Curated reference and analysis. Last full review: July 9, 2026
Verify all figures against ISO sources before relying on them for project decisions.
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CAISO

California Independent System Operator · Most of California
www.caiso.com/Last updated: 2026-07-09Tier:ChallengedConfidence:MediumFERC · Show-cause: active (EL26-71)

Docket EL26-71. CAISO does not study load interconnections — utility tariffs govern them — which is exactly what the show-cause order now probes. Show-cause response due Aug 17, 2026.

Bottom line

Longest interconnection timelines in the country (~9 yrs), a massive backlogged queue, and comparatively modest data-center demand make CAISO a hard place to site large load despite active reform.

Author analysis. Review against primary sources before relying on this for project decisions.

Verified facts and placeholders

Facts
Total queue MW
140,000 MWstale · as of 2026-06-22
Total queue projects
413stale · as of 2026-06-22
Avg interconnection wait
9.2 yearsstale · as of 2026-06-22
Large-load queue MW
4,500 MWstale · as of 2026-06-22
Queue status
reform-in-progress
Large-load posture
Developing
Generation queue notes
Cluster 15 (~347 GW) on hold while Cluster 14 (~94 GW) clears; ~185 GW in Cluster 14 and prior. New zonal, scored interconnection process (commercial interest 30% / viability 35% / system need 35%) approved by FERC. Merchant zones (<50 MW available capacity) require developers to fund upgrades. Interconnection Process Enhancements (IPE) 5.0 in progress.
Large-load posture rationale
Structurally, CAISO does not study load interconnections — utility tariffs govern them — which is exactly what FERC's show-cause order (EL26-71) now probes. ~4.5 GW of data-center demand sits in the 2025-2026 transmission planning cycle. The CEC forecasts CAISO-footprint data-center load growing 1.8 GW by 2030 and 4.9 GW by 2040 — small against ERCOT and PJM. CAISO opened a Large Load Considerations initiative (issue paper January 30, 2026).
Primary source
www.caiso.com/generation-transmission/generation/generator-interconnection

Analyst read

Editorial analysis
Tier
Challenged
Rationale
Longest interconnection timelines in the country (~9 yrs), a massive backlogged queue, and comparatively modest data-center demand make CAISO a hard place to site large load despite active reform.
What's working
  • Zonal scored process and heightened readiness gates are starting to improve queue throughput.
  • No flex alerts since 2022, suggesting reliability reforms are holding.
What's working against
  • ~9.2-year average timelines, the longest of any ISO.
  • Merchant-zone cost exposure and high development costs; modest data-center demand vs. PJM/ERCOT.
One thing to watch
Whether IPE 5.0 and Track 3 reforms meaningfully cut timelines for Cluster 16 and beyond.
Analyst note
California is reforming a genuinely clogged queue and making progress, but the timelines remain the worst in the country and data-center demand is comparatively light. For large-load siting it is a low-priority market unless a project has a specific California reason to be there. CAISO took 347 GW of Cluster 15 applications and let 68 GW through. The screen is the story: California filters hard at the door rather than carry a speculative queue.

Major announced projects in this market

Exhibit 2 · supporting

Project signal tracking is intentionally blank in this baseline edition.

Recent reforms

Source-backed
  1. 2026-01
    Large Load Considerations initiative

    CAISO opened a Large Load Considerations initiative with an issue paper January 30, 2026, working the seams between utility-level load interconnection and CAISO transmission planning.

    Source
  2. 2024-10
    Zonal interconnection reform approved

    FERC approved CAISO's zonal, scored interconnection process applying to Cluster 15, designating merchant zones where developers fund upgrades.

    Source
  3. 2025-10
    IPE 5.0 draft final proposal

    CAISO released Interconnection Process Enhancements 5.0 draft final proposal, refining scoring, deliverability, and readiness reforms.

    Source

Upcoming milestones

Source-backed
  1. 2026-08-17
    Show-cause response due (EL26-71)

    CAISO must justify or reform its large-load posture by August 17, 2026 (Nov 15 with abeyance). Because CAISO does not directly study load interconnections, its remedy will differ structurally from PJM's.

    Source
  2. 2026
    Track 3 second FERC filing

    CAISO to file second Track 3 reforms in 2026, with more granular processing timelines for Cluster 16 and future clusters.

    Source
  3. 2026-07
    Monterey Park data-center ban

    Monterey Park, Calif. voters approved a ballot measure banning data centers inside city limits — an early example of prohibition by referendum. (Data Center Knowledge, July 2026.)

    Source

Sources & last updated

Provenance
Last updated
2026-07-09
Primary source
https://www.caiso.com/generation-transmission/generation/generator-interconnection
Source registry