Solar PV System Calculator
International Standards and Best Practice
Solar
Battery
Inverter
Controller
MCB
SPD
Wiring
Structure
Solar Panel Sizing
Required (Wp) = Daily Load (Wh) ÷ (Peak Sun Hours × Performance Ratio)
Daily Load (Wh)
Peak Sun Hours (h)
Performance Ratio (0.7‑0.85)
Calculate
0
Watts Peak (Wp)
Battery Sizing
Capacity (Ah) = (Daily Load × Autonomy) ÷ (Voltage × DoD × Efficiency)
Daily Load (Wh)
Days of Autonomy
Battery Voltage (V)
12V
24V
48V
Battery Type
Lead‑acid (50% DoD, 85% eff)
Lithium‑ion (80% DoD, 95% eff)
Calculate Battery Size
0
Ampere Hours (Ah)
Battery Backup Time
Time (h) = (Ah × V × DoD × SoH × Eff) ÷ Load (W)
Total Load (W)
Battery Capacity (Ah)
Battery Voltage (V)
12V
24V
48V
Depth of Discharge (DoD)
State of Health (SoH)
100%
95%
90%
85%
80%
75%
70%
60%
50%
System Efficiency
Calculate Backup Time
0
Hours
Inverter Sizing
Inverter (W) = Peak Load × 1.25‑1.5
Peak Load (W)
Safety Factor
1.25 (Standard)
1.35 (Recommended)
1.5 (High)
Calculate
0
Watts
Charge Controller Sizing
PWM: I = P_pv ÷ V_bat; MPPT: I × 1.25
PV Array Power (W)
Battery Voltage (V)
12V
24V
48V
Controller Type
PWM
MPPT
Calculate
0
Amperes
MCB Sizing
DC: I ≥ 1.25×Isc; AC: I ≥ 1.25×P/(V×PF)
Circuit Type
DC (PV)
AC (Inverter)
Short‑Circuit Current Isc (A)
Open‑Circuit Voltage (V)
AC Power (W)
AC Voltage (V)
Power Factor
Calculate
0
A (MCB rating)
SPD Sizing
Uc ≥ 1.2×V; Up ≤ 0.8×Vw
System Type
DC
AC
Voc (V)
Grid Voltage (V)
Risk Level
Low (5kA)
High (10kA)
Equipment Withstand (V)
Calculate
0
Uc (V)
0
In (kA)
0
Up (V)
Wiring Sizing
A = (2×L×I) / (V×VD×K)
Length one way (m)
Current (A)
System Voltage (V)
Voltage Drop (%)
3% (DC)
5% (AC)
Conductor
Copper (K=56)
Aluminium (K=35)
Calculate
0
mm²
Structure Geometry
AB = AC×sinθ; BC = √(AC²−AB²)
Hypotenuse (mm)
Tilt Angle θ (°)
Calculate
Height
0
mm
Base
0
mm
References & Standards
Solar Panel:
IEC 61215, IEC 61724, NEC 690 – Performance ratio method.
Battery Sizing:
IEC 61427, NEC 706 – Capacity based on autonomy, DoD, efficiency.
Battery Backup Time:
IEEE 485, IEC 61427 – Usable energy = Ah × V × DoD × SoH × η.
Inverter Sizing:
IEEE 1547, UL 1741 – 125% continuous load.
Charge Controller:
NEC 690.8, IEC 62509 – MPPT factor 1.25.
MCB Sizing:
IEC 60898 (AC), IEC 60947-2 (DC), NEC 690.8 – 125% of current.
SPD Sizing:
IEC 61643-31 (DC), IEC 61643-11 (AC) – Uc ≥ 1.2×Voc, Up ≤ 0.8×Vw.
Wiring Sizing:
IEC 60364-5-52, NEC 310 – Voltage drop limits.
Structure:
ASCE 7, IEC 62846 – Trigonometric layout.