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Investor-owned utilityAvista Utilities interconnection application
Avista Utilities is an investor-owned utility serving 376,350 residential customers in Idaho, Montana, Washington (EIA-861, 2025). Applications: PowerClerk (Avista SGI PowerClerk). Gridpol files Avista Utilities 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 Avista Utilities’s official sources (see below). Required attachments and storage rules only visible inside PowerClerk; Montana service territory not checked.
Avista Utilities at a glance
Avista Corp (Avista Corp)
TypeInvestor-owned utility
EIA utility ID20169
Residential customers376,350 (EIA-861, 2025)
Net-metered residential customers5,938 (EIA-861, 2025)
Service territory9 counties in Idaho, 1 county in Montana, 9 counties in Washington
How to applyPowerClerk – Avista SGI PowerClerk · official link
Who submitsMost applications submitted by the solar installer; self-installers enter themselves as both customer and installer.
Export compensationNEM – Net metering (WA, ID)
Excess kWh banked; bank resets March 31 each year; no cash payout. WA meter aggregation to one additional meter; not in Idaho.
Receipt notice within 5 business days; completeness within 10 business days; approval/disapproval within 20 business days.
Documents Avista Utilities asks for
- Interconnection application formInterconnection application in PowerClerk (systems up to 100 kW) Gridpol prepares this.
- Other utility-specific documentRequest to Energize submitted by installer through PowerClerk after installation; detailed attachment list shown in PowerClerk (not on public page)
How the Avista Utilities process runs
- Submit interconnection application in PowerClerk with fee
- Receipt notice (5 BD), completeness (10 BD), approval (20 BD)
- Install per local code and permits
- Installer submits Request to Energize in PowerClerk
- Avista checks interconnection and installs meters
- Approval to energize; net metering starts
Fees
| Fee | Applies to | Note |
|---|---|---|
| $100 | Systems up to 25 kW | Non-refundable, due at submission |
| $500 | Systems > 25 kW |
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 |
|---|---|---|
| Net metering | 100 kW | |
| PURPA / SGIP | 5000 kW | Small generators up to 5 MW via OATT SGIP |
| Net metering cap | 100 kW |
Net metering first-come first-served up to state caps.
Sources
- Avista - Getting connected: https://www.myavista.com/energy-savings/green-options/go-solar/getting-connected (retrieved 2026-11-13)
- Avista - Learn about net metering: https://www.myavista.com/energy-savings/green-options/go-solar/learn-about-net-metering (retrieved 2026-11-13)
Other utilities in Washington
- Puget Sound Energy (PSE)1,104,338
- Seattle City Light472,309
- Snohomish County PUD349,905
- Clark Public Utilities223,119
- Tacoma Power (Tacoma Public Utilities)177,554
- Rocky Mountain Power (UT, ID, WY) / Pacific Power (OR, WA, CA)114,998
- PUD No 1 of Benton County50,835
- PUD No 1 of Cowlitz County48,849
- PUD No 2 of Grant County43,160
- PUD No 1 of Chelan County42,571
$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
Applications are typically submitted within 2 business days after complete documents. Utility review times are set by each utility.