Author: Mac Millan
CAISO Large Load Information Session Summary (Feb 5, 2026)
1. Meeting Overview: CAISO Large Load Information Session
CAISO’s Large Load session focused on the growth of data centers and EV charging on planning, interconnection, and operations. CAISO noted that approximately 4.5 GW of data center demand is currently being studied in the 2025–2026 transmission planning cycle, while utilities continue to see a steady rise in large-load service and interconnection applications. The discussion saw large-load growth as a change that will influence transmission development and regulatory coordination going forward.
2.CAISO Large Load System and Market Context: Data Center Growth, EV Charging and Electrification Processes
Large-load growth is being driven primarily by data centers, with additional contributions from EV charging and broader electrification of industrial processes. CAISO indicated that it is accelerating and is already shaping transmission planning and interconnection.
The California Energy Commission projects data center load in the CAISO balancing area to grow 1.8 GW by 2030 and 4.9 GW by 2040. These forecasts are being incorporated into demand modeling, procurement planning, and transmission discussions.
The CEC develops demand forecasts, CPUC provides resource planning inputs, and CAISO integrates these into transmission planning and interconnection. The planning responsibilities are coordinated in this manner.
3. Key Agenda Items and Takeaways
Transmission and resource planning: CAISO highlighted the 2022 MOU between the ISO, CPUC, and CEC, which defines how demand forecasting, resource planning, and transmission development are coordinated. Integrated planning has enabled roughly 31 GW of new resources to come online since 2020 and is now being used to position the system for continued large-load growth.
Large-load interconnection pathways: Large loads may interconnect through either distribution or transmission systems. Where loads are co-located with generation or storage, interconnection processes are split between the transmission owner (for load) and CAISO’s resource interconnection process (for generation).
Transmission service offerings: CAISO also discussed their introduction of customized transmission service options aimed at enabling faster interconnection and reducing infrastructure costs, such as interim or non-firm service while system upgrades are completed. These concepts remain early-stage, with no defined structure yet for implementation or applicability to existing versus new loads.
Cost allocation: Cost allocation for large-load interconnection remains largely governed by utility retail tariffs (e.g., CPUC Rules 15, 16, and 30). Co-located generation follows ISO tariff structures or state/local tariff pathways. Federal direction is evolving, with FERC indicating that large loads and hybrid facilities may be responsible for the full cost of assigned network upgrades and exploring how grid and ancillary service benefits should be reflected in rate structures.
Technical requirements: Technical requirements of large loads was a major focus including:
- Voltage and frequency ride-through capability
- Limits on rapid ramping
- Pulsating load characteristics observed in AI-driven computing.
These behaviors can introduce stability challenges such as oscillations, sub-synchronous resonance, and fluctuations. Power quality, modeling approaches, study methodologies, and compliance expectations were also highlighted.
A technical working group involving CAISO, utilities, and other operators is reviewing existing requirements across regions and planning parametric studies to determine whether ISO-specific standards are needed, with alignment to NERC.
Operational requirements and system integration: Operational readiness with emphasis on balancing authority responsibilities as large loads affect real-time system behavior and frequency response. Participating and non-participating loads include telemetry, planned operating schedules, acceptable ramp rate, and a 24/7 curtailable capability.
CAISO pointed to impacts on demand forecasting and market participation. As flexible loads increase, maintaining predictability becomes more critical. The Demand and Distributed Energy Market Integration (DDEMI) initiative is expected to address participation rules and design considerations. Coordination between transmission and distribution planning was also highlighted as a priority.
4. Technical or Process Implications
The discussion suggests CAISO is still defining how new transmission service offerings for large loads will function, but there is clear urgency to move quickly and shorten interconnection timelines.
At the same time, technical expectations appear more established. Requirements around ride-through capability, ramp behavior, telemetry, and modeling are already being shaped, with the remaining work focused on standardization and formal adoption.
Co-location of large loads with generation and storage was highlighted, introducing coordination with load and resource interconnection processes and likely affecting project timelines.
Overall, the direction points toward faster interconnection pathways paired with tighter technical and operational expectations.
5. Risks, Open Questions, or Watch Items
A key uncertainty is how customized transmission service offerings will ultimately be structured. While CAISO signaled interest in enabling new service models, there is currently no defined structure for implementation or clarity on whether they will apply to new loads only or also to existing customers.
PG&E Application to the CPUC proposing a new electric rule tariff to interconnect transmission-level customers seeking retail service (Electric Rule 30)
6. What’s Next
CAISO will continue coordination with state agencies, local regulators, and utilities on technical standards, planning approaches, and operational expectations for large loads.
The ISO is also monitoring federal activity related to large-load interconnection and co-located development, including direction from FERC. Stakeholder engagement will continue as planning and service offerings evolve.
Navigating CAISO Large Load Processes
Large-load projects in CAISO are moving toward faster pathways, but with tighter technical, modeling, and operational expectations. We help data center and large-load developers assess interconnection risks early, align technical assumptions with CAISO requirements, and navigate evolving transmission and service options.
If you’re evaluating a large-load or co-located project in CAISO, contact ZEG to get early clarity before commitments are locked in.
References
Video – Large Load Information Session – Feb 05, 2026
Issue Paper – Large Load Consideration – Jan 20, 2026
Presentation – Large load Considerations – Stakeholder Information Session – Feb 05, 2026
