☀️ Basic Solar System Configuration

📍 Location & Solar Panel

Latitude (°N positive, °S negative)

Peak Sun Hours (daily average)

hrs

Reference: Desert 6-7h, Sunny 5-6h, Moderate 4-5h, Cloudy 3-4h

Panel Wattage (STC rating)

Number of Panels

panels

System Efficiency

Accounts for: wiring losses, MPPT efficiency, temperature, dust. Typical: 75-85%

35°

Face South

Daily Energy Production

1,600 Wh

≈ 584 kWh/year

🔋 Battery & Load Sizing

Battery Voltage

Days of Autonomy (cloudy days backup)

days

Max Depth of Discharge

Lead-acid: 50% · LiFePO4: 80% · Li-ion: 80-90%

Target Daily Load

Laptop: 50Wh · Fridge: 1000-1500Wh · LED bulb: 10Wh × hrs

Recommended Battery

167 Ah

Battery Wh Capacity

2,000 Wh

Max Continuous Load

66 W

Energy Balance

+600 Wh

MPPT Controller Sizing

30A

Minimum controller current rating

Understanding Solar Systems

System Components

Solar Panels (PV): Convert sunlight to DC electricity. Rated in watts at Standard Test Conditions (STC: 1000W/m², 25°C). Real-world output is typically 75-85% of rating due to temperature, angle, and losses.

MPPT Charge Controller: Maximum Power Point Tracking controllers optimize power extraction from panels and safely charge batteries. More efficient than PWM controllers, especially when panel voltage is higher than battery voltage. Size by: Panel Watts ÷ Battery Voltage × 1.25 safety factor.

Battery Bank: Stores energy for use when sun isn't shining. Size based on daily load × days of autonomy ÷ depth of discharge. LiFePO4 batteries allow deeper discharge (80%) vs lead-acid (50%).

Inverter: Converts DC battery power to AC for household loads. Size at 1.25-1.5× your largest load. Pure sine wave inverters required for sensitive electronics.

Optimal Panel Angle

For fixed panels, the optimal tilt angle roughly equals your latitude. Adjust seasonally: latitude + 15° in winter, latitude - 15° in summer. In the Northern Hemisphere, panels should face South; in the Southern Hemisphere, face North.

Peak Sun Hours

Peak sun hours (PSH) represent hours of 1000W/m² equivalent sunlight. A location with 5 PSH receives the same energy as 5 hours of full noon sun. Look up your location's PSH on resources like Global Solar Atlas.

Quick Sizing Rules

Panel sizing: Daily Wh need ÷ Sun hours ÷ 0.8 efficiency = Panel watts needed
Battery sizing: Daily Wh × Autonomy days ÷ DoD% ÷ Battery voltage = Ah needed
MPPT sizing: Total panel watts ÷ Battery voltage × 1.25 = Minimum amps
Inverter sizing: Largest load × 1.5 = Minimum inverter watts

Solar Calculator