MS — Power Infrastructure Updated 2026-07-17

Mississippi

MISO/SERC Solar Data Center PPAs Queue Bottlenecks Transmission Constraints

1. Grid operator and market structure

  • RTO/ISO footprint: MISO expanded in 2013 to include portions of four southern states, including Mississippi, placing much of Entergy Mississippi’s service area in MISO South. MISO, 2013-12-19
  • Non-MISO / other utility areas: TVA serves local power companies in parts of north and central Mississippi, while Mississippi Power serves 23 southeast Mississippi counties and is outside Entergy Mississippi’s MISO service territory. TVA, accessed 2026-07-17 Mississippi Power, accessed 2026-07-17
  • Retail market structure: EIA’s Mississippi profile reports no energy-only provider retail sales, consistent with a regulated retail market rather than retail choice. EIA Mississippi State Profile, accessed 2026-07-17

2. Interconnection queue

  • MISO-wide queue pressure remains the main public proxy: Public MISO materials do not provide a Mississippi-only, data-center-specific queue breakout; the best public indicators remain MISO-wide large-load and transmission-planning materials. MISO Large Load Additions, accessed 2026-07-17 MISO Transmission Expansion Plan, accessed 2026-07-17
  • Queue reforms already accepted by FERC remain in effect: MISO’s 2024 queue reforms increased milestone payments, withdrawal penalties, and site-control requirements, and FERC accepted the changes in Docket ER24-340. FERC eLibrary ER24-340, 2024-01-19
  • MISO large-load process is under active reform: MISO says its expedited framework uses zero-injection generation agreements, ERAS generation studies, and expedited transmission-project review, while a new large-load study process remains under development. MISO’s public target is approval within 120 days where studies and agreements are complete; this is a regional framework, not a Mississippi retail tariff. MISO Large Load Additions, accessed 2026-07-17
  • FERC show-cause/reform order: On June 18, FERC opened Docket EL26-70 and directed MISO and its transmission owners within 60 days either to show that the tariff remains just and reasonable or propose changes covering large-load applications and studies, upgrade-cost transparency and recovery, co-location and behind-the-meter service, and flexible/interim service. The order did not itself establish a Mississippi-specific interconnection rule. FERC Order, 2026-06-18

3. Ratepayer protection (large-load tariffs / cost allocation)

  • PSC special-contract oversight precedent: The PSC approved a special contract for Mississippi Power and Compass Datacenters Jan I, LLC in February 2025; MDA’s project announcement put the Meridian/Lauderdale County campus at about 500 MW. Mississippi PSC, 2025-02-07 MDA, 2025-01-09
  • Entergy/Amazon confidentiality remains the central 2026 ratepayer issue: A May 2026 Synapse report for Earthjustice and Environmental Advocates Mississippi argued that SB 2001 curtailed ordinary PSC oversight and confidentiality makes it difficult to verify whether Entergy’s data center customers are paying their full incremental costs. Earthjustice/Synapse, 2026-05-28
  • Estimated residential bill impact: Synapse estimated that Entergy Mississippi residential customers had already paid about $38 million by March 2026 for investments related to serving data centers, that the amount would reach $74 million by year-end 2026, and that the average residential bill was about $10.60/month higher; the report stresses uncertainty because key filings are confidential. Earthjustice, 2026-05-28 Mississippi Today, 2026-05-28
  • Utility counterclaim: Entergy issued a March 5, 2026 “Fair Share Plus” pledge, asserting about $5 billion in projected savings across Arkansas, Louisiana, and Mississippi and $2 billion+ for Mississippi customers, based on data center customer agreements and regulatory treatment. Entergy, 2026-03-05
  • No statewide standardized large-load tariff located: Through July 17, the PSC’s public docket and meeting materials showed special contracts, statutory confidentiality, and policy recommendations for standard contracts rather than a PSC-adopted statewide large-load tariff. Mississippi PSC Dockets, accessed 2026-07-17 Earthjustice/Synapse, 2026-05-28
  • Additional contract-protection disclosure, but not public contract terms: At the July AI task-force hearing, Entergy said its AWS contracts include a minimum bill, a contract term, and termination provisions; the testimony did not disclose the values or publish the contracts. Mississippi Today, 2026-07-14

4. Generation adequacy (major projects, storage, shortfall concerns)

  • Entergy Mississippi generation additions: Entergy’s Superpower Mississippi plan includes the 754 MW Delta Blues Advanced Power Station near Greenville, the planned 754 MW Vicksburg Advanced Power Station, and the planned 754 MW Traceview Advanced Power Station in Ridgeland. Entergy, 2024-11-07 Entergy, 2025-10-21 Entergy Mississippi Traceview, accessed 2026-07-17
  • Data-center-driven savings claim: Entergy stated in January 2026 that Amazon’s Mississippi data center plans came with a $13 billion investment and that Amazon-related funding would help avoid $1.3 million in replacement costs, $700 million in future fuel expenses, and $300 million of grid-modernization funding otherwise charged to customers. Entergy, 2026-01-09
  • Amazon expansion increases load pressure: Amazon’s April 9, 2026 update described an additional $11 billion Madison County expansion plus a $1 billion Hinds County project, bringing Amazon’s Mississippi planned data-center investment to $25 billion. Amazon, 2026-04-09 Entergy, 2026-04-09
  • Generation buildout quantified: Synapse’s May report identified five Entergy projects pre-certified as data-processing-load-related: three 754 MW combined-cycle plants (Delta Blues, Vicksburg, and Traceview) plus 80 MW Delta Solar and 190 MW Penton Solar, totaling 2,532 MW and an estimated $3.884 billion. The report said Entergy disclosed $757.6 million spent on the listed facilities in 2025; the costs and benefits remain disputed because customer agreements and portions of cost recovery are confidential. Synapse/Earthjustice report, 2026-05-28
  • Behind-the-meter gas generation at xAI: MDEQ’s March permit covers 41 permanent turbines, but xAI continued adding separate temporary-mobile units. MDEQ confirmed 46 at the Southaven site in May; regulator correspondence reviewed by Reuters later identified at least 57 Mississippi turbines associated with Colossus 2 without federal clean-air permits. xAI and MDEQ maintain that these mobile units are exempt, while pending plaintiffs dispute that reading. Mississippi Today, 2026-05-11 Reuters, 2026-07-14

5. Utility load forecasts and IRP filings (data center demand)

  • Amazon load signal: Amazon’s four-site statewide plan is $25 billion and 2,000 jobs. A MISO large-load announcement list identifies the original Madison County Amazon buildout at 1,034 MW phased across 2025–2027; no public source located provides a current MW allocation for all four Mississippi sites. Amazon, 2026-04-09 MISO Large Load Facility Additional Information, 2024-12-06
  • Amazon operating/construction status: As of June 9, five Canton buildings were operating with plans at least to double the footprint; Ridgeland was in early construction; and Clinton and Vicksburg were in site-preparation/pre-construction. Amazon also said five Mississippi renewable projects enable 616 MW of new wind and solar, a company portfolio claim rather than site-matched 24/7 supply. Mississippi Today, 2026-06-09
  • Clinton load/project signal: WLBT confirmed Amazon Data Services as the buyer/developer of a $750 million Clinton data center on a 99-acre former Milwaukee Tool site; Entergy later described the Clinton project as $1 billion. WLBT, 2026-03-04 Entergy, 2026-04-09
  • xAI load signal: Mississippi Free Press reported that xAI’s MACROHARDRR Southaven facility is part of a cluster that Elon Musk said would take xAI training compute toward nearly 2 GW, while the Southaven turbine permit itself covers 41 gas-fired turbines. Mississippi Free Press, 2026-02-17 Mississippi Free Press, 2026-03-10
  • Compass and AVAIO load signals: Compass remains publicly associated with roughly 500 MW of Mississippi Power supply in Meridian/Lauderdale County, while AVAIO’s Brandon project is associated with local water/wastewater legislation rather than a public PSC large-load tariff. MDA, 2025-01-09 Mississippi Legislature SB 3410 history, 2026-04-08
  • Additional project signals without disclosed MW: Corderill committed at least $100 million of equipment as a Compass Meridian tenant; Clarksdale rezoned 648 acres for a possible multi-billion-dollar campus but reported no final project or energy requirement. Neither announcement changes the published 500 MW Compass campus figure or supplies a Clarksdale MW estimate. Mississippi Economic Development Council, 2026-04-23 City of Clarksdale FAQ, 2026-03-23
  • Regional forecast: MISO’s April long-term forecast expects 8–14 GW of data-center growth across its full footprint in 2026–2027 and warns that announcements and planning submissions create wide uncertainty about timing and realization. This is not a Mississippi allocation, but it is the relevant regional adequacy context. MISO 2026 Long-Term Load Forecast, 2026-04-13

6. Behind-the-meter / co-location / direct PPAs

  • Utility-served model: Compass/Mississippi Power remains the clearest utility-served data center model, using a PSC-approved special contract for a very large load. Mississippi PSC, 2025-02-07
  • Self-generation model: xAI’s Southaven project is the clearest Mississippi behind-the-meter/self-generation model, with disputed temporary/mobile turbines and a separate permanent-turbine permit. Earthjustice, 2026-04-14 Mississippi Free Press, 2026-03-10
  • Prado AI declaratory-opinion proceeding: Prado AI asked the PSC in Docket 2026-AD-10 whether generating electricity and including it in leases for tenants at a proposed Jackson-area AI/semiconductor campus would make Prado a regulated public utility. The PSC declined on May 29 to issue an opinion because the facts were insufficient, leaving unresolved both utility status and whether a generation CPCN would be required; Entergy and Mississippi Power had opposed Prado’s interpretation. Mississippi PSC May utility docket, accessed 2026-07-17 Mississippi Today, 2026-06-01
  • Direct PPA / co-location evidence: No executed Mississippi-specific direct PPA or public FERC co-location agreement for a Mississippi data center was identified through July 17. The Prado dispute and MISO/FERC proceedings show that behind-the-meter and co-located service rules remain unsettled. FERC Order, 2026-06-18 Mississippi Today, 2026-07-14

7. Transmission constraints and upgrades

  • State energy-infrastructure funding: HB 1393’s new Mississippi Energy Infrastructure Fund can support local-entity facilities related to approved projects, including data centers, but utilities cannot be direct recipients. Mississippi Legislature HB 1393 history, 2026-04-08 Mississippi Legislature HB 1393 enrolled text, 2026-04-08
  • Grid modernization claim: Entergy said Amazon and other large-customer revenues and savings would support $300 million of grid-modernization funding not charged to other customers, within a nearly $1 billion grid-modernization program; Amazon likewise stated it would fund $300 million in grid improvements and cover all costs associated with its new data center campuses. Entergy, 2026-01-09 Amazon, 2026-04-09
  • Regional queue/seam constraints: Mississippi-specific transmission bottlenecks remain difficult to identify publicly. FERC’s June order specifically requires MISO either to justify or improve transparency around network upgrades and costs driven by large loads, confirming that this remains an open regional planning issue. FERC Order, 2026-06-18

Source notes and gaps

  • Public utility filings still do not provide a transparent, site-by-site MW and cost-allocation table for Amazon, AVAIO, xAI, Compass, and emerging Jackson/Clinton projects.
  • The largest unresolved Mississippi energy-policy question is not whether load is growing, but whether confidential special contracts and statutory cost-recovery paths fully protect non-data-center customers from incremental generation, transmission, and distribution costs.