Hawaiʻi solar incentives
Updated November 3, 2026 · Reviewed by Bruce Ekimura, Founder and President
For a Hawaiʻi home, the solar tax credit in 2026 is the state credit: 35% of the system's cost, up to $5,000 for a single-family solar PV system. The 30% federal homeowner credit ended for systems placed in service after December 31, 2025. Act 24 adds a $40 million yearly cap, an income limit and state certification from 2027, and ends the state credit after the 2029 tax year.
At a glance
Every credit, rebate and program in one table, with the deadline and the official source.
| Incentive | Amount or cap | Deadline and timing | Source |
|---|---|---|---|
| Hawaiʻi solar tax credit (RETITC): solar PV, single-family home | 35% of cost, up to $5,000 per system | Ends for tax years beginning after Dec 31, 2029. From 2027: HSEO certification; application period closes March 1, 5:00 p.m. HST | Act 24 |
| Hawaiʻi solar tax credit (RETITC): solar water heating, single-family | 35% of cost, up to $2,250 per system | Same timing as above | Act 24 |
| Act 24 statewide cap | $40 million per calendar year, 2027–2030; shared pro rata if exceeded | Applies to credits claimed in 2027 for systems placed in service in 2026, unless exempt under EO 26-02 | Act 24, TIR 2026-02 |
| Federal residential credit (25D) | Ended | Not available for property placed in service after Dec 31, 2025; unused 2025 credit carries to 2026 | IRS |
| Federal commercial credit (48E) | For businesses and third-party-owned systems | Solar must begin construction by July 4, 2026 or be placed in service by Dec 31, 2027; storage exempt from the in-service deadline | SEIA |
| Hawaiʻi Energy solar water heater rebate | Up to $2,750 instant rebate; tune-up up to $325 | Through June 30, 2027, while funds last; not available on Kauaʻi | Hawaiʻi Energy |
| Hawaiian Electric BYOD Plus (batteries) | $400 per kW committed, plus $400 per kW for qualifying LMI customers | New battery paired with renewables; 5-year agreement | Hawaiian Electric |
| Honolulu property tax | Rooftop solar isn't assessed | Ongoing | ROH § 8-10.12 |
General information, not tax advice. Ask a tax professional how these credits apply to you.
Solar tax credit 2026
The short version for 2026: the federal homeowner credit is gone, the Hawaiʻi state credit is still here, and the rules for claiming it tighten in 2027.
The federal one already has for homeowners. The Residential Clean Energy Credit (Section 25D) isn't available for property placed in service after December 31, 2025 (IRS). Hawaiʻi's 35% state credit isn't going away in 2026. It continues through the 2029 tax year, with Act 24's cap, income limit and certification starting in 2027 (Act 24).
No homeowner whose system is placed in service in 2026, even if the contract was signed or paid in 2025. The 30% federal credit still exists for businesses and for the owners of leased and PPA systems through Section 48E, if solar construction began by July 4, 2026 or the system is placed in service by December 31, 2027 (SEIA).
For a home: the state credit, at 35% of cost up to $5,000 for PV and $2,250 for solar water heating. Alongside it, Hawaiian Electric's BYOD Plus pays for new batteries, Hawaiʻi Energy offers an instant solar water heater rebate, and Honolulu doesn't assess rooftop solar for property tax. Each one is explained below.
It depends on your usage, roof and budget, and losing the federal credit makes the math tighter. The other side of that math is the bill: from November 1, 2026, Hawaiian Electric's Oʻahu residential rate is 48.6 to 52.3 cents per kWh, depending on usage. Our guide to the Hawaii electricity cost breaks down current rates, and what solar costs in Hawaiʻi shows how incentives change the net price.
State credit
Hawaiʻi's Renewable Energy Technologies Income Tax Credit (RETITC) lets you claim 35% of the actual cost of a solar system on your state return, up to a cap for each system (Act 24).
| System | Single-family home | Multi-family (per unit) | Commercial |
|---|---|---|---|
| Solar PV (electricity) | $5,000 | $350 | $500,000 |
| Solar water heating | $2,250 | $350 | $250,000 |
Any credit larger than your tax bill carries over to the next year's income tax (Tax Facts 2022-2).
For a PV system, you can take the credit as a refund if you reduce it by 30%. The election can't be revoked (Tax Facts 2022-2).
Filers with Hawaiʻi AGI of $20,000 or less ($40,000 or less filing jointly) can claim the refund without the 30% reduction (Tax Facts 2022-2).
Act 24 (SB 3125)
Governor Green signed SB 3125 as Act 24 on May 21, 2026 (EO 26-02). It keeps the 35% rate and the per-system caps and adds four changes (Act 24). The state energy office says the changes begin with taxable years after December 31, 2026 (HSEO).
1
Total credits are limited to $40 million in each calendar year from 2027 through 2030. If certified claims go over the cap, each claimant gets a share in proportion to their costs (Act 24).
2
Only filers with adjusted gross income of $175,000 or less, or $350,000 or less filing jointly, can claim the credit (Act 24).
3
The Hawaiʻi State Energy Office (HSEO) certifies each claim before you file (Act 24). See how it works below.
4
The credit doesn't apply to taxable years beginning after December 31, 2029 (Act 24).
The changes drew wide coverage in May 2026, including Hawaiʻi Public Radio and the Honolulu Star-Advertiser.
2026 systems
Often, yes. Executive Order 26-02, signed June 8, 2026, says systems placed in service in 2026 aren't subject to the $40 million cap if either condition below is met (EO 26-02). The Department of Taxation explained how it applies in TIR 2026-02 on July 31, 2026 (TIR 2026-02).
Exempt
The system was completed before Act 24 was signed.
Exempt if you can show it
You invested resources in the system's financing, planning, design, permitting or installation before May 21, 2026, and can show that to HSEO and the Department of Taxation.
HSEO says it will post filing instructions on its RETITC page as they're developed (HSEO). Until then, keep your contract, deposit receipts, financing papers and permit records together.
From 2027
1
Your system is completed during the calendar year.
2
Before March 1 of the following year, file a statement with HSEO listing your adjusted gross income, the system's actual cost and the credit you're claiming. The application period closes March 1 at 5:00 p.m. Hawaiʻi Standard Time.
3
By May 31, HSEO tells each applicant the credit amount it certified.
4
Use the certified amount when you claim the credit on your Hawaiʻi return.
Source: Act 24, § 235-12.5(f) and (h).
Federal
Not for homeowners. The Residential Clean Energy Credit (Section 25D), which covered 30% of solar and battery costs, isn't available for property placed in service after December 31, 2025 (IRS). A home system finished in 2026 doesn't qualify, even if you signed or paid in 2025.
Unused 2025 credit: if your 2025 tax bill was too small to use the whole credit, you can carry the unused portion to 2026 (IRS Form 5695 instructions).
Leases and PPAs: when a third party owns the system, that owner claims the commercial credit (Section 48E), not you. Solar projects must begin construction by July 4, 2026 or be placed in service by December 31, 2027 (SEIA). If you're weighing ownership against a lease, see solar lease vs buy in Hawaiʻi.
Quote check
If a 2026 quote for a home system subtracts a 30% federal credit, it's out of date. Ask for the price before incentives, with the state credit, BYOD Plus and any rebate shown separately.
Businesses
Businesses, landlords and developers have their own caps and a different federal credit.
35% of cost, up to $500,000 per PV system and $250,000 per solar water heating system, subject to the same Act 24 cap and certification (Act 24).
Solar must have begun construction by July 4, 2026, or be placed in service by December 31, 2027. The in-service deadline doesn't apply to energy storage (SEIA).
Start from your electric bills and peak usage, then have your advisor confirm which credits, depreciation and timing apply before you sign. See commercial solar on Oʻahu.
Other programs
$400 per kW of committed battery capacity upfront, plus $400 per kW for qualifying low- to moderate-income customers. New batteries paired with renewables only, on a 5-year agreement (Hawaiian Electric). See our BYOD Plus guide.
Up to $2,750 instant rebate on a solar water heater and up to $325 on a tune-up, through June 30, 2027, while funds last. Not available on Kauaʻi (Hawaiʻi Energy). See solar water heating in Hawaiʻi.
Devices that convert sunlight into electricity or heat aren't treated as property and aren't assessed, so rooftop solar doesn't raise your assessed value (ROH § 8-10.12).
Batteries
A battery counts toward the RETITC as an accessory to a PV system only if it's installed and placed in service on the same property in the same tax year as that system. A battery added in a later year doesn't qualify (TIR 2022-02). For a battery added to existing solar, BYOD Plus is the main incentive. Compare options on our battery storage page and Tesla Powerwall page. For prices and payback, see Powerwall cost and payback.
Paperwork
Paying over time? See solar financing in Hawaiʻi. For the full install-to-claim timeline on a home, read our residential solar page.
FAQ
The federal one already has for homeowners. The IRS says the 30% Residential Clean Energy Credit isn't available for home systems placed in service after December 31, 2025. Hawaiʻi's 35% state solar tax credit continues in 2026 and runs through the 2029 tax year, with new limits under Act 24 starting in 2027.
Yes. Hawaiʻi's Renewable Energy Technologies Income Tax Credit still pays 35% of a solar system's cost, up to $5,000 for a single-family PV system and $2,250 for a solar water heater. Executive Order 26-02 exempts many systems placed in service in 2026 from Act 24's yearly cap.
No homeowner with a system placed in service in 2026. The federal 30% credit for businesses and for third-party owners of leased systems (Section 48E) continues for solar projects that began construction by July 4, 2026 or are placed in service by December 31, 2027. If you couldn't use all of a 2025 credit, you can carry the unused part to 2026.
Act 24, signed May 21, 2026, keeps the 35% rate and the per-system caps. It adds a $40 million statewide cap each year from 2027 through 2030, an income limit of $175,000 AGI ($350,000 filing jointly), certification by the Hawaiʻi State Energy Office, and an end date after the 2029 tax year.
It is if the system was completed before May 21, 2026. A system placed in service later in 2026 can also be exempt if you invested resources in its financing, planning, design, permitting or installation before May 21, 2026, and can show that to the State Energy Office and the Department of Taxation.
For a system installed in one year, you file a certified statement with the Hawaiʻi State Energy Office before March 1 of the next year, listing your adjusted gross income, the system's actual cost and the credit you're claiming. HSEO tells you your certified credit by May 31, and you use that amount on your Hawaiʻi return.
Only as an accessory to a PV system installed and placed in service on the same property in the same tax year. A battery added in a later year doesn't qualify for the state credit. Hawaiian Electric's BYOD Plus pays a separate upfront incentive of $400 per kW committed for new batteries.
For a PV system, you can elect to take the credit as a refund if you reduce it by 30%, and the election can't be revoked. Filers with Hawaiʻi adjusted gross income of $20,000 or less, or $40,000 filing jointly, can claim the refund without the reduction. Otherwise unused credit carries forward.
Sources
Free evaluation
Alternate Energy Hawaii has installed solar on Oʻahu since 1993. We'll show the price before incentives and each credit, rebate and program your system is likely to qualify for. Your tax professional confirms the tax side.