Solar in Hawaii: payback, sun by city and utility-scale capacity
Hawaii pays back in 4.3 years at $3.00 a watt (rank 1 of 51), 9.2 years shorter than the middle state. 1,714 kWh per kW (rank 4) at 40.59 ¢ (rank 1 from the top): sun and price equally drives it. Across 5 Hawaii cities, yearly output runs from 1,161 kWh per kW in Kailua to 1,664 in Kahului. Aug is the best month at 155 kWh per kW and Dec the worst at 123. Utility-scale solar in Hawaii: 578 MW in 35 plants, 10.2% of 2025 generation; 171 MW more under construction or planned.
Hawaii: payback 4.3 years, rank 1 of 51
| Measure | Value | Rank of 51 | Median state |
|---|---|---|---|
| Output of 1 kW a year, kWh | 1,714 | 4 | 1,372 |
| Home price, ¢ per kWh | 40.59 | 1 | 15.37 |
| Value of 1 kW a year | $696 | 1 | $222 |
| Payback at $3.00 a watt | 4.3 years | 1 | 13.5 years |
EIA-861 (2024): 98,447 home net-metered systems in Hawaii, 220.5 per 1,000 accounts (rank 1), average 5.4 kW.
Sizes and prices per watt in Hawaii
| Hawaii kW | kWh a year | Value a year | Cost at $2.50 | At $3.00 | At $3.50 | t CO2 |
|---|---|---|---|---|---|---|
| 4 | 6,856 | $2,783 | $10,000 | $12,000 | $14,000 | 4.3 |
| 6 | 10,283 | $4,174 | $15,000 | $18,000 | $21,000 | 6.5 |
| 8 | 13,711 | $5,565 | $20,000 | $24,000 | $28,000 | 8.6 |
| 10 | 17,139 | $6,957 | $25,000 | $30,000 | $35,000 | 10.8 |
| 12 | 20,567 | $8,348 | $30,000 | $36,000 | $42,000 | 12.9 |
| Hawaii $ per watt | 100% retail | 75% | 50% | 25% |
|---|---|---|---|---|
| $2.00 | 2.9 | 3.8 | 5.7 | 11.5 |
| $2.50 | 3.6 | 4.8 | 7.2 | 14.4 |
| $3.00 | 4.3 | 5.7 | 8.6 | 17.2 |
| $3.50 | 5.0 | 6.7 | 10.1 | 20.1 |
| $4.00 | 5.7 | 7.7 | 11.5 | 23.0 |
Hawaii: 1,714 kWh/kW × 40.59 ¢ = 696 a year per kW; the 30% column (3.0 years at $3.00) is arithmetic only.
CSVSun inside Hawaii: 5 cities, 36% apart
| Hawaii city | kWh per kW a year | Against state point | Sun, kWh/m2 a day | Payback at $3.00 | Residents |
|---|---|---|---|---|---|
| Honolulu | 1,586 | -7.5% | 5.69 | 4.7 | 346,323 |
| Hilo | 1,266 | -26.2% | 4.58 | 5.8 | 48,223 |
| Kahului | 1,664 | -2.9% | 5.98 | 4.4 | 27,068 |
| Kailua | 1,161 | -32.3% | 4.26 | 6.4 | 21,851 |
| Kapaa | 1,350 | -21.2% | 4.86 | 5.5 | 10,886 |
Hawaii state point 21.12, -157.49; city points Honolulu 21.32, -157.85; Hilo 19.69, -155.08; Kahului 20.87, -156.47; Kailua 19.65, -156.00; Kapaa 22.09, -159.35. Panel and method: solar method.
Output by month in Hawaii cities: 12 rows
| Hawaii month | Honolulu | Hilo | Kahului | Kailua | Kapaa |
|---|---|---|---|---|---|
| Jan | 123.7 | 110.9 | 125.4 | 118.2 | 106.5 |
| Feb | 117.9 | 89.9 | 121.8 | 90.9 | 92.5 |
| Mar | 134.6 | 101.6 | 137.8 | 101.7 | 108.6 |
| Apr | 136.2 | 107.3 | 140.0 | 94.9 | 119.1 |
| May | 139.6 | 114.5 | 148.8 | 85.6 | 122.9 |
| Jun | 144.3 | 110.2 | 146.4 | 80.6 | 121.8 |
| Jul | 140.8 | 117.4 | 150.3 | 92.4 | 125.8 |
| Aug | 151.4 | 111.1 | 156.7 | 94.0 | 128.0 |
| Sep | 150.1 | 110.2 | 146.6 | 95.7 | 126.7 |
| Oct | 128.6 | 110.2 | 145.4 | 103.8 | 111.7 |
| Nov | 112.2 | 84.4 | 127.4 | 101.8 | 89.4 |
| Dec | 106.2 | 98.0 | 117.3 | 101.4 | 96.9 |
Hawaii: 5 cities, best month 157 and worst 81 kWh per kW across them.
CSVBest and worst month in Hawaii: Aug 155, Dec 123 kWh per kW
| Hawaii month | kWh per kW | Price ¢ | Value per kW | kWh per kW per sun unit |
|---|---|---|---|---|
| Jan | 132.0 | 40.51 | $53.47 | 0.77 |
| Feb | 132.3 | 42.69 | $56.48 | 0.75 |
| Mar | 153.2 | 41.11 | $62.98 | 0.76 |
| Apr | 148.6 | 42.44 | $63.07 | 0.76 |
| May | 147.6 | 41.03 | $60.56 | 0.75 |
| Jun | 143.9 | 40.96 | $58.94 | 0.75 |
| Jul | 150.1 | 39.36 | $59.08 | 0.75 |
| Aug | 155.4 | 38.90 | $60.45 | 0.75 |
| Sep | 152.2 | 39.54 | $60.18 | 0.75 |
| Oct | 149.4 | 39.74 | $59.37 | 0.76 |
| Nov | 126.0 | 40.20 | $50.65 | 0.76 |
| Dec | 123.3 | 41.62 | $51.32 | 0.76 |
Hawaii: December to February give 23% of a year (rank 51 of 51, 1 = most winter); the best month is 1.3 times the worst. Output per unit of sun is highest in Jan (0.77) and lowest in Sep (0.75); PVWatts lowers cell output when the panel is hot, and the sun angle changes with the season. Our runs use one fixed 14% loss figure for every place, so snow or soiling in Hawaii is not modelled separately.
Utility-scale solar in Hawaii: 578 MW
Hawaii: 578 MW of operable utility-scale solar in 35 plants across 4 counties (EIA-860, 2025), rank 35 of 51; 400 W per resident, rank 19. Solar made 10.2% of Hawaii's net generation in 2025 (EIA-923), rank 9, +3.4 points against the national share. Biggest plants: Ho'Ohana Solar 1 in Honolulu County, 65 MW (2025); AES Maui Kuihelani Solar Hybrid in Maui County, 60 MW (2024); Kawailoa Solar in Honolulu County, 49 MW (2019). By county: Honolulu 355 MW, Kauai 80 MW, Hawaii 75 MW, Maui 68 MW. Proposed: 39 MW under construction (3 plants) and 132 MW planned (3 plants); batteries 517 MW running and 160 MW proposed.
| Hawaii year | MW added | Cumulative share of today's MW |
|---|---|---|
| 2019 | 144 | 25% |
| 2020 | 6 | 26% |
| 2021 | 4 | 27% |
| 2022 | 39 | 33% |
| 2023 | 66 | 45% |
| 2024 | 72 | 57% |
| 2025 | 111 | 77% |
Net metering and CO2 in Hawaii
EIA-861 (2024): 98,447 home net-metered systems in Hawaii, 220.5 per 1,000 accounts (rank 1), average 5.4 kW.
6 kW in Hawaii: 10,283 kWh a year displaces 6.5 t CO2 at 0.628 kg per kWh, +3.4 t against the average state.
Hawaii utilities and solar payback
| Hawaii utility | Homes | Price ¢ | Value of 1 kW | Payback at $3.00 |
|---|---|---|---|---|
| Hawaiian Electric Co Inc | 276,206 | 42.87 | $735 | 4.1 yr |
| Hawaii Electric Light Co Inc | 78,386 | 48.31 | $828 | 3.6 yr |
| Maui Electric Co Ltd | 61,811 | 43.96 | $753 | 4.0 yr |
| Kauai Island Utility Cooperative | 30,109 | 41.29 | $708 | 4.2 yr |
Hawaii among its neighbours
| Closest to Hawaii | Payback, years | kWh per kW | Price, ¢ | Utility-scale solar, points of generation | Miles away |
|---|---|---|---|---|---|
| Hawaii (this page) | 4.3 | 1,714 | 40.59 | 10.2 | - |
| California | +1.2 | -27 | -8.05 | +16.6 | 2,501 |
| Oregon | +13.0 | -584 | -25.22 | -6.1 | 2,568 |
| Washington | +17.2 | -652 | -27.48 | -9.6 | 2,690 |
| Nevada | +8.2 | +104 | -27.44 | +20.6 | 2,699 |
Hawaii against its neighbours in the payback ranking
- Hawaii, rank 1: 4.3 years
- +2 places, California +1.2 years against Hawaii
- +3 places, Massachusetts +3.4 years against Hawaii
Your numbers for Hawaii
Limits in Hawaii
Hawaii: with the old 30% credit (IRS, ended 2025) payback would be 3.0 years instead of 4.3, so the calculator starts at 0%. No Hawaii export rates in our data: output counts at 40.59 ¢. All limits.
Sources for Hawaii
- PVWatts v8 (NLR), 5 Hawaii cities and one state point: 1,714 kWh per kW
- EIA-860 2025 and EIA-923 2025: 578 MW of solar in Hawaii
- EIA-861 2024: 98,447 net-metered systems in Hawaii
- EIA retail sales 2025: 40.59 ¢ per kWh in Hawaii
- IRS 25D (ended 2025): 3.0 years in Hawaii with it; licences and periods for Hawaii
More about Hawaii
Hawaii electricity hub, Hawaii EV charging: 399 stations, where Hawaii ranks for rooftop solar, 4.3 years against 51 states, Hawaii calculators.
Questions
Solar payback in Hawaii?
4.3 years at $3.00 a watt; 3.6 at $2.50; 5.0 at $3.50; 1,714 kWh per kW at 40.59 ¢.
Winter cut in Hawaii solar output?
December to February give 23% of the year; Aug makes 155 kWh per kW and Dec 123.
Net metering in Hawaii?
98,447 systems, 220.5 per 1,000 accounts, rank 1.
Where in Hawaii is solar best?
Yes: 36% between Kailua and Kahului in yearly output.
Hawaii sunshine for solar panels?
1,714 kWh per kW a year at the state point, rank 4 of 51; from 1,161 in Kailua to 1,664 in Kahului.
Hawaii electricity from solar, what share?
10.2% of 2025 net generation, rank 9 of 51, +3.4 points against the nation.
Hawaii utility-scale solar capacity?
578 MW in 35 plants (EIA-860), 400 W per resident, rank 19; 171 MW proposed.
Hawaii pays half price for exports?
Payback 8.6 years at a 50% retail share.
CO2 displaced in Hawaii?
6.5 t a year on 6 kW at 0.628 kg per kWh.
Federal solar credit in Hawaii: still available?
Ended 2025 (IRS 25D); with it Hawaii payback would be 3.0 years, not 4.3.