System size determines both cost and paybackSolar systems are sized in kilowatts (kW). A typical Honolulu home uses 10,000–14,000 kWh/year, requiring a 7–10 kW system. Larger systems cost more upfront but generate more excess power for net metering credits. Your electricity bill and roof space determine the optimal size — a reputable installer will provide a custom production estimate before quoting.
State and local incentives still available — federal credit expiredThe 30% federal residential solar tax credit (ITC) expired on December 31, 2025 and no longer applies to new residential installations in 2026. Your gross cost is $41,800 — no federal credit reduces this further. However, many states offer their own solar tax credits or rebates, and most utilities in Honolulu offer net metering programmes that allow you to sell excess power back at retail rates. Ask every installer to provide a full breakdown of state, local, and utility incentives available in Honolulu — these vary significantly and can still meaningfully reduce your net cost.
Roof condition must be addressed before panels are installedSolar panels have a 25–30 year lifespan. Installing them on a roof with less than 10–15 years of life remaining means removing and reinstalling the panels when the roof needs replacement — adding $2,000–$5,000 in additional cost. Have your roof independently inspected before committing to solar. In Honolulu, seasonal factors affect pricing affects how quickly roofing materials age.
Net metering policy determines return on investmentNet metering allows you to sell excess solar generation back to your utility at retail rates — dramatically improving payback. Net metering policies vary significantly by state and utility in Honolulu. If your utility offers full retail net metering, payback periods are typically 6–9 years. If net metering has been reduced or eliminated, payback extends significantly. Verify your current utility's net metering rate before making a final decision.
Panel brand and warranty matter over a 25-year horizonTier-1 panels (LG, Panasonic, SunPower, Qcells) carry 25-year product and performance warranties backed by financially stable manufacturers. Budget panels from unknown brands may offer the same warranty on paper but provide no practical recourse if the manufacturer fails in year 8. The premium for Tier-1 panels is typically $500–$1,500 on a full system — worth it for a 25-year asset.
Installer certification and local track recordLook for installers with NABCEP (North American Board of Certified Energy Practitioners) certification — the industry's highest credential. In Honolulu, check references from installations done at least 3–5 years ago to evaluate long-term service. Avoid large national companies that use inexperienced local subcontractors — local installers with NABCEP certification and verifiable local references are the gold standard.