ER26-3650-000 · 2026-09-18 · Mississippi Public Service CommissionArkansas Public Service Commission

Protest of Mississippi Public Service Commission et al. re Midcontinent Independent System Operator, Inc.'s 08/28/2026 filing

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 UNITED STATES OF AMERICA 
BEFORE THE 
FEDERAL ENERGY REGULATORY COMMISSION 
 
Midcontinent Independent System Operator, 
Inc. 
) 
) 
                           Docket No. ER26-3650-000 
 
 
PROTEST OF THE SOUTHERN REGULATORS 
 
The Mississippi Public Service Commission and the Arkansas Public Service Commission 
(together, the Southern Regulators) protest MISO’s1 August 28, 2026 filing to establish 
interconnection reliability requirements for large loads.2  Southern Regulators support Entergy’s3 
Limited Protest4 and request for relief and offer the following additional comments.5  
First, the Filing provides only a general overview of interconnection requirements 
applicable to large loads. It lacks the specific detail needed to actually interconnect to the grid.  
Absent that detail, developers and the transmission owners are unable to design, purchase and 
install the correct equipment to operate large loads (e.g., refineries, data centers).  A general 
description is not enough.  And, in the absence of those requirements, developers and transmission 
owners run the risk and expense of installing equipment, consistent with good utility practices, 
only to then replace that equipment at great expense after MISO later publishes the actual 
requirements.  MISO’s approach is analogous to building a house based on a picture instead of 
technical drawings. 
Second, when it finally develops the requirements, MISO unreasonably proposes to place 
them in Business Practice Manuals (BPMs).  MISO can easily change BPMs with minimal or no 
 
1 Midcontinent Independent System Operator, Inc. (MISO). 
2 Midcontinent Independent System Operator, Inc., Interconnection Reliability Requirements for Large Loads, 
Docket No. ER26-3650-000 (filed Aug. 28, 2026) (Filing). 
3 Entergy includes Entergy Services, LLC. and its operating companies: Entergy Arkansas, LLC, Entergy Louisiana, 
LLC, Entergy Mississippi, LLC, Entergy New Orleans, LLC, and Entergy Texas, Inc. 
4 Limited Protest of Entergy Services, LLC, Docket No. ER26-3650-000 (filed Sept. 18, 2026) (Entergy Protest).  
5 Southern Regulators file these comments pursuant to Rules 212 and 214 of the Federal Energy Regulatory 
Commission’s (FERC or Commission) Rules of Practice and Procedure. 18 C.F.R. §§ 385.212 and 385.214 (2026).

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input from market participants. Any recommendation market participants do provide regarding a 
BPM is treated as a suggestion that MISO may ignore.  Developers and transmission owners have 
no recourse to challenge a BPM other than by filing a complaint at FERC.  These requirements 
will impose significant costs on developers and transmission owners; changing the requirements 
will further increase those costs.  As Entergy explained, the Rule of Reason mandates that these 
requirements be placed in the Tariff where they are subject to FERC’s oversight to ensure they are 
just and reasonable.6 
Finally, the remedy Entergy seeks – that MISO make a compliance filing that clearly 
identifies these requirements and places them in the tariff – is fully within FERC’s authority.  
Conclusion 
Consistent with Entergy’s Limited Protest, the Southern Regulators ask that FERC 
condition acceptance of MISO’s Filing by requiring MISO to file the specific interconnection 
requirements in the Tariff, not in the BPMs. 
 
 
 
 
 
Barton Norfleet 
Special Counsel; Federal Energy Affairs  
Mississippi Public Service Commission  
501 N. West Street, Suite 201-A  
P.O. Box 1174  
Jackson, MS 39215-1174  
Phone: (601) 961-5821  
barton.norfleet@psc.ms.gov  
 
 
Respectfully submitted, 
 
/s/ William D. Booth  
 
William D. Booth 
Orrie A. Walsvik 
Michael Best & Friedrich LLP 
1000 Maine Avenue, S.W. 
Suite 400  
Washington, D.C. 20024 
Phone: (202) 747-9560 
wdbooth@michaelbest.com 
orrie.walsvik@michaelbest.com 
 
Attorneys for the Mississippi Public 
Service Commission  
 
6 Entergy Protest at 3-17.

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/s/ Bridgette Frazier  
Bridgette Frazier  
Luke Kinder 
Commission Counsel  
Arkansas Public Service Commission  
1000 Center Street  
P.O. Box 400  
Little Rock, AR 72201-4314  
Telephone: (501) 682-5816 
(501) 682-5766  
bridgette.frazier@arkansas.gov  
luke.kinder@arkansas.gov 
 
Attorneys for the Arkansas Public Service 
Commission 
 
Dated September 18, 2026

CERTIFICATE OF SERVICE 
I hereby certify that I have this day served the foregoing document upon the parties designated 
on the official service list for the above-captioned docket in accordance with the requirements of 
Rule 2010 of the Commission’s Rules of Practice and Procedure. 
Dated at Madison, Wisconsin on this 18th  day of September, 2026. 
 
 
 
 
 
Respectfully submitted, 
/s/ Orrie Walsvik 
Orrie Walsvik 
Michael Best & Friedrich LLP 
1 S. Pinckney Street  
Suite 700 
Madison, WI 53703 
Phone: (608) 257-3055 
Orrie.walsvik@michaelbest.com