Updated as of October 22, 2026 · Reviewed by Bruce Ekimura, Founder and President
Solar in Honolulu averages $3.42 per watt installed as of October 2026, or about $27,400 for a typical 8 kW home system before incentives. Hawaiʻi's 35% state tax credit, capped at $5,000 per single-family system, lowers that. The 30% federal homeowner credit has ended. A 13 kWh battery adds about $9,600.
EnergySage, which tracks real installer quotes, puts Honolulu at $3.42 per watt installed as of October 2026. The average Honolulu system is 8.03 kW at about $27,430 before incentives, with most quotes between $23,316 and $31,544 (EnergySage). Statewide, the average is $3.46 per watt (EnergySage).
| System size | Average price before incentives | Hawaiʻi state credit (35%, max $5,000) | After state credit |
|---|---|---|---|
| 5 kW | $17,086 | $5,000 | $12,086 |
| 6 kW | $20,503 | $5,000 | $15,503 |
| 7 kW | $23,920 | $5,000 | $18,920 |
| 8 kW | $27,338 | $5,000 | $22,338 |
| 10 kW | $34,172 | $5,000 | $29,172 |
Prices: EnergySage Honolulu averages, October 2026 (EnergySage). State credit: 35% of cost, capped at $5,000 per single-family PV system (Act 24). Solar only, no battery. Trackers differ: SolarReviews lists $2.82 per watt for Hawaiʻi, but its page still subtracts the 30% federal credit that no longer applies to purchased home systems (SolarReviews).
A solar price should be the full cost of a working, approved system on your roof, not just the panels. These line items belong in every Oʻahu quote.
| Line item | What it covers |
|---|---|
| Design and engineering | Sizing from your bills, panel layout, structural and electrical plans |
| Panels, inverters and racking | The equipment itself; brand and model change the price (EnergySage) |
| Wiring and installation labor | Mounting, roof penetrations and flashing, conduit and connection to your panel |
| Permits and inspections | Building and electrical permits and the inspections that close them out |
| Hawaiian Electric interconnection | The application through the Customer Interconnection Tool and an advanced meter for Smart Renewable Energy programs (Hawaiian Electric) |
| Monitoring | An app or portal that shows production and alerts you to faults |
Not usually included: a battery, a new roof, or a main electrical panel upgrade. Those are priced separately below.
EnergySage puts home batteries in Honolulu County at an average of $741 per kWh as of October 2026. Solar plus storage systems there range from about $17,997 to $54,559 (EnergySage).
| Battery size | Average installed price |
|---|---|
| 10 kWh | $7,407 |
| 13 kWh | $9,630 |
| 20 kWh | $14,815 |
| 26 kWh | $19,259 |
Hawaiian Electric pays $400 per kW you commit to a 2-hour daily export window, once, with no cap. Committing 5 kW earns $2,000. Qualifying lower-income households get another $400 per kW (Hawaiian Electric).
A battery counts toward the state credit only when it's installed with the solar, on the same property, in the same tax year. One added later doesn't qualify (TIR 2022-02).
Daytime solar exported under Smart Renewable Energy Export earns 13.5¢ per kWh, while Oʻahu homes paid an average of 40.54¢ per kWh in 2025 (Hawaiian Electric, Hawaiian Electric). A battery lets you use that solar at night instead.
Pricing a Tesla Powerwall? See our Powerwall cost and payback guide.
These items don't show up in average price-per-watt figures, but they often decide whether a quote is complete.
| Extra | Why it matters | Learn more |
|---|---|---|
| Roof replacement first | If your roof is near the end of its life, replace it before solar. Removing and reinstalling panels later adds labor you pay twice for. | Roofing |
| Main panel or service upgrade | Older homes may need a larger main panel to connect solar and a battery safely. | Electrical services |
| Backed-up subpanel | Partial backup moves essential circuits to a separate panel the battery powers. | Battery storage |
| Tile, steep or complex roofs | More labor and special mounting hardware raise the price per watt. | Site visit |
| Future loads | An EV charger or new AC means a larger system now, or a second project later. | EV charging |
Any home solar quote that still subtracts a 30% federal credit is out of date. Here's what applies now.
| Incentive | Amount | Rules | Source |
|---|---|---|---|
| Hawaiʻi state tax credit (RETITC) | 35% of cost, up to $5,000 per single-family PV system | From 2027: $40M yearly statewide cap, income limits ($175,000 single / $350,000 joint AGI) and state certification. Many 2026 systems are exempt from the cap if completed, or if you invested in them, before May 21, 2026 | Act 24, EO 26-02 |
| Federal residential credit (25D) | Ended | Not available for property placed in service after December 31, 2025 | IRS |
| Leases and PPAs | Owner claims the federal Section 48E credit | Solar must begin construction by July 4, 2026 or be placed in service by December 31, 2027; storage isn't subject to the in-service deadline | SEIA |
| Hawaiian Electric BYOD Plus | $400 per kW committed | New battery paired with renewables; 5-year agreement | Hawaiian Electric |
| Honolulu property tax | Not assessed | Rooftop solar doesn't raise your assessed value | ROH § 8-10.12 |
General information, not tax advice. Full rules: Hawaiʻi solar tax credit guide.
Three typical Oʻahu homes, priced from published averages. Use the one closest to yours as a starting point, then get a quote based on your own bills and roof.
Assumptions for all three: EnergySage Honolulu average prices for October 2026 (solar, batteries); a cash purchase by an owner-occupant of a single-family home; adjusted gross income within Act 24's limits; no roof or panel upgrade needed. The state credit is shown at its $5,000 maximum; Act 24's $40 million yearly cap could reduce it if statewide claims exceed the cap (Act 24). BYOD Plus at $400 per kW committed (Hawaiian Electric).
Two people, modest daytime use, no battery.
| 5 kW solar at $3.42/W | $17,086 |
| State credit (35%, capped) | −$5,000 |
| Estimated net cost | $12,086 |
35% of $17,086 is $5,980, so the $5,000 cap applies.
Evening AC and cooking; wants backup for essentials.
| 8 kW solar | $27,338 |
| 13 kWh battery | $9,630 |
| State credit (capped, battery installed same year) | −$5,000 |
| BYOD Plus, 5 kW committed | −$2,000 |
| Estimated net cost | $29,968 |
The battery is counted with the solar for the state credit, but the $5,000 cap still applies.
Central AC, an EV and whole-home backup goals.
| 10 kW solar | $34,172 |
| 26 kWh battery | $19,259 |
| State credit (capped) | −$5,000 |
| BYOD Plus, 10 kW committed | −$4,000 |
| Estimated net cost | $44,431 |
Whole-home backup may also need a main panel upgrade, not included here.
For payback, EnergySage estimates about 10 years for an average Honolulu solar system, with about $46,210 in savings over 25 years (EnergySage). See how we calculate yours on our solar payback page.
Get more than one itemized quote. Check each one against this list before you compare prices.
Financing changes the total you pay. Compare cash, loan and lease offers on our solar financing page.
In Honolulu, solar averages $3.42 per watt installed as of October 2026, so a typical 8 kW system costs about $27,400 before incentives. Most quotes fall between about $23,300 and $31,500. Hawaiʻi's 35% state tax credit takes off up to $5,000 per single-family system. Batteries, roof work and panel upgrades are extra.
EnergySage's October 2026 quote data puts Honolulu at $3.42 per watt and the Hawaiʻi average at $3.46 per watt, including installation. Larger systems usually cost a little less per watt. Divide any quote's price by its watts to compare offers of different sizes on the same basis.
About $741 per kWh in Honolulu County, according to EnergySage: roughly $9,600 for a 13 kWh battery and $19,300 for 26 kWh. Hawaiian Electric's BYOD Plus pays back $400 per kW committed, and the battery counts toward the state credit only if it's installed with the solar in the same tax year.
Yes, the state one. Hawaiʻi's credit pays 35% of the cost, up to $5,000 for a single-family PV system. From 2027 it has a $40 million yearly cap, income limits and state certification. The 30% federal credit ended for home systems placed in service after December 31, 2025, though leasing companies can still claim a commercial credit.
EnergySage estimates about 10 years for an average Honolulu system, with roughly $46,000 in savings over 25 years. Your payback depends on your usage, your Hawaiian Electric program and whether you add a battery. Daytime exports earn only 13.5¢ per kWh, so using more of your own solar shortens it.
System size, equipment brands, roof type and condition, electrical upgrades, battery size and the installer all change the price. A lower quote may leave out permits, a panel upgrade or a battery, or still subtract the ended federal credit. Compare itemized quotes line by line and on price per watt.
If your roof is near the end of its life, yes. Panels last decades, and removing and reinstalling them for a later re-roof adds labor you'd pay for twice. Have the roof inspected before you sign, and make sure the quote states whether roof work is included.
Alternate Energy Hawaii has installed solar on Oʻahu since 1993 from our Pearl City office. Send 12 months of Hawaiian Electric bills and we'll give you an itemized estimate: price before incentives, price per watt, battery options, your state credit and BYOD Plus amounts, and a payback estimate.