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Hawaii / Local permit guide

Hilo Solar Permit Guide

Your local requirements. The official sources. A clearer next step.

Electric utility
Hawaii Electric Light Company (HELCO)Source linked
Local pathway
Expedited Permit Process for PV SystemsProject-specific eligibility conditions apply.
See your permit path

County of Hawai'i ·

Hilo Solar Permit Checklist
Printed from mygridpermit.com/hawaii/hilo/solar-permit-guide/ · Last verified 2026-08-13 · County of Hawai'i Department of Public Works, Building Division / HELCO · Verify current requirements before relying on this checklist. Programs and fees change.
Source healthLast verified 2026-08-134 official sources5 of 6 core facts verified
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Informational only. This page is not legal, engineering, or permit advice. Every fact below links to the official source it came from and shows how confident we are in it. Verify current requirements with County of Hawai'i Department of Public Works, Building Division and HELCO before making a decision.

Research coverage

Your permit path,
at a glance.

This shows what GridPermit has verified for Hilo. It does not show the status of a specific project.

  1. 01Permit authorityCounty of Hawai'i Department of Public Works, Building DivisionAuthority sourced
  2. 02DocumentsChecklist includes conditional itemsConditions apply
  3. 03InspectionInspection guidance for HiloSteps sourced
  4. 04Utility & PTOHawaii Electric Light Company (HELCO)Utility path sourced

01 / Know your path

Two approvals.
One project.

Local authority

Permit & inspection

County of Hawai'i Department of Public Works, Building Division

Local requirements
Electric utility

Interconnection & PTO

Hawaii Electric Light Company (HELCO)

Utility requirements

A local permit and utility permission to operate are different approvals. Check the local sequence and requirements below.

How to read this guide

GridPermit collects Hawaii residential solar and permitting facts directly from official sources (city, county, and state government sites, utilities, and public utilities commissions) and shows only what we can verify, with a confidence score and a link to where it came from. Nothing here is estimated or inferred beyond what's stated below. See our methodology for the rules this page follows.

Battery/solar incentive program on record

No battery/storage incentive program is on record for this locality.

02 / Prepare your application

What you need.

0 of 9 markedSaved only on this device; not confirmation of permit readiness.

Sources & confidence

Confidence: High (0.95)

Source(s): Guidelines for Permitting a Residential Photovoltaic (PV) System (rev. 10.10.12) and PV Bulletin PV 2012-01

Permit fees

Both the electrical permit fee (specific to alternate energy power sources, tiered by system kW) and the general building permit fee (tiered by estimated construction valuation) apply, since a PV installation requires both a building permit and an electrical permit under Hawai'i County Code. Higher building-permit valuation tiers ($25,001-$50,000 and $50,001+) also exist in the source table but are less relevant to typical residential PV systems and were omitted for brevity; see source PDF for the complete table.

  • Electrical permit fee — alternate energy power source (generators, capacitors, reactors, transformers), not more than 5 kW: $10 (flat fee)

    Hawai'i County Code Chapter 9, Section 9-40(q). 1 kW is treated as equivalent to 1 kVA for this fee.

  • Electrical permit fee — alternate energy power source, over 5 kW but not over 15 kW: $24 (flat fee)

    Hawai'i County Code Chapter 9, Section 9-40(q).

  • Electrical permit fee — alternate energy power source, over 15 kW: $40 (flat fee)

    Hawai'i County Code Chapter 9, Section 9-40(q).

  • Building permit fee — $0 to $500 estimated valuation: $10 (flat fee)

    Hawai'i County Code Chapter 5, Section 5-35, Table 1-A.

  • Building permit fee — $501 to $2,000 estimated valuation: $10 (plus $1.50 per additional $100 or fraction thereof up to $2,000)

    Hawai'i County Code Chapter 5, Section 5-35, Table 1-A.

  • Building permit fee — $2,001 to $25,000 estimated valuation: $32.5 (plus $7.50 per additional $1,000 or fraction thereof up to $25,000)

    Hawai'i County Code Chapter 5, Section 5-35, Table 1-A.

Sources & confidence

Confidence: High (0.95)

Source(s): Guidelines for Permitting a Residential Photovoltaic (PV) System (rev. 10.10.12) and PV Bulletin PV 2012-01

Rebates on record

Rebates on record

Renewable Energy Technologies Income Tax Credit (RETITC) — Solar Energy System

Statewide Hawaii state income tax credit for solar energy systems (HRS 235-12.5): 35% of actual installed cost, capped at $5,000 per system for single-family residential property (lower of the two), $350 per unit for multi-family residential, or $500,000 per system for commercial property. A separate, higher-value $2,250 cap applies if the system's primary purpose is solar water heating rather than PV. Any utility rebate received must be deducted from system cost before computing the credit. Applies statewide to any Hawaii taxpayer regardless of county/island — a genuine reusable statewide fact, not utility- or county-specific.

Status on file: active. Verify current status before relying on this.

Sources & confidence

Confidence: High (0.9)

Source(s): HRS §235-12.5 — Renewable energy technologies; income tax credit

Utility and generation supplier

Utility

Hawaii Electric Light Company (HELCO)

Confirmed via the Hawaii Public Utilities Commission's own page (which names Hawai'i Electric Light Company as the utility serving 'The Big Island', one of four PUC-regulated electric utilities, each island having its own unconnected grid) and Hawaiian Electric's own corporate site. HELCO is a subsidiary of Hawaiian Electric Industries operating under its own tariff for Hawaii Island, distinct from HECO (Oahu) and MECO (Maui).

Sources & confidence

Confidence: High (0.9)

Source(s): Smart Renewable Energy Programs, Energy — Electric Utilities Regulated by the Hawaii PUC

Generation supplier

Hawaii Electric Light Company (HELCO) (utility)

Some supporting official material could not be independently confirmed from the full source in GridPermit's latest review. Verify the current requirement with the authority before relying on it.

Sources & confidence

Confidence: Medium (0.6)

Source(s): Smart Renewable Energy Programs

Interconnection

https://www.hawaiianelectric.com/products-and-services/smart-renewable-energy-programs

Confidence: Medium (0.6)

Permit authority

County of Hawai'i Department of Public Works, Building Division

Sources & confidence

Confidence: High (0.95)

Source(s): Guidelines for Permitting a Residential Photovoltaic (PV) System (rev. 10.10.12) and PV Bulletin PV 2012-01

Permit page: https://www.dpw.hawaiicounty.gov/divisions/building

Inspection steps

  • Building and electrical inspections may be requested in any order following installation of panels on the roof (per PV Bulletin PV 2012-01)
  • For roof-mounted systems, the Building Division provides ladders to inspectors; in the interim, contractors must provide ladders and fall protection at the time of inspection
Sources & confidence

Confidence: High (0.9)

Source(s): Guidelines for Permitting a Residential Photovoltaic (PV) System (rev. 10.10.12) and PV Bulletin PV 2012-01

Eligibility constraints

  • Property types: residential
  • Max system size (AC): Not yet verified.
  • Max system size (DC): Not yet verified.
  • Max thermal capacity: Not yet verified.
  • Program/pathway: Expedited Permit Process for PV Systems
  • Other conditions:
    • All photovoltaic systems for residential and non-residential installations require a building permit (Hawai'i County Code Chapter 9, Sec. 9-33(b))
    • Electrical design drawings and specifications must bear the approval of a Hawai'i-registered electrical engineer
    • Permits are issued only to Hawai'i State licensed building, electrical, or photovoltaic contractors (HRS Section 444)
    • Fasteners must not occur in roof framing beyond the exterior wall line without engineered calculations
    • Roof-mounted systems using Iron Ridge, Unirac, or Solar Mount mounting systems are pre-approved (no professional stamp required) up to 30 ft height in Wind Zones A/B/C and Seismic Zones A/B/C/D; systems in Wind Exposure D (within 1/4 mile of the ocean) or Seismic Zones E/F require licensed architect/structural engineer review
    • No material deviation from reviewed plans/specifications is permitted without prior electrical-engineer-of-record approval
Sources & confidence

Confidence: High (0.9)

Source(s): Guidelines for Permitting a Residential Photovoltaic (PV) System (rev. 10.10.12) and PV Bulletin PV 2012-01

Official contacts

Official contacts

Confidence: High (0.9)

Need a solar installer who handles permits in Hilo?

EnergySage is an independent solar marketplace where you can request property-specific pricing from installers familiar with local permitting.

Compare quotes from solar installers →

You'll continue on EnergySage's website. GridPermit links to EnergySage as an independent third-party resource. This link is not currently tracked for compensation.

Official sources

Official sources

Frequently Asked Questions

What utility serves solar customers in Hilo, Hawaii?

Hawaii Electric Light Company (HELCO) is the interconnection and distribution utility for Hilo. The same utility is also listed as the default electricity generation supplier.

What documents are required for a solar permit in Hilo?

Commonly required documents include: Structural Evaluation Worksheet (Steps 1 and 2); Location/site plan showing major structures (1"=20' or larger preferred); Roof plan (1"=8') showing PV array with 3' clear space along the roof ridge, array supports, framing members, and mounting structure construction; Standard electrical diagram showing PV array configuration, wiring, overcurrent protection, inverter, disconnects, required markings/labels, and AC connection to the building; Specification sheets and installation manuals for all manufactured components (PV modules, inverters, combiner box, mounting system); Two sets of drawings/site plans stamped by a Hawai'i-registered electrical engineer (per Hawai'i County Code Chapter 9, Sec. 9-33(b) and HRS Section 444); Completed Building Permit Worksheet and Electrical Permit Application; Framing plan showing rafter-strengthening detail; Licensed Hawai'i state architect or structural engineer review/approval (professional stamp).

Who do I contact about solar permits in Hilo?

DPW Building Division — East Hawai'i (Hilo), phone 808-961-8331, email cohbuild@hawaiicounty.gov.

Disclaimers: This page is for informational purposes only and is not legal, engineering, financial, tax, or permit advice. GridPermit is not a solar installer, contractor, engineering firm, public utility, or government agency. Requirements, fees, and program terms change. Verify current requirements with County of Hawai'i Department of Public Works, Building Division and HELCO before starting a project. Last verified 2026-08-13.

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