Illinois — Energy Landscape

Key Finding: Illinois's operational generation fleet is overwhelmingly dominated by solar energy, accounting for 98.5% of all plants and 95.5% of the total installed capacity.

Dominance of Solar in Illinois's Operating Fleet

The current operational fleet in Illinois is characterized by a significant concentration of solar projects, with other fuel sources playing a comparatively minor role in terms of both plant count and capacity.

• Solar: 462 plants, totaling 8.5 GW — represents 98.5% of all operational plants and 95.5% of the state's total capacity.
• Battery Storage: 3 plants, totaling 320 MW — contributes 3.6% to the state's capacity, primarily supporting grid stability.
• Natural Gas: 3 plants, totaling 53 MW — a negligible portion, representing less than 1% of total capacity.
• Wind: 1 plant, at 2 MW — indicates an extremely limited operational wind presence.

Leading Operational Plants by Capacity

The largest operational plants further emphasize the solar-centric nature of Illinois's generation fleet, with hybrid projects also making a notable appearance among the top assets.

1. Steward Creek Solar Phase 1 (IL): 1,200 MW
2. Double Back Diamond (IL): 592.8 MW
3. Pulaski Solar (IL): 417.4 MW
4. Meadow Springs Renewable Energy (Hybrid) (IL): 300 MW
5. Heritage Prairie Solar LLC (IL): 300 MW

This data indicates that Illinois has established a generation fleet with a strong emphasis on large-scale solar projects,

Development and Commitment Signals

• Meta secured 100% of the output from a major US solar project in a PPA signed on 2026-07-14, indicating strong corporate clean energy demand in Illinois.

• The Byron and Braidwood nuclear generating stations are boosting power capacity to support data center growth, as reported on 2026-05-17.

• EDP Renewables completed the Pleasantville Solar project in Illinois, with construction concluded on 2026-03-29, signaling new renewable capacity additions.

Constraint and Regulatory Signals

• A mass casualty chemical exposure response occurred at the Byron Nuclear Generating Station on 2026-03-10, highlighting operational risks within the fleet.

• An accidental sounding of nuclear sirens in LaSalle County on 2026-03-09 and a fire at the CWLP power plant in Springfield on 2026-02-25 indicate intermittent operational challenges and safety concerns.

• Several federal policy filings and notices were observed, including a 'Combined Notice of Filings' on 2026-07-15 and a waiver period notice for Northern Illinois Hydropower, LLC on 2026-05-12, suggesting ongoing regulatory activity affecting the state's power sector.

The news signals for Illinois reflect a dynamic environment with concurrent development successes and operational challenges, alongside continuous regulatory engagement at both state and federal levels.

The Illinois interconnection queue is entirely dominated by solar projects, with a substantial pipeline of 21.7 GW across 118 projects, signaling a strong future emphasis on utility-scale solar development within the state.

Solar Dominance in Interconnection Queue

• The Illinois interconnection queue comprises 118 projects, exclusively consisting of solar technology, totaling 21.7 GW.

• All but two projects, or 116 projects, are currently active, indicating a high degree of project viability within the queue.

• No wind, battery storage, or hybrid projects are present in the queue, indicating a singular focus on solar development.

Largest Solar Projects in the Queue

• The largest proposed solar project in Illinois is 820.6 MW.

• Two other substantial solar projects are in the queue: one at 500 MW and another at 343 MW.

• The Surplus; Glacier Moraine project adds another significant solar capacity of 360 MW.