Public power district

IID interconnection application

IID is a public power district serving 142,916 residential customers in California (EIA-861, 2025). Applications: PowerClerk (IID Rooftop Solar PowerClerk (customer or contractor account)). Gridpol files IID interconnection applications for licensed installers – solar, storage and EV chargers – with single-line diagram and site plan, unlimited for $500 a month.

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Process verified from IID’s official sources (see below). Confirmed from archived official IID pages/PDFs (iid.com returns 403 to server). Open: fee table ambiguous for Net Billing review fee ($800 vs. waived); PE-stamp requirement in Rules vs. web page; CSP/meter fee amounts; check-sheet still mentions email submission (superseded by PowerClerk).

IID at a glance

Utility

Imperial Irrigation District

Type

Public power district

EIA utility ID

9216

Residential customers

142,916 (EIA-861, 2025)

Net-metered residential customers

11,728 (EIA-861, 2025)

Service territory

3 counties in California

How to apply

PowerClerk – IID Rooftop Solar PowerClerk (customer or contractor account) · official link

Who submits

Customer or contractor creates a PowerClerk account and submits (email submissions not accepted since 1 Jan 2024). Host customer must be the name on the IID contract account and signs the Net Billing Interconnection Agreement; installer needs current CSLB license (A, B, C-10 or C-46). One Interconnection Request per Point of Interconnection; capacity expansions treated as new requests.

Export compensation

Net billing – IID Net Billing Program - Distributive Self-Generation Service (Schedule DG)
NEM closed (cap reached 2016). Monthly netting of delivered/received energy; imports billed at regular rate, exports paid at DSG rate (6.98 cents/kWh shown on page, variable, based on IID's lowest wholesale solar contract cost). Monthly or annual billing preference.

Review time (official)

IID Rules: completeness acknowledgment normally within 10 business days; Initial Engineering Review within 10 business days after complete; Interconnection Study 20 business days (Non-Standard 60); written parallel-operation authorization within 10 business days of compliance, and for Schedule DG no later than 30 business days after complete application, signed IA and AHJ final inspection. Deficiencies must be cured within 30 business days (one 30-day extension).

Documents IID asks for

Interconnection application form<10 kW AC: one-page Application for Interconnection; >=10 kW AC and microgrids: Rule (Regulation) 21 Application Gridpol prepares this.
Single-line diagram (one-line)One-line diagram with local jurisdiction (AHJ) approval; IID check sheet/example available Gridpol prepares this.
Site plan / site layoutSite plan with AHJ approval; must match BOM and AC disconnect Gridpol prepares this.
Inverter spec sheetInverter manual/specification; inverter must be CEC-approved; smart inverters required
Net metering / net billing agreementNet Billing Interconnection Agreement (<=1 MW) with account no., meter no., site address, kW AC-CEC; signed by host customer on IID account
Other utility-specific documentBill of Materials; utility AC disconnect cut sheet (IID Rule 21 standard); first page of CA Solar Consumer Protection Guide initialed; Customer Service Proposal (CSP) application / service order number for solar inspection payment
PV module spec sheet (when applicable)Check-sheet requires CEC-approved panels (listed on BOM)
Final inspection sign-offBuilding permit sign-off submitted after installation
Other utility-specific document (when applicable)Microgrid Interconnection Guidelines compliance for microgrids; ESS per Attachment 1 of IID Interconnection Rules

How the IID process runs

Verify package with IID check-sheets; create customer or contractor account on IID PowerClerk
Pay solar inspection fee via CSP and upload application, one-line, site plan, BOM, disconnect cut sheet, inverter manual, Net Billing agreement, consumer guide page in PowerClerk
IID completeness review (~10 business days) and Initial Engineering Review (10 business days); study if needed
IID grants permission to proceed (approval required before work begins); signed Interconnection Agreement
Install; obtain AHJ final inspection; upload building permit sign-off
IID inspection, bi-directional meter, written authorization for parallel operation (PTO); do not operate before written permission

Fees

Fee	Applies to	Note
$255	Solar inspection, per interconnection application received after 1 May 2025	Prices subject to change; other CSP charges may apply
	Bi-directional meter	Customer pays meter replacement if existing meter cannot measure two-way flow (PU Code 2827); amount per CSP pricing sheet
$800 / $600	Net Billing (Distributive Self-Generation): Initial Engineering Review / Interconnection Study (Table C.1)	Rules state Initial Engineering Review fee is waived for Schedule DG applications; table is ambiguous
$1,000	Commercial and Virtual Net Billing Interconnection Study	Only if Initial Engineering Review fails
$5,000	Non-Standard Process study (non-NEM export generation or energy storage)

Utility fees are paid by the installer or customer; they are not part of the Gridpol plan.

Size levels and limits

Level	Up to	Note
<10 kW AC	10 kW	One-page application
>=10 kW AC / microgrids (Standard Process)	1000 kW	Rule 21 application; Initial Engineering Review + Interconnection Study if needed
Non-Standard Process		Non-NEM export generation or energy storage; study 60 business days
Net metering cap	1000 kW

Net Billing Interconnection Agreement covers renewable generating facilities of 1 MW or less; Rule 21 applies to GF <=1 MW. Sizes by total inverter AC nameplate.

Storage, EV and stamps

Battery storage

ESS must meet Attachment 1 of IID Rules for Interconnection: sizes by total inverter AC nameplate; smart contactor between main panel and critical load panel to isolate DG+ESS on outage; labeling of panels and breakers; ESS disconnect/overcurrent protection; IID representative must inspect and approve; smart inverter with storage must communicate state of charge. Storage/non-NEM export may follow Non-Standard Process (study, $5,000, 60 business days).

PE stamp

IID Rules for Interconnection (eff. 7 Mar 2023) C.1.b: single-line and site-plan diagrams must be approved/stamped by the AHJ and stamped by a Professional Electrical Engineer; the IID web page lists only AHJ approval. Confirm with IID. – PE-stamped drawings are not included in Gridpol.

Common issues the utility lists

Host customer name, site address, contract account number or IID meter number incorrect/inconsistent across documents
Bill of Materials not matching other documents; AC disconnect info not matching site plan/BOM or not meeting IID Rule 21 standard
Non-CEC-approved panels or inverter, wrong inverter manual
Installer CSLB license not current (A, B, C-10, C-46)
Missing CSP service order number for solar inspection payment (delays)
Deficiencies not cured within 30 business days -> request deemed withdrawn; application >1 year without signed IA may be cancelled

Gridpol’s pre-submission check covers these before we file.

Sources

IID - Distributed Generation Interconnection (archive.org capture 2026-05-09; iid.com blocks server): https://web.archive.org/web/20260509161538/https://www.iid.com/power/rooftop-solar/interconnection (retrieved 2026-11-13)
IID - Net Billing (archive.org capture 2026-05-23): https://web.archive.org/web/20260523004659/https://www.iid.com/power/rooftop-solar/interconnection/net-billing (retrieved 2026-11-13)
IID Application for Interconnection - Application Package Check-Sheet (rev. 05/21/2018; read via archive.org 2026 capture): https://www.iid.com/home/showpublisheddocument/17021/636625013852000000 (retrieved 2026-11-13)
IID Rules for Interconnection of Distributed Generation Facilities (effective 7 Mar 2023; read via archive.org 2026 capture): https://www.iid.com/home/showpublisheddocument/6309/638140618150200000 (retrieved 2026-11-13)

Other utilities in California

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Gridpol Unlimited

$500 / month

Unlimited interconnection applications. 12-month agreement, signed online. The agreement starts the day you sign; first invoice right away, then monthly.

Unlimited interconnection applications
Single-line diagram and site plan for every application
Pre-submission check against the utility’s requirements
Homeowner e-signature link for the authorization
Filing in your utility portal accounts or by the utility’s method
Utility questions, corrections and resubmissions
Follow-up through approval, inspection and PTO
Customer list, exports, API and webhooks

Get started

Applications are typically submitted within 2 business days after complete documents. Utility review times are set by each utility.