Hilo Solar Permit Guide
Hawaii Electric Light Company (HELCO) territory · County of Hawai'i
Overview
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.
Permit fees
- 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.
Rebates
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.
Utility and generation supplier
Utility
Hawaii Electric Light Company (HELCO)
Generation supplier
Hawaii Electric Light Company (HELCO) (utility)
Hawaiian Electric's Smart Renewable Energy (Smart DER) framework — SRE Export, SRE Non-Export, and Bring Your Own Device Plus — is a company-wide program described on Hawaiian Electric's own site without an island-specific carve-out, so this record reuses the same statewide-HEI-family program facts documented in hi-honolulu-honolulu-heco.json (see that record's generation_supplier.notes for the fuller Smart DER description), applied here at moderate confidence since this session did not independently reload a HELCO-specific page confirming identical terms apply to Hawaii Island.
Required documents
- Structural Evaluation Worksheet (Steps 1 and 2) (required when: always, attached to drawings)
- Location/site plan showing major structures (1"=20' or larger preferred) (required when: always, for both building and electrical submittals)
- Roof plan (1"=8') showing PV array with 3' clear space along the roof ridge, array supports, framing members, and mounting structure construction (required when: always)
- Standard electrical diagram showing PV array configuration, wiring, overcurrent protection, inverter, disconnects, required markings/labels, and AC connection to the building (required when: always)
- Specification sheets and installation manuals for all manufactured components (PV modules, inverters, combiner box, mounting system) (required when: always)
- 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) (required when: always, for all residential and non-residential PV installations)
- Completed Building Permit Worksheet and Electrical Permit Application (required when: always)
- Framing plan showing rafter-strengthening detail (required when: only if combined PV array weight exceeds 5 lbs/sq ft, rafters are over-spanned per the guide's supplied span tables, or per-attachment dead load exceeds 45 lbs)
- Licensed Hawai'i state architect or structural engineer review/approval (professional stamp) (required when: only for Iron Ridge/Unirac/Solar Mount roof-mounted systems installed above 30 ft, OR within Wind Exposure D (within 1/4 mile of the ocean), OR within Seismic Zones E or F — per County PV Bulletin PV 2012-01)
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
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
Official contacts
- DPW Building Division — East Hawai'i (Hilo), phone: 808-961-8331, email: cohbuild@hawaiicounty.gov, official website
- DPW Building Division — West Hawai'i (Kailua-Kona), phone: 808-323-4720, email: cohbuild@hawaiicounty.gov, official website
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 has a partner relationship with EnergySage; this link is not currently tracked, and whether the partnership results in compensation to GridPermit has not yet been confirmed.
Sources
- Guidelines for Permitting a Residential Photovoltaic (PV) System (rev. 10.10.12) and PV Bulletin PV 2012-01, County of Hawai'i, Department of Public Works, Building Division (government). Accessed 2026-08-12.
- HRS §235-12.5 — Renewable energy technologies; income tax credit, Hawaii State Legislature (government). Accessed 2026-08-13.
- Smart Renewable Energy Programs, Hawaiian Electric (parent company of HELCO) (utility). Accessed 2026-08-12.
- Energy — Electric Utilities Regulated by the Hawaii PUC, Hawaii Public Utilities Commission (puc). Accessed 2026-08-12.
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 default electricity generation supplier is Hawaii Electric Light Company (HELCO), a utility, separate from Hawaii Electric Light Company (HELCO).
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.