Cost of Solar Panels in Hawaii 2026: $3.46/W, Grid Power at 47 Cents/kWh
Hawaii solar averages $3.46 per watt including installation, $20,735 for a 6kW system before incentives, per EnergySage Hawaii data (October 2026). That is about a third above the $2.60 national average on the same marketplace. But Hawaii's average residential electricity price, 47.18 cents per kWh in August 2026 against 18.16 cents for the US (EIA Electric Power Monthly, Table 5.6.A), is the highest of any state, so every kWh your panels displace is worth more here than anywhere else. New systems on Hawaiian Electric's islands go on the Smart DER tariff (export or non-export) introduced on 1 April 2024.
Hawaii Cost by System Size
| System size | At $3.46/W | + Powerwall 3 at $13,473 |
|---|---|---|
| 5 kW | $17,300 | $30,773 |
| 6 kW | $20,760 | $34,233 |
| 7 kW | $24,220 | $37,693 |
| 8 kW | $27,680 | $41,153 |
| 10 kW | $34,600 | $48,073 |
Rows are system size times EnergySage's $3.46/W Hawaii average, before incentives (EnergySage's own 6 kW figure, $20,735, uses an unrounded rate). Battery column adds EnergySage's typical all-in Powerwall 3 installed cost of $13,473 (national marketplace figure, May 2026). The Battery Bonus rebate closed to new participants on 1 July 2024; its successor BYOD Plus pays for a battery committed to a daily two-hour grid dispatch. State of Hawaii also offers a Renewable Energy Technologies Income Tax Credit (RETITC): 35% of cost, capped at $5,000 per 5 kW of PV on a single-family home (see below).
Why Hawaii Is Different From the Mainland
Hawaii has the most-distorted electricity economics of any US state. Three structural factors converge: extreme grid isolation (each island is its own grid, no interconnection to other states), heavy dependence on imported petroleum for generation (imported oil still fuels much of the islands' generation), and a small load base that prevents economies of scale that mainland US grids enjoy.
Net effect: a residential price of 47.18 cents per kWh in August 2026, about 2.6 times the US average of 18.16 cents (EIA). Hawaii also has aggressive state-policy commitments to 100% renewable electricity by 2045 (HRS 269-92), which means strong policy support for distributed PV and storage. Combined with strong year-round sun (4.5 to 6.3 kWh/m²/day across the locations in the table below), the financial case for residential solar is the strongest in the country.
The complication: high daytime solar penetration on small island grids has saturated midday export capacity. Hawaiian Electric has cycled through tariff regimes over the past decade trying to balance new-customer solar adoption with grid stability. The current one, Smart DER, replaced the older tariffs for new customers in 2024.
HECO Tariff Options for Residential Solar
Smart DER Export: The system can send surplus energy to the grid for bill credits. Open to new customers since 1 April 2024.
Smart DER Non-Export: The system generates for self-use only and sends nothing to the grid, so a battery is what captures midday output for the evening. The older Customer Grid-Supply, CGS Plus, Smart Export and Customer Self-Supply tariffs closed to new customers on 29 March 2024.
BYOD Plus (battery incentive): The successor to Battery Bonus, which closed to new participants on 1 July 2024. Available since 15 May 2025, it pays an incentive for a battery that sends energy to the grid during a set two-hour period every day for at least three years. Source: Hawaiian Electric, Customer Choice.
Hawaii Production by Region
| Location | Insolation | 6kW annual production | Utility |
|---|---|---|---|
| Honolulu (Oahu south) | 5.6 | 9,400 kWh | HECO |
| Kaneohe (Oahu windward) | 4.8 | 8,300 kWh | HECO |
| Kahului (Maui) | 5.6 | 9,400 kWh | MECO |
| Hilo (Big Island east, wet) | 4.5 | 7,900 kWh | HELCO |
| Kona (Big Island west, dry) | 6.3 | 10,200 kWh | HELCO |
| Lihue (Kauai) | 5.5 | 9,200 kWh | KIUC |
Source: NREL PVWatts v8. KIUC (Kauai Island Utility Cooperative) operates independently from HECO/MECO/HELCO and has its own net-metering replacement program that includes some grid export at compensation rates.
RETITC: Hawaii's State Tax Credit
Hawaii's Renewable Energy Technologies Income Tax Credit (RETITC) gives single-family homes a credit of the lesser of 35% of the actual cost or $5,000 per PV system, and Form N-342 counts each 5 kilowatts of output capacity as one system, allocating the cost per kW (Hawaii Department of Taxation, Instructions for Form N-342, rev. 2025). A system larger than 5 kW therefore claims more than one capped credit.
Example, following the form's allocation lines: a 6 kW system at EnergySage's $20,735 is $3,456 per kW. The first 5 kW ($17,279) earns the lesser of 35% ($6,048) or $5,000, so $5,000; the remaining 1 kW ($3,456) earns 35%, $1,210. Total credit $6,210, net cost $14,525. The federal residential clean energy credit ended on 31 December 2025, so it no longer stacks. Check the allocation with your tax preparer.
By default the credit is nonrefundable: any excess over your Hawaii income tax liability carries forward until used. For solar you can instead make an irrevocable election to take it as refundable at a 30% reduction, and households whose income is all exempt retirement income, or whose Hawaii AGI is $20,000 or less ($40,000 married filing jointly), can have the excess refunded in full. File Form N-342 with your state income tax return.
Frequently Asked Questions
How much do solar panels cost in Hawaii in 2026?
EnergySage puts the Hawaii average at $3.46 per watt including installation, or $20,735 for a 6kW system before incentives (updated October 2026, from quotes on its marketplace). That is about a third above its $2.60 per watt national average. The state RETITC then cuts the net cost; the federal 30% credit ended for systems placed in service after 31 December 2025.
Why is Hawaii payback so fast?
Hawaii's average residential electricity price was 47.18 cents per kWh in August 2026, against a US average of 18.16 cents (EIA Electric Power Monthly, Table 5.6.A), so a kWh your panels displace is worth about 2.6 times the mainland average. Exports under the Smart DER export tariff earn a bill credit rather than the retail price, so the value of each kWh depends on how much of it your home uses directly or stores in a battery.
Does Hawaii still have net metering?
No, not for new installs. Hawaii's traditional Net Energy Metering (NEM) closed to new applicants in October 2015. Hawaiian Electric closed its Customer Grid-Supply, CGS Plus, Smart Export and Customer Self-Supply tariffs to new customers on 29 March 2024. New rooftop systems go on the Smart DER tariff, which began on 1 April 2024: the export version sends surplus to the grid for bill credits, the non-export version is for self-use only.
Is the Hawaii Battery Bonus still available?
No. Hawaiian Electric's Battery Bonus program closed to new participants on 1 July 2024. Its successor, Bring Your Own Device (BYOD) Plus, opened on 15 May 2025: it pays an incentive for a battery that sends energy to the grid during a set two-hour period every day for at least three years. Hawaiian Electric publishes the current BYOD Plus terms on its program pages.
Do I need a battery with solar in Hawaii?
It depends on the Smart DER option you choose. On the non-export option nothing goes to the grid, so midday output your home cannot use is wasted unless a battery stores it for the evening. On the export option the surplus earns a bill credit instead, and a battery is a choice rather than a requirement; it can also qualify for BYOD Plus if you commit to the daily two-hour dispatch.
What's the payback on Hawaii solar?
Work it from your own numbers. As an upper bound: a 6kW system in Honolulu produces about 9,400 kWh a year (PVWatts), and if every one of those kWh replaced grid power at the August 2026 statewide average of 47.18 cents, it would avoid about $4,435 a year. Exported kWh earn a lower bill credit, so the real saving is below that unless your home or a battery uses all of it. Divide your quoted price, less the state RETITC, by your realistic annual saving.
What about Maui and Big Island specifically?
Maui and Hawaii Island customers of Hawaiian Electric are on the same Smart DER and BYOD Plus programs as Oahu, but each island has its own rate schedule, so use the per-kWh price on your own bill. Kauai is served by KIUC, a cooperative with its own solar programs. Installer choice is narrower outside Oahu, which is a reason to collect more than one quote.