Interconnection request and study
New resources interested in interconnecting to the ISO controlled grid are required to complete a study process. To begin the study process, resources must submit an Interconnection Request into a tariff-defined study process.
Transmission-level resource interconnection
In general, if the desired interconnection voltage level is listed below, an Interconnection Request should be filed with the ISO. Review the Interconnection Area Substation Point of Interconnection (POI) List to determine if the desired POI is ISO controlled. Contact IRInfo@caiso.com for additional assistance.
- Pacific Gas & Electric service area: transmission lines 60 kV and higher
- Southern California Edison service area: several 66 kV and 115 kV lines and all transmission lines 220 kV and 500 kV
- San Diego Gas & Electric service area: transmission lines 69 kV and higher
- Municipal utility service areas: some lines owned by the municipal utilities but outside of the cities’ boundaries
- Valley Electric Association service area: transmission lines 138 kV
- GridLiance West service area: transmission lines 230 kV and 500 kV
- Ten West Link Delaney to Colorado River (DCRT): 500 kV transmission line
- DesertLink Harry Allen to Eldorado (DSLK): 500 kV transmission line
- Other transmission lines: Trans-Elect NTD Path 15, Startrans, Trans Bay Cable, Western Area Power Administration-Path 15, and several lines outside the ISO Balancing Authority which have been turned over to ISO for operational control
Informational presentations and guidelines
The generator interconnection planning process provides a pathway for power plants to interconnect to the ISO controlled grid. We provide information and resources to help you understand and comply with requirements.
Resource Interconnection Standards Fair
Hosted annually, this educational forum provides stakeholders with an opportunity to learn more about the ISO’s interconnection process and recent changes affecting Cluster 15. The last fair was held Sept. 17, 2024, see the event page for presentation and video recording.
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Resource Interconnection Standards Fair Questions and Answers11/06/2024, 9:59 AM
Answers to questions related to the CAISO Resource Interconnection Standards Fair
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Presentation - Resource Interconnection Standards Fair 202409/20/2024, 11:30 AM
Information on the many facets of the interconnection application process - from the requirements, how to apply, and what to expect during the process.
- Resource Interconnection Standards Interconnection Study Timeline09/16/2024, 3:15 PM
- Generator Interconnection Deliverability Allocation Procedures Customer Guidelines08/30/2024, 9:51 AM
Commercial Interest
To allocate commercial interest points to Interconnection Customers, a Load Serving Entity must do the following at least two months prior to the Cluster Application Window’s opening: 1) Provide the CAISO written, electronic notice of intent to participate in the points allocation. The notice must include (a) the publicly accessible website used by the Load Serving Entity; and (b) the contact information for the person or department Not current tariff language This document includes pending language Pending Tariff Language conducting the points allocation for the Load Serving Entity. 2) Publish on the publicly accessible website (a) the selection criteria or consideration factors for awarding points; and (b) the contact information for the person or department conducting the points allocation for the Load Serving Entity. Public websites requiring registration are permissible. Within five (5) Business Days after the deadline for Load Serving Entities to provide their notices, the CAISO will publish on the CAISO Website the contact information, website, and points allocation for each participating Load Serving Entity.
Load Serving Entities submitting commercial interest points must do so no later than ten (10) days after the CAISO provides the list of Interconnection Requests.
Affidavits from non-Load Serving Entities must be executed by an authorized representative. The affidavit must attest the counterparty is supporting the Interconnection Request in support of corporate policy goals on sustainability; the capacity of the Interconnection Request aligns with its individual needs; the counterparty and its holding company, if any, is not affiliated with the Interconnection Customer or its holding company; and that the counterparty and its holding company and affiliates support this Interconnection Request only, and no other Interconnection Requests in this Cluster Application Window.
- Cluster 15 Interconnection Request Intake Process Training on LSE Commercial Interest Scoring Process09/11/2024, 12:09 PM
- C15 Commercial Interest Information11/27/2024, 10:30 AM
- Affidavit Non-LSE Commercial Interest11/20/2024, 8:58 AM
Submit an interconnection request for study
Determine which available study process is appropriate for your interconnecting facility then submit an interconnection request to begin the study. Sample reference documents are available below. Requests will only be accepted through the Grid Resource Interconnection Portal.
Grid Resource Interconnection Portal (GRIP)
The resubmission window is now closed.
Interconnection study options
The ISO has three interconnection options for resources interconnecting to the high voltage ISO controlled transmission system:
1. Cluster study process
Designed for most interconnection customers. See Pending Tariff Appendix KK Section 3.
REQUIREMENTS
- Completed interconnection request
- Study deposit
- Evidence of site control or regulatory limitation and site control deposit
- Technical data
APPLICATION RESUBMISSION WINDOW
- The application Resubmission Window is open Oct 1, 2024, to Dec 2, 2024
- This window is only open to projects that were deemed complete in the 2023 Cluster 15 application window
2. Fast track study process
Designed for interconnection customers developing or adding less than 5 MW and is requesting Energy Only Deliverability. See Pending Tariff Appendix KK Section 5.
REQUIREMENTS
- No larger than 5 MW
- Energy Only Deliverability status
- Must pass all screens*, as detailed in Tariff Appendix DD Section 5.2.1
- Completed interconnection request
- Non-Refundable $500 processing fee
- Evidence of site exclusivity
- Technical data
* Customer Options meetings are needed if they fail screens. Additional supplemental review meeting based on the outcomes of the customer options meetings (includes a short study process and additional deposit for estimated costs).
REQUEST WINDOW
- An applicant may apply at any time of the year
3. ISO as an affected system study
Designed for interconnection customer in Balancing Authority Areas that may affect the reliability of the ISO Controlled Grid. See Pending Tariff Appendix KK Section 14.5.
REQUIREMENTS
Forms and resources
Interconnection study resources, supplemental examples and documents
- Appendix B to Generator Interconnection Study Process Agreement09/30/2022, 3:23 PM
- Briefing on Resources Available for Near Term Interconnection12/05/2023, 3:03 PM
- Evaluation of Generator Reactive Capability - White Paper09/02/2021, 11:26 AM
- Generating Facility Data - Sample Solar and Battery
- Generating Facility Data - Sample Wind
- Inverter-Based Interconnection Requests (IBR) Dynamic Model Review Guideline10/07/2021, 10:10 AM
- ISO Inverter-Based Model Validation Procedure03/30/2023, 9:17 AM
- Pre-Application Report Request Form11/09/2016, 12:56 PM
- Prohibited Project Names03/13/2023, 12:02 PM
- Upgrade and Cost Responsibility Implementation11/27/2019, 9:50 AM
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Resource Interconnection Standards Fair Questions and Answers11/06/2024, 9:59 AM
Answers to questions related to the CAISO Resource Interconnection Standards Fair
-
Presentation - Resource Interconnection Standards Fair 202409/20/2024, 11:30 AM
Information on the many facets of the interconnection application process - from the requirements, how to apply, and what to expect during the process.
- Resource Interconnection Standards Interconnection Study Timeline09/16/2024, 3:15 PM
- Generator Interconnection Deliverability Allocation Procedures Customer Guidelines08/30/2024, 9:51 AM
- Site Exclusivity/Control Demonstration Form06/14/2024, 4:24 PM
Affected systems
The ISO will notify the Affected System Operators that are potentially affected by the Interconnection Customer’s Interconnection Request. If required by an Identified Affected System, the Interconnection Customer will sign separate study agreements with the Identified Affected System and pay for necessary studies. See Tariff Appendix DD, section 3.7.
- Affected Systems Contact List11/04/2024, 2:28 PM
Participating transmission owner financial security instruments
Use our standardized forms to post Interconnection Financial Security with the applicable Participating Transmission Owner.
Cluster 15 Instructions for Commercial Readiness, Merchant Deposit, Study Deposit and Application Fee requirements
DCR Transmission (DCRT)
- Letter of Credit - DCRT04/05/2018, 8:46 AM
DesertLink
- DesertLink - Letter of Credit09/26/2024, 10:12 AM
- DesertLink Surety Bond10/09/2024, 11:59 AM
GridLiance West (GLW)
- Guaranty - GLW09/20/2024, 10:21 AM
- Letter of Credit - GLW09/18/2024, 5:31 PM
Horizon West Transmission (HWT)
- HWT - Letter Of Credit10/28/2024, 1:04 PM
- HWT - Guaranty10/28/2024, 1:03 PM
LS Power Grid California
- LS Power Grid California - Letter of Credit09/26/2024, 10:12 AM
- LS Power Grid California Surety Bond10/09/2024, 11:59 AM
OC TRANSMISSION LLC
- Letter of Credit - OC Transmission LLC10/18/2024, 9:53 AM
Pacific Gas and Electric Co. (PG&E)
- Surety Bond - PG&E Interconnection Facilities06/04/2024, 2:02 PM
- PG&E Escrow Agreement - Transmission Tariff05/21/2024, 3:28 PM
- Surety Bond - PG&E Network Upgrades05/21/2024, 3:28 PM
- Letter of Credit - PG&E05/21/2024, 3:28 PM
Southern California Edison (SCE)
- SCE - Grid Interconnection Guaranty10/21/2024, 1:29 PM
- SCE - Certificate of Deposit Instructions10/21/2024, 1:28 PM
- SCE - Grid Interconnection Escrow Agreement US Bank10/21/2024, 1:28 PM
- SCE - Grid Interconnection Surety Bond10/21/2024, 1:28 PM
- SCE - Grid Interconnection Standby Letter of Credit10/21/2024, 1:28 PM
San Diego Gas and Electric (SDG&E)
- Surety Bond SDG&E Cluster 15 and Subsequent Clusters11/14/2024, 8:35 AM
- Guaranty SDG&E Cluster 15 and Subsequent Clusters11/14/2024, 8:35 AM
- Letter of Credit SDG&E Cluster 15 and Subsequent Clusters11/14/2024, 8:35 AM
- Guaranty - SDG&E06/04/2024, 2:02 PM
- Letter of Credit - SDG&E06/04/2024, 2:01 PM
- Surety Bond - SDG&E05/24/2024, 4:29 PM
Valley Electric Association (VEA)
- Letter of Credit - VEA04/17/2013, 3:17 PM
- Surety Bond - VEA04/17/2013, 2:41 PM
Participating transmission owner per unit costs
Learn the anticipated costs of procuring and installing facilities required to interconnect generation to the applicable Participating Transmission Owner.
- Current Emergency Interconnection Network Upgrade Maximum10/02/2024, 11:08 AM
- Current Reliability Network Upgrade Reimbursement Maximum10/02/2024, 9:10 AM
Current cost guides
- SDGE 2023 Final Per Unit Cost Guide09/18/2023, 10:49 AM
- VEA 2023 Final Per Unit Cost Guide09/18/2023, 10:49 AM
- SCE 2023 FInal Per Unit Cost Guide09/18/2023, 10:49 AM
- GLW 2023 Final Per Unit Cost Guide09/18/2023, 10:49 AM
- PGAE 2023 Final Per Unit Cost Guide09/18/2023, 10:49 AM
- DCRT 2023 Final Per Unit Cost Guide09/18/2023, 10:49 AM
- DSLK 2023 Final Per Unit Cost Guide09/18/2023, 10:49 AM
Generator interconnection planning process
Continue on in the generator interconnection planning process.
Related ISO Tariff and Business Practice Manuals
The California ISO operates under the terms and conditions of its FERC-approved tariff. Business practice manuals provide detailed rules, procedures and examples for the administration, operation, planning and accounting requirements of the ISO and the market that are consistent with the ISO tariff.
The ISO has filed Tariff Amendments to Comply with Order No. 2023. The documentation below contains draft language pending FERC approval.
- Draft Resource Interconnection Standards Business Practice Manual
- FERC Order and IPE 2023 Pending ISO Tariff Appendix DD
- FERC Order and IPE 2023 Pending ISO Tariff Appendix KK
- FERC Order 2023 Pending ISO Tariff Appendix A
- FERC Order 2023 Pending ISO Tariff Appendix DD
- FERC Order 2023 Pending ISO Tariff Appendix KK
- FERC Order 2023 Pending ISO Tariff Appendix LL
- FERC Order 2023 Pending ISO Tariff Appendix MM
- FERC Order 2023 Pending ISO Tariff Section 25
The current FERC approved Tariff sections are below.
- ISO Tariff05/18/2024, 7:42 PM
- ISO Tariff, Section 2504/05/2024, 11:14 AM
- ISO Tariff, Appendix DD - Generator Interconnection Deliverability Allocation Procedures (GIDAP)04/05/2024, 11:14 AM
- Business Practice Manual for Generator Interconnection and Deliverability Allocation Procedures05/16/2024, 3:29 AM
- Business Practice Manual for Generator Interconnection Procedures05/16/2024, 3:29 AM
- Business Practice Manual for Generator Management05/16/2024, 3:29 AM
- Business Practice Manual for Transmission Planning Process05/16/2024, 3:29 AM
- Business Practice Manual for Distributed Generation for Deliverability05/16/2024, 3:29 AM