PG&E Rule 21 Interconnection: 2026 Guide for Solar Installers

PG&E is one of the largest solar interconnection territories in the country, and its Rule 21 process affects a large share of California PV projects. The PG&E NEM 2 to Solar Billing Plan transition hit its deadline on April 14, 2026. That means the Your Projects portal is absorbing a wave of pending applications and extension requests right now.

This guide walks through the PG&E solar interconnection process from an installer workflow perspective. You'll find a breakdown of the Rule 21 fast track review vs. supplemental review decision and Your Projects portal submission mechanics. It also covers common reasons a PG&E interconnection application gets rejected and realistic timelines from first submission through PTO.

This guide is written for residential and light commercial solar installers submitting PG&E Rule 21 applications through Your Projects. Most Rule 21 content is written for homeowners. This one is built for the crew running the submission.

Need a PG&E Rule 21 application prepared by people who do this every day? Create a GreenLancer account to begin shopping for solar interconnection and design services.

Sign Up

PG&E Rule 21 Interconnection at a Glance

PG&E Rule 21 interconnection is the utility review process for customer-sited solar, storage, and other generating facilities connecting to PG&E's distribution system under California's Rule 21 tariff. For installers, the process typically involves a Your Projects submission, equipment validation, single-line diagram review, final electrical clearance, and PTO.

The PG&E Solar Interconnection Process, Step by Step

1. Confirm the customer account, service ID, meter, and tariff eligibility

2. Prepare the single-line diagram and equipment documentation

3. Submit the Rule 21 application through the Your Projects portal

4. Respond to any deficiency notices within the portal deadline

5. Complete Fast Track, Supplemental Review, or Detailed Study as assigned

6. Install the system and pass AHJ inspection

7. Upload final electrical clearance to Your Projects

8. Receive Permission to Operate (PTO)

What PG&E Rule 21 Is and Why the 2026 Stakes Changed

Rule 21 is the CPUC-approved electric tariff that governs how generating facilities connect to PG&E's distribution system. It covers interconnection, operating, and metering requirements for behind-the-meter generation. That means residential solar, commercial PV, and most paired energy storage jobs in PG&E territory fall under Rule 21.

The CPUC Rule 21 page maintains the full tariff language and active rulemakings. Two issues pushed Rule 21 into sharper installer focus this year. The first is the NEM 2 sunset completing on April 14, 2026. The second is a growing list of projects stuck in the Your Projects portal awaiting engineering review.

Rule 21 vs. WDT: Customer-Sited vs. Wholesale Projects

PG&E's Wholesale Distribution Tariff (WDT) is a FERC-jurisdictional pathway for generators selling energy into wholesale markets or delivering to the ISO grid. Rule 21 is the CPUC-jurisdictional pathway for customer-sited generation that connects behind the meter and serves on-site load. Projects on Rule 21 either export through the Solar Billing Plan, export under legacy NEM 2, or operate in non-export mode.

Project purpose usually determines the right path, not just project size. A 900 kW rooftop system serving a distribution warehouse's own load goes through Rule 21. A similarly sized ground mount selling under a power purchase agreement is a WDT project.

PG&E's Role vs. CPUC's Role

The CPUC writes and updates Rule 21. PG&E administers it inside its service territory, which means the utility handles engineering review, portal operation, deficiency notices, and Permission to Operate issuance. The PG&E interconnections and renewables page lists technical guidance documents, standard diagrams, and current forms.

Understanding that split matters when disputes come up. PG&E runs the day-to-day process, but the rules of engagement are set at the Commission level.

PG&E NEM 2 to Solar Billing Plan Transition: What Changed on April 14, 2026

The deadline itself is simple, even if the downstream implications are not. NEM 2 applications submitted on or before April 14, 2023, need final electrical clearance submitted to PG&E by 11:59 p.m. on April 14, 2026, to stay on the legacy NEM 2 tariff.

Projects that hit that window keep their tariff. Projects that missed it move to the Solar Billing Plan (also called Net Billing Tariff or NEM 3.0). Export compensation is based on avoided-cost values rather than retail-rate credits, so the economics are usually much less favorable than legacy NEM 2, especially for PV-only systems.

For business customers, PG&E begins Solar Billing Plan billing in March 2026 for new applicants and for customers transitioning off NEM 2 or an expired 20-year legacy period. Light commercial installers should confirm which tariff year applies to each project before promising customer economics.

What Happens to Projects That Missed the Deadline

Per PG&E's published guidance, the existing application stays active. Completed engineering reviews and queue position are generally preserved unless a material project change requires another review. The customer signs updated agreements for the Solar Billing Plan, completes any remaining inspection or documentation requirements, and moves toward Permission to Operate.

What's lost is the economics, not the project itself. The system still gets built, interconnects, and runs, and export compensation reflects the newer Solar Billing Plan rules under NEM 3.0 rather than the retail-rate crediting of NEM 2.

NEM 2 Building Permit Extension Requests

PG&E allows extension requests in limited cases, particularly when the delay was utility-related. Review PG&E's current extension criteria before telling a customer they are likely to qualify. Approval is not guaranteed, and the volume of post-deadline requests has been substantial.

The request is submitted through an online form, and PG&E reviews each case individually. The PG&E Net Energy Metering program page links to the extension request form and current eligibility language.

Customer Economics After Transition

Solar Billing Plan customers receive export credits tied to the Avoided Cost Calculator. That value varies by time of day and season, and PG&E has layered on a temporary export rate adder for new customers that declines annually over a five-year window.

Set expectations early with any customer getting transitioned. The payback math shifts in most residential cases, and battery attach rates jump accordingly.

Rule 21 Fast Track vs. Supplemental Review: Which Path Your Project Takes

Most residential and small commercial solar projects in PG&E territory qualify for Fast Track review. That's good news because Fast Track is faster, cheaper, and more predictable than the alternatives. Here's how the decision actually plays out.

Fast Track Eligibility

Many standard Solar Billing Plan and non-export projects can proceed through Fast Track, but eligibility and review path depend on project type, export behavior, voltage level, size, and circuit conditions. Exporting Rule 21 projects up to 3 MW on 12 kV or higher interconnections in PG&E territory are generally eligible per thresholds documented in the NREL Rule 21 background report. Eligibility is different from passing though. A project can be eligible for Fast Track and still fail the screens.

Initial Review: Screens A Through M

Initial Review runs a series of automated and engineering checks. These cover DER penetration on the circuit, aggregate generation relative to minimum load, voltage, protective coordination, and several technical constraints tied to the point of interconnection. Projects that pass all Initial Review screens interconnect without further study.

When Supplemental Review Is Triggered

Failing specific Initial Review screens kicks the project into Supplemental Review, which applies screens N through P. Supplemental Review is more granular and can clear a project to interconnect without full study. It carries an additional non-refundable fee and adds review time.

If a project fails Supplemental Review, it moves into Detailed Study. That path is more expensive, slower, and may identify distribution upgrade requirements.

Detailed Study: When Fast Track Fails

For residential and light commercial installers, a Detailed Study usually signals that the project has unusual export, circuit, storage, or service constraints. Flag that risk early because it can change both timeline and customer economics. The study identifies any upgrades required to safely accommodate the generation, with costs allocated per Rule 21's cost responsibility rules.

Rule 21 Notification-Only vs. Standard Review

Some small non-export generating facilities qualify for a Notification-Only process under a CPUC pilot. That's a simpler pathway than the full Fast Track review, but PG&E still reviews documentation and has the authority to revoke PTO if deficiencies show up. "Simple PV-only" does not mean "no review friction," so treat every Rule 21 submission as a real review process.

Pre-Screening Your Site Before You Submit

Running a pre-submission site check prevents a surprising amount of rework. Verify each of these items before you start the portal application:

• ☐ Service size and existing main panel rating

• ☐ Existing DERs already on the customer account

• ☐ ICA map circuit capacity for the service address

• ☐ Planned export level and tariff selection

• ☐ Storage operating mode (export, non-export, limited export)

• ☐ CEC equipment listing for every module, inverter, and battery

• ☐ Customer-of-record match on the PG&E account

Watch for secondary network constraints in parts of San Francisco and Oakland. PG&E notes it may not be able to interconnect generators in certain areas served by secondary network systems. If your job falls in those zip codes, verify feasibility before submitting.

Sign Up

The PG&E Your Projects Portal: Step-by-Step Submission Workflow

Your Projects is where every Rule 21 generation interconnection application gets submitted. It replaced the older Customer Connections Online system and has improved over several cycles. The portal still rejects incomplete applications aggressively though, and getting the submission right the first time is the biggest lever on your PG&E solar interconnection timeline.

Getting Generation Contractor Access

Solar contractors need approved access before initiating any generation application. The Your Projects portal updates page covers the request process and which approvals unlock which application types. Expect to provide CSLB license information, company details, and contact info for the responsible contractor.

Starting a Rule 21 Generation Application

Once inside the portal, you'll start a new generation application tied to a specific service address and meter. The portal pulls customer account data and existing service information to pre-populate fields. That's why customer-of-record mismatches cause so many early rejections. Double-check the account holder before submitting.

Uploading Supporting Documents and Paying the Fee

The portal accepts digital uploads for spec sheets, the single-line diagram, and required signed forms. Fees are paid through the portal at submission. Standard NEM-class interconnection is $145 for projects 1 MW or under, and the Rule 21 Interconnection Request Fee per Table E.1 is $800 for other generation projects.

Checklist: What Your PG&E Rule 21 Submission Package Needs

☐ Completed interconnection application with correct customer of record, service agreement ID, and meter ID

☐ CEC-listed modules and inverters selected from the portal drop-down

☐ Single-line diagram showing point of interconnection, disconnects, OCPDs, and grounding

☐ Equipment spec sheets for modules, inverters, and storage if applicable

☐ Signed Agreement and Authorization (A&A) form

☐ California Solar Consumer Protection signed disclosures for residential non-self-install

☐ CSLB contractor license information matching the state record

☐ HIS registration number where applicable

☐ Load calculations confirming panel ampacity

☐ NEM 2 Building Permit Extension Request form (only if applicable)

☐ Application fee payment through the portal

Installers should confirm who is authorized to sign the PG&E interconnection agreement before submitting the application. On residential jobs that's usually the homeowner of record, and on light commercial it may be the property owner, tenant, or an authorized representative listed on the PG&E account.

The CPUC California Solar Consumer Protection Guide is the authoritative reference for residential disclosures. If AHJ permit documentation is part of the package, GreenLancer's guide on how to get a solar permit breaks down what reviewers typically ask for.

What PG&E Wants to See on Your Single-Line Diagram

The single-line diagram is the document reviewers look at first, and it drives more deficiency notices than any other part of the submission. PG&E engineering reviewers need the electrical relationship and major components visible at a glance. That means switchgear, protective relays, transformers, circuit breakers, operating voltages and capacities, customer loads, the interconnection point, and metering and disconnect details where applicable.

Checklist: PG&E Single-Line Diagram Must-Haves

☐ Point of interconnection clearly labeled

☐ Main service panel rating and main breaker size

☐ PV inverter AC output rating

☐ ESS inverter rating and operating mode for battery-paired systems

☐ AC disconnect if required by service configuration

☐ Metering configuration

☐ OCPDs and breaker sizes

☐ Export limit or PCS notes where applicable

☐ Existing generation or storage on-site

☐ Equipment labels and model numbers matching the application inputs

Using PG&E's Standard SLDs vs. Custom Diagrams

PG&E publishes a library of standard single-line diagrams covering common residential and small commercial configurations. If your project matches one of the standard templates, using it reduces review time because the reviewer isn't interpreting a new drawing. Custom diagrams are fine for complex systems, but warrant extra scrutiny before submission.

GreenLancer's breakdown of the solar energy diagram covers how single-line diagrams fit into the larger permit package. The solar three-line diagram guide covers the additional detail some AHJs and utilities expect beyond a single-line view.

Why CEC-Listed Equipment Shortens Review

PG&E's portal drop-downs pull from the California Energy Commission Solar Equipment Lists program. If your module, inverter, or battery is on the list, you select it from the dropdown and move on. If it isn't, you'll need to submit additional documentation proving the equipment meets Rule 21 inverter requirements under IEEE 1547-2018 and UL 1741 SA/SB, and review time goes up. The CEC equipment list data portal is worth checking before any job hits the design stage.

Why Battery-Paired Systems Get Flagged More Often

Storage projects fail portal review at higher rates than PV-only jobs. The issue is rarely the battery hardware itself. It's the way the application documents the operating mode, charging source, and export behavior.

Common Storage-Specific Rejection Points

• Charging source: Grid-charging vs. PV-only charging affects tariff eligibility and needs explicit declaration

• Export control: Non-export or limited-export settings require a certified Power Control System (PCS) if the project is routed through Fast Track as an export-limited configuration

• Backup mode: Systems that operate in parallel during grid outages need documentation of islanding behavior and transfer switch configuration

• Nameplate math: Storage AC output plus PV AC output sometimes exceeds service size limits, a common flag on multi-battery residential jobs

• SLD clarity: Operating modes need to be visible on the single-line, not buried in the application form

PG&E maintains a dedicated guide for energy storage charging issues under Rule 21, linked from the main interconnections page. Reviewing that document before finalizing any battery-paired submission is time well spent.

Limited Export and Limited Generation Profile Projects

Limited-export configurations and Limited Generation Profile (LGP) projects are increasingly common on constrained circuits and multi-battery residential jobs. Export limits need to be documented clearly in the application, and PCS settings must match what's submitted. Mismatches between the application, the SLD, and the installed hardware are a common trigger for deficiency notices and re-review.

Storage-specific documentation and operating mode declarations are handled end to end by GreenLancer's PV interconnection service.

The Top Your Projects Portal Rejection Triggers

Every installer who has run a high volume of PG&E interconnection applications has seen the same deficiency patterns. Here are the most common failure points, organized so you can run a quick audit before hitting submit.

Checklist: Pre-Submission Audit

• ☐ Customer of record mismatch between PG&E account and property arrangement

• ☐ Blank or incomplete required fields anywhere in the application

• ☐ Equipment not in the CEC portal drop-down (unlisted module, inverter, or battery)

• ☐ Incorrect inverter anti-islanding Group setting for the installed equipment

• ☐ Storage AC totals exceeding service size when combined with PV output

• ☐ Single-line diagram missing the utility disconnect, point of interconnection, or PV breaker value

• ☐ Wrong tariff selected for the application date (NEM 2, SBP, NBTV, NBTA)

• ☐ CSLB contractor license number mismatch or expired license on file

• ☐ HIS registration missing where required by CPUC consumer protection rules

• ☐ Final electrical clearance not uploaded when requesting PTO

The PG&E Contractor Resources page maintains PG&E's own list of common deficiencies and tips for first-submission approval. GreenLancer's guide to AHJ solar permitting success covers complementary best practices on the building department side.

Your Rule 21 Timeline: From Submission to Permission to Operate

Realistic timeline expectations help everyone on the project team. Here's how the PG&E solar interconnection timeline breaks down when the submission is clean.

🗓️ Day 0 to 15: Initial Portal Review

PG&E runs a completeness check after submission. If the application and package are complete and accurate, the project moves into engineering review. If anything is missing or misaligned, you'll receive a deficiency notice with a response window.

🗓️ Day 15 and Beyond: PG&E Rule 21 Engineering Review

Engineering review runs the Fast Track Initial Review screens. Standard residential and small commercial projects typically clear this stage in a few weeks. Projects that trigger Supplemental Review add time proportional to the review complexity. Jobs that hit Detailed Study can extend review by months.

Post-Installation: Final Electrical Clearance

After the install is complete and the AHJ issues final inspection sign-off, you upload the final electrical clearance to Your Projects. This is the signal to PG&E that the system is built, inspected, and ready for PTO. Don't submit clearance prematurely, and don't delay after inspection passes.

PG&E PTO Process: From Final Electrical Clearance to Permission to Operate

PG&E typically issues Permission to Operate within 5 to 10 business days after receiving complete final electrical clearance. The stated maximum is around 30 business days. Total project duration from first portal submission to PTO varies, but a clean residential job with no Supplemental Review can reasonably target 2 to 6 weeks through interconnection.

Filing the interconnection application in parallel with AHJ permitting is the biggest compression lever on total project timeline. Many installers lose weeks by treating interconnection as a post-install task. GreenLancer's solar permit design service supports a parallel-track workflow that keeps both streams moving.

Handling Deficiency Notices and Material Project Changes

Getting a deficiency notice isn't a disaster. Missing the response window on one usually is. Here's how to work through the most common post-submission issues.

Responding to Deficiency Notices

Some deficiency notices and correction requests have short response windows, often only a few business days. Treat every PG&E notice as time-sensitive and verify the specific deadline shown in Your Projects rather than assuming a uniform cure period. Missing a deadline can mean PTO revocation, queue position loss, or full resubmission.

When a deficiency notice arrives, pull the original application, identify the specific field or document being flagged, correct it, and resubmit before the portal deadline. Log every change so you can reference it if questions come up later.

Material Changes That Can Trigger Re-Review

PG&E preserves completed engineering reviews and queue position unless a material project change requires another review. Changes that typically trigger re-review include:

• Inverter make or model swap

• Storage capacity or inverter sizing change

• Export setting change, such as moving from non-export to exporting

• Service panel upgrade or change in point of interconnection

• Battery configuration or operating mode change

• Array size change beyond what was originally submitted

If a mid-project change is unavoidable, contact PG&E before resubmitting. Some changes can be handled with a documentation update. Others require starting portions of the review over.

Fees, Rule 21 Section K Disputes, and CPUC EIDR

Rule 21 Section K governs the dispute process. For most installer-side issues, emailing PG&E's Rule 21 disputes address (Rule21Disputes@pge.com) is the right first step. If informal resolution fails, the CPUC Expedited Interconnection Dispute Resolution process is available. For systemic issues affecting installers across PG&E territory, industry groups like CALSSA and SEIA's distributed solar initiative work at the policy level.

Streamline PG&E Rule 21 Interconnection With GreenLancer

PG&E interconnection work is specialized labor. It takes portal experience, current knowledge of tariff eligibility rules, utility-ready single-line diagrams, and the patience to chase deficiency notices through short cure windows. For high-volume installers, that adds up to a full-time role most crews don't have a budget for.

What GreenLancer Handles vs. What Stays With Your Team

A clear division of responsibility keeps every workflow running cleaner:

• GreenLancer covers: PG&E-ready single-line diagrams, Rule 21 application prep, engineering review support, PE stamps, deficiency response, and CEC equipment validation

• Installer owns: Field installation quality, AHJ inspection, customer signatures and consent forms, final electrical clearance upload, and site-specific equipment accuracy

Complete the form below to get started

PG&E Rule 21 Interconnection FAQs

How long does PG&E Rule 21 interconnection take in 2026?

Fast Track projects typically clear in 2 to 6 weeks. Supplemental Review adds weeks, and Detailed Study can add months. Post-installation PTO after final electrical clearance is usually 5 to 10 business days, with a stated maximum of 30 business days.

What's the difference between PG&E Rule 21 and WDT interconnection?

Rule 21 is CPUC-jurisdictional and covers customer-sited behind-the-meter generation. WDT (Wholesale Distribution Tariff) is FERC-jurisdictional and applies to generators selling into wholesale markets or delivering to the ISO grid. Project purpose drives the decision, not just size.

Can my customer still enroll in NEM 2 after April 14, 2026?

Only if final electrical clearance was submitted to PG&E on or before 11:59 p.m. April 14, 2026, or if PG&E granted a utility-related extension. Without one of those, the project transitions to the Solar Billing Plan.

What happens if my customer's project auto-transitions to Solar Billing Plan?

The application stays active. Completed engineering reviews and queue position are generally preserved unless a material change triggers re-review. The customer signs updated agreements for the Solar Billing Plan and completes any remaining requirements to reach PTO. Export compensation shifts from retail-rate NEM 2 credits to Avoided Cost Calculator rates.

Does my project need Supplemental Review or just Fast Track Initial Review?

Projects passing all Initial Review screens (A through M) interconnect without Supplemental Review. Failing specific screens triggers Supplemental Review (screens N through P) with an additional non-refundable fee. Checking the ICA map for your circuit before submission gives you a reasonable prediction of which path your project will take.

What's the PG&E Rule 21 interconnection application fee?

$145 for standard NEM-class or Solar Billing Plan projects 1 MW or under. $800 for most other Rule 21 generation projects, including standalone non-export battery storage. Supplemental Review and Detailed Study carry additional fees on top of the initial application cost.

Can I submit a PG&E interconnection application before AHJ permitting is complete?

Yes, and high-volume installers routinely do. PG&E advises submitting the single-line diagram early so engineers can flag issues before field rework. Running interconnection and AHJ permitting in parallel is the biggest lever on the total project timeline.

What's the most common cause of Your Projects portal rejection?

Incomplete applications drive most deficiency notices. Customer-of-record mismatch, missing fields, unlisted equipment, and SLD issues are the most common causes. Use the pre-submission audit checklist above to catch them before submitting.

How do I request a NEM 2 Building Permit Extension for a customer?

Submit PG&E's online NEM 2 Building Permit Extension Request form before the project transitions. PG&E reviews each case individually and notifies of approval or denial. Utility-related delays have the best chance of approval.

What inverter certifications does PG&E require under Rule 21?

Inverters must meet IEEE 1547-2018 and UL 1741 SA/SB grid-support inverter requirements and must appear on the CEC Grid Support Inverter List. Your Projects portal drop-downs are pre-filtered to CEC-listed equipment in most application types.

What should installers do when a PG&E interconnection application gets rejected?

Review the deficiency notice in Your Projects. Compare every field against the customer account and the single-line diagram. Confirm all equipment is on the CEC Solar Equipment List. Correct the specific issue flagged and resubmit before the deadline shown in the portal. If the fix involves a material project change like an equipment swap or export setting change, expect re-review of the engineering portion.