A full worked residential rooftop PV design — module and string sizing against real temperature-corrected Voc/Vmp math, string inverter selection, NEC 690.12 rapid shutdown compliance, and a production estimate checked against actual household usage.
The project brief: a Denver, Colorado home with 10,800 kWh/year of usage and a south-facing, 30° gable roof wants an 8.0 kW DC rooftop array. Framed as this program's baseline PV integration project, it is the smallest complete residential system that still touches every core discipline the later, larger projects build on — module and array sizing, cold-weather and hot-weather voltage math, inverter selection, code-mandated rapid shutdown, and a production estimate weighed against real consumption.
This module walks the whole design the way a real PV designer would: a worked NEC 690.7 cold-weather Voc calculation that forces a two-string array layout, a high-temperature Vmp check against the inverter's minimum tracking voltage, module-level rapid shutdown compliance under NEC 690.12, and a NEC 705.12 backfed-breaker interconnection check against the home's actual 200A panel. The full worked numbers, complete bill of materials, and finished design reasoning are part of the unlocked module below.