1. What is a Solar Panel Wattage Calculator?

Definition: This calculator estimates the wattage of solar panels needed based on your energy requirements, available sunlight, and system performance.

Purpose: It helps homeowners and solar installers determine the appropriate solar panel size for specific energy needs.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P \) — Solar panel wattage (watts)
• \( Load \) — Energy required (watt-hours)
• \( H \) — Sunlight hours (hours)
• \( PR \) — Performance ratio (decimal, typically 0.75)

Explanation: The energy requirement is divided by the product of sunlight hours and performance ratio to determine the needed panel wattage.

3. Importance of Solar Panel Sizing

Details: Proper sizing ensures your solar system meets energy needs without over-investing in unnecessary capacity.

4. Using the Calculator

Tips: Enter your daily energy requirement in watt-hours, average sunlight hours (default 5), and performance ratio (default 0.75). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine my energy requirement (Load)?
A: Calculate your daily watt-hour usage by summing the power consumption of all devices you want to power.

Q2: What's a typical performance ratio?
A: Most systems have a PR between 0.7-0.8, accounting for losses from temperature, wiring, inverters, etc.

Q3: How do I find sunlight hours for my location?
A: Check solar insolation maps or use tools from NASA or NREL that provide average daily sunlight hours.

Q4: 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.

Q5: Does this account for battery storage?
A: No, this calculates panel size only. Battery capacity should be calculated separately based on your autonomy needs.