Calculators
Solar PV System Sizing
DC array size, module count, year-1 AC energy, capacity factor, and 25-year lifetime energy for a grid-tied PV system. Uses the NREL PVWatts methodology with plane-of-array irradiance, DC:AC ratio, system losses, and cell-temperature derate.
Method: DC size = Target AC × DC:AC. Cell temperature approximated as Tamb(°C) + 25 °C NOCT rise. Temperature derate = 1 + TempCoef · (Tcell − 25). Specific yield = POA · ηinv · (1 − losses) · Tderate. Lifetime energy is geometric series sum with annual degradation factor. References: NREL PVWatts v8 methodology; IEC 61724–1:2017; IEEE 1547–2018; NREL NSRDB TMY3 for POA data.
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