Solar calculator for Hawaii
Panels, system size, cost and payback for Hawaii, from your own power bill.
The average Hawaii home uses 495 kWh a month and pays 42.9 cents per kWh, which puts Hawaii at among the highest electricity prices in the country, which is what makes solar pay back faster. Summer cooling drives the bill in Hawaii, and that load lands in the sunniest hours, which suits solar. A south-facing fixed array there makes about 1,622 kWh per installed kW a year, and the worst winter month still gets 4.88 peak sun hours a day. Drop in your own bill below and the numbers on this page are replaced by yours.
A worked example for Hawaii
Take the average home: 495 kWh a month, which is 5,940 kWh a year, at 42.9 cents per kWh (EIA, 2024 residential averages, as of 2026-11). Sized to cover all of that use, the tool returns 3.7 kWdc and 9 panels, needing about 189 square feet of roof. The installed estimate is $9,119 (national median, EnergySage H2 2025), yearly savings are about $2,548, and simple payback is 3.6 years, with no incentive applied.
Sun and yield in Hawaii
We use 1,622 kWh per installed kW per year for Hawaii, from NREL PVWatts v8 for the state's largest city at a 20 degree south-facing tilt (via TheGreenWatt, as of 2026-11). The darkest month averages 4.88 peak sun hours a day, which matters if you plan to go off-grid or size a battery. A different roof angle or heavy shade changes this, so treat it as a starting point.
Incentives
The 30% federal tax credit ended for homeowner purchases after December 31, 2025, so none is applied here. See the tax credit guide. Look up Hawaii and your own utility for net metering terms and any local programs before relying on a payback number.
Planning estimate. Permits, interconnection approval and a licensed electrician are required for grid-tied systems.
Questions
How many solar panels does a Hawaii home need?
The average Hawaii home uses 5,940 kWh a year (EIA 2024). At about 1,622 kWh per installed kW, covering all of it takes 3.7 kWdc, or 9 panels. Your own bill will move that up or down.
How much does solar cost in Hawaii?
For the average-home example the installed estimate is $9,119 at the national median of $2.49 per watt (EnergySage, H2 2025, as of 2026-11). We have no sourced Hawaii price multiplier, so local quotes will differ.
Is there a federal solar tax credit in Hawaii?
The 30% federal tax credit ended for homeowner purchases after December 31, 2025. Check your state, utility and local programs separately.
Where does the Hawaii sun figure come from?
1,622 kWh per kW per year and 4.88 winter peak sun hours come from NREL PVWatts v8 runs for Hawaii's largest city, compiled by TheGreenWatt (as of 2026-11). Real yield varies across the state.
Is my bill uploaded?
No. Your bill is read in your browser and never uploaded.