Solar panels in Hawaii
Roofs across Hawaii get about 1,787 hours of usable sunlight a year, and electricity costs 42.1¢/kWh. That combination puts a typical system's payback at 3.1 years. Here's the detail, from real rooftop data across 2 Hawaii cities.
Check your own roof in Hawaii → These are regional figures; your roof's size, pitch and shading move them a lot.
How Hawaii compares
Hawaii gets more sunlight than 80% of the cities we measure, and its electricity costs more than 98% of states and provinces. Both matter, but not equally: the electricity rate usually matters more, because solar saves money by replacing power you would otherwise buy. A sunny state with cheap power often pays back slower than a cloudy state with expensive power. Why that happens →
Solar by city in Hawaii
| City | Sun hrs/yr | Panels | Net cost | Payback |
|---|---|---|---|---|
| Honolulu | 1,787 | 18 | $14,364 | 3.1 yrs |
| Hilo | 1,510 | 22 | $17,556 | 3.8 yrs |
What a system costs in Hawaii
| System | Size | kWh/yr | Net cost | Saves/yr | Payback |
|---|---|---|---|---|---|
| 8 panels | 3.2 kW | 4,861 | $6,384 | $2,046 | 3.1 yrs |
| 12 panels | 4.8 kW | 7,291 | $9,576 | $3,069 | 3.1 yrs |
| 16 panels | 6.4 kW | 9,721 | $12,768 | $4,093 | 3.1 yrs |
| 20 panels | 8 kW | 12,152 | $15,960 | $4,689 | 3.4 yrs |
| 26 panels | 10.4 kW | 15,797 | $20,748 | $5,073 | 4.1 yrs |
Payback stops improving as systems grow, then gets worse. You can only save on electricity you were going to buy, so once a system covers your usage the extra panels mostly export at a lower rate.
Hawaii solar incentives
Every US household can claim the 30% federal residential clean energy credit, which is what the "after credit" figures above assume. On a $20,520 system that is $6,156 back. How the credit works →
State, utility and municipal incentives stack on top and change often — Hawaii may offer rebates, property or sales tax exemptions, or performance payments. We deliberately don't list specific state programmes here because they change several times a year and stale numbers are worse than none. The DSIRE database is the standard reference and is kept current.
Hawaii solar questions
Is solar worth it in Hawaii?
At 42.1¢/kWh and 1,787 usable sun hours, a typical system pays back in about 3.1 years and returns roughly $99,665 over 25 years. That is a solid return.
How many solar panels do I need in Hawaii?
About 18 panels for a home using 10,800 kWh a year. Each 400W panel produces roughly 608 kWh annually at Hawaii sunlight levels.
How much do solar panels cost in Hawaii?
A 7.2 kW system runs about $20,520 before incentives and $14,364 after the 30% federal credit. Quotes vary widely by installer and roof complexity — get three.
Worth reading before you buy
Regional estimates generated 2026-08-22 from Google Solar API rooftop samples across 2 Hawaii cities, and average Hawaii electricity rates. Not a quote and not financial or tax advice.