A worked example: 8 kW in Hawaii
An 8 kW system — about 19 × 425-watt panels — at Hawaii's assumed installed cost of $2.90–$3.90 per watt runs roughly $23,200–$31,200 before incentives. At about 1,580 kWh of production per installed kW, it would generate around 12,640 kWh per year. Valuing self-consumed electricity at the assumed $0.42/kWh retail rate and exports conservatively, first-year savings land near $4,374 — a simple payback of roughly 5–7 years.
There is no federal tax credit in that math: the Section 25D residential credit ended for systems installed after December 31, 2025. State or utility incentives, where they exist, would shorten payback from here.
Average cost of solar panels in Hawaii by system size
Most Hawaii quotes land between 6 and 12 kW. At the state's assumed $2.90–$3.90 per watt, here is what each size costs to install, what it produces, and how long it takes to pay for itself on electricity savings alone — no incentives applied.
| System size | Panels | Installed cost | Annual production | Est. payback |
|---|---|---|---|---|
| 6 kW | 15 | $17,400–$23,400 | 9,480 kWh | 5–7 yrs |
| 8 kW | 19 | $23,200–$31,200 | 12,640 kWh | 5–7 yrs |
| 10 kW | 24 | $29,000–$39,000 | 15,800 kWh | 5–7 yrs |
| 12 kW | 29 | $34,800–$46,800 | 18,960 kWh | 5–7 yrs |
Size should follow your electricity usage, not a round number — these are reference points, not a recommendation. Note that cost per watt rises on smaller systems, because permitting, labor and the inverter do not shrink with the array.
What solar costs per kWh in Hawaii
Spread across a 25-year life, with 0.5%/yr panel degradation and no financing cost, solar electricity in Hawaii works out to roughly 7.8¢–10.5¢ per kilowatt-hour. The Hawaii retail rate this page assumes is 42.0¢. That gap — not the sticker price — is what determines whether solar pays here, and it is why a sunnier state with cheap electricity can be a worse investment than a cloudier one with expensive electricity. See how every state compares on cost per kWh.
Net metering and export rates in Hawaii
Hawaii ended traditional net metering in 2015. Current options such as Smart Export and the Battery Bonus successor programs favor battery storage and limit or time-restrict grid exports.
Export rules are worth reading as an incentive, because they set what every kilowatt-hour you do not use on site is worth — see how Hawaii compares with every other state on net metering.
Hawaii solar incentives
Hawaii offers a state income tax credit of 35% of system cost (capped, commonly at $5,000 for residential systems) — one of the strongest state credits in the country.
The most valuable program is 35% state tax credit (capped at $5,000). With no federal credit for 2026 installs, state and utility programs are now the whole picture — see the full Hawaii incentives guide.
What changes a Hawaii solar quote?
Equipment, roof condition, electrical upgrades, permitting, labor, system size, batteries and financing can all change the installed price. Savings also depend on the specific utility rate, how much solar electricity the home uses directly, and what the utility pays for exports.
Frequently asked questions
What is the average cost of solar panels in Hawaii?
The average installed cost in Hawaii runs $2.90–$3.90 per watt before incentives, which puts a 6 kW system at $17,400–$23,400, an 8 kW at $23,200–$31,200, and a 10 kW at $29,000–$39,000. Spread over a 25-year life, that works out to about 7.8¢–10.5¢ per kilowatt-hour, against a Hawaii retail rate assumed at 42.0¢.
How much does it cost to install solar panels in Hawaii?
Installation is not priced separately — the $2.90–$3.90 per watt above is a turnkey figure covering panels, inverter, racking, labor, permitting and interconnection. What moves it most in HI is roof complexity, whether the main panel needs upgrading, and whether a battery is included. Expect a site visit to change any online estimate, including this one.
How much do solar panels cost in Hawaii?
Using an assumed installed cost of $2.90–$3.90 per watt, a typical 8 kW home system in Hawaii costs roughly $23,200–$31,200 before incentives. Smaller and larger systems scale roughly with size, though small systems cost more per watt.
Is solar worth it in Hawaii?
With Hawaii electricity around $0.42/kWh and production around 1,580 kWh per installed kW per year, an 8 kW system could save roughly $4,374 in year one, for a simple payback of about 5–7 years with no federal credit. Whether that is "worth it" depends on your rate plan, export compensation, roof, and how long you plan to stay in the home.
How many solar panels do I need in Hawaii?
It depends on your electricity usage, not your roof. At Hawaii's assumed 1,580 kWh per installed kW, a 6 kW system (about 15 panels at 425 watts) generates roughly 9,480 kWh a year, and a 10 kW system (about 24 panels) roughly 15,800 kWh. Compare that against your annual kWh from a utility bill — our calculator sizes it from your monthly bill in about a minute.
Does Hawaii have net metering?
Hawaii ended traditional net metering in 2015. Current options such as Smart Export and the Battery Bonus successor programs favor battery storage and limit or time-restrict grid exports.
What solar incentives does Hawaii offer in 2026?
Hawaii offers a state income tax credit of 35% of system cost (capped, commonly at $5,000 for residential systems) — one of the strongest state credits in the country. Note that the federal Section 25D residential credit ended for systems installed after December 31, 2025, so state, local and utility programs are now the main incentives for purchased systems.
Is there still a federal solar tax credit in Hawaii?
No — the 30% federal residential clean energy credit (Section 25D) ended for systems installed after December 31, 2025 under the One Big Beautiful Bill Act. Leased or PPA systems may still benefit indirectly because the system owner can claim the commercial 48E credit through 2027.
Use this as a starting point
This page provides broad state assumptions, not a current market survey or binding quote. Before purchasing, verify applicable incentives, utility rules, installer licensing, warranties and financing terms.
Where these numbers come from
State assumptions are informed by public data and reviewed periodically (September 2026):