Solar PV System Calculator
Professional Engineering Tool for Solar System Design
Solar Panels
Batteries
Inverters
Charge Controllers
MCB Sizing
SPD Sizing
Wiring
Structure
Solar Panel Sizing
Required Panel Capacity (Wp) = (Daily Load × 1.3) ÷ (Peak Sun Hours × System Efficiency)
Daily Load (Wh)
Peak Sun Hours (PSH)
System Efficiency (0.75-0.85)
Calculate Panel Capacity
0
Watts Peak (Wp)
Applicable Standards
IEC 61215 - PV module performance
NEC 690 - U.S. PV system sizing
IEC 61724 - System monitoring
Battery Sizing
Battery Capacity (Ah) = (Daily Load × Days of Autonomy) ÷ (Battery 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)
Lithium-ion High (90% DoD, 95% eff)
Calculate Battery Capacity
0
Ampere Hours (Ah)
Applicable Standards
IEC 61427 - Battery performance for PV systems
NEC 706 - Energy storage systems
UL 1973 - Battery safety standard
Inverter Sizing
Inverter Size (W) = Peak Load (W) × Safety Factor (1.25-1.5)
Peak Load (W)
Safety Factor
1.25 (Standard - NEC 690.8)
1.35 (Recommended)
1.5 (High Safety)
Calculate Inverter Size
0
Watts (W)
Applicable Standards
IEEE 1547 - Grid interconnection
UL 1741 - U.S. safety standard
IEC 62109 - Global inverter safety
Charge Controller Sizing
PWM: Current = PV Power ÷ Battery Voltage
MPPT: Current = (PV Power ÷ Battery Voltage) × 1.25
Total PV Array Power (W)
Battery Voltage (V)
12V
24V
48V
Controller Type
PWM
MPPT (Recommended)
Calculate Controller Current
0
Amperes (A)
Applicable Standards
NEC 690.8 - Overcurrent protection
UL 1741 - U.S. safety certification
IEC 62109 - Global safety standard
MCB Sizing
DC Side: I_MCB ≥ 1.25 × I_sc
AC Side: I_MCB ≥ 1.25 × (P_AC ÷ (V_AC × PF))
Circuit Type
DC Side (PV Array)
AC Side (Inverter Output)
PV Array Short-Circuit Current (A)
Open-Circuit Voltage (V)
AC Power (W)
AC Voltage (V)
Power Factor
Calculate MCB Rating
0
Amperes (A)
Applicable Standards
IEC 60898 - AC MCB performance
IEC 60947-2 - DC MCB performance
NEC 690.8 - Overcurrent protection
UL 489 - MCB safety standard
Surge Protective Device (SPD) Sizing
Voltage Rating: U_c ≥ 1.2 × V_system
Protection Level: U_p ≤ 0.8 × Equipment withstand voltage
System Type
DC Side (PV Array)
AC Side (Grid Connection)
Open-Circuit Voltage V_oc (V)
Grid Voltage (V)
Risk Assessment
Low Risk (I_n = 5kA)
High Risk (I_n ≥ 10kA)
Equipment Withstand Voltage (V)
Calculate SPD Specifications
0
U_c (V)
0
I_n (kA)
0
U_p (V)
Applicable Standards
IEC 61643-31 - PV DC SPDs
IEC 61643-11 - General SPD requirements
NEC 690.8 - Overvoltage protection
Wiring Sizing
Wire Area (mm²) = (2 × L × I) ÷ (V × VD × K)
Cable Length - One Way (m)
Current (A)
System Voltage (V)
Voltage Drop (%)
3% (DC Circuits)
5% (AC Circuits)
2% (Critical Circuits)
Conductor Material
Copper (K=56)
Aluminum (K=35)
Installation Environment
DC Rooftop (PV Wire USE-2)
AC/DC Indoor (THHN/THWN-2)
High Temperature (XLPE)
Calculate Wire Size
0
mm² Cross-Sectional Area
Applicable Standards
NEC 690.8 - PV circuit ampacity
IEC 60364-5-52 - Voltage drop limits (3% DC, 5% AC)
UL 4703 - PV wire standards
Solar Panel Structure Calculation
AB = AC × sin(θ) BC = √(AC² - AB²)
Hypotenuse AC (mm)
Tilt Angle θ (Degrees)
A
B
C
θ
AB
BC
AC
Structural diagram for solar panel mounting (AB = vertical, BC = base, AC = hypotenuse)
Calculate Structure Dimensions
Vertical Height (AB)
0
mm
Base Distance (BC)
0
mm
Structural Design Notes
Ensure structure can withstand wind speeds of at least 120 km/h
Use corrosion-resistant materials (aluminum or galvanized steel)
Mounting structure should allow for seasonal angle adjustments
Foundation depth should be at least 1/6 of the total height