Solar Array String Sizer

Computes the maximum and minimum number of PV modules per string per NEC 2023 Article 690.7 (cold-weather V_oc) and 690.8 (1.25× I_sc), checked against inverter MPPT window. Required CSV columns: design_name, module_Voc, module_Vmp, module_Isc, module_Imp, beta_Voc_pct_per_C, beta_Vmp_pct_per_C, T_min_C, T_max_cell_C, inv_Vdc_max, inv_MPPT_min, inv_MPPT_max, inv_Idc_max_per_mppt, n_mppts.

CSV Input

Method: module voltages corrected from STC (25 °C) using V(T) = V_STC · (1 + β · (T − 25) / 100). Maximum string length from V_oc,cold · N ≤ V_dc,max (NEC 690.7(A)). Minimum string length from V_mp,hot · N ≥ 1.05 · V_MPPT,min to avoid MPPT dropout. Upper-MPPT bound from V_mp,cold · N ≤ V_MPPT,max. Parallel strings per MPPT from I_sc · 1.25 ≤ I_dc,max per NEC 690.8(A)(1). STC basis per IEC 61215 / IEC 61730; interconnection per IEEE 1547-2018. Always cross-check against the specific inverter datasheet — some units have tighter V_oc limits than nameplate suggests.

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