YOUR CURRENT ROLE AND JOB RESPONSIBILITIES. 
16 
A. 
As Senior Manager of Strategic Assessment, I lead MISO’s evaluation and framing of 
17 
emerging reliability risks and the development of practical, implementable solutions, 
18 
including the ongoing operational requirements for Large Load.    
19 
Q. 
HAVE YOU PREVIOUSLY SUBMITTED TESTIMONY IN A REGULATORY 
20 
PROCEEDING? 
21 
A. 
No.   
22 
 
23

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II. 
PURPOSE OF TESTIMONY 
1 
Q. 
WHAT IS THE PURPOSE OF YOUR TESTIMONY? 
2 
A. 
The purpose of my testimony is to support MISO’s proposal to apply a defined set of 
3 
reliability requirements to certain loads, defined as Large Loads.1  
4 
Q. 
HOW DOES THE IRR FILING ADDRESS THE CONCERNS RAISED IN THE 
5 
COMMISSION’S SHOW CAUSE ORDER RELATED TO LARGE LOADS IN THE 
6 
MISO REGION? 
7 
A. 
As discussed below in greater detail, the IRR proposal defines “Large Load” and is 
8 
responsive to several of the concerns raised by the Commission in the Order Instituting 
9 
Proceeding Under Section 206 of the Federal Power Act2 in Docket No. EL26-70-000 by 
10 
proposing Tariff revisions that are responsive to the concerns raised in the Show Cause 
11 
Order regarding ongoing operational requirements for Large Loads.  More specifically, the 
12 
IRR proposal includes Tariff revisions to include visibility, ramp rate, and disturbance ride-
13 
through requirements applicable to Large Loads, along with transition provisions to 
14 
minimize disruption to commercial arrangements.  The IRR proposal does not introduce 
15 
new transmission service products, pro forma service agreements, or address potential cost 
16 
shifting contemplated by the Show Cause Order.  Matters involving new transmission 
17 
service products, study processes and potential cost shifting for Large Loads will be 
18 
 
1  
As discussed below, MISO proposes to defined Large Load as Load with Demand of 50 MW or more associated 
with any facility or aggregation of facilities located at a single substation behind one or more Point(s) of 
Withdrawal from the Transmission System that is owned, operated, or controlled by: (a) a single entity or (b) a 
group of entities that will coordinate with respect to the profile of the Load.  Large Load does not include Load 
used exclusively for charging an Electric Storage Resource. 
2  
Midcontinent Independent System Operator, Inc., Order Instituting Proceeding Under Section 206 of the Federal 
Power Act, 195 FERC ¶ 61,212 (2026) (“Show Cause Order” or “SCO”).

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addressed in future Federal Power Act Section 205 filings expected to be submitted prior 
1 
to November 16, 2026. 
2 
III. 
THE RISE OF LARGE LOADS AND  
3 
RELATED INTERCONNECTION REQUESTS 
4 
 
5 
Q. 
PLEASE DESCRIBE THE EMERGENCE OF LARGE LOADS IN THE MISO 
6 
REGION.  
7 
A. 
The MISO region is experiencing a significant increase in both the scale and pace of Large 
8 
Load development.  MISO’s 2026 Long-Term Load Forecast3 indicates that the region is 
9 
experiencing load growth at levels not seen in decades, driven in large part by 
10 
unprecedented large load activity and accelerating project announcements.  Data centers 
11 
and advanced manufacturing are among the primary drivers of this growth, with some 
12 
projects seeking to develop on timelines significantly shorter than those traditionally 
13 
associated with generation and transmission infrastructure.  This combination of increased 
14 
volume and accelerated development is changing the manner in which MISO must plan for 
15 
and reliably integrate new load.  
16 
Q. 
PLEASE DESCRIBE THE RELIABILITY CONSIDERATIONS NECESSARY TO 
17 
ACCOMMODATE THE ACCELERATED INTERCONNECTION OF LARGE 
18 
LOADS IN THE MISO REGION.  
19 
A. 
Accommodating the accelerated interconnection of Large Loads requires MISO to ensure 
20 
that the Transmission System can reliably plan for and operate these facilities as they come 
21 
online.  Key reliability considerations include sufficient visibility into Large Load 
22 
 
3  
See MISO’s 2026 Long-Term Load Forecasting (LTLF) Results Summary (April 13, 2026), available at : 
https://cdn.misoenergy.org/20260413%20LTLF%20Workshop%202026%20Long%20Term%20Load%20Forec
ast%20Summary_UPDATED750524.pdf

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characteristics and operating behavior, accurate forecasting and modeling, and 
1 
requirements that address operational risks such as rapid change in demand, disturbance 
2 
response, including ride-through capability.  
3 
Certain Large Load characteristics—including rapid changes in demand, sudden loss of 
4 
significant load, or dynamic interactions between power-electronic equipment and the 
5 
Transmission System—may affect system performance during normal operations and 
6 
contingency conditions.  Under certain system conditions, these behaviors may increase 
7 
operational uncertainty, contribute to system stability concerns, affect post-disturbance 
8 
recovery, stress transmission facilities, or create additional challenges in maintaining the 
9 
real-time balance of supply and demand.  
10 
These considerations do not imply that all large loads create the same reliability risk.  
11 
Reliability impacts may vary depending on facility type, operating characteristics, 
12 
electrical design, system strength, and local transmission conditions.  Accordingly, MISO’s 
13 
approach is intended to be scalable and risk-informed to ensure reliability requirements 
14 
remain proportional to demonstrated system risk.   
15 
Q. 
PLEASE DESCRIBE THE NERC GUIDANCE AND INDUSTRY DIRECTION 
16 
INFORMING THIS FILING. 
17 
A. 
The North American Electric Reliability Corporation (“NERC”), through the Large Loads 
18 
Working Group, has identified emerging large loads as an increasing reliability 
19 
consideration for the Bulk Power System.  NERC has identified reliability risks associated 
20 
with the rapid growth and changing characteristics of large loads and has issued 
21 
whitepapers, incident reviews, a Reliability Guideline, and a Level 3 Alert addressing those 
22

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risks.4  Across these efforts, NERC has emphasized the need for improved load data and 
1 
modeling, real-time telemetry and high-resolution monitoring, more accurate near-term 
2 
forecasting, information regarding ramping and operating characteristics, and better 
3 
understanding of how large loads perform during grid disturbances. 
4 
The industry’s direction is also moving beyond voluntary guidance toward formal 
5 
reliability requirements.  In 2026, NERC initiated Project 2026-02 to develop definitions, 
6 
registration criteria, and Reliability Standards for computational load integrations.5  On 
7 
July 16, 2026, the Commission directed NERC to file by December 31, 2026, one or more 
8 
new or modified Reliability Standards addressing Bulk-Power System reliability risks 
9 
associated with the integration of computational loads and associated definitions.  The 
10 
Commission also directed NERC to develop revisions to its Rules of Procedure, including 
11 
registry criteria necessary for the registration of computational load entities, and stated that 
12 
it expects NERC to submit those proposed revisions by December 31, 2026.6  Consistent 
13 
with that directive, in August 2026, NERC opened 30-day comment periods on proposed 
14 
Rules of Procedure revisions establishing registration criteria for computational load 
15 
 
4  
Essential Action to Industry – Computational Load Modeling, Studies, Instrumentation, Commissioning, 
Operations, Protection, and Control, NERC (May 4, 2026), available at 
https://www.nerc.com/globalassets/programs/bpsa/alerts/level-3-computational-load-alert.pdf; See Draft large 
Load Disturbance Performance, NERC (Dec. 10, 2026), available at https://www.nerc.com/globalassets/who-
we-are/standing-
committees/rstc/llwg/draft_llwg_white_paper_large_load_disturbance_performance_tosubmit.pdf. 
5  
Project 2026-02 Computational Load, NERC, https://www.nerc.com/standards/reliability-standards-under-
development/2026-02-computational-loads (last visited Aug. 27, 2026). 
6  
Reliability Standard(s) Pertaining to Computational Load Integration, 196 FERC ¶ 61,031 (July 16, 2026).

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entities and on proposed Reliability Standards CLO-001, CLO-002, and CLO-003 under 
1 
Project 2026-02, with comments due September 18, 2026.7 
2 
MISO’s IRR proposal is also consistent with the direction being taken by other ISOs and 
3 
RTOs.  In particular, FERC has accepted Southwest Power Pool’s (“SPP”) High Impact 
4 
Large Load (“HILL”) framework, which establishes enhanced study and ongoing 
5 
reliability requirements for qualifying large loads.8  Like MISO’s IRR proposal, SPP’s 
6 
framework includes requirements addressing load forecasting, real-time telemetry, phasor 
7 
measurement data, ride-through performance, and limitations on rapid changes in load 
8 
demand.  SPP specifically requires HILLs to provide real-time telemetry, comply with 
9 
ramp limits, and meet ride-through requirements, and requires PMU or similar high-
10 
resolution measurement equipment to support model validation, dynamic performance 
11 
monitoring, and post-event analysis. 
12 
MISO’s proposed framework addresses many of these same reliability needs, while 
13 
tailoring the applicability of individual requirements to the characteristics and risks 
14 
observed within the MISO footprint.  As described more fully below, MISO applies 
15 
foundational data, modeling, telemetry, forecasting, and audit requirements to all Large 
16 
Loads, while applying additional PMU, ride-through, and ramp requirements specifically 
17 
to Computational Loads. 
 
18 
 
7  
Proposed Computational Load ROP Revisions, NERC, https://www.nerc.com/who-we-are/rules-of-
procedure/proposed-changes-to-rules-of-procedure (last visited Aug. 27, 2026). See also, Project 2026-02 
Computational Loads, NERC, https://www.nerc.com/standards/reliability-standards-under-development/2026-
02-computational-loads (last visited Aug. 27, 2026). 
8  
The Commission approved SPP’s proposal on January 14, 2026. See Southwest Power Pool, Inc., 194 FERC ¶ 
61,031 (Jan. 14, 2026).

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Q. 
PLEASE DESCRIBE THE RELIABILITY NEEDS DRIVING THIS FILING.  
1 
A. 
MISO is experiencing increasing levels of Large Load development being evaluated 
2 
through transmission planning, Expedited Project Review (“EPR”), and other 
3 
interconnection-related processes.  Existing MISO planning and operational processes 
4 
provide a strong foundation for evaluating reliability impacts; however, the increasing size, 
5 
concentration, and changing characteristics of Large Loads create a need for greater 
6 
consistency in the information, visibility, and performance expectation necessary to 
7 
reliably plan and operate the Transmission System.    
8 
Accordingly, MISO proposes a reliability-based framework for Large Loads that 
9 
complements existing MISO planning, interconnection, and operational processes.  The 
10 
framework is intended to improve visibility into Large Load characteristics and behavior, 
11 
support accurate representation of these facilities in planning and operational analyses, and 
12 
establish scalable and technically justified requirements that reflect demonstrated 
13 
reliability risks. 
14 
Q. 
HAS MISO TAKEN ANY STEPS TO ADDRESS LARGE LOAD INTEGRATION 
15 
IN THE PAST? 
16 
A. 
Yes.  In recent years, MISO established the Expedited Resource Addition Study (“ERAS”) 
17 
as a targeted, temporary process to issue a Generator Interconnection Agreement in three 
18 
months.  MISO has also improved its Transmission Expansion Plan’s EPR process to 
19 
quickly approve transmission upgrades necessary to address urgent needs associated with 
20 
the addition of large loads.  As discussed further below, MISO’s large load initiatives are 
21 
designed to support reliability at interconnection, speed to reliable power, and reliable 
22 
system operations as large load additions continue to accelerate across the footprint.   
23

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Q. 
PLEASE EXPLAIN WHY THESE EXISTING EFFORTS ARE INSUFFICIENT.  
1 
A. 
While these initiatives provide important benefits, they do not fully address the reliability 
2 
and operational challenges associated with accelerating large load growth.  Existing 
3 
planning reforms primarily focus on generation additions and transmission development 
4 
timelines.  Likewise, broader reliability initiatives were not specifically designed to address 
5 
the unique characteristics and operational challenges presented by large load and 
6 
computational load additions.  Accordingly, additional Tariff-based solutions are necessary 
7 
to establish clear reliability expectations, improve operational visibility, and facilitate 
8 
timely integration of large loads in a manner that is both reliable and non-discriminatory. 
9 
Q. 
HOW 
IS 
MISO 
PROPOSING 
TO 
ACCELERATE 
THE 
RELIABLE 
10 
INTEGRATION OF LARGE LOADS IN THE MISO REGION? 
11 
A. 
MISO is proposing to implement a reliability-based framework to support the 
12 
interconnection and ongoing operational challenges of Large Loads within the MISO 
13 
region.  The objective is to establish scalable, technically justified, and risk-informed 
14 
expectations that improve visibility into large load behavior, support planning and 
15 
operational readiness, and preserve reliable operation of the Transmission System and Bulk 
16 
Electric System.  The proposed framework is intended to complement existing MISO 
17 
planning, interconnection, and operational processes and align, to the extent practical, with 
18 
emerging NERC guidance and industry practices. 
 
19

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IV. 
MISO’S LARGE LOAD INTERCONNECTION RELIABILITY 
1 
REQUIREMENTS PROPOSAL 
2 
Q. 
PLEASE PROVIDE AN OVERVIEW OF MISO’S PROPOSED RELIABILITY 
3 
REQUIREMENTS FOR LARGE LOADS.  
4 
A. 
MISO’s IRR proposal establishes a reliability framework surrounding Large Load 
5 
interconnection that is focused on visibility of Large Loads and management of the ongoing 
6 
operational impacts Large Loads present.  In addition to the specific reliability 
7 
requirements codified in the Tariff, the IRR proposal also provides key transition 
8 
provisions related to the application of specific requirements that seek to minimize 
9 
disruption to existing commercial arrangements for Large Loads, including those 
10 
commercial arrangements that were nearing completion at the time of this filing.  The 
11 
distinct categories of requirements are:  
12 
1. 
Visibility Requirements - Data, Modeling, Telemetry, and Forecasting 
13 
Requirements: These requirements establish expectations for facility information, 
14 
electrical models, real-time telemetry, monitoring, short-term and forecasting, and 
15 
other operational visibility requirements necessary to support planning studies, 
16 
operational assessments, and accurate representation of Large Load behavior and 
17 
system impacts.   
18 
2  
Phasor Measurement Unit (PMU) Requirements: In addition to the broader 
19 
visibility requirements above, the PMU requirements establish enhanced 
20 
monitoring expectations for Computation Loads through high-resolution, time-
21 
synchronized measurements.  PMU data provides MISO with greater visibility into 
22 
facility behavior during system disturbances and rapid operating changes, 
23

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supporting model validation, performance verification, disturbance analysis, and 
1 
identification of potential dynamic interactions with the Transmission System. 
2 
3. 
Ramp Requirements: These requirements 
address the rate at which 
3 
Computational Loads may increase or decrease consumption during stable-state 
4 
transitions.  Managing rapid changes in demand helps reduce real-time supply-
5 
demand imbalances, sudden change in transmission power flows, and associated 
6 
operational impacts, while supporting more reliable system operation.  Ramp-rate 
7 
limits do not apply during fault or disturbance conditions when necessary for 
8 
equipment protection or to satisfy ride-through performance requirements. 
9 
4. 
Ride-Through 
Requirements: These 
requirements 
establish 
minimum 
10 
disturbance performance expectations during voltage and frequency disturbances 
11 
to reduce the risk of unnecessary disconnection or customer-initiated rapid 
12 
reductions in Demand during credible system events.   
13 
MISO recognizes that the Commission also included a study process that evaluates and 
14 
manages the unique reliability and operational challenges Large Loads create when 
15 
receiving Transmission Service  in its discussion of ongoing operational requirements in 
16 
the Show Cause Order.  The IRR proposal addresses requirements applicable to Large Load 
17 
facilities themselves.  MISO evaluates and manages unique reliability and operational 
18 
challenges through studies, including a stability assessment, as part of its MTEP and EPR 
19 
processes.  MISO intends to address enhancements to stability assessment study processes 
20 
in a future Federal Power Act Section 205 filing.  Those future study processes will focus 
21 
on identifying system-level reliability impacts associated with load additions and 
22

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determining whether transmission or other system-level solutions are necessary, as part of 
1 
a broader set of load addition and transmission service study requirements. 
2 
A. 
DEFINITIONS 
3 
Q. 
PLEASE IDENTIFY THE NEW DEFINITIONS MISO PROPOSES TO 
4 
IMPLEMENT THROUGH THIS FILING.  
5 
A. 
The following definitions are provided to support consistent interpretation of the reliability 
6 
framework described in this filing:   
7 
• 
Computational Load: Large Load comprised of 25 MW or more of Demand from 
8 
information technology equipment, such as servers, storage, and networking 
9 
hardware. 
10 
• 
Large Load: Load with Demand of 50 MW or more associated with any facility 
11 
or aggregation of facilities located at a single substation behind one or more Point(s) 
12 
of Withdrawal from the Transmission System that is owned, operated, or controlled 
13 
by: (a) a single entity or (b) a group of entities that will coordinate with respect to 
14 
the profile of the Load.  Large Load does not include Load used exclusively for 
15 
charging an Electric Storage Resource. 
16 
• 
Large Load Equipment: Any of the facilities, devices, or equipment that 
17 
constitutes a part of a Large Load, or are used to interconnect the Large Loads to 
18 
the Transmission System.   
19 
• 
Point(s) of Withdrawal: The point where a non-transmission facility used to 
20 
withdraw Energy from the Transmission System to serve Load connects to the 
21 
Transmission System.   
 
22

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Q. 
HOW DID MISO ARRIVE AT THE PROPOSED DEFINITION OF LARGE 
1 
LOAD? 
2 
A. 
MISO developed the proposed Large Load definition through review of emerging industry 
3 
practices, consideration of the reliability needs within the MISO region, and stakeholder 
4 
feedback.  MISO reviewed approaches being developed or used by NERC and other RTOs, 
5 
including PJM, SPP, and ERCOT.  While those approaches vary, they generally recognize 
6 
that sufficiently large, concentrated load additions warrant additional visibility and 
7 
reliability consideration. 
8 
Based on that review, MISO selected a 50 MW threshold as a reasonable and 
9 
administratively clear starting point, consistent with industry precedent and sufficiently 
10 
significant to warrant application of MISO’s Large Load requirements.  The definition is 
11 
based on gross load rather than net load so that MISO has visibility into the full electrical 
12 
demand and characteristics of the facility. 
13 
Finally, MISO also defined Large Load at the facility or site level rather than solely at an 
14 
individual point of interconnection.  This allows loads under common ownership or 
15 
coordinated operational control at a single site to be considered together, including where 
16 
the site is served through multiple points of interconnection. 
17 
Q. 
WHY IS 50 MW A REASONABLE THRESHOLD FOR LARGE LOAD IN THE 
18 
MISO REGION? 
19 
A. 
MISO determined that 50 MW is a reasonable threshold based on industry precedent, 
20 
including from PJM and SPP, and the need for a clear and administratively workable means 
21 
of identifying significant, concentrated loads that warrant additional reliability visibility.  
22

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A load of this magnitude is sufficiently large that its characteristics and behavior can be 
1 
relevant to transmission planning and system operations.  
2 
Importantly, the 50 MW threshold serves as an applicability threshold; it does not mean 
3 
that every Large Load at or above 50 MW presents the same reliability risk.  MISO’s 
4 
proposed requirements recognize differences in facility characteristics by establishing 
5 
baseline visibility requirements for Large Loads while applying certain additional 
6 
performance requirements to Computational Loads where their operating characteristics 
7 
warrant additional consideration.  This approach provides a clear threshold while allowing 
8 
the requirements to remain proportional to the reliability needs being addressed. 
9 
Q. 
WHY DOES MISO DEFINE “COMPUTATIONAL LOAD”? 
10 
A. 
MISO defines Computational Load to distinguish a subset of Large Loads that may exhibit 
11 
operational characteristics different from more traditional loads, including rapid changes 
12 
in demand, highly coordinated control behavior, and power-electronic responses during 
13 
system disturbances.  This distinction allows MISO to apply certain incremental 
14 
requirements—such as ramp, PMU, and ride-through requirements—only where those 
15 
characteristics warrant additional reliability consideration.  Defining Computational Load 
16 
therefore supports a more targeted and risk-informed approach, rather than applying the 
17 
same requirements to all Large Loads regardless of facility type or operating behavior. 
18 
Q. 
WHY IS A DEFINITION OF COMPUTATIONAL LOAD NECESSARY FOR THIS 
19 
FILING? 
20 
A. 
A definition of Computational Load is necessary because certain proposed requirements 
21 
are intended to apply only to Large Loads with operating characteristics that warrant 
22 
additional reliability consideration.  Computational Loads may exhibit rapid and 
23

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coordinated changes in demand, significant power-electronic behavior, and distinct 
1 
responses to Transmission System disturbances.  Defining this subset allows MISO to 
2 
apply incremental requirements—such as ramp, PMU, and ride-through requirements—in 
3 
a targeted manner rather than applying them to all Large Loads.  As noted above, this 
4 
supports a scalable and risk-informed approach in which requirements are aligned with the 
5 
characteristics and reliability risks they are intended to address. 
6 
Q. 
HOW DOES MISO’S PROPOSED DEFINITION OF COMPUTATIONAL LOAD 
7 
ALIGN WITH NERC’S PROPOSED DEFINITION? 
8 
A. 
MISO’s proposed definition of Computational Load is closely aligned with NERC’s 
9 
developing definition of computational load.  Both approaches identify computational load 
10 
based on electric demand associated with information technology equipment, such as 
11 
servers, storage, and networking hardware.  This common approach focuses on the 
12 
underlying electrical equipment and characteristics of the load rather than on a particular 
13 
industry or customer type. 
14 
MISO has tailored the applicability of its requirements to the needs of the MISO 
15 
Transmission System, while NERC is separately developing registration criteria and 
16 
Reliability Standards to determine which Computational Load Owners and Operators will 
17 
be subject to mandatory NERC requirements.  Accordingly, differences in applicable 
18 
thresholds or scope do not represent a fundamental difference in the definition of 
19 
Computational Load; rather, they reflect the different purposes and responsibilities of 
20 
MISO and NERC. 
21 
MISO will continue to monitor NERC’s ongoing standards development and seek 
22 
alignment as those requirements are finalized. 
23

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B. 
SCOPE AND APPLICABILITY 
1 
Q. 
PLEASE DESCRIBE THE SCOPE OF THIS FILING. 
2 
A. 
This filing proposes reliability requirements and a reliability-based framework applicable 
3 
to Transmission Customers taking Transmission Service on behalf of Large Load 
4 
interconnected to the MISO Transmission System.  These requirements are needed to allow 
5 
MISO to plan for and ensure the reliable operations of Large Loads that may materially 
6 
affect the Transmission System or Bulk Electric System due to their size, operating 
7 
behavior, electrical characteristics, or dynamic performance.  The filing includes the 
8 
following principal requirements: 
9 
• 
Definitions and Applicability: Establishes which facilities qualify as Large Loads and 
10 
Computational Loads and identifies when the requirements apply. 
11 
• 
Data Requirements: Establishes the facility and operational information MISO needs 
12 
to understand Large Load characteristics and expected behavior. 
13 
• 
Model Requirements: Requires appropriate electrical models so Large Loads can be 
14 
accurately represented in MISO planning and operational analyses. 
15 
• 
Telemetry Requirements: Provides real-time visibility into Large Load demand and 
16 
operating conditions to support reliable system operations. 
17 
• 
Forecasting Requirements: Establishes short-term and other forecast information 
18 
needed to anticipate Large Load demand and operating changes. 
19 
• 
PMU Requirements for Computational Loads: Provides high-resolution, time-
20 
synchronized measurements to support disturbance analysis, model validation, and 
21 
performance verification. 
22

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• 
Ramp Requirements for Computational Loads: Establishes limits on rapid increases 
1 
or decreases in demand during stable-state transitions to help manage operational 
2 
impacts. 
3 
• 
Ride-Through Requirements for Computational Loads: Establishes minimum 
4 
voltage and frequency disturbance-performance expectations to reduce unnecessary 
5 
disconnection and sudden load loss. 
6 
• 
Implementation and Transitional Provisions: Establishes compliance timing, 
7 
responsibilities, and transition mechanisms for existing and developing facilities. 
8 
Taken together, these provisions address reliability needs at the facility and information 
9 
levels by establishing clearer expectations for how Large Loads are represented, monitored, 
10 
forecasted, and expected to perform.  MISO intends to address additional enhancements to 
11 
its study processes in a subsequent filing, including analyses used to identify broader 
12 
system-level reliability impacts and, where necessary, appropriate system-level solutions. 
13 
Q. 
DOES THE IRR FILING PROPOSE NEW TRANSMISSION PRODUCTS? 
14 
A. 
No.  This IRR proposal focuses specifically on reliability requirements applicable to Large 
15 
Loads in the MISO region.  MISO will address new transmission products in a separate 
16 
Federal Power Act Section 205 filing. 
17 
Q. 
TO WHOM WILL THE PROPOSED REQUIREMENTS APPLY?   
18 
A. 
The proposed requirements in this filing apply to the Large Load as set forth in the Tariff 
19 
and the Business Practices Manual for Large Load, and as discussed further below.   
20 
Subject to the transition provisions discussed below, all Large Loads will be subject to the 
21 
applicable visibility requirements including: Basic Facility Data, Modeling, Telemetry, 
22 
Forecast Data, and Audit requirements.  In addition, the Computational Load component 
23

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of a Large Load, as defined in the Tariff, is additionally subject to the Phasor Measurement 
1 
Unit, Ride-Through, and Ramp requirements.   
2 
As previously discussed, MISO recognizes that not all Large Loads present the same 
3 
reliability risks.  Accordingly, MISO has limited the application of PMU, Ramp and Ride-
4 
Through requirements to the Computational Load component of a Large Load, which 
5 
reflects the increased operational risk Computational Loads place on the Transmission 
6 
System.  As previously stated, the IRR proposal is intended to provide a scalable and risk-
7 
informed framework that may be applied in a manner proportional to demonstrated 
8 
reliability need, system conditions, and facility characteristics.   
9 
Q. 
WHICH ENTITIES ARE RESPONSIBLE FOR COMPLIANCE WITH THE 
10 
REQUIREMENTS PROPOSED IN THIS FILING? 
11 
A. 
The IRR proposal establishes that the Transmission Customer taking Transmission Service 
12 
on behalf of a Large Load is responsible for ensuring compliance with each of the 
13 
applicable requirements set forth in the new Tariff section 37A.  The term “Transmission 
14 
Customer” is currently defined in the MISO Tariff as: “Any Eligible Customer (or its 
15 
Designated Agent) that (i) executes a Service Agreement, or (ii) requests in writing that the 
16 
Transmission Provider file with the Commission, a proposed unexecuted Service 
17 
Agreement to receive Transmission Service under Module B of this Tariff.” This term is 
18 
used in the Module A, Common Tariff Provisions, to include customers receiving 
19 
Transmission Service under Module B of this Tariff, including any customer receiving 
20 
HVDC Service.    
21

Tab C 
Page 18 
 
Q. 
WHY IS IT JUST AND REASONABLE TO APPLY THE INTERCONNECTION 
1 
RELIABILITY REQUIREMENTS TO A TRANSMISSION CUSTOMER TAKING 
2 
TRANSMISSION SERVICE ON BEHALF OF A LARGE LOAD? 
3 
A. 
Requiring the Transmission Customer to prove compliance with the requirements 
4 
established in the IRR proposal is consistent with the Show Cause Order’s discussion of 
5 
imposing requirements on an “Eligible Customer” and recognizes that the ultimate owner 
6 
of a Large Load may not participate directly in MISO’s markets or otherwise have 
7 
contractual privity to MISO.  All Large Loads interconnected to the Transmission System, 
8 
however, will be required to procure Transmission Service through a Transmission 
9 
Customer pursuant to the Tariff.  As a result, the Transmission Customer will be required 
10 
to enter into a transmission service agreement, which incorporates by reference, the terms 
11 
of the Tariff, including the requirements proposed herein.  As such, applying the 
12 
requirements established in the IRR proposal to a Transmission Customer taking 
13 
Transmission Service on behalf of a Large Load establishes a legally enforceable 
14 
framework though which all reliability requirements imposed on a Large Load may be 
15 
enforced.    
16 
 
C. 
TRANSITION PROVISIONS 
17 
Q. 
HOW DOES THE IRR FILING RECOGNIZE EXISTING COMMERCIAL 
18 
ARRANGEMENTS, 
AND 
COMMERCIAL 
ARRANGEMENTS 
NEAR 
19 
COMPLETION, AS CONTEMPLATED BY THE SHOW CAUSE ORDER? 
20 
A. 
The IRR Filing includes transition provisions that are intended to provide certainty to 
21 
existing commercial arrangements and commercial arrangements that were near 
22 
completion at the time of this filing.  The requirements, which I discuss further below, 
23

Tab C 
Page 19 
 
consider the Service Commencement Date of the Transmission Service to serve a Large 
1 
Load, whether transmission projects or upgrades associated with the Large Load have been 
2 
approved by the MISO Board in MTEP 2026, or a prior MTEP, and when transmission 
3 
projects or upgrades associated with the Large Load has been submitted to the MISO EPR 
4 
process.  The “Service Commencement Date” is the date MISO or an Independent 
5 
Transmission Company (“ITC”) begins to provide service pursuant to the terms of an 
6 
executed Service Agreement, or the date MISO or an ITC begins to provide Transmission 
7 
Service under the MISO Tariff. 
8 
Q. 
WHAT IS THE MTEP / EPR CONDITION? 
9 
A. 
For purposes of the transition provisions, Load will satisfy the “MTEP/EPR Condition” if 
10 
it is associated with a transmission project that either: (a) has been approved by the MISO 
11 
Board in MTEP 2026, or a prior MTEP; or, (b) has been submitted to MISO for EPR on or 
12 
prior to June 18, 2026, in accordance with Attachment FF of the Tariff. 
13 
Q. 
WHAT IS THE SIGNIFICANCE OF LINKING APPROVAL OF TRANSMISSION 
14 
PROJECTS FOR LARGE LOAD INTERCONNECTIONS TO MTEP 2026, OR A 
15 
PRIOR MTEP? 
16 
A. 
Under current processes, MISO does not have a Load interconnection process.  As such, 
17 
specific Load additions are not submitted to MISO for individual study in MISO’s planning 
18 
processes; however, the need for transmission upgrades or related projects to support a new 
19 
Load can be identified through MISO’s MTEP or EPR processes.  Linking the transition 
20 
provisions discussed below to approvals received in MTEP 2026, or prior, recognizes the 
21 
existing commercial arrangements and more immediate, non-speculative, nature of the 
22 
Load additions and associated Transmission System upgrades. 
23

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Page 20 
 
Q. 
WHY DO THE PROPOSED TRANSITION PROVISIONS ALLOW FOR 
1 
SUBMISSIONS OF LOAD OR TRANSMISSION UPGRADES THROUGH EPR 
2 
ON OR BEFORE JUNE 18, 2026? 
3 
A. 
The June 18, 2026, date coincides with the Commission’s issuance of the Show Cause 
4 
Order and establishes a date on which all parties were on notice that significant changes to 
5 
MISO’s Tariff, and requirements for Large Loads in particular, should be expected in the 
6 
near future.  In addition, application of this date in the terms of the transition provision 
7 
recognizes projects that had been previously submitted to MISO for study in the EPR 
8 
process on, or prior to, the date of the Show Cause Order without opening a window during 
9 
which parties could submit speculative EPR or MTEP projects. 
10 
Q. 
PLEASE DESCRIBE THE TRANSITION PROVISIONS PROPOSED IN THIS 
11 
FILING. 
12 
A. 
MISO proposes to implement the following transition provisions:  
13 
First, MISO proposes to fully exempt, or “grandfather,” any Large Load that has a Service 
14 
Commencement Date on or prior to December 4, 2026, from all requirements of the 
15 
proposed Section 37A, with respect to the portion of the Large Load that has procured 
16 
Transmission Service as of the Service Commencement Date.  Any modification or series 
17 
of modifications to a Load that meets the MTEP/EPR Condition, which results in a 
18 
cumulative increase of 25 MW or more in Transmission Service for such Load and with a 
19 
Service Commencement Date after December 4, 2026, may subject the additional Load to 
20 
certain requirements, depending on MTEP / EPR approval date and the Service 
21 
Commencement Date of the Transmission Service for the additional Load. 
22

Tab C 
Page 21 
 
Second, MISO proposes that a Large Load, or a portion of a Large Load, that does not have 
1 
a Service Commencement Date prior to December 4, 2026, but that meets the MTEP/EPR 
2 
Condition shall be subject to the visibility requirements set forth in Sections 37A.1 through 
3 
37A.5 and Section 37A.8, and shall be exempt from the ramp and ride-through 
4 
requirements set forth in Sections 37A.6 through 37A.7.   
5 
Third, MISO proposes that a Large Load, or a portion of Large Load, that does not have a 
6 
Service Commencement Date prior to December 4, 2026, and that has not met the 
7 
MTEP/EPR Condition, but has submitted Load associated with a transmission project to 
8 
the Transmission Provider for EPR on or after June 19, 2026, but on or before October 31, 
9 
2026, shall be subject to all requirements set forth in this Section 37A, provided that 
10 
Transmission Provider may waive the ride-through requirements set forth in Section 37A.6 
11 
based upon a determination that: a) exemption from such requirements would not have an 
12 
adverse reliability impact; and, b) compliance with such requirements would result in 
13 
significant costs. 
14 
Q. 
WHY DOES MISO PROVIDE A POTENTIAL EXEMPTION FROM RIDE-
15 
THROUGH REQUIREMENTS FOR PROJECTS SUBMITTED BETWEEN JUNE 
16 
19, 2026, AND OCTOBER 31, 2026? 
17 
A. 
MISO provides a potential exemption from the ride-through requirements for certain 
18 
projects submitted between June 19, 2026, and October 31, 2026, to provide a reasonable 
19 
transition for projects that were nearing completion at the time of this filing. 
20 
The June 19, 2026, date immediately follows the Commission’s June 18, 2026 Show Cause 
21 
Order, which recognized that Large Loads were at different stages of development and 
22 
directed that prospective reforms minimize disruption to existing commercial 
23

Tab C 
Page 22 
 
arrangements and provide reasonable time for arrangements nearing completion.  The 
1 
October 31, 2026, cutoff date establishes a finite transition period, after which prospective 
2 
projects are expected to account for MISO’s ride-through requirements as part of their 
3 
development and design. 
4 
Importantly, the provision does not provide an automatic exemption from ride-through 
5 
requirements.  Rather, it provides a pathway for eligible projects to demonstrate, through 
6 
the applicable reliability assessment, that operation without full ride-through capability 
7 
would not result in an adverse reliability impact.  Where such a determination cannot be 
8 
made, appropriate ride-through capability or mitigation would still be required. 
9 
This approach balances the need to recognize projects that may have made material design, 
10 
procurement, or commercial commitments before the new requirements were fully 
11 
established with MISO’s responsibility to maintain reliable operation of the Transmission 
12 
System. 
13 
Q. 
ARE LARGE LOADS THAT DO NOT MEET THE MTEP/EPR CONDITION 
14 
EXEMPT? 
15 
A. 
No.  A Large Load, or a portion of a Large Load, that does not meet the MTEP/EPR 
16 
Condition shall be subject to all applicable requirements set forth in proposed Section 37A. 
17 
Q. 
HOW DID MISO DEVELOP THESE TRANSITION PROVISIONS? 
18 
A. 
MISO developed the transition provisions through a deliberate process that considered both 
19 
identified reliability needs and practical implementation considerations for Large Loads at 
20 
different stages of development.  MISO evaluated the reliability objectives of the proposed 
21 
requirements, presented and discussed potential transition approaches through the MISO 
22 
stakeholder process, and considered stakeholder feedback regarding project status, 
23

Tab C 
Page 23 
 
implementation readiness, and the potential economic and other impacts of applying new 
1 
requirements to existing and late-stage projects.  Based on that process, MISO refined the 
2 
transition framework to provide appropriate treatment for existing and previously approved 
3 
projects while applying the new requirements prospectively and preserving MISO’s ability 
4 
to address demonstrated material adverse impacts to Transmission System reliability. 
5 
 
D. 
LARGE LOAD RELIABILITY REQUIREMENTS 
6 
Q. 
PLEASE SUMMARIZE THE PROPOSED RELIABILITY REQUIREMENTS. 
7 
A. 
The proposed framework consists of the following categories of reliability requirements 
8 
intended to address planning, operational, disturbance performance, and system stability 
9 
considerations associated with Large Loads:   
10 
Requirement Category 
General Applicability 
Data, Modeling, 
Telemetry, and 
Forecasting, 
Requirements 
Generally applicable to all Large Loads to provide MISO 
with the information, models, operational visibility, and 
forecasts necessary to support transmission planning and 
reliable system operations. 
Phasor Measurement 
Unit (PMU) 
Requirements 
Applicable to Computational Loads to provide high-
resolution, time-synchronized measurement capability 
supporting monitoring, model validation, post-event 
analysis, and reliability assessment. 
Ramp Requirements 
Applicable to Computational Loads. Ramp limits address 
up- and down-ramp behavior during stable-state transitions 
and are measured in aggregate across the applicable Point(s) 
of Withdrawal. 
Ride-Through 
Requirements 
Applicable to Computational Loads. Computational Loads 
must remain connected and continue operation during 
voltage and frequency disturbances within the performance 
criteria established by MISO. 
The applicability of individual requirements, implementation details, exemptions, and 
11 
compliance approaches are discussed below.   
12

Tab C 
Page 24 
 
1. 
Basic Facility Data and Modeling 
1 
Q. 
PLEASE DESCRIBE THE RELIABILITY OBJECTIVE FOR THE PROPOSED 
2 
DATA AND MODELING REQUIREMENTS.  
3 
A. 
The objective of the proposed data and modeling requirements is to ensure sufficient 
4 
visibility into the characteristics, operating behavior, and electrical performance of Large 
5 
Loads necessary to support reliable planning, interconnection, commissioning, operations, 
6 
and post-event analysis.  As emerging Large Loads increasingly exhibit dynamic operating 
7 
characteristics and concentrated demand, and utilize sophisticated power-electronic 
8 
equipment and controls, additional facility information, telemetry, and modeling detail 
9 
may be necessary to evaluate reliability impacts under both normal and contingency 
10 
conditions.  Data and modeling requirements are intended to support reliable operation of 
11 
the Transmission System by improving the accuracy of planning assumptions, 
12 
strengthening operational awareness, supporting disturbance analysis and model 
13 
validation, and enabling more consistent evaluation of system performance associated with 
14 
Large Load integration.  These requirements provide a framework for obtaining facility 
15 
information, electrical models, telemetry, monitoring data, and operational visibility 
16 
necessary to support planning studies, operational assessments, commissioning activities, 
17 
and reliability evaluations.   
18 
Q. 
PLEASE DESCRIBE THE PROPOSED DATA REQUIREMENTS.  
19 
A. 
The proposed data requirements are intended to ensure that MISO has sufficient 
20 
information to understand the configuration and electrical characteristics of each Large 
21 
Load.  Transmission Customers must provide basic facility information, one-line diagrams, 
22

Tab C 
Page 25 
 
and information describing the electrical characteristics of the Large Load and associated 
1 
Large Load Equipment. 
2 
The requirements also establish an ongoing obligation to provide timely updates when the 
3 
characteristics of the Large Load change.  Those updates may include changes in Load 
4 
MW amounts, firm and non-firm demand, dispatchable Load, power factor, metering, 
5 
telemetry, breaker configuration, staged load additions, and annual energy.  The 
6 
Transmission Customer must also coordinate with the applicable Transmission Owner in 
7 
accordance with MISO’s load interconnection guidance and applicable NERC standards. 
8 
Together, these requirements help ensure that MISO has current and accurate facility 
9 
information to support planning and reliable operation of the Transmission System. 
10 
Q. 
PLEASE DESCRIBE THE PROPOSED MODELING REQUIREMENTS.  
11 
A. 
The proposed modeling requirements are intended to ensure that MISO has accurate and 
12 
sufficiently detailed representations of Large Loads for transmission planning and 
13 
reliability analysis.  Transmission Customers must provide verified electrical models and 
14 
detailed load profiles with enough information for MISO to evaluate system performance 
15 
under normal and contingency conditions. 
16 
Before service begins, the Transmission Customer must submit final verified models 
17 
reflecting the facility’s as-built configuration and actual operating characteristics.  The 
18 
models must also be maintained and updated over time, and material modifications must 
19 
be submitted to MISO for study and approval before implementation. 
20 
Together, these requirements help ensure that MISO’s planning and reliability studies are 
21 
based on current and representative Large Load models. 
22

Tab C 
Page 26 
 
2. 
Load Forecasting Requirements 
1 
Q. 
PLEASE DESCRIBE THE RELIABILITY OBJECTIVE FOR THE PROPOSED 
2 
LOAD FORECASTING REQUIREMENTS.  
3 
A. 
Large Loads can change system conditions rapidly, and unlike traditional demand, their 
4 
behavior cannot be forecasted accurately using historical load patterns, even when modeled 
5 
with weather and calendar data in MISO’s short-term forecasting system.   
6 
Q. 
PLEASE 
DESCRIBE 
THE 
PROPOSED 
LOAD 
FORECASTING 
7 
REQUIREMENTS.  
8 
A. 
The proposed short and medium-term forecasting requirements are intended to provide 
9 
MISO with timely and accurate visibility of expected Large Load demand.  Transmission 
10 
Customers must provide Day-Ahead and Real-Time Load Forecasts directly to MISO to 
11 
support the Reliability Assessment Commitment, Security Constrained Economic 
12 
Dispatch, and other reliability studies.  The forecasts must be updated to reflect the most 
13 
current information regarding expected demand. 
14 
MISO also provided an extended implementation period for these requirements.  
15 
Compliance is required by the latter of the Large Load’s Service Commencement Date or 
16 
September 1, 2027, providing Transmission Customers with additional time to establish 
17 
the forecasting capabilities, data processes, and related procedures necessary to provide 
18 
reliable day-ahead and real-time Load Forecasts to MISO. 
19 
3. 
Telemetry and PMU Requirements 
20 
Q. 
PLEASE DESCRIBE THE RELIABILITY OBJECTIVE FOR THE PROPOSED 
21 
TELEMETRY AND PHASOR MEASUREMENT UNIT REQUIREMENTS.  
22

Tab C 
Page 27 
 
A. 
The objective of the proposed Telemetry and PMU requirements is to provide MISO with 
1 
the real-time visibility and high-resolution measurement capabilities necessary to reliably 
2 
integrate Large Loads.  Continuous, high-resolution visibility into the behavior of Large 
3 
Loads is needed because the size, rapid changes in consumption, and dynamic behavior of 
4 
Large Loads can create or exacerbate reliability risks. 
5 
Telemetry provides the foundational real-time visibility into Large Load operation.  The 
6 
proposed Telemetry requirements apply to all applicable Large Loads and provide MISO 
7 
and Transmission Owners with real-time information regarding Large Load electrical 
8 
conditions and operating behavior through SCADA/ICCP data.  This information supports 
9 
real-time monitoring, balancing of supply and demand, contingency analysis, and 
10 
identification of abnormal operating conditions. 
11 
For Computational Loads, the proposed PMU requirements provide additional high-
12 
resolution, time-synchronized measurements needed to monitor and verify dynamic 
13 
performance that may not be adequately captured by conventional telemetry.  
14 
Computational Loads can exhibit rapid changes in real and reactive power and can respond 
15 
rapidly to voltage and frequency disturbances, including through partial reductions in 
16 
consumption or disconnection.  PMUs, or comparable high-resolution measurements, 
17 
enable MISO to: monitor and verify disturbance performance, including ride-through and 
18 
active-power recovery behavior; characterize rapid changes in consumption and oscillatory 
19 
behavior; validate and refine models used in reliability studies; and, support post-event 
20 
analysis. 
21 
The PMU requirements therefore complement, rather than duplicate, conventional 
22 
telemetry by providing the measurement resolution necessary to observe and evaluate the 
23

Tab C 
Page 28 
 
fast dynamic behavior of Computational Loads.  Figure 1 illustrates the difference in 
1 
measurement resolution between conventional SCADA telemetry and PMU data.   
2 
 
 
3 
 
4 
Figure 1: Differences between SCADA and PMU 
5 
Q. 
PLEASE DESCRIBE THE PROPOSED TELEMETRY REQUIREMENTS.  
6 
A. 
The telemetry requirements are intended to provide MISO with reliable, real-time visibility 
7 
into Large Load operations.  The Transmission Customer must provide real-time telemetry 
8 
through an approved communication path using Inter-Control Center Communications 
9 
Protocol (“ICCP”), maintain commercially reasonable levels of data availability and 
10 
accuracy, and promptly correct data or modeling issues.  This also requires individual 
11 
metering for Large Loads and, where applicable, generation located behind the same Point 
12 
of Withdrawal so that MISO can accurately distinguish and assess the relevant load and 
13 
related generation behavior. 
14 
MISO also provides an extended implementation period for these requirements.  
15 
Compliance is required by the latter of the Large Load’s Service Commencement Date or 
16 
September 1, 2027, providing Transmission Customers and Transmission Owners 
17

Tab C 
Page 29 
 
additional time to establish the necessary metering, ICCP communications, data mappings, 
1 
and related processes needed to provide reliable and accurate telemetry to MISO.  
2 
Q. 
DOES THE PROPOSAL IDENTIFY SPECIFIC PHASOR MEASUREMENT 
3 
REQUIREMENTS FOR COMPUTATIONAL LOADS? 
4 
A. 
Yes.  The PMU requirements apply specifically to Computational Loads and are intended 
5 
to provide MISO with high-resolution, time-synchronized visibility into their electrical 
6 
behavior to support disturbance analysis, model validation, performance verification, and 
7 
broader reliability assessments.  Prior to the applicable Service Commencement Date, 
8 
phasor measurement recording and communications equipment must be installed on the 
9 
Transmission Owner’s side of the Point of Withdrawal and become part of the 
10 
Transmission Owner’s interconnection facilities. 
11 
The proposal also provides flexibility regarding the equipment used to satisfy the 
12 
requirement.  Existing or newly installed equipment, such as protective relays or digital 
13 
fault recorders, may be used in place of a stand-alone PMU where they provide equivalent 
14 
measurement quality, resolution, and time synchronization. 
15 
Q. 
DOES 
THE 
PROPOSAL 
PROVIDE 
GUIDANCE 
REGARDING 
THE 
16 
INSTALLATION OF PHASOR MEASUREMENT CAPABILITY FOR A LARGE 
17 
LOAD? 
18 
A. 
Yes.  For Computational Loads subject to the phasor measurement requirements, the 
19 
proposal provides guidance regarding both the location of the measurement capability and 
20 
the entity responsible for its installation. 
21 
The phasor measurement capability is generally required on the Transmission Owner’s side 
22 
of the Point of Withdrawal so that MISO can obtain high-resolution, time-synchronized 
23

Tab C 
Page 30 
 
measurements of the facility’s interaction with the Transmission System.  The proposal 
1 
also provides flexibility in how this capability is provided.  Existing or newly installed 
2 
equipment, including protective relays or other recording devices, may be used where they 
3 
provide measurement capability equivalent to a dedicated PMU. 
4 
The responsibility for installing and maintaining this capability is assigned to the 
5 
Transmission Owner, at the expense of the Transmission Customer.  This differs from 
6 
requirements for data, models, forecasts, and other facility information, which rely on 
7 
information within the knowledge or control of the Transmission Customer.  The phasor 
8 
measurement requirement involves physical monitoring capability located on 
9 
transmission-side facilities that are owned and maintained by the Transmission Owner.  
10 
Assigning this responsibility to the Transmission Owner therefore aligns the obligation 
11 
with the entity that controls the facilities necessary to install, maintain, and integrate the 
12 
measurement equipment with the applicable communications and monitoring 
13 
infrastructure. 
14 
4. 
Ramp Requirements 
15 
Q. 
PLEASE DESCRIBE THE RELIABILITY OBJECTIVE FOR THE PROPOSED 
16 
RAMP REQUIREMENTS.  
17 
A. 
The reliability objective of ramp requirements is to manage the operational impacts that 
18 
can result when a Computational Load increases or decreases its demand rapidly during 
19 
stable-state transitions. 
20 
Computational Loads may have the capability to change significant amounts of demand 
21 
over a relatively short period of time and, in some cases, to do so in a highly coordinated 
22 
manner.  Rapid changes of this magnitude can create short-term supply-demand 
23

Tab C 
Page 31 
 
imbalances, cause sudden changes in transmission power flows, and increase the 
1 
operational actions needed to maintain reliable system conditions. 
2 
Establishing reasonable limits on the rate at which a Computational Load may increase or 
3 
decrease its demand provides an established operating envelope within which the 
4 
Transmission Provider can maintain generation-load balance and ensure the coincident risk 
5 
of multiple Computational Loads does not result in broader reliability impacts.  
6 
 
7 
Figure 2: Ramp Rate Risk Profile 
8 
Q. 
PLEASE DESCRIBE THE PROPOSED RAMP REQUIREMENTS.  
9 
A. 
The proposed ramp requirements are intended to ensure that changes in Computational 
10 
Load demand occur at a rate that can be reliably accommodated by the Transmission 
11 
System.  The requirements establish up- and down-ramp limits during stable-state 
12 
transitions, measured in aggregate across the applicable Points of Withdrawal, while 
13 
allowing eligible generation or other resources to provide ramp smoothing.   
14

Tab C 
Page 32 
 
5. 
Ride-Through Requirements 
1 
Q. 
PLEASE DESCRIBE THE RELIABILITY OBJECTIVE FOR THE PROPOSED 
2 
RIDE-THROUGH REQUIREMENTS.  
3 
A. 
The proposed ride-through requirements reduce the risk of unnecessary Computational 
4 
Load disconnection or rapid changes in Demand during voltage and frequency disturbances 
5 
and to support predictable disturbance performance during credible Transmission System 
6 
events.  Computational Loads may include fast-acting power-electronic equipment and 
7 
controls with dynamic operating behavior, and their response to Transmission System 
8 
disturbances may materially affect system performance, operational reliability, and post-
9 
contingency recovery.  Establishing minimum ride-through performance expectations is 
10 
therefore intended to reduce the risk of significant or simultaneous changes in Demand and 
11 
support overall system stability and post-disturbance recovery. 
12 
Consistent with emerging industry practices and NERC guidance, the proposed ride-
13 
through requirements address three fundamental aspects of Computational Load 
14 
performance: continued connection and stable operation during disturbances within the 
15 
applicable ride-through criteria, appropriate active power response while riding through 
16 
voltage and frequency disturbances, and active power recovery following disturbance 
17 
clearance.  The technical basis and detailed performance criteria supporting these 
18 
requirements are described in MISO’s published Large Load Technical Compendium.9   
19 
 
9  
See MISO’s Interconnection Reliability Requirements for Large Load Technical Compendium, August 2026; 
available at: 
https://cdn.misoenergy.org/20260827%20LLWG%20Item%2002c%20MISO%20Large%20Load%20Interconn
ection%20Reliability%20Requirements_Technical%20Compendium777982.pdf.

Tab C 
Page 33 
 
Q. 
PLEASE DESCRIBE THE GENERAL PRINCIPLES UNDERLYING THE 
1 
PROPOSED RIDE-THROUGH REQUIREMENTS.  
2 
A. 
The proposed ride-through requirements apply at the applicable Point(s) of Withdrawal 
3 
and establish the voltage and frequency conditions under which Computational Loads are 
4 
required to remain connected to the Transmission System and continue operation.  When 
5 
system conditions remain within the applicable ride-through criteria, Computational Loads 
6 
are required to remain connected without unnecessary disconnection. 
7 
The requirements further establish expectations for Computational Load performance 
8 
while riding through disturbances and following disturbance recovery.  During voltage 
9 
disturbances, the appropriate active power response may vary depending on the severity of 
10 
the disturbance, with greater flexibility in active power response during more severe 
11 
voltage depressions to support continued connection and stable operation.  Following 
12 
disturbance clearance, active power is expected to recover in a controlled and predictable 
13 
manner consistent with Transmission System reliability needs.  During frequency 
14 
disturbances, Computational Loads are expected to maintain predictable active power 
15 
consumption while riding through the disturbance in accordance with the applicable 
16 
performance requirements. 
17 
The proposed Tariff establishes the core ride-through obligation, while the technical basis 
18 
and detailed performance criteria supporting MISO's proposal are described in MISO's 
19 
published Large Load Technical Compendium.  Detailed implementation, evaluation, and 
20 
compliance requirements will be established through MISO's applicable Business Practices 
21 
and address the following:   
22

Tab C 
Page 34 
 
• Applicability: Applies to Computational Loads subject to MISO’s ride-through 
1 
requirements. 
2 
• Stay connected: Requires the facility to remain connected during qualifying voltage 
3 
and frequency disturbances. 
4 
• Stable operation: Requires the facility to maintain stable behavior during the 
5 
disturbance and avoid unnecessary tripping. 
6 
• Post-disturbance recovery: Requires active power to recover in a controlled manner 
7 
that supports reliable Transmission System operation. 
8 
• Demonstration of capability: Requires the Transmission Customer to provide models, 
9 
studies, equipment information, testing, or other evidence demonstrating compliance. 
10 
Additional detail can be found in the Large Load Technical Compendium.  
11 
V. 
STAKEHOLDER ENGAGEMENT AND EFFECTIVE DATE 
12 
Q. 
PLEASE DESCRIBE HOW THE STAKEHOLDER PROCESS INFORMED 
13 
MISO’S IRR PROPOSAL. 
14 
A. 
MISO has engaged in detailed discussions with stakeholders on Large Load issues since 
15 
2024 in various stakeholder entities and workshops.  MISO first discussed Large Loads 
16 
with stakeholders in the context of EPR process improvements at the Planning Advisory 
17 
Committee (“PAC”) and Planning Subcommittee (“PSC”) in 2024 and 2025.  Moreover, 
18 
since 2024, MISO has discussed coordinating the MTEP and Definitive Planning Phases 
19 
(“DPP”) processes to accommodate Large Loads at the PSC.  MISO additionally discussed 
20 
Large Load citing methodology at the November 18, 2025, Futures Redesign Workshop. 
21 
MISO introduced the Large Load Interconnection Reliability Requirements at the Large 
22 
Loads Workshop on January 30, 2026.  The workshop addressed the challenges associated 
23

Tab C 
Page 35 
 
with reliably interconnecting large loads, focusing on defining reliability requirements and 
1 
improving the speed of integration while maintaining reliability to support member plans 
2 
and goals.  Following the January 30th workshop, MISO discussed the Large Load 
3 
Interconnection Reliability Requirements at the PAC and the Large Load Working Group 
4 
(“LLWG”).10  
5 
At the February 25, 2026, PAC, MISO proposed a definition of Large Load and provided 
6 
a high-level overview of the Large Load Interconnection Reliability Requirements.  MISO 
7 
requested stakeholder feedback on the Large Load definition.  At the April 20, 2026, 
8 
LLWG, MISO provided a revised large load definition based on stakeholder feedback and 
9 
presented the Large Load Interconnection Reliability Requirements.  MISO requested 
10 
feedback on the Large Load Interconnection Reliability Requirements.  At the April 22, 
11 
2026, PAC, MISO shared the revised Large Load definition that had been shared 
12 
previously at the LLWG.  MISO additionally presented transition provisions it developed 
13 
to address pending but unbuilt Large Load.  
14 
At the May 14, 2026, LLWG, MISO responded to stakeholder feedback from the April 20 
15 
LLWG meeting, provided proposed Tariff language for the Large Load Interconnection 
16 
Reliability Requirements, and provided an updated Large Load definition.  In response to 
17 
stakeholder feedback MISO revised the applicability language to provide additional clarity, 
18 
included transitional provisions that offer flexibility during implementation, and 
19 
incorporated a phased-in implementation to support readiness across customers and 
20 
utilities.  MISO additionally updated its Large Load definition based on stakeholder 
21 
 
10  A table listing the stakeholder meetings, including links to the presentations, is provided as Attachment A 
hereto.

Tab C 
Page 36 
 
feedback.  Specifically, in response to stakeholder feedback regarding MISO’s initial 
1 
proposal allowing multiple Points of Interconnection (“POI”), MISO proposed only 
2 
allowing multiple POIs if the ZGIA is located at one of the stations, i.e. Points of 
3 
Withdrawal of a Large Load Campus.  MISO requested feedback on the Large Load 
4 
Interconnection Reliability Requirements Tariff draft.  At the May 27, 2026, PAC, MISO 
5 
presented the updated Large Load definition, including the revisions to applicability and 
6 
transitional provisions, to ensure clarity on implementation of Interconnection Reliability 
7 
Requirements.  
8 
At the June 10, 2026, LLWG, MISO responded to stakeholder feedback and presented the 
9 
Tariff redlines for the Large Load Interconnection Reliability Requirements based on 
10 
stakeholder feedback.  Stakeholder feedback significantly influenced the revised Tariff 
11 
language, particularly around applicability, transition provisions, and requirement specific 
12 
language.  Namely, MISO: (1) updated Tariff and BPM language to clarify treatment of 
13 
existing loads, any expansions, and the applicability date; (2) updated the transitional 
14 
provision to allow more flexibility; (3) updated the Applicability section to distinguish 
15 
between Computational and Non-Computational Loads, and applied only ramp, PMU, 
16 
ride-through, and advanced modeling requirements to Computational Loads; (4) updated 
17 
the Transmission Customer definition to clearly define roles and responsibilities; (5) 
18 
expanded process detail across several Tariff sections, including applicability screening, 
19 
pre-MTEP/EPR timing, and transitional provisions for inflight projects; and (6) clarified 
20 
that Tariff applicability for the ramp, PMU, and ride-through requirements align with 
21 
NERC’s emerging definition of Computational Loads and NERC’s Load Modeling Task 
22 
Force technical discussions.  MISO additionally revised the Large Load definition by 
23

Tab C 
Page 37 
 
removing the Large Load Campus construct in response to stakeholder feedback.  In 
1 
addition, MISO published a technical compendium outlining the technical details of the 
2 
proposal that will be included in the Business Practice Manual. 
3 
At the June 29, 2026, LLWG, MISO reviewed Tariff redlines for the Large Load definition 
4 
and Large Load Interconnection Reliability Requirements based on stakeholder feedback.  
5 
Stakeholder feedback significantly influenced the revised Tariff language, specifically 
6 
around applicability, transition provisions, and requirement specific language.  MISO 
7 
additionally described how its proposed framework is consistent with the Commission’s 
8 
Show Cause Order and noted that the framework is also in line with the emerging NERC 
9 
guidance and broader industry practices.  Furthermore, MISO described how its 
10 
interconnection framework relies on the Tariff to set requirements and its BPM to guide 
11 
consistent implementation, noting that it is targeting Large Load BPM development to take 
12 
place from June to September 2026.  MISO requested stakeholder feedback on the Tariff 
13 
updates.  
14 
MISO separately presented on Large Load Telemetry and PMU Requirements, with the 
15 
purpose of establishing SCADA telemetry requirements for Large Loads, and PMU 
16 
requirements for Computational Loads to provide situational awareness and support system 
17 
reliability across the MISO footprint.  Specifically, MISO will require real-time SCADA 
18 
telemetry from large loads via ICCP to support real-time monitoring and analysis, and real-
19 
time SCADA telemetry from generation behind same POI as Large Load will also be 
20 
required for real-time monitoring and optimal market dispatch; generator telemetry shall 
21 
not be netted with load.  Furthermore, MISO will require PMU or similar device at the 
22

Tab C 
Page 38 
 
Large Load with computational load to support dynamic monitoring in real-time.  MISO 
1 
requested stakeholder feedback on The Large Load Telemetry and PMU Requirements.  
2 
MISO also presented on Large Load Operation Forecast Requirements, proposing that 
3 
Large Loads submit short-term forecasts to reliably manage their variability.  In particular, 
4 
MISO proposed Large Load forecast submission at the CP node level, on hourly and 5-
5 
minute cadences aligned with commitment and dispatch and defined forecast error 
6 
measurement and submission monitoring, noting that it is considering mechanisms to 
7 
incentivize accurate submissions.  MISO highlighted that NERC has called for short-term 
8 
forecast submissions from Large Loads, that SPP requires them today, and that CAISO has 
9 
identified the same visibility gap.  MISO requested stakeholder feedback on this topic.   
10 
At the July 15, 2026, PAC, MISO informed stakeholders that the Steering Committee 
11 
approved reassignment of the Large Load definition to the LLWG.  At the July 16, 2026, 
12 
LLWG, MISO noted in its liaison report that there is a transition plan to manage active 
13 
projects, explaining that a key consideration has been ensuring reliability while avoiding 
14 
disruption to loads at a late stage of development.  MISO noted that this consideration is 
15 
reflected in the Commission’s Show Cause Order and that it has received stakeholder 
16 
feedback indicating that its current proposal does not achieve this directive.  Therefore, 
17 
MISO revised its approach to apply full requirements only to loads that MISO has not yet 
18 
approved through its planning processes, and to apply visibility requirements to a broader 
19 
set of large loads.   
20 
MISO also discussed the Large Load BPM framework and development, focusing on 
21 
changes for interconnection and operational reliability requirements.  MISO proposed a 
22 
“hub-and-spoke” BPM framework consisting of a new Large Load BPM, the “hub,” 
23

Tab C 
Page 39 
 
supported by updates to existing BPMs and manuals, the “spokes.”  MISO requested 
1 
stakeholder feedback on the Large Load BPM framework.  
2 
At the July 27, 2026, LLWG, MISO reviewed Tariff redlines for the Large Load definition 
3 
and Large Load Interconnection Reliability Requirements based on stakeholder feedback.  
4 
MISO noted that its BPM development timeline has been extended to December 2026.  
5 
MISO also provided updates to its Technical Compendium.  MISO requested stakeholder 
6 
feedback on its Tariff updates.  
7 
At the August 12, 2026, LLWG, MISO reviewed the informal stakeholder feedback on the 
8 
reliability requirement updates provided at the July 27, 2026, LLWG.  MISO discussed the 
9 
additional refinements it made to its proposal based on informal stakeholder feedback.  
10 
As described above, throughout the stakeholder engagement period, MSO has solicited 
11 
feedback from stakeholders and provided written and verbal responses to that feedback.  
12 
MISO’s stakeholder process has contributed to substantive design changes in MISO’s 
13 
filing and the collaborative process with stakeholders resulted in a comprehensive proposal 
14 
for addressing Large Loads in the MISO footprint.  MISO appreciates the willingness of 
15 
all its stakeholders and state regulators to review and comment on this final proposal, which 
16 
MISO believes reasonably accommodates concerns raised by stakeholders. 
17 
In addition to the stakeholder meetings, MISO’s external affairs and large load teams have 
18 
met with individual stakeholders and RERRAs to inform them about MISO’s proposal and 
19 
answer questions.  MISO is aware that this is a pressing topic in the MISO footprint and 
20 
commits to working with stakeholders and RERRAs to address any questions that may 
21 
arise. 
22

Tab C 
Page 40 
 
Q. 
WHAT EFFECTIVE DATE HAS MISO REQUESTED FOR THE LARGE LOAD 
1 
INTERCONNECTION REFORM PROPOSAL?  
2 
A. 
MISO has requested a proposed effective date of December 4, 2026.  This is the day after 
3 
which the MISO Board is expected to approve the MTEP 2026 projects and aligns with the 
4 
IRR transition provisions described above.    
5 
VI. 
CONCLUSION 
6 
Q. 
DOES THIS CONCLUDE YOUR TESTIMONY? 
7 
A. 
Yes. 
8

Affidavit of Beibei Li 
  
COUNTY OF HAMILTON 
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STATE OF INDIANA 
) 
Beibei Li, being duly sworn, deposes and states that she prepared the Prepared Direct 
Testimony of Beibei Li, and the statements contained therein are true and correct to the best of 
her knowledge and belief. 
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Beibei Li   
SUBSCRIBED AND SWORN BEFORE ME, this WU day of August, 2026. 
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JENNIFER L MILLER 
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February 22, 2033 
  
  
  
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Commission Number; 
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1 
Attachment A – Table of Stakeholder Meetings and Materials 
MEETING DATE 
MATERIALS 
January 30, 2026 Large Load Workshop 
Large Load Additions Workshop 
February 25, 2026 PAC 
Large Load Interconnection Reliability 
Requirements (PAC-2024-1) 
April 20, 2026 LLWG 
Large Load Overview 
 
New Large Load Issue Submissions 
 
Large Load Interconnection Reliability 
Requirements (LLWG) 
April 22, 2026 PAC 
PAC April 2026: PAC: Large Load Definition 
(PAC-2024-1) 
May 14, 2026 LLWG 
Large Load Interconnection Reliability 
Requirements (LLWG) 
May 27, 2026 PAC 
Large Load Definition Update 
June 10, 2026 LLWG 
Large Load Interconnection Reliability 
Requirements (LLWG) 
 
Interconnection Reliability Requirements 
Technical Compendium  
June 29, 2026 LLWG  
Large Load Interconnection Reliability 
Requirements 
(LLWG) 
 
Large Load Telemetry and PMU 
Requirements 
 
Large Load Operational Forecast 
Requirements 
 
Interconnection Reliability 
Requirements for Large Load Technical 
Compendium  
July 15, 2026 PAC  
Liaison Report 
July 16, 2026 LLWG 
Liaison Report 
 
Large Load BPM Development 
(LLWG) 
July 27, 2026 LLWG 
Large Load Interconnection Reliability 
Requirements 
(LLWG)

2 
August 12, 2026 LLWG  
Large Load Interconnection Reliability 
Requirements 
(LLWG) 
August 27, 2026 LLWG 
Large Load Interconnection Reliability 
Requirements Clean Tariff (LLWG) 
 
Large Load Interconnection Reliability 
Requirements Redline Tariff (LLWG) 
 
Large Load Interconnection Reliability 
Requirements Redline comparison (LLWG)