Wyoming solar calculator

Live production from NLR (formerly NREL) PVWatts V8. Wyoming has STATUTORY 1:1 retail net metering for residential systems up to 25 kW under Wyo. Stat. §37-16-101..104 — but it's under active legislative threat for 2026 buyers. CURRENT MECHANISM: monthly production offsets consumption at FULL RETAIL (~$0.115/kWh); net excess generation (NEG) is credited as kWh and ROLLS FORWARD month-to-month at retail value. At the START OF EACH CALENDAR YEAR, leftover NEG credits are CASHED OUT at the utility's AVOIDED COST (Rocky Mountain Power Schedule 37, currently about $0.03/kWh). Modeled here at retail-match export ($0.115/kWh) since monthly NEG carries forward at retail and right-sized residential systems rarely accumulate large annual surplus. System cap 25 kW (statutory; covers any residential install). Rocky Mountain Power (PacifiCorp — dominant IOU) modeled as the default; Montana-Dakota Utilities serves eastern WY with similar terms; rural co-ops vary (some use avoided cost — verify if not on RMP or MDU). Federal §25D = $0 for systems installed after Dec 31, 2025 (OBBBA repeal, signed July 4, 2025) — no federal credit for a 2026 cash purchase. NO state income tax credit (Wyoming has NO state income tax at all). Property tax NOT EXEMPT — Wyo. Stat. §39-11-105 does NOT include a residential solar exemption (claims of a "2022 statewide exemption" are NOT in statute). Sales tax EXEMPT for renewable-generation equipment up to 25 kW under Wyo. Stat. §39-15-105 / §39-16-105 — this is a REAL statutory exemption (state sales tax about 4%). NO SREC, no RPS. NO statewide battery rebate. NO state utility rebate confirmed — reject any quote citing a "$3,000 / 50% state rebate" (not a live state program). Install pricing about $2.50-3.50 per watt (modeled at $2.95 default, editable). Typical solar-only payback 13-17 years with federal $0 and retail-offset net metering. Sources citing about 10-year payback assume the now-dead 30% federal credit — neither applies to a 2026 cash buyer. Low Wyoming retail rates (~$0.115/kWh) limit savings per kWh; cheap install pricing and the sales tax exemption partly offset. MAIN RISK: SENATE FILE 111 (2025) directs the WY PSC to set new "just and reasonable" compensation for systems installed behind the meter on or after January 1, 2026, with leftover credits sold at avoided cost. The 1:1 retail era is under direct legislative threat for new systems; PSC implementation is pending. Combined with Rocky Mountain Power rate-increase requests (about 30% in 2023, 15% in 2024) — compensation structure for 2026 buyers in flux. Right-size to annual usage — surplus only earns avoided cost. Defaults: south-facing roof mount, 20° tilt, 14% losses.