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Investor-owned utility

Unitil (New Hampshire) interconnection application

Unitil (New Hampshire) is an investor-owned utility serving 69,081 residential customers in New Hampshire (EIA-861, 2025). Applications: PowerClerk (Unitil Interconnection Program Portal (PowerClerk, announced Feb 2025; 'Company online application system')). Gridpol files Unitil (New Hampshire) 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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Partly researched from official sources. verify on first project: unitil.com, energy.nh.gov and gc.nh.gov block all our fetchers (403) and archive.org is unreachable; details above come from search-index text of official Unitil pages. Confirm PowerClerk login URL, full document list, fees, steps to PTO, storage rules and En 1000 tiers/timelines.

Unitil (New Hampshire) at a glance

Utility

Unitil Energy Systems (Unitil Corporation)

Type

Investor-owned utility

EIA utility ID

24590

Residential customers

69,081 (EIA-861, 2025)

Net-metered residential customers

2,574 (EIA-861, 2025)

Service territory

2 counties in New Hampshire

How to apply

PowerClerk – Unitil Interconnection Program Portal (PowerClerk, announced Feb 2025; 'Company online application system')

Who submits

Applicant creates account in Unitil's Interconnection Program Portal to submit and track applications; written applications may be mailed to Unitil, Exeter NH (per earlier snippet). Customer/installer roles and LOA not confirmed.

Export compensation

Net billing – NH Net Metering
NH net metering per Puc 900; current export credit structure not retrieved.

Review time (official)

NH DOE En 1000 interconnection rules (RUL 2024-007) adopted 7/17/26 (posted by Unitil 2026-08) replace Puc 900 interconnection provisions for DER; text not retrievable (unitil.com and energy.nh.gov 403) - verify tiers/timelines.

Documents Unitil (New Hampshire) asks for

  • Interconnection application formSimplified/Fast Track application (systems up to 1 MW) via online portal Gridpol prepares this.
  • Single-line diagram (one-line)One-line diagram with initial application showing main panels, DER connection breaker/line tap, metering; revision log signed/initialed by designer (Unitil DER design guideline, search-index text) Gridpol prepares this.
  • Other utility-specific document (when applicable)Certificate of Completion for Interconnection after installation (Unitil form, Rev 2019); Puc 900 also requires AC/DC protection schematics for net-metered facilities

Fees

FeeApplies toNote
$500Optional pre-application report

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

Size levels and limits

LevelUp toNote
Simplified/Fast Track1000 kWUnitil steps page (search-index text)
Standard>1 MW
Net metering cap1000 kW

NH net metering (Puc 900) up to 1,000 kW; En 1000 (adopted 7/17/26) may change tiers.

Storage, EV and stamps

PE stamp

One-line diagram PE-stamped for facilities larger than 25 kVA (Unitil Guideline GL-DT-TC-10, Dec 2025; search-index text, PDF blocked). – PE-stamped drawings are not included in Gridpol.

Sources

New Hampshire interconnection rule

En 1000 text (adopted July 2026 per brief) could not be read: gc.nh.gov unreachable from all tools, no archive.org copy, DOE rules page still lists only En 900. Levels, timelines, fees, insurance, disconnect and documents left empty - fill from En 1000 text.

Commission

New Hampshire Public Utilities Commission / NH Department of Energy (rules En 900, En 1000)

Interconnection rule

N.H. Code Admin. R. En 1000 (interconnection, rulemaking RUL 2024-007); net metering En 900 (formerly Puc 900) – En 1000 Interconnection rules · source

Applies to

Rate-regulated distribution utilities: Eversource (PSNH), Liberty Utilities, Unitil, and NH Electric Cooperative; municipal utilities not covered

Export compensation

NEM – RSA 362-A:9; En 900; Net Metering Tariff 2023 (NEM 2023)
Residential/small commercial up to 100 kW AC behind the meter; larger facilities up to 1,000 kW (political subdivisions 5,000 kW). Statutory per-utility aggregate limit. Compensation per 2023 net metering tariff (DOE overview PDF).

Not bound by the rule

Customers of municipal electric utilities must ask their utility whether net metering is available (NH DOE page).

Other utilities in New Hampshire

All New Hampshire 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