1. What is a Solar System Size Calculator?

Definition: This calculator estimates the required solar system size in watts based on your energy needs, available sunlight, and system performance.

Purpose: It helps homeowners and solar installers determine the appropriate solar panel system size for a given energy requirement.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P \) — System size (watts)
• \( Load \) — Daily energy requirement (watt-hours)
• \( H \) — Average daily sunlight hours
• \( PR \) — Performance ratio (system efficiency)

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

3. Importance of Proper Solar Sizing

Details: Correct solar system sizing ensures adequate power generation, maximizes return on investment, and prevents system over- or under-sizing.

4. Using the Calculator

Tips: Enter your daily energy needs in watt-hours, average 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: The performance ratio (typically 0.7-0.8) accounts for system losses from temperature, wiring, inverters, and other factors.

Q2: How do I find my daily energy requirement?
A: Check your electricity bills for kWh usage and convert to watt-hours (1 kWh = 1000 Wh), or use an energy audit tool.

Q3: Where can I find sunlight hours for my area?
A: Consult solar maps or databases like NASA's or NREL's solar resource data for your specific location.

Q4: Should I include battery storage in this calculation?
A: This calculates the solar array size needed. Battery storage calculations require additional factors like days of autonomy.

Q5: Does this account for seasonal variations?
A: No, it's based on average daily values. For year-round reliability, size for your worst-case month and adjust accordingly.