Hawaii solar calculator

Live production from NLR (formerly NREL) PVWatts V8. Hawaii is the most unusual residential solar market in the US in 2026. Traditional net metering ENDED in 2015 — new customers use Customer Grid-Supply Plus (exports credited below retail, ~$0.10–$0.28 range, modeled here at $0.15 as a conservative estimate) or Customer Self-Supply (essentially no export credit). Self-consumed solar offsets the highest retail rates in the US (~40¢/kWh on Oahu) — so a battery is practically essential, not optional. RETITC offers 35% of system cost, capped at $5,000 (HRS §235-12.5; new Act 24 added a $40M statewide aggregate cap — individual cap still applies, verify with DoTax). Hawaii has no statewide sales tax; most counties exempt added value from property tax (Honolulu offers 25 years). This calculator models the HECO / Oahu CGS+ case. Defaults: south-facing roof mount, 20° tilt, 14% losses.