Solar panels in Hilo, HI
Roofs in Hilo get about 1,510 hours of usable sunlight a year — less than 51% of the cities we've measured. Here's what that means in cost, savings and payback, using real rooftop data rather than a national average.
Check your specific roof in Hilo → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.
What a typical Hilo solar system costs
A 22-panel system (8.8 kW) is about right for an average Hilo home using 10,800 kWh a year. It would produce roughly 11,295 kWh annually and offset 100% of that usage.
| System | Size | kWh/yr | Net cost | Saves/yr | Payback |
|---|---|---|---|---|---|
| 8 panels | 3.2 kW | 4,107 | $6,384 | $1,729 | 3.7 yrs |
| 12 panels | 4.8 kW | 6,161 | $9,576 | $2,594 | 3.7 yrs |
| 16 panels | 6.4 kW | 8,214 | $12,768 | $3,458 | 3.7 yrs |
| 20 panels | 8 kW | 10,268 | $15,960 | $4,323 | 3.7 yrs |
| 26 panels | 10.4 kW | 13,348 | $20,748 | $4,815 | 4.3 yrs |
Notice that payback barely improves as systems get bigger, and eventually gets worse. That's because you can only save money on electricity you were going to buy anyway. Once a system covers your usage, extra panels mostly generate exports at a much lower rate.
Why Hilo gets 1,510 sun hours
That figure comes from Google's analysis of real rooftops across Hilo — it already accounts for shading from trees, chimneys and neighbouring buildings, which is why it's lower than the raw "hours of daylight" figures you'll see elsewhere. An unusually open, unshaded roof in Hilo reaches about 1,636 hours, roughly 8% better than typical.
The numbers behind this page
| Typical usable sunlight | 1,510 hrs/yr |
|---|---|
| Unshaded roof | 1,636 hrs/yr |
| Electricity rate (Hawaii avg) | 42.1¢/kWh |
| Installed cost assumed | $2.85/W |
| Panel size assumed | 400 W |
| Federal tax credit | 30% |
| Typical household usage | 10,800 kWh/yr |
| Power used as generated | 33% |
| Paid for exported power | full retail (net metering) |
| Rooftops sampled here | 9 |
| Google imagery from | 2013 |
Nearby cities
See all of Hawaii → statewide sunlight, rates, incentives and every city we've measured.
Hilo solar questions
How many solar panels do I need in Hilo?
About 22 panels for an average home. Hilo roofs get 1,510 usable sun hours a year, so each 400W panel produces roughly 513 kWh annually.
Is solar worth it in Hilo?
At 42.1¢/kWh and 1,510 sun hours, a typical system pays for itself in about 3.8 years and returns roughly $97,416 over 25 years. That is a solid return.
How much do solar panels cost in Hilo?
A 8.8 kW system costs about $25,080 before incentives and $17,556 after the 30% federal tax credit. Prices vary by installer, roof complexity and equipment.
Worth reading before you buy
Estimates only, generated 2026-08-22 from Google Solar API rooftop samples and average Hawaii electricity rates. Not a quote and not financial advice. Your roof, usage, utility plan and local incentives will change these numbers — get real quotes before buying.