Solar Panel Cost in Kahului, HI 2026: ~10.8-Year Payback
In Kahului, HI, an 8 kW system at $3.39/W produces about 1,301 kWh per kW and pays back in roughly 10.8 years at 43.96¢/kWh with the federal credit at $0.
· Source: EIA Electric Power Monthly Table 5.6.A (July 2026 data) · next EIA update ~Oct 23
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- Kahului production
- 1,301 kWh/kW/yr
- Hawaii average
- 1,550 kWh/kW/yr
- Electricity rate
- 48.0¢/kWh
- 8 kW installed cost
- ~$27,120
- 2026 federal credit
- $0
- Payback (utility math)
- 10.8 years
Why this number
A kilowatt of panels in Kahului produces about 1,301 kWh a year, placing it 2 of 4 among the Hawaii cities modeled here. The state spans Honolulu at 1,610 down to Kaneohe at 1,157, a 39% span, and Kahului sits inside it at a payback of about 10.2 years.
An 8 kW system in Kahului, priced out
| Metric | Estimate for Kahului | Hawaii statewide |
|---|---|---|
| Production, unshaded 20° south | 1,301 kWh per kW/yr | 1,550 kWh per kW/yr |
| 8 kW output after a 10% roof derate | ~9,367 kWh/yr | ~11,160 kWh/yr |
| Average residential rate | 48.0¢/kWh (EIA) | 48.0¢/kWh |
| Installed cost, 8 kW | ~$27,120 at $3.39/watt | ~$27,120 |
| 2026 federal credit | $0 | $0 |
| Export rule | Net billing — exports credited below retail | Net billing — exports credited below retail |
| Export credit modeled | 13.50¢/kWh | 13.50¢/kWh |
| Annual value of that output | ~$2,557 | ~$3,047 |
| Rough payback (your utility) | 10.8 years | 8.6 years (state-average model) |
| 25-year net position | $48,909 | — |
Only the first two rows differ. Everything financial — rate, tariff, price per watt — is inherited from Hawaii without change, which is the point: a city page that quietly used a different electricity rate from its state page would be guessing, not measuring.
Doing nothing is not free either. Twenty-five years of the electricity an 8 kW Kahului array would produce, with rates rising at 2.5% a year, comes to roughly $153,573.
Electricity isn’t only for panels — the heat pump vs. furnace cost calculator compares heating costs at Kahului’s own 48.0¢/kWh rate.
Run it with your own bill
Shared methodology · identical on every city page
- Production figures are unshaded, south-facing, 20° PVGIS values. A real roof — its own pitch, orientation, a tree or a chimney — typically produces 10–25% less; every payback here already carries a 10% real-roof derate.
- Paybacks include $150/yr of running costs and one $2,000 inverter replacement in year 14, which is why they run longer than paybacks quoted elsewhere.
- State export rules cover investor-owned, state-regulated utilities. Municipal utilities and rural electric cooperatives are exempt in most states and set their own terms.
- Installed cost is the state-level EnergySage market figure, not a city quote; a swing of 50¢/W moves payback by roughly a year and a half either way. Get three quotes before trusting any payback — including ours.
Hawaii is not one solar market
Across the 4 Hawaii cities with their own modeled figures, production spans 39% — Kaneohe at 1,157 kWh per kW to Honolulu at 1,610. Every column except production is identical down this table: same 48.0¢/kWh retail rate, same export regime, same $3.39/W installed cost. The payback differences are caused by weather and nothing else.
| Location | kWh per kW per year | 8 kW output | Annual value | Payback |
|---|---|---|---|---|
| Honolulu | 1,610 | 11,592 kWh | $3,165 | 8.3 yrs |
| Kahului (this page) | 1,301 | 9,367 kWh | $2,557 | 10.2 yrs |
| Hilo | 1,177 | 8,474 kWh | $2,314 | 11.2 yrs |
| Kaneohe | 1,157 | 8,330 kWh | $2,274 | 11.4 yrs |
| Hawaii state average | 1,550 | 11,160 kWh | $3,047 | 8.6 yrs |
Against the state figure, Kahului runs 16% below Hawaii’s 1,550 kWh per kW — a payback 2.2 years longer than the statewide 8.6-year estimate on the same hardware at the same price.
What sets Kahului apart
Well below Honolulu but far above Hilo, which is the range Hawaii covers in a couple of hundred miles.
Your utility, officially
Hawaii’s average residential rate is 48.0¢/kWh, but the bill in Kahului comes from Maui Electric Co Ltd at 43.96¢ — 8.4% below the state figure. These are the residential figures Kahului’s utility reported to the U.S. Energy Information Administration on Form EIA-861 for 2024 — computed as revenue ÷ sales from the official file, not estimated:
| Utility | EIA ID | Residential avg price | Residential customers | Net-metering (residential, self-reported) |
|---|---|---|---|---|
| Maui Electric Co Ltd | 11843 | 43.96¢/kWh | 61,811 | 13774 customers / 85.014 MW |
How exports are treated matters as much as the headline price: Maui Electric Co Ltd is modeled here under the state’s net billing rules, and that treatment is baked into every payback figure on this page.
Kahului homes are billed by Maui Electric Company — MECO, an investor-owned Hawaiian Electric company — at a 2024 EIA-861 average of 43.96¢/kWh across 61,811 residential customers. Only its Big Island sibling HELCO, at 48.31¢, charges more among the utilities we track. Rates like this rewrite the solar question entirely. On the mainland, the argument is usually about whether a 13-to-18-cent kilowatt-hour justifies the hardware; on Maui, every kilowatt-hour your roof produces and you consume avoids a purchase at nearly 44 cents, and no incentive program anywhere moves the needle as much as that single fact.
Maui’s residents have responded accordingly. MECO reported 13,774 residential net-metering customers and 85.014 MW to EIA for 2024 — about 22% of the homes it serves, roughly one in four or five, with a healthy 6.2 kW average system. That saturation is in the same league as Oahu’s, and it happened under some of the most heavily revised export rules in the country.
Those rules are set statewide. The current program for new systems is Smart Renewable Energy (SRE) Export, effective October 1, 2024 — the same day the legacy programs (CGS+, Smart Export, Battery Bonus) closed to new customers. SRE pays a time-varying export credit locked for seven years; we model the daytime rate of 13.5¢/kWh, since midday is when a battery-less rooftop actually exports. The spread tells you how to build: self-consumption is worth 43.96¢, a midday export 13.5¢ — better than three to one. Hawaii’s program design is an explicit argument for storage, and on Maui the argument is only slightly less forceful than on the Big Island.
On sunshine, Kahului is Hawaii’s middle case: 1,301 kWh per kW of unshaded south-facing capacity — 19% behind leeward Honolulu’s 1,610, about 10% ahead of soaked Hilo’s 1,177. That is the range one island chain covers in a couple of hundred miles. The curious result of price and weather moving in opposite directions: at 43.96¢, a Kahului kilowatt of capacity earns roughly $572 a year in avoided purchases — within a few dollars of Hilo’s, and far beyond any mainland city we cover.
The money picture: the federal §25D residential credit is $0 for 2026 cash and loan purchases, having expired December 31, 2025. Hawaii’s own Renewable Energy Technologies Income Tax Credit (Form N-342) survives at 35% capped at $5,000 per system, with a requirement that the system be at least 5 kW. Installed costs are mainland-plus: EnergySage quotes average $3.39/W in Hawaii. One caveat: Kahului’s yield was modeled from three of five cluster points — the coast cost us the others — so read 1,301 as a well-grounded estimate, not a measurement.
Source: EIA Form EIA-861, 2024 final release , accessed 2026-09-02. Average price is total residential revenue divided by total residential sales for the year — your own rate depends on your tariff and usage tier.
Kahului against the rest of Hawaii
Same rate, same export rule, same installed price per watt — only the sunshine changes:
| City | kWh per kW | Payback |
|---|---|---|
| Honolulu | 1,610 | 8.3 years |
| Kahului | 1,301 | 10.2 years |
| Hilo | 1,177 | 11.2 years |
| Kaneohe | 1,157 | 11.4 years |
A 39% production span across one state is the reason a single statewide number is only ever a starting point.
What Hawaii pays Kahului for exported power
Hawaii does not credit exports at the retail rate, and that rule reaches Kahului unchanged. The program is Smart Renewable Energy (SRE) Export , in force since 2024-10-01, crediting surplus power at a published rate of 13.50¢/kWh against a retail rate of 48.0¢.
Oahu TOU export: 13.5c daytime, 18.9c night, 32.9c evening peak, locked for 7 years. Modeled on the daytime rate, because that is when a rooftop array actually exports.
CGS+, Smart Export and Battery Bonus are now legacy programs, closed to new customers since 1 October 2024.
Because a typical home uses only about 40% of its generation as it is produced, most of what a Kahului array makes is sold at that lower rate. That is why the payback above is 10.8 years and not the 5.9 years the same hardware would return under full-retail net metering. Raising self-consumption is the lever that closes the gap.
Sources and method
- Production: modeled with PVGIS v5.2 PVcalc (European Commission JRC) using the PVGIS-NSRDB radiation database — the same NREL satellite dataset PVWatts draws on for the Americas. Assumptions: 4 kWp, standard c-Si, 14% system loss, roof mounting, 20-degree tilt, due south, horizon shading on. The 1,301 kWh per kW figure for Kahului is a modeled location point, not an interpolation from the Hawaii average. PVGIS is free to use with JRC attribution requested; the underlying NSRDB is public domain (NREL/DOE).
- Real-roof derate: a separate 10% deduction for azimuth, pitch and shading, applied in the shared model rather than folded into the production data — so you can adjust it if your roof is genuinely unobstructed.
- Electricity rate: U.S. Energy Information Administration, average price by state . This is Hawaii’s residential average; EIA does not publish a Kahului figure, so the state rate is used and labeled as such.
- Export rules: Smart Renewable Energy (SRE) Export , from our Hawaii state page and the shared export-rules dataset behind it.
- State average rate: EIA Table 5.6.A, July 2026 data (released Sep 2026), used for every state-average comparison on this page.
- Payback model: shared with the solar savings calculator and the state pages — 2.5%/yr utility inflation, 0.5%/yr degradation, $150/yr running costs, one $2,000 inverter replacement in year 14, federal credit $0. The rest of the toolset — battery, sizing, financing — is under all calculators .
- Incentives: DSIRE . City and utility programs change more often than state ones — check yours directly.
Electricity rate, export regime, production figure and installed cost on this page were last verified on 30 August 2026. Export credits reset on annual tariff cycles and incentive budgets run out mid-year, so treat every figure as a snapshot at that date and confirm current terms before acting. Nothing here is tax or financial advice.
Frequently asked questions
How much do solar panels cost in Kahului in 2026?
About $27,120 for a typical 8 kW system at $3.39 per watt, before any incentive. With the federal credit at $0 in 2026 that is close to your net cost. Note that the price per watt is a Hawaii market average — there is no reliable city-level cost data, so treat it as a starting point and get three quotes.
What is the solar payback in Kahului?
Roughly 10.8 years on this model, using Kahului’s own production figure of 1,301 kWh per kW and its own utility tariff (43.96¢/kWh) with each utility’s real export treatment. That includes $150 a year of running costs and one inverter replacement, which many published paybacks leave out.
Is Kahului better or worse for solar than the rest of Hawaii?
Against the state figure, Kahului runs 16% below Hawaii’s 1,550 kWh per kW — a payback 2.2 years longer than the statewide 8.6-year estimate on the same hardware at the same price.
Is solar worth it in Kahului in 2026?
At 48.0¢/kWh and 1,301 kWh per kW, an 8 kW system in Kahului pays back in about 10.2 years on this model. Treat that as a starting point for reading real quotes rather than as a quote: your roof’s orientation, its shading and the price you are actually offered will move it more than your city does.
How we calculated this
Year-1 saving = production (kW × the city’s modeled kWh per kW) × the blended kWh value (retail rate for self-use, the state export rule for exports). Payback = net cost ÷ year-1 saving, with the federal credit at $0 for 2026 purchases and cost per watt from the state’s installed-price band. Production is modeled from PVGIS/NSRDB irradiance for the city.Sources: U.S. Energy Information Administration (EIA) electricity rates · DSIRE incentive records · public IRS/OBBBA guidance. Figures are modeled estimates, not quotes or tax advice. See our methodology.
Compare with the rest of Hawaii
- Solar panel cost in Hawaii — The statewide picture: Hawaii’s rate, incentives, export rules and the 1,550 kWh per kW average this page corrects.
- Solar panel cost in Honolulu — 1,610 kWh per kW and a 8.3-year payback — better than Kahului on identical hardware.
- Solar panel cost in Hilo — 1,177 kWh per kW and a 11.2-year payback — worse than Kahului on identical hardware.
- Solar panel cost in Kaneohe — 1,157 kWh per kW and a 11.4-year payback — worse than Kahului on identical hardware.
- Solar panel cost in Eureka — 1,302 kWh per kW in California — the closest production match to Kahului in our data.
- Solar panel cost in Springfield — 1,296 kWh per kW in Illinois — the closest production match to Kahului in our data.
- All city solar figures — The 66 US cities with their own modeled production data, and the spreads between them.