Interconnecting under SCE’s TOT

SCE’s Transmission Owner Tariff (SCE’s TOT) describes the interconnection operating and metering requirements for wholesale load customers and transmission expansions to SCE’s transmission system.  Visit the “TO Tariff Activities” section and the “SCE Transmission Owner Tariff” expandable section on our Regulatory – FERC Open Access Information  page for the latest on tariff and Formula Transmission Rates.

Generator Interconnection Procedures

SCE’s is a Participating Transmission Owner (or PTO) to the CAISO, and as such, SCE’s transmission system is under the control and operation of the CAISO. Requests for interconnecting new generation projects to SCE’s transmission system, or modification to existing generation projects connect to SCE’s transmission system, are administered by the CAISO.

New requests for interconnection of generation projects to SCE’s transmission system are processed under the CAISO Tariff Appendix DD - Generator Interconnection And Deliverability Allocation Procedures (known as the “GIDAP”). Links to the CAISO Tariff and the GIDAP (and all attachment and all appendices are provided below).

• CAISO Conformed Tariff (as of April 24, 2015)
• CAISO Tariff (by section and appendix)
• CAISO Appendix DD - Generator Interconnection And Deliverability Allocation Procedures (“GIDAP”) (as of December 19, 2014)

For additional Information regarding the CAISO’s process to interconnect new generation projects please visit:

• CAISO’s Generator Interconnection

Other Important Reference Documents.

Additional Information. Please consult with your local planning or permitting authority to verify any local permitting requirements. SCE does not provide permitting services.

1. SCE’s Interconnection Handbook provides information regarding technical requirements for installing and operating your generation system in a safe and reliable manner.
2. SCE’s Electrical Service Requirements (ESR) manual provides guidance and instructions pertaining to electrical service connections. Its purpose is to assist electrical contractors, engineers, architects, and manufacturers engaged in the installation of electrical service wiring and equipment.
3. To find out if the circuit you have chosen to interconnect your project is on SCE’s transmission or distribution system, please send a question with the identified pole number and the voltage (kV) of the line selected to interconnectionQA@sce.com.
4. For information regarding interconnection to SCE’s distribution system, please visit our WDAT page or our Rule 21 page.
5. For any other questions regarding SCE’s TOT, or to find information about our interconnection processes, please email interconnectionQA@sce.com.

Eligibility for Interconnection Under SCE's TOT

SCE’s TOT is applicable for wholesale load customers and transmission expansions interconnecting to SCE’s transmission system. There is no size limitation to request interconnection to SCE’s transmission system.

Interconnection of New Wholesale Generation Projects

New generation projects seeking interconnection to SCE’s transmission system are required to submit an application to the CAISO in accordance with CAISO’s GIDAP (Generator Interconnection And Deliverability Allocation Procedures). Please visit the CAISO’s homepage for information on how to submit an application for interconnection.

For additional Information regarding the CAISO’s process to interconnect new generation projects please visit:

• CAISO’s Generator Interconnection

Application for Interconnection of New Wholesale Load or Transmission Expansion Projects

New wholesale load projects or transmission expansions seeking interconnection to SCE’s transmission system are required to do so under SCE’s TOT.

In order to review the requirements for interconnection, the customer is required to submit to SCE the following documents along with your application:

1. A written request with a complete description of the applicant and the proposed project, including:
   • The identity, address, telephone number, and facsimile number of the customer
   • The proposed interconnection point(s) to the CAISO Controlled Grid
   • The requested maximum amount of interconnection capacity
   • The proposed date for energizing the interconnection and the term of the interconnection service;
2. A single-line drawing
3. Site/plot plan drawing, if available
4. Diagrams, manufacturer’s data, and written descriptions of the facilities

SCE reserves the right to request additional information necessary to review the scope of the proposed project to make a determination on the need for studies or any other analysis to evaluate the interconnection request.

Interconnection Request Fees. At this time, there is no interconnection application fee required for wholesale load or transmission expansion customers seeking to interconnect to SCE’s transmission system.

Once completed, please email electronic copies of your application package (items 1 through 4, above) to Grid.Interconnections@sce.com, or alternatively, mail your documents to:

Grid Interconnection & Contract Development
Southern California Edison
2244 Walnut Grove Ave
Rosemead, CA 91770

What Happens After Submitting Your Application For Interconnection. Following the submittal of the application package, SCE’s assigned project manager will coordinate the review of the information provided with the application; an assigned engineer will perform a validation of the technical data as well. Once the application package is deemed complete and valid, SCE’s project manager will schedule a scoping meeting with the customer to discuss the details of the project and to identify the studies necessary to evaluate the interconnection.

System Impact Study. If SCE determines that a system impact study is required to evaluate the impacts of the new interconnection in SCE’s electric system, the scope of the study, its timelines and costs, will be discussed with the customer at the scoping meeting. A system impact study agreement is required to perform the study; the costs of performing the study are the responsibility of the customer proposing interconnection. The procedures to perform the system impact study are described in Section 10.7 of SCE’s TOT.

Facilities Study. If the system impact study indicates that additions or upgrades to the CAISO’s control grid or SCE’s electric system are needed to satisfy an applicant’s request for interconnection, SCE will discuss the scope of the study, its timelines and costs, with the customer during the results meeting for the system impact study. A facilities study agreement is required to perform the study; the costs of performing the study are the responsibility of the customer proposing interconnection. The procedures to perform the facilities study are described in Section 10.9 of SCE’s TOT.

Interconnection Agreement. The results of the system impact study and the facilities study will be the basis for the scope and estimated cost to be included in the interconnection agreement (IA). Within thirty (30) calendar days following the results meeting for the final interconnection study report, the customer must request SCE to provide a draft IA. Normally SCE will provide a draft IA within thirty (30) calendar days from the request. At that point, SCE and the customer will begin negotiations to complete the IA under the guidelines provided in Section 8.1.3 of SCE’s TOT.