Largest utilities in Hawaii
Investor-owned utility · 276,853 residential customers · Hawaii
Applications: Own online portal – Customer Interconnection Tool (CIT, GridUnity)
Interconnection process and documents →Investor-owned utility · 79,318 residential customers · Hawaii
Applications: Own online portal – Customer Interconnection Tool (CIT, GridUnity)
Interconnection process and documents →Investor-owned utility · 61,877 residential customers · Hawaii
Applications: Own online portal – Customer Interconnection Tool (CIT, GridUnity)
Interconnection process and documents →Electric cooperative · 30,335 residential customers · Hawaii
Interconnection process and documents →Export compensation among the researched Hawaii utilities: Net billing. Rules differ by utility – see each utility page.
Hawaii interconnection rule
Hawaii Public Utilities Commission (HI PUC)
Interconnection rulePUC-approved utility tariff Rule 14H (Hawaiian Electric Rule No. 14, Section H, with Appendix I technical requirements, Appendix II applications/agreements, Appendix III process overview); Dockets 2014-0192 and 2019-0323 – Interconnection of Distributed Generating Facilities Operating in Parallel with the Company's Electric System · source
Applies toHawaiian Electric (Oahu, Hawaii Island, Maui County) via its PUC-approved tariff Rule 14H. No statewide administrative-code interconnection rule; Kauai Island Utility Cooperative (KIUC, PUC-regulated) has its own tariff rules (not reviewed).
Application formUtility-specific Interconnection Application: Exhibit A to Appendix II, Appendix II-A or II-B (non-export, momentary parallel) or other Company-approved application, with standard interconnection agreement.
TimelinesUtility provides requirements and agreement within 5 business days of request; completeness review within 15 business days; Initial Technical Review within 15 business days of complete application; Supplemental Review 20 business days; IRS 150 calendar days; interconnection facilities identification 15 business days; executable agreement within 5 business days; fully executed agreement within 15 business days after customer-executed agreement and closed City/County permits (Rule 14H Appendix III).
InsurancePer PUC D&O No. 22248 (Docket 03-0371) the utility does not impose a standardized insurance requirement; customer must carry commercially reasonable insurance or self-insure and disclose/provide evidence before executing the standard agreement (Appendix III Sec. 5). Program System Size is used to determine insurance requirements in agreements.
External disconnectCustomer furnishes a manual, visible-break isolation device (disconnect switch or rack-out breaker), accessible to and lockable open by utility personnel; existing service disconnect may be used if compliant; label 'Customer Generating Facility'. Interrupting device must be utility-accessible for facilities > 10 kW (Rule 14H App. I).
Export compensationUtility-specific – HRS §§ 269-101 to 269-111 (net energy metering); PUC D&O No. 33258 (Oct. 12, 2015, Docket 2014-0192)
D&O 33258 closed retail NEM for Hawaiian Electric to new customers and created Customer Grid-Supply (fixed export credit) and Customer Self-Supply (non-export); later CGS+ / Smart Export (2018), and current Hawaiian Electric programs referenced in Rule 14H: Rule 22 Customer Self-Supply, Rule 27 NEM+, Rule 32 Smart Renewable Energy Program (Smart DER). Existing NEM customers grandfathered.
No municipal utilities. KIUC (cooperative, PUC-regulated) follows its own PUC-approved interconnection tariff and DER programs.
| Level | Up to | Criteria / review / fee |
|---|---|---|
| Expedited Review (non-export: Customer Self-Supply Rule 22, NEM+ Rule 27, Smart Renewable Energy Program Non-export Rider Rule 32; momentary-parallel App. II-B) | Systems that will not export except as allowed under those rules | |
| Simplified Interconnection (pass Initial Technical Review screens) | All Initial Technical Review screens passed (no fixed kW threshold in Appendix III) · Initial Technical Review within 15 business days of complete application | |
| Supplemental Review | One or more Initial Technical Review screens failed · 20 business days after customer elects to proceed | |
| Interconnection Requirements Study (IRS) | If Supplemental Review determines IRS needed; customer pays IRS cost estimate · 150 calendar days after agreement and payment · Customer pays IRS cost |
- Hawaiian Electric Rule No. 14 incl. Rule 14H and Appendices I-III: https://www.hawaiianelectric.com/documents/billing_and_payment/rates/hawaiian_electric_rules/14.pdf (retrieved 2026-11-13)
- HI PUC DER Phase 1 D&O summary (not fully reviewed): https://puc.hawaii.gov/wp-content/uploads/2015/10/DER-Phase-1-DO-Summary.pdf (retrieved 2026-11-13)
- HRS Chapter 269 (net energy metering part): https://data.capitol.hawaii.gov/hrscurrent/Vol05_Ch0261-0319/HRS0269/HRS_0269-.htm (retrieved 2026-11-13)
All 4 utilities in Hawaii
- Hawaiian Electric (Oahu)276,853
- Hawaiian Electric (Hawaii Island)79,318
- Hawaiian Electric (Maui County)61,877
- Kauai Island Utility Cooperative30,335
Residential customers in Hawaii per EIA-861 (2025). Customer counts = bundled + delivery-only service (EIA-861 Part A + Part D). Service territory is reported by county; a county can be served by several utilities.
$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.