Interconnection FAQs

Even for wholesale generation, you must have an Interconnection Agreement with PG&E to meet federal and state regulations. This agreement helps to address:

• Safety. All electrical generation systems can be dangerous if they aren’t operated properly. If your system connects to our electric grid, safeguards must be in place for protecting you, our personnel and other customers.
• Reliability. We must be able to deliver power to our customers when needed. If a fault or trip occurs on your generation system, we must be able to find the problem so other customers can continue to get power.
• Government regulation. The federal government and state of California require an Interconnection Agreement.

For wholesale distribution generation interconnection, we require submission of your request with an online application. Visit "Your Projects."

Access the following documents for related information:

• Get our checklist to help you through the process. Download Wholesale Distribution Online Application Checklist (PDF, 260 KB).
• Learn more about wholesale distribution generation. Refer to Section 1.3 of the Wholesale Distribution Tariff (WD Tariff). Download PACIFIC GAS AND ELECTRIC COMPANY, Wholesale Distribution Tariff (WD Tariff), FERC Electric Tariff Volume No. 4 (PDF, 1.73 MB).

For wholesale transmission generation interconnection, you must make your request through the California Independent System Operator (CAISO). Download Appendix 1 Interconnection Request (DOC, 141 KB).

Get information about the CAISO Tariff. Download Appendix Y GIP – For Interconnection Requests – Generator Interconnection Procedures (GIP) (PDF, 638 KB).

We handle the process for generators interconnecting with the wholesale distribution system. New applicants for interconnection within this system must follow the procedures and complete the proper forms. Get the forms. Download PACIFIC GAS AND ELECTRIC COMPANY, Wholesale Distribution Tariff (WD Tariff), FERC Electric Tariff Volume No. 4 (PDF, 1.73 MB).

CAISO handles the interconnection procedures for generators interconnecting with the wholesale transmission system. New applicants for interconnection under this system must follow the procedures and complete the proper forms for the CAISO Tariff. Get the forms. Download Appendix Y GIP – For Interconnection Requests – Generator Interconnection Procedures (GIP) (PDF, 638 KB).

Get an overview of the process and application timelines for distribution interconnection requests. Download Generator Interconnection Process – Wholesale Distribution Overview (PDF, 293 KB).

Get an overview of the process and application timelines for transmission interconnection requests. Download Generator Interconnection Process Wholesale Transmission Overview (PDF, 289KB).

No, you can’t submit simultaneous requests. The number of projects continues to grow, and each system must be modeled accurately. Systems also must be identified for necessary upgrades to accommodate interconnection requests. We can’t allow applicants to submit a distribution interconnection application and a transmission interconnection application for the same project. You can choose to submit applications in a serial fashion, but not in parallel. That is, the former interconnection request must be withdrawn prior to submittal of the application in serial. This policy helps to continue the equal treatment of our developers.

We maintain a public queue for the Federal Energy Regulatory Commission (FERC) Generator Interconnection Procedures (GIP) distribution-level projects. Download Public Queue (XLS, 580 KB).

We enforce the following guidelines to help ensure equitable treatment:

• We grant one extension of 20 business days wherever the generator interconnection procedure (GIP) allows for an extension.
• We don’t accept requests to place distribution interconnection projects on hold.

Any modification to machine data, equipment configuration or the interconnection site of the generating facility that has not been agreed upon in writing by the distribution provider and the interconnection customer may be considered a withdrawal of the interconnection request. If this situation occurs, the interconnection customer may be required to submit a new interconnection request, unless each party properly notifies the other, and a reasonable time is provided to fix the problems created by the changes.

Get more information about modifications. Download PACIFIC GAS AND ELECTRIC COMPANY, Wholesale Distribution Tariff (WD Tariff), FERC Electric Tariff Volume No. 4 (PDF, 1.73 MB).

PLEASE NOTE: The following sections of the document are applicable to modifications:

• Section 3.5.8, Modifications in Between the System Impact and Facilities Study
• Section 4.11.2, Modifications in Between the Phase I and Phase II Interconnection Studies

More information on modifications is located in Section R.3.d.v of Rule 21, Modifications.

NOTE: Modifications are not permitted to the Fast Track process under either the WD Tariff or Rule 21.

For your application to be considered complete (administrative data adequacy) and for your project to be assigned a queue position, it must contain the following:

• A completed Wholesale Distribution Interconnection Request Form (Attachment 2), Rule 21 Exporting Generator Interconnection Request or Generating Facility Interconnection Application For Non-Export Or Certain Net Energy Metered Generating Facilities (Between 30 kW and 1,000 kW).
• A completed Appendix A form. Download Appendix A – Generating Facility Data (PDF, 208 KB)
• The application fee. Generation Interconnection Services sends an invoice letter with instructions on wire payment when an interconnection request is received.
• A single-line diagram (SLD). View an example. Download sample drawing (PDF, 102 MB)
• A site plan. View an example. Download Example Site Plan (PDF, 548 KB)
• Site control or exclusivity per Section 1.5 of Attachment I: GIP of the PG&E WD Tariff and Section E.2.d. of Rule 21.

When your interconnection request is complete, you're assigned a queue position.

The following resources provide more information on required documentation and timelines for completing an interconnection request for the different wholesale and Rule 21 programs:

• Visit Export Power
• Download Electric Rule No. 21 Generating Facility Interconnections (PDF, 7.52 MB)

A single-line diagram (SLD) is a schematic drawing that illustrates:

• Major electric switchgear
• Protective function devices, including:
  • Relays
  • Current transformer configurations and wiring
  • Potential transformer configurations and wiring
  • Circuit breakers and fuses
• Wires
• Generators
• Transformers
• Meters and other devices

An SLD provides a qualified engineer with essential details about system design and safety. View an example of an SLD. Download SAMPLE DRAWING (PDF, 102 MB).

You can prove site control through documentation that shows:

• Ownership of a leasehold interest in or a right to develop a site for constructing the generating facility
• An option to purchase or get a leasehold site for constructing the generating facility
• Exclusivity or other business relationship between the interconnection customer and the entity with the right to sell, lease or grant you the right to possess or occupy a site for constructing the generating facility

View documentation examples. Download PACIFIC GAS AND ELECTRIC COMPANY, Wholesale Distribution Tariff (WD Tariff), FERC Electric Tariff Volume No. 4 (PDF, 1.73 MB).

After we receive your completed application package and applicable fees, you are invited to meet with us to discuss the scope of your project. This meeting is called a scoping meeting. During your scoping meeting, you and representatives from our Generation Interconnection Services discuss the following:

• Our engineering team's review of the impact of and minimum requirements for establishing an electrical connection between your installation and our distribution system
• Expectations for how long it will take us to study and understand the impact and requirements for the electrical connection
• An overview of the study process and important milestones

The cost to interconnect to our electric system depends on the site and the capacity of the generation you want to install. The electric system nearest to your site might not have the capacity to receive the amount of generation you propose. Specific interconnection facilities, distribution upgrades and network upgrades might be necessary for an interconnection request. The interconnection study process informs you of the scope, schedule and cost of any upgrades your project needs.

For distribution projects, Sections 3.11 and 4.23 of the Generation Interconnection Procedures and Section 4.a of Rule 21 require interconnection customers to post interconnection financial security to remain in the interconnection study process. For transmission projects, Section 11 of the Generation Interconnection and Deliverability Allocation Process requires interconnection customers to post interconnection financial security throughout the stages of the study process. The interconnection financial security posted may be any combination of the following types of financial instruments:

• An irrevocable and unconditional letter of credit issued by a bank or financial institution that has a credit rating of A or better by Standard and Poor’s or A2 or better by Moody’s
• An irrevocable and unconditional surety bond issued by an insurance company that has a credit rating of A or better by Standard and Poor’s or A2 or better by Moody’s (no longer accepted for distribution projects)
• An unconditional and irrevocable guaranty issued by a company that has a credit rating of A or better by Standard and Poor’s or A2 or better by Moody’s
• A cash deposit standing to the credit of the distribution provider and in an interest-bearing escrow account maintained at a bank or financial institution that is acceptable to the distribution provider or participating transmission owner
• A certificate of deposit in the name of the distribution provider issued by a bank or financial institution that has a credit rating of A or better by Standard and Poor’s or A2 or better by Moody’s (not accepted for distribution projects)
• A payment bond certificate in the name of the distribution provider issued by a bank or financial institution that has a credit rating of A or better by Standard and Poor’s or A2 or better by Moody’s (not accepted for distribution projects)

The Fast Track process is for the following situations:

• Existing facilities with infrastructure already built
• New proposed interconnections of certified generation without any new construction of upgrades (construction of interconnection facilities is permitted)
• Distribution or transmission capacity restrictions met

For more information about the Wholesale Distribution Fast Track process, refer to the screens in Section 2.2.1 of Attachment I: GIP of the WD Tariff. Download PACIFIC GAS AND ELECTRIC COMPANY, Wholesale Distribution Tariff (WD Tariff), FERC Electric Tariff Volume No. 4(PDF, 1.73MB).

Learn the requirements to qualify for the Rule 21 Fast Track process in Section F.1.b. of Rule 21. Download ELECTRIC RULE NO. 21 GENERATING FACILITY INTERCONNECTIONS (PDF, 7.52 MB).

Learn more about the CAISO transmission voltage fast track process in Section 5 of the Generation Interconnection and Deliverability Allocation Process (GIDAP). Download California Independent System Operator Corporation – Fifth Replacement Tariff – Appendix DD (PDF, 802 KB).

The Independent Study Process (ISP) evaluates an interconnection request for a generating facility independently of other projects. In the case of projects connected at the transmission voltage level, the interconnection customer must also provide an objective demonstration that the queue cluster will not accommodate the desired commercial operation date for the generating facility. An ISP involves a System Impact Study and a Facilities Impact Study. Both of these studies must be completed within 60 business days. To become eligible for an ISP, you must pass an Electrical Independence Test (EIT) after you apply. This test involves determining if another, earlier queued interconnection request in the area has an electrical dependence (on both distribution and transmission) on the interconnection request undergoing the EIT. If you have a distribution project, you can find out your potential for passing the test by viewing the active projects connecting to the substations at your point of interconnection. No such file is available for transmission projects. Download Public Queue (XLS, 580 KB).

The ISP can take six to 12 months to complete. You may apply for an ISP at any time. However, if your project fails either part of the EIT, you must wait to reapply under the ISP for a similar point of interconnection (WD Tariff only). The following time frames apply to the waiting period:

• Until the earlier queued interconnection request completes the study process (Rule 21 only); or
• Until the next cluster window to apply under the CSP; or
• Twelve months from the date you were informed of the failure of the EIT

The Cluster Study Process (CSP) evaluates a group of interconnection requests collectively. You may apply for a CSP (under the WD Tariff) only during the cluster window each year. Engineering analyses for CSP requests are conducted in two phases. Phase I and Phase II studies identify distribution and reliability network issues or upgrades required to do the following:

• Mitigate thermal overloads and voltage violations
• Address short-circuit and stability issues
• Address other reliability issues

Full-Capacity Delivery means that your generating facility interconnects to our distribution system and delivers its full output to the aggregate of load on the CAISO grid. The delivery must be consistent with the CAISO reliability criteria, procedures and On-Peak Deliverability Assessment.

Become familiar with the requirements of your PPA for resource adequacy. If you apply for Full-Capacity Delivery, you must commit to delivering at maximum power whenever possible. A network-wide engineering analysis is required to mitigate any potential impact on transmission-level voltage facilities.

Energy-Only Delivery means that your generating facility interconnects to our distribution system, but does not deliver its full output to the aggregate of load on the grid. In this case, you’re responsible only for the costs of reliability network upgrades and not for the costs of delivery network upgrades. An Energy-Only project may deliver intermittently and be asked to shut down if electrical constraints occur.

Distribution projects may apply for the Annual Deliverability Assessment during the cluster window. We perform this study in coordination with CAISO to allocate any existing available capacity without requiring upgrades.

In the distribution study processes, you can pursue Full-Capacity Deliverability Status in three ways:

• Full-Capacity Deliverability Study (FCDS). Apply for Full-Capacity Deliverability on the initial application form. This study requires a $10,000 deposit. The FCDS takes two years to complete Phase 1 and Phase 2 studies in order to identify equipment upgrades needed to build the deliverability capacity for the project.
• Annual Full-Capacity Deliverability Study (AFCDS). This study requires a $10,000 study fee. The AFCDS takes two years for yes/no results. No option is available to build additional capacity at the point of interconnection.
• Distributed Generation Deliverability Study (DGDS). Apply annually for a free three-month study process to allocate existing deliverability capacity identified at each node/substation.

Transmission projects select Full-Capacity or Energy-Only status during the submission of their interconnection request. Projects that selected Energy-Only can also request deliverability. For more information on the allocation of deliverability, refer to Section 8.9 of the CAISO GIDAP.

If the assumptions established at the beginning of your study process change, an updated study may be required to re-evaluate the impact of your project on the distribution system. You are responsible for paying for an updated study. Examples of changes that might prompt an updated study include:

• Withdrawal of a higher queued project
• Change in interconnection date
• Change in interconnection customer’s queue position
• Change in interconnection plan
• Change in the generating size of the project

After your scoping meeting, you can request to have the generating size of your proposed facility adjusted. Changes are acceptable during the scoping meeting only for Rule 21. Get information on making modifications after the scoping meeting by reading Section 1.4. of Attachment I: GIP of the WD Tariff. Download PACIFIC GAS AND ELECTRIC COMPANY, Wholesale Distribution Tariff (WD Tariff), FERC Electric Tariff Volume No. 4 (PDF, 1.73 MB).

Our distribution and transmission systems run across our service territory. The interconnection site you propose might be near distribution or transmission facilities (60 kilovolts [kV] and greater is considered the PG&E transmission system; the Southern California Edison transmission system voltage is 230 kV and greater). We review and connect your generating facility to your proposed point of interconnection, whether that is transmission or distribution. However, transforming your power to the interconnection voltage level is your responsibility. Be sure to account for the cost of this transformation in your project budget. Find out the voltage of the electric facility nearest to your project site.

Use our map to find substations by identifying areas with a circuit voltage of 12 kV or 21 kV and substation capacities that suggest a higher success rate for photovoltaic (PV) generator interconnection. Each highlighted area on the map contains at least one substation transformer and shows the approximate capacity of the largest transformer.

The map is a tool to help contractors and developers identify potential PV project sites. The map is not a guarantee that generators can interconnect at any particular time and place. Several factors affect whether you can interconnect your PV system to the electric distribution system, including:

• Size of the PV system and substation
• Circuit load and capability
• Voltage considerations
• Cost of interconnection

Actual interconnection requirements and costs are determined after detailed studies compare your specific project location, size and application date to other projects in the area. Independent of our interconnection process, government permitting procedures that are designed to minimize environmental and land use impacts might limit the suitability of sites highlighted on the map.

We acquire rights of way or easements from landowners for utility purposes only. A third-party line doesn’t qualify for a right of way or an easement because it’s not an asset we own and maintain. Therefore, we can’t assume liability for it.

We acquire the amount of land necessary to build transmission lines, distribution lines and substations on a case-by-case basis in compliance with California Public Utility Commission’s (CPUC) General Order No. 95 (GO95). Learn about GO95. Download STATE OF CALIFORNIA – RULES for Overhead Electric Line Construction (PDF, 2.67 MB).
We typically don’t acquire more land than necessary unless we plan to expand. In addition, landowners grant us rights to land for specific purposes only. We can’t extend the rights to another party or make changes without the landowner’s agreement.

We consider gen-ties as the distribution provider’s interconnection facilities. We own and maintain these facilities at the interconnection customer’s expense. Either the interconnection customer or PG&E can engineer and construct these facilities.

We don’t own and maintain gen-ties for generating facilities that connect to our wholesale transmission system. Only the interconnection customer can engineer and construct those facilities.

No, the interconnection customer is responsible for acquiring the land rights for gen-tie construction for the following:

• Distribution facilities
• Transmission facilities
• Distribution interconnection

No, you can’t build on our poles. In limited circumstances, we may construct, own and maintain gen-tie lines on our poles in accordance with CPUC rules and programs.

To add wholesale transmission or distribution lines to existing poles, we must evaluate whether the existing poles can support the new lines in a double-circuit configuration, either side by side or on top of each other. The latter configuration typically requires a taller pole in order to maintain GO95 compliance. Find out more about GO95. Download STATE OF CALIFORNIA – RULES for Overhead Electric Line Construction (PDF, 2.67MB).

Regardless of pole replacement or modifications, we are also required by CPUC General Order 131D to submit and request a permit to conduct this work. These requirements can have a significant financial impact on your project.

The following types of agreements detail the terms of interconnection with PG&E:

• CAISO Tariff agreement for transmission customers (facilities of 60 kV or greater). If you plan to interconnect to the CAISO-controlled grid, you must complete one of these two agreements:
  • Large Generator Interconnection Agreement (LGIA) for facilities greater than 20 megawatts (MW). Download CAISO TARIFF APPENDIX CC – Large Generator Interconnection Agreement for Interconnection Requests in a Queue Cluster Window (PDF, 301 KB).
  • Small Generator Interconnection Agreement (SGIA) for facilities less than 20 MW. Download Appendix T – Small Generator Interconnection Agreement (PDF, 152 KB).

NOTE: This CAISO Tariff agreement is a three-party agreement between you, CAISO and PG&E. Under this agreement, you may select any PPA, depending on whether you plan to sell power under CPUC or FERC jurisdiction. If you sign a CAISO Tariff agreement, CAISO oversees your agreement.

• If you plan to interconnect to the PG&E-controlled distribution grid, you must execute either of the following agreements:
  • Rule 21 agreement. Depending on the level of study required for your project, this is either a Fast Track Study or a Detailed Study Process Interconnection Agreement. The agreement is between you and PG&E. If you sign a Rule 21 agreement, the CPUC oversees your agreement.
  • WD Tariff agreement for facilities of less than 60 kV. Either an LGIA or an SGIA applies:
    • LGIA for facilities greater than 20 MW. Download ATTACHMENT H: Large Generator Interconnection Agreement (LGIA) – STANDARD LARGE GENERATOR INTERCONNECTION AGREEMENT (PDF, 443 KB).
    • SGIA for facilities less than 20 MW. Download ATTACHMENT F: Small Generator Interconnection Agreement (SGIA) (For Generating Facilities No Larger Than 20 MW)(PDF, 272 KB).

The WD Tariff agreement is a two-party agreement between you and PG&E. If you sign a WD Tariff agreement, the FERC oversees your agreement.

For generators interconnecting with the PG&E distribution grid, the type of agreement you may enter into is determined by the type of PPA you sign:

• If you sign a PPA other than a Public Utility Regulatory Policy Act (PURPA) PPA, you must execute a WD Tariff agreement. An example of a PG&E PURPA PPA is the AB 1613 program. You can also choose to use a WD Tariff agreement in conjunction with any PPA.
• If you sign a PURPA PPA and interconnect with our distribution grid, you’re eligible to sign a Rule 21 agreement.

To meet customer load, PG&E purchases wholesale electric energy and capacity from generators and suppliers. We periodically conduct solicitations/requests for offer (RFOs) for conventional and renewable electricity in accordance with GIP. The GIP doesn’t constitute an agreement by PG&E to purchase the electric output of the generator. When we conduct a specific solicitation/RFO to purchase new energy and/or capacity, we announce the RFO to possible bidders through email and on our website.

You can contact PG&E Energy Procurement. Visit Wholesale Electric Power Procurement.

To get a transmission pressure (60 pounds per square inch gauge [psig] or greater) natural gas connection for a new generator, review our process guide and other related documents.

For a new generator that requires distribution pressure (less than 60 psig), access our online resources.

A qualifying facility is an existing generating facility that interconnects with our transmission or distribution system and produces energy in any of the following forms:

• Wind
• Hydroelectric
• Biomass
• Waste
• Geothermal

Qualifying facilities can also be cogeneration facilities that produce electricity and another form of thermal energy. Energy deregulation allows these generators to choose the markets in which they sell the electricity they generate.