Otter Tail Power interconnection application

Otter Tail Power is an investor-owned utility serving 104,750 residential customers in Minnesota, North Dakota, South Dakota (EIA-861, 2025). Applications: Own online portal (Otter Tail Simplified Application (Smartsheet form)). Gridpol files Otter Tail Power 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 Otter Tail Power’s official sources (see below). Base application fee and timelines: see MN DIP; ND/SD processes not researched.

Otter Tail Power at a glance

Utility

Otter Tail Power Co (Otter Tail Corp)

Type

Investor-owned utility

EIA utility ID

14232

Residential customers

104,750 (EIA-861, 2025)

Net-metered residential customers

89 (EIA-861, 2025)

Service territory

30 counties in Minnesota, 34 counties in North Dakota, 11 counties in South Dakota

How to apply

Own online portal – Otter Tail Simplified Application (Smartsheet form) · official link

Who submits

Installer or customer; online form or mail paper application with fee to Otter Tail Power, Attn: Interconnection Coordinator, 215 S. Cascade St., Fergus Falls MN 56538-0496. Fees payable online (Paymentus).

Export compensation

NEM – Small Power Producer Rider – Net Energy Billing Rate (MN 12.01)

Review time (official)

Per MN DIP (not stated on page).

Documents Otter Tail Power asks for

Interconnection application formMN DIP Attachment 2 Simplified Application (≤20 kW certified inverter); Attachment 3 Fast Track Gridpol prepares this.
Single-line diagram (one-line)Single line diagram Gridpol prepares this.
Site plan / site layoutSite diagram Gridpol prepares this.
Inverter spec sheetUL 1741 SB (3rd Ed.) certified, Utility Required Profile (URP) since 1/1/2024
Battery spec sheet (when applicable)Exhibit B 'For Energy Storage'
Other utility-specific documentURP-AS 'Applied Settings' file returned after witness test/site inspection
Other utility-specific documentCertificate of Completion (Exhibit C)
Interconnection agreementMN DIA / Uniform Statewide Contract

How the Otter Tail Power process runs

Submit Simplified Application online (or mail) + fee
Review per MN DIP Section 2
Sign MN DIA
Install; inspection
Witness test and site inspection; return URP-AS applied settings file
Certificate of Completion (Exhibit C)
Permission to operate

Fees

Fee	Applies to	Note
per Attachment 3 + $30	All MN applications	$30 state surcharge remitted to MN PUC; base fee not stated on page (MN DIP max $100 simplified)

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
Simplified	20 kW	certified inverter-based
Fast Track		MN DIP
Study	10000 kW
Net metering cap	40 kW

ND/SD use separate state processes (ND DG application process docs)

Storage, EV and stamps

Battery storage

Exhibit B energy storage details required for storage; UL 1741 SB with URP.

Common issues the utility lists

Inverter not UL 1741 SB certified or URP settings not applied

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

Sources

Otter Tail Power Minnesota Interconnection: https://www.otpco.com/customer-resources/how-to-connect-to-our-power-grid/minnesota-interconnection/ (retrieved 2026-11-13)
Otter Tail Technical Specifications Manual for MN DER 2025: https://www.otpco.com/media/iwvlskbg/otps-technical-specification-manual_2025.pdf (retrieved 2026-11-13)
Otter Tail MN 12.01 Small Power Producer Rider: https://www.otpco.com/media/uvplwynh/mn_1201.pdf (retrieved 2026-11-13)

Other utilities in Minnesota

All Minnesota 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.