Siting Intelligence
Grid Interconnections
Estimated interconnection fees, study timelines, and queue data for every major Independent System Operator (ISO) and Regional Transmission Organization (RTO) across the United States. Data sourced from FERC filings, ISO tariffs, and the 2024 Generator Interconnection Scorecard.
Important: Study fees shown are deposits paid to fund engineering studies — they are partially refundable and represent only a fraction of total interconnection cost. Network upgrade costs (the actual cost to build transmission infrastructure) are project-specific and are billed separately — they can range from near zero to hundreds of millions of dollars. Timelines reflect application to commercial operation including construction, not study phases alone.
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7 of 7 ISOs| ISO / RTO | Process | FERC | Total Timeline | Study Phases | Queue Size | 2024 Grade | |
|---|---|---|---|---|---|---|---|
SPP Southwest Power Pool | Cluster | Yes | 12–24 mo (1–2 yrs) | 90–120 days (Phase 1) | 150 GW 561 projects | C- | |
ERCOT Electric Reliability Council of Texas | Rolling | No | 18–36 mo (1.5–3 yrs) | 3–9 months | 418 GW 1,874 projects | A | |
ISO-NE ISO New England | Cluster | Yes | 18–24 mo (1.5–2 yrs) | ~75 days (feasibility) | 34 GW 200 projects | B | |
NYISO New York Independent System Operator | Cluster | Yes | 18–24 mo (1.5–2 yrs) | 6–12+ months (Phase 1) | 26 GW 191 projects | C | |
MISO Midcontinent Independent System Operator | Cluster | Yes | 18–36 mo (1.5–3 yrs) | 6–12+ months (Phase 1) | 174 GW 1,696 projects | C- | |
PJM PJM Interconnection | Cluster | Yes | 18–24 mo (1.5–2 yrs) | 90 days (Phase 1) | 145 GW 1,426 projects | D | |
CAISO California Independent System Operator | Cluster | Yes | 24–36 mo (2–3 yrs) | 6–12+ months (Phase 1) | 158 GW 255 projects | C |
Grades from 2024 Generator Interconnection Scorecard (Grid Strategies / Brattle Group / Advanced Energy United)·Queue data from LBNL Queued Up 2025 and ISO public disclosures·Fees from ISO OATT filings and FERC-published tariff schedules·Data last updated: March 2026
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