Distributed Generation (Rule 21 Retail Generators)

Rule 21 Ombudsman Information

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

Brian Kirchner

NEW! Apply for Rule 21 Non-Export Projects (Form 79-974) using our online application form.

NEW! Apply for Rule 21 Export Projects (Form 79-1145) using our online application form.

Distributed Generation (DG), also referred to as Retail Generators, applies to customers who install generators to reduce the amount of power they purchase from the utility or enter into a Public Utility Regulatory Policy Act (PURPA) Power Purchase Agreement (PPA). These generators may be powered by solar, wind, hydro, fuel cell, or natural gas. They typically operate in parallel with Pacific Gas and Electric Company and may or may not sell their power to any third parties through a PURPA PPA. Sometimes they may, per California Public Utilities Commission (CPUC) Section 218, sell or provide electricity to other limited parties via a direct ("over the fence") transaction that does not otherwise use utility or ISO facilities.

DG Interconnection Basics

The interconnection requirements for Distributed Generation (DG) are determined by the California Public Utilities Commission (CPUC). DG generators are also referred to as Rule 21 Generators. Electric Rule 21 outlines the interconnection, operational and metering requirements for generating facilities that are connected to the Pacific Gas and Electric Company (PG&E) distribution system.

Secondary Networks: Parts of San Francisco and Oakland are served by secondary network distribution lines, which pose special problems for interconnections. If you are planning a project in San Francisco or Oakland, please contact PG&E's Generation Interconnection Services department to discuss your plans, before you start work on your project.

Frequently Asked Questions

Where can I find an Electric Rule 21 application?

DG interconnection procedures are contained in Rule 21. In addition to a completed Generating Facility Interconnection Application for Non-Export or certain Net Energy Metered Generating Facilities (Between 30 kW and 1,000 kW) (Form 79-974) or Rule 21 Exporting Generator Interconnection Request (Form 79-1145), applicants must also include a check for $800, made payable to Pacific Gas and Electric Company, along with all supporting documentation. To ensure that the application package is complete, refer to the following table:

ApplicationMake sure that ALL applicable sections for your generator are completed.
Application FeeElectronic applications will not be deemed complete until the check for $800 is received (unless exempt).
Site PlanShow generator location with respect to building, transformer, main switchboard, utility disconnect switch and other pertinent electrical equipment.
Single Line DrawingMust include net generation meter (if required) and utility disconnect switch with manufacturer and model number.
Three Line DrawingRequired if the generator is not certified or an external relay is used.
Proposed Relay SettingsRequired if the generator is not certified or an external relay is used.
Protection Operating DescriptionRequired if the generator is not certified or an external relay is used.

Submit the application package to Pacific Gas and Electric Company either by registered U.S. mail or by e-mail: gen@pge.com ATTN: Interconnection Services Mail Code N7L, P.O. Box 770000 San Francisco, CA 94177-0001.

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Is there an application review process or timeline?

In accordance with Rule 21, Pacific Gas and Electric Company will conduct some or all of the following interconnection reviews to determine the interconnection requirements for a generation project.

  1. Application Review: The application will normally be acknowledged and reviewed for completeness within 10 business days of PG&Es receipt of the application. The application must be complete before PG&E can move on to the initial review.
  2. Initial Review: The review shall be completed, absent any extraordinary circumstances, within 10 business days of PG&Es acceptance of the completed application. This review will determine if the generation facility qualifies for a simplified interconnection or if a supplemental review is required.
  3. Supplemental Review: The review, if required, should be completed within 20 business days of deeming the application complete. Payment of $2,500 by the applicant for the supplemental review must be submitted to us within 10 days of issuance of review. The review will determine if the generation facility can be interconnected or if a Detailed Interconnection Study is required first.
  4. Detailed Interconnection Study: The applicant must enter into an agreement with Pacific Gas and Electric Company to perform additional studies, facility design/engineering, and cost estimates for required interconnection facilities. The study is at the applicant's expense.

Prior to interconnecting generation projects to Pacific Gas and Electric Companys (PG&E) distribution system, the applicant must execute some or all of the following agreements:

Generating Facility Interconnection Agreement: (79-973)
This standard CPUC approved agreement authorizes applicant to interconnect and operate its generating facility in parallel with PG&Es distribution system. It establishes the ongoing business relationship between the applicant and PG&E including operating and communication protocols.

Standby Agreement: (79-285)
This standard CPUC approved agreement covers provision of electric standby service to applicants who require Pacific Gas and Electric Company to reserve capacity and stand by ready at all times to deliver electricity on an irregular or non-continuous basis.

Natural Gas Service Agreement: (79-756)
To qualify for Schedule G-EG, Gas Transportation Service to Electric Generation, electric generators must complete a standard CPUC Natural Gas Service Agreement (NGSA) along with supplementary exhibits. This agreement is available upon request.

Special Facilities Agreement: (79-280)
This standard CPUC approved agreement is between Pacific Gas and Electric Company and the applicant and specifies the cost of the interconnection facilities that must be constructed to interconnect. This agreement is available upon request.

Note: The interconnection agreements above are posted for illustrative purposes only. These agreements should not be downloaded and completed by individual interconnection applicants. The agreements will be filled out by PG&E Generation Interconnection Services (GIS) project manager after the completion of the review and study process, and sent to customer-applicants for execution. The GIS project manager will work with you to ensure that the appropriate agreements are properly prepared, at the appropriate time, and guide your project to interconnection.

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What agreements need to be executed to complete an interconnection?

What is customer generation departing load?

Rule 21 retail generators that supply all or part of the electric load for their facilities either through on-site generation or from an over-the-fence (OTF) source "depart" from the Pacific Gas and Electric Company's electric grid. These generators may incur certain financial obligations known as nonbypassable charges (NBCs) as a result of their departing load. Learn more about Customer Generation Departing Load.

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What is a Pre-parallel Inspection?

Once the customer notifies PG&E that the generator is ready for the pre-parallel inspection, scheduling an inspection can take up to 10 days for certified generators with no external relays and up to 30 days for all other generators depending on resource availability. The following items must be complete prior to scheduling the inspection with PG&E:

  1. Execute all required agreements.
  2. Install net generation electric output meter if required.
  3. Provide a copy of the final signed building permit for the generation facility.
  4. Customer to complete all electric work required by Pacific Gas and Electric Company.
  5. PG&E has completed installation of (PG&E-owned) gas service/meter if required.
  6. Commissioning test complete and certified.

Once the inspection is scheduled for non-certified generators or certified generators with external relays, the following information must be received by PG&E a minimum of 15 days prior to the inspection:

  1. PG&E approval of single line and three line relay drawings. (An electronic version is preferred.)
  2. Electronic submittal of the completed DG5 Form (PDF, 70 KB). (One form for each generator.)
  3. Completed Basic Info Requirement Form (PDF, 58 KB).
  4. Approved commissioning test results of relay field "bench tests" provided. (An electronic version is preferred.)
  5. Commissioning Test Certification Form

Note: To establish a smooth efficient process it is imperative that the Transmission Interconnection Handbook (Sections G1-5) and Distribution Interconnection Handbook be followed to ensure that our interconnection and protection requirements are met and supporting documentation is provided and approved by PG&E prior to the inspection.


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Are there any financial incentives or assistance programs?

The Self-Generation Incentive Program provides financial incentives to customers who install new "clean" on-site distributed generation (DG) facilities up to 5 megawatt (MW). This statewide program was implemented as part of a legislative effort to reduce electric demands on the grid in California. The program began accepting applications in July 2001 and is expected to continue through 2007.

The generation facilities must be certified to operate in parallel with the electric system grid (i.e., not back-up generationand must meet other criteria established by the CPUC). Though residential customers are not barred from the program, it is designed primarily for business or large institutional customers.

NOTE: An application for the Self-Generation Incentive Program only addresses the incentive program. The Rule 21 interconnection application (Form 79-974) must also be used to address the physical and contractual aspects of interconnection.

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Is there a timeline or schedule for an Interconnection project?

The timeline for completing the Electric Rule 21 interconnection process varies. Project energy needs, location, and impacts on the PG&E grid are all factors. This chart includes typical project timelines.

Type of InterconnectionTimeline
Simplified Interconnection3 to 6 months
Supplemental Review3 to 7 months
Detailed Interconnection Study4 to 10 months

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What are the most common reasons for Interconnection project delays?

Delays to an interconnection project can be caused by a variety of factors. These variables can include: location, energy needs, distribution system infrastructure, and size of generator. Some of the more common problems that can cause delay include:

  1. When an Applicant changes the proposed project design.
  2. When an Applicant does not perform a Commissioning Test before the Pre-Parallel Inspection is scheduled. (Please see PPI (PDF, 77 KB) and Commissioning Test (PDF, 93 KB) checklists.)
  3. When an Applicant uses non-certified and non-approved generation equipment (this includes: protective relays disconnect switches, transformers, or generators).

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How much does it cost to interconnect to the PG&E grid?

Electric Rule 21 project costs vary depending on a number of factors: energy needs, location, and the system impacts.

Note: For more information please review the California Energy Commissions (CEC) website.

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How might my DG interconnection effect my Natural Gas supply arrangements?

If the generation facility operates on natural gas delivered by Pacific Gas and Electric Company, an Application for Gas Service must be submitted to the local PG&E Service Planning Department for processing in accordance with Gas Rule(s) 15/16. Please note that additional charges and associated agreements may be required to provide a new or upgraded gas service. An initial engineering deposit fee of $1,500 is normally required for this part of the project.

If gas service is billed under the G-EG rate schedule for the generation facility, a separate Pacific Gas and Electric Company gas meter must be installed for proper billing. A Pacific Gas and Electric Company net generation electric output meter may be required depending on project specification.

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Contact Us

Please call our Generation Interconnection hotline at (415) 972-5676 or send an email message to: gen@pge.com.

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