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Municipal utility

City of Longmont interconnection application

City of Longmont is a municipal utility serving 41,483 residential customers in Colorado (EIA-861, 2025). Gridpol files City of Longmont 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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Colorado’s commission rule (4 CCR 723-3, Rules 3850-3859 (Interconnection Procedures and Standards)) does not bind municipal utilitys; City of Longmont sets its own interconnection policy. We confirm its form on the first project. Cooperatives (C.R.S. 40-9.5-118): must offer net metering at least 10 kW residential / 25 kW commercial, 1:1 monthly carryforward, annual excess handled as co-op decides, must comply with PUC interconnection standards and insurance requirements (may reduce/waive insurance). Municipal utilities with >=5,000 customers (C.R.S. 40-2-124(7)): net metering at least 10 kW residential / 25 kW C&I, must adopt and post functionally similar small-generator interconnection standards; written explanation required for denials.

City of Longmont at a glance

Utility

City of Longmont

Type

Municipal utility

EIA utility ID

11187

Residential customers

41,483 (EIA-861, 2025)

Net-metered residential customers

1,070 (EIA-861, 2025)

Service territory

2 counties in Colorado

Documents City of Longmont asks for

  • Interconnection application formFilled in by us from your project data in the utility’s portal or on its form. Gridpol prepares this.
  • Single-line diagram (one-line)Drawn by us from your equipment data: modules, strings, inverter, battery, disconnects, point of interconnection, meter. Gridpol prepares this.
  • Site plan / site layoutDrawn by us from your roof sketch or photos: array, inverter, battery, disconnect, meter and main panel locations. Gridpol prepares this.
  • PV module spec sheetManufacturer data sheet of the modules.
  • Inverter spec sheetManufacturer data sheet (string inverter, microinverter or hybrid inverter).
  • Customer signatureThe account holder signs the application or authorization. We send the signature link.
  • Recent electric billName, service address, account and meter number must match the application.
  • Final inspection sign-offApproved electrical inspection from the authority having jurisdiction after installation.

Typical documents for US utilities – not yet verified for City of Longmont. We confirm City of Longmont’s exact list on the first project.

Colorado interconnection rule

Commission

Colorado Public Utilities Commission

Interconnection rule

4 CCR 723-3, Rules 3850-3859 (Interconnection Procedures and Standards) – Rules Regulating Electric Utilities - Interconnection Procedures and Standards · source

Applies to

PUC-regulated (investor-owned) utilities - Xcel Energy (PSCo) and Black Hills Colorado Electric - for non-FERC-jurisdictional interconnection of retail renewable DG and other DER incl. storage. Cooperatives must comply with the PUC interconnection standards and insurance requirements per C.R.S. 40-9.5-118(2)(d); municipal utilities adopt functionally similar standards.

Application form

Standard interconnection application form prescribed in the rule (Level 1 application/agreement text in Rule 3854); fees set in each utility's interconnection tariff

Timelines

Receipt notice 3 business days; completeness notice 10 business days (applicant has 10 business days to cure); Level 1 screens 10 business days and approval 10 business days; Level 2 initial review 15 business days; customer signs agreement within 30 business days, utility countersigns within 2; Level 1 witness test/inspection within 10 business days of certificate of completion; operational approval letter 3 business days after successful commissioning; pre-application report 20 business days.

Fees

Processing fee/deposit as specified in the request and the utility's Commission-approved interconnection tariff; no other fees unless the procedures specify. Customer pays upgrades, interconnection facilities, interconnection metering and Level 2/3 commissioning witness costs.

Insurance

Level 1: interconnection customer not required to provide general liability insurance (Rule 3854(c)(VII)).

Export compensation

NEM – C.R.S. 40-2-124(1)(e); 4 CCR 723-3-3664
IOUs: no fixed kW cap; Rule 3664 limits system to 120% of average annual consumption and service entrance capacity (statute as amended allows retail DG up to 200% of expected consumption). Excess kWh carried forward 1:1 monthly; paid at average hourly incremental cost within 60 days of year-end unless customer elects indefinite rollover.

Not bound by the rule

Cooperatives (C.R.S. 40-9.5-118): must offer net metering at least 10 kW residential / 25 kW commercial, 1:1 monthly carryforward, annual excess handled as co-op decides, must comply with PUC interconnection standards and insurance requirements (may reduce/waive insurance). Municipal utilities with >=5,000 customers (C.R.S. 40-2-124(7)): net metering at least 10 kW residential / 25 kW C&I, must adopt and post functionally similar small-generator interconnection standards; written explanation required for denials.

Other utilities in Colorado

All Colorado utilities →

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.

Get started – $500/month unlimited