Utah solar calculator

Live production from NLR (formerly NREL) PVWatts V8. Utah's traditional 1:1 retail net metering is CLOSED to new customers. NEW 2026 INSTALLS are on Rocky Mountain Power SCHEDULE 137 ('Net Billing Service') — INSTANTANEOUS NETTING with exports credited at the Export Credit Rate (ECR), NOT retail. Self-consumed solar offsets retail in real time (~$0.11/kWh); any instantaneous EXCESS exported is credited at the ECR. ECR is SEASONAL: about 5.7¢/kWh summer, about 4.2¢/kWh winter — modeled here at about $0.05/kWh seasonal-average (about half retail). ECR is RECALCULATED ANNUALLY by the Utah PSC each March 1 — a 2026 buyer CANNOT lock a long-term export value; the rate may fall further. GRANDFATHERING (NOT applied to 2026 default): Schedule 135 customers (pre-Nov 15, 2017) keep 1:1 retail through 2035; Schedule 136 'Transition Program' customers (Nov 15, 2017 - Oct 31, 2020) get about 90-92.5% of retail through 2032. New 2026 installs get NEITHER. System cap 25 kW residential. Rocky Mountain Power (PacifiCorp — dominant IOU serving about 80%+ of UT) modeled as default; a handful of municipal utilities (e.g. St. George Energy Services, Murray City Power) still offer full retail net metering — coverage caveat, NOT a selector. Federal §25D = $0 for systems installed after Dec 31, 2025 (OBBBA repeal, signed July 4, 2025). NO state income tax credit — the Utah RESTC residential PV credit (sometimes cited as "25% / $1,600") ENDED for systems installed in 2024 and later; reject any 2026 quote that includes a Utah RESTC line item. Property tax NOT EXEMPT at statewide level; verify with county assessor. Sales tax EXEMPT under Utah Code §59-12-104 for alternative-energy generation equipment — through JUNE 30, 2027 (a 2026 purchase qualifies). Combined Utah sales tax averages about 7.2%; about $1,400 saved on a typical $20,000 system. NO SREC, no RPS. ROCKY MOUNTAIN POWER WATTSMART BATTERY PROGRAM is a LIVE incentive when battery added: about $400/kW battery power upfront (capped about $2,000), PLUS about $15/kW/year performance payment for 3 years — APPLIES ONLY WHEN BATTERY IS ADDED (panels-only systems do not qualify). Install pricing about $2.55 per watt (modeled default, editable). Typical solar-only payback 15-20 years with federal $0 and ECR export at about half retail. Sources citing about 9-12 year payback assume BOTH the dead 30% federal credit AND the old Schedule 135 retail net metering — neither applies to a 2026 cash buyer. Self-consumption and batteries critical because exports earn only half retail. MAIN RISK: ECR is recalculated annually by PSC each March 1 — forward export uncertainty; Utah has also been cutting renewable incentives over time (HB 264 phase-outs, new generation taxes); sales tax exemption sunsets June 30, 2027. Defaults: south-facing roof mount, 20° tilt, 14% losses.