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IN — Power Infrastructure Updated January 8, 2026

Indiana

MISO/PJM Natural Gas Solar Wind Storage Data Center PPAs Queue Bottlenecks Transmission Constraints

Overview

Indiana is in the middle of a major power transition. Coal plants like AES Indiana’s Petersburg units are converting to natural gas, while northern Indiana utility NIPSCO plans a large new gas plant specifically to serve data centers. Meanwhile, the state is adding over a gigawatt of solar capacity across rural counties, with tech companies like Amazon and Meta signing long-term power contracts.

Generation Projects

Natural Gas

Indiana’s largest utilities are betting on natural gas to replace retiring coal capacity and meet surging data center demand.

  • AES Indiana Petersburg Units 3 & 4 repower: The Indiana Utility Regulatory Commission (IURC) approved converting the Petersburg coal units to natural gas, with construction starting by end of 2025 and completion by end of 2026. The same plan adds 250 MW of solar and 180 MW of battery storage in Pike County.[1]
  • NIPSCO data center gas plant: Northern Indiana Public Service Company (NIPSCO) is planning a large natural gas plant through a new subsidiary, NIPSCO Generation LLC, designed to serve data centers. Air permit filings estimate emissions up to 7 million tons of CO2 per year, reflecting significant load growth tied to data center demand in northern Indiana.[2]

Solar

Indiana’s flat farmland is attracting utility-scale solar developers, with several major projects online or under construction.

  • Mammoth Solar: This Doral Renewables project spans Starke and Pulaski counties and is expected to total 1.3 GW across multiple phases. Mammoth North, the first phase, produces about 400 MW and operates under a long-term power purchase agreement (PPA) with AEP Energy.[4]
  • Riverstart III Solar Park: EDP Renewables completed this 100 MW solar facility in Randolph County. Amazon contracted all output through a long-term PPA, adding to EDP’s 1.7 GW Indiana portfolio.[5]

Wind

Indiana’s wind development is concentrated in the state’s northern tier, where stronger wind resources and open land converge.

  • Blackford Wind: This 200 MW project in Blackford County is scheduled for construction in 2025, with operations expected in early 2026. The project will interconnect to AEP’s Keystone-Desoto 345 kV line.[6]

Battery Storage

Indiana is adding utility-scale battery storage to support grid reliability as coal plants retire.

  • Pike County BESS at Petersburg: The IURC approved a standalone 200 MW / 800 MWh battery system at AES Indiana’s Petersburg Generating Station, targeting operation by December 2024 to support MISO winter reliability.[9]
  • Petersburg Energy Center storage: AES Indiana’s broader Petersburg plan pairs the gas repower with 250 MW of solar and 180 MW of battery storage, with construction expected to start in 2025 and finish in 2026.[1]

Transmission and Grid

Indiana sits at the border of two regional grids — MISO in the west and PJM in the east — which means transmission upgrades are critical for moving power across the state.

  • Olive-Reynolds 345 kV rebuild: Indiana Michigan Power (I&M) and AEP Transmission plan to rebuild about 68 miles of 345 kV line between Olive and Reynolds substations, plus relocate roughly 2 miles of line and upgrade the Olive substation. The work replaces aging 1950s infrastructure in western Indiana.[7]
  • MISO LRTP Tranche 1 upgrades: MISO’s long-range transmission plan (LRTP) Tranche 1 includes 345 kV projects that address reliability needs in Indiana and mitigate 16 thermal overloads in the state. These upgrades matter for large-load growth across northern and central Indiana.[8]

Data Center Power Agreements

Tech companies are signing long-term contracts to secure Indiana’s new renewable capacity for their data center operations.

  • Amazon + Riverstart III: Amazon contracted all 100 MW from EDP Renewables’ Riverstart III solar park in Randolph County, linking Indiana solar supply to Amazon’s data center power needs.[5]
  • Meta + Solarpack: Meta signed two long-term Environmental Attribute Purchase Agreements (EAPAs) with Solarpack for two Indiana solar projects totaling 210 MW. The agreements support Meta’s Indiana operations and its data center buildout in southern Indiana.[10]

Interconnection Queue

Indiana sits in two regional grids, and both MISO and PJM are struggling with interconnection backlogs — which means new projects face long wait times.

  • MISO queue reforms: MISO’s 2024 queue-improvement filing adds milestones, penalties, and tighter site-control requirements, and it proposes a cap on total MW per cycle to manage backlog risk. These reforms signal persistent interconnection congestion across the MISO footprint that includes most of Indiana.[11]
  • PJM queue reform: PJM shifted from a serial queue to a first-ready, first-served cycle process, with new tariff parts effective January 3, 2023 and a transition date of July 10, 2023. This affects Indiana Michigan Power territory that sits in PJM.[12]
  • Indiana large-load interconnection rules: The IURC approved a settlement defining terms for connecting data centers and other large loads, involving I&M, Amazon, Google, Microsoft, and state advocates. The agreement indicates a formal process to manage very large interconnection requests.[13]

What to Watch

  • NIPSCO’s data center gas plant: Air permit filings are public, but the full scale, timeline, and customer list remain unclear. Watch for IURC filings and public hearings.
  • SMR study follow-up: Indiana commissioned a 2024 small modular reactor (SMR) study evaluating technology, siting, and coal-to-nuclear conversion options. The report does not announce a specific nuclear plant project, but it signals state interest in future SMR siting.[3]
  • MISO and PJM queue backlogs: Both regional grids are reforming their interconnection processes. Watch for how these reforms affect the timeline for new solar, wind, and battery projects in Indiana.

Sources

[1] AES Indiana, “AES Indiana receives approval to repower remaining Petersburg units from coal to natural gas,” November 6, 2024, https://www.aesindiana.com/press-release/aes-indiana-receives-approval-repower-remaining-petersburg-units-coal-natural-gas (accessed January 8, 2026).

[2] Rebecca Thiele (IPB News), “NIPSCO plans large natural gas plant to serve data centers through new subsidiary,” Indiana Public Radio, September 25, 2025, https://indianapublicradio.org/news/2025/09/nipsco-plans-large-natural-gas-plant-to-serve-data-centers-through-new-subsidiary/ (accessed January 8, 2026).

[3] Seungjin Kim, Ph.D., Study on Small Modular Reactor Technology and Its Impact for Indiana, Indiana Office of Energy Development, October 31, 2024, https://www.in.gov/oed/files/IOED-SMR-Report_Final-0225.pdf (accessed January 8, 2026).

[4] Doral Renewables, “Mammoth North Solar,” n.d., https://doral-llc.com/projects/mammoth-north-solar-3/ (accessed January 8, 2026).

[5] EDP Renewables North America, “EDP Renewables North America Adds 100 MW Amazon-backed Solar Park to Existing 1.7 GW Portfolio in Indiana with Completion of Riverstart III,” April 1, 2025, https://www.edp.com/en/north-america/na/media/edp-renewables-north-america-adds-100-mw-amazon-backed-solar-park-existing (accessed January 8, 2026).

[6] Blackford Wind Energy, LLC, “Blackford Wind,” n.d., https://blackfordwind.com/ (accessed January 8, 2026).

[7] AEP Transmission, “Olive - Reynolds 345 kV Transmission Line Rebuild,” n.d., https://www.aeptransmission.com/indiana/Olive-Reynolds/ (accessed January 8, 2026).

[8] Midcontinent Independent System Operator (MISO), LRTP Tranche 1 Portfolio Detailed Business Case, June 25, 2022, https://cdn.misoenergy.org/LRTP%20Tranche%201%20Detailed%20Business%20Case625789.pdf (accessed January 8, 2026).

[9] Paul Ciampoli, “Indiana Regulators Approve Battery Storage Project at Site of Coal-Fired Plant,” Public Power, January 30, 2024, https://www.publicpower.org/periodical/article/indiana-regulators-approve-battery-storage-project-site-coal-fired-plant (accessed January 8, 2026).

[10] Zoya Mirza, “Meta to bring 210 MW of solar energy to Indiana,” ESG Dive, May 15, 2024, https://www.esgdive.com/news/meta-to-bring-210-mw-of-solar-energy-to-indiana/716220/ (accessed January 8, 2026).

[11] Midcontinent Independent System Operator (MISO), “Generator Interconnection Queue Improvements (PAC-2023-1),” January 30, 2024, https://cdn.misoenergy.org/20240130%20IPWG%20Item%2008%20Generator%20Interconnection%20Queue%20Improvements%20(PAC-2023-1)631506.pdf (accessed January 8, 2026).

[12] PJM Interconnection, “Interconnection Process Reform,” n.d., https://www.pjm.com/planning/service-requests/interconnection-process-reform (accessed January 8, 2026).

[13] Ethan Howland, “Indiana regulators approve ‘large load’ interconnection rules,” Utility Dive, February 20, 2025, https://www.utilitydive.com/news/indiana-iurc-large-load-interconnection-data-center-aep-amazon-google/740452/ (accessed January 8, 2026).