Electric Rule 21

Electric Rule 21 Package

The parallel operation of a self-generation unit requires interconnection with SDG&E’s distribution system. The first step is to fill out the required documents that are a part of the Electric Rule 21 Package.

Download Electric Rule 21 Package Documents

Interconnection, operating and metering requirements are described in electric Rule 21, approved by the California Public Utilities Commission (CPUC).

Interconnection Requests to be studied under the Distribution Group Study Process shall either be (a) an Independent Study Process Interconnection Request that passed screen Q and failed Screen R for which the Applicant elects to continue to the next available Distribution Group Study, or (b) an Interconnection Request submitted during a Distribution Group Study Application window that passes Screen Q.

Please refer to Rule 21 for a description of Screens R and Q

New Interconnection Requests for the Independent Study Process will NOT be accepted during the Distribution Group Study application window dates listed above.

Apply Now for Electric Rule 21 Behind the Meter

Rule 21 Tariff

Rule 21 Distribution Group Study Process Webinar Presentation – August 26, 2014

SDG&E Generation Interconnection Request Queue

SDG&E WDAT Interconnection Queue (pdf)

SDG&E WDAT & Rule 21 Interconnection Queue (pdf)

SDG&E provides non-discriminatory access to the grid for all generation projects that request interconnection to the grid under Federal Energy Regulatory Commission (FERC) regulations, the California Independent System Operator (CAISO) Tariff and the SDG&E tariff.

Rule 21 Pre-Application Report

Information about the available capacity on utility equipment in a particular area can be obtained prior to submitting a formal application for interconnection of an Electric Rule 21 project. 

Click on the link below for more information about the type information available, and also to obtain the request form. 

To submit a form via email please print out the form, fill it out, scan it, and attach it to an email to DGInquiries@semprautilities.com.  It can also be submitted via postal service to:

Customer Generation
San Diego Gas & Electric Company
8316 Century Park Ct, CP52F
San Diego, CA 92123

A processing fee is required to obtain the requested information, however, please do not send payment with your request.  SDG&E will provide an invoice for all requests. The information request form can be accessed at:

Rule 21 Pre Application Report Request

Rule 21 Interconnection Request

Applicants for Electric Rule 21 generator projects that will export power to the SDG&E system shall submit a completed Interconnection Request (IR).  Applicants shall submit a separate IR for each point of interconnection.  The IR form can be accessed at: 

Exporting Generator Interconnection Request

Rule 21 Interconnection Agreement for Cluster Study or independent study process

Rule 21 Independent Study Process Study Agreement


Documentation of site control or site exclusivity must also be submitted with the IR.  The completed IR form with evidence of site exclusivity can be submitted via email to DGapplications@semprautilities.com or via postal mail to:

Customer Generation
San Diego Gas & Electric Company
8316 Century Park Ct, CP52F
San Diego, CA 92123

After submittal of the IR, SDG&E shall provide an invoice for a non-refundable Interconnection Request Fee of $800.

Fast Track Generation Interconnection Agreement

Applicants for Fast Track generator projects that choose to proceed to a Generation Interconnection Agreement shall notify SDG&E, in compliance with the provisions of Rule 21 section F.2.e.  SDG&E shall provide Applicant with a draft Generator Interconnection Agreement for Applicant’s signature within fifteen (15) business days of Applicant’s request.  An incomplete Generator Interconnection Agreement is provided for reference at:

Generator Interconnection Agreement
For Exporting Generation Facilities Interconnecting Under the Fast Track Process

Upon receipt of a draft Generator Interconnection Agreement, Applicant has ninety (90) calendar days to sign and return the Generator Interconnection Agreement. Applicant shall provide written comments, or notification of no comments, to the draft Generator Interconnection Agreement and appendices within thirty (30) Calendar days.

Emergency/Standby Generator (w/transfer switch only)

A standby generator that is permanently connected to a customer's electric wiring system supplies electricity to a building when SDG&E’s service is not available. Permanently installed generators must not be connected to another power source, such as to SDG&E's electric system that can cause back-feed problems. Back-feeding is where electricity from a generator flows into a building's wiring, through SDG&E's electric meter to the SDG&E transformer and then into SDG&E's electric grid.

A double-pole, double-throw transfer switch is the recommended device to keep a generator from back-feeding into SDG&E's electric grid. The transfer switch breaks the path of electricity between the utility’s power and the customer’s main electrical panel. This is the best way to protect you, your neighbors and SDG&E’s line crews from back-feed.

If you are installing or have installed a permanent emergency/standby generator, please download the information form and provide the requested information. The California Health and Safety Code requires that a customer notify the utility of a permanent standby generator installation. Additionally, this information will allow SDG&E to check for any design attributes that could allow the generator to inadvertently back-feed into SDG&E’s electrical system. 

Rule 21 Ombudsman Information

To address disputes regarding Rule 21 missed timelines, please contact SDG&E’s appointed ombudsman.

Joe McCawley


Additional Resources

Qualifying Facility (QF)*Information on how to become a Qualifying Facility (QF).

Code of Federal Regulations, Title 18, Part 292*
Federal Energy Regulatory Commission (FERC), Department of Energy – Regulations under Sections 201 and 210 of the Public Utility Regulatory Policies Act (PURPA) of 1978 with regard to small power production and cogeneration.

California Public Utilities Code Section 216.6*
For information on the waste heat recovery criteria.


For more information or assistance with your application, email our Self Generation Team

Customer Generation
San Diego Gas & Electric
8316 Century Park Court, CP52F
San Diego, CA  92123

Office:  (858) 636-5581

E-mail: DGInquiries@semprautilities.com