1. What is a Solar Panel Wattage Calculator?

Definition: This calculator determines the required solar panel wattage based on your energy needs, available sunlight hours, and system efficiency.

Purpose: It helps homeowners and solar installers properly size solar panel systems for optimal energy production.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_w \) — Solar panel wattage needed (watts)
• \( E_{kWh} \) — Daily energy consumption (kilowatt-hours)
• \( t_{sun} \) — Average daily peak sun hours (hours)
• \( \eta_{solar} \) — System efficiency factor (0-1)

Explanation: The energy requirement is converted to watt-hours, then divided by available sunlight hours and system efficiency to determine required panel wattage.

3. Importance of Proper Solar Sizing

Details: Correct solar panel sizing ensures your system meets energy demands, maximizes return on investment, and prevents under/over-sizing issues.

4. Using the Calculator

Tips: Enter your daily energy needs in kWh, average sun hours for your location (default 5), and system efficiency (default 0.75). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What are typical sun hours for my area?
A: Sun hours vary by location (3-6 hours average in most regions). Check solar radiation maps for your specific area.

Q2: Why is system efficiency less than 1?
A: Efficiency accounts for losses from inverters, wiring, temperature, dust, and panel orientation (0.75 is typical).

Q3: Should I round up the calculated wattage?
A: Yes, it's recommended to round up to the nearest standard panel size and add 10-20% buffer for cloudy days.

Q4: How do I find my daily energy consumption?
A: Check your electricity bill for monthly kWh usage, then divide by 30 for daily average.

Q5: Does this include battery storage?
A: No, this calculates panel requirements only. Battery sizing requires additional calculations based on autonomy days needed.