1. What is a Solar System Watts Calculator?

Definition: This calculator estimates the power (in watts) required for a solar system based on energy needs, sunlight hours, and system performance.

Purpose: It helps solar installers and homeowners determine the appropriate solar panel system size for their energy requirements.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P \) — System power (watts)
• \( Load \) — Daily energy requirement (watt-hours)
• \( H \) — Peak sunlight hours per day
• \( PR \) — Performance ratio (system efficiency factor)

Explanation: The energy load is divided by the product of sunlight hours and performance ratio to determine the required system power.

3. Importance of Solar System Sizing

Details: Proper system sizing ensures reliable power supply, maximizes return on investment, and prevents over- or under-sizing of solar components.

4. Using the Calculator

Tips: Enter your daily energy needs in watt-hours, average peak sunlight hours for your location, and performance ratio (default 0.75). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the performance ratio?
A: It accounts for system losses (typically 0.7-0.8) including temperature effects, wiring losses, inverter efficiency, and dirt on panels.

Q2: How do I find my daily energy load?
A: Sum the watt-hours of all devices you'll power, or check your electricity bill for daily kWh usage (multiply by 1000 to get Wh).

Q3: What are typical sunlight hours?
A: This varies by location (3-6 hours in most areas). Check solar insolation maps for your region.

Q4: Should I include a safety margin?
A: Yes, consider adding 10-20% to the calculated power for system aging and unexpected loads.

Q5: Does this account for battery storage?
A: No, this calculates the solar array size. Battery sizing requires additional calculations based on autonomy days.