1. What is a Solar Panel Calculator for Hot Water?

Definition: This calculator estimates the number of solar panels needed to meet your hot water requirements based on energy needs, panel output, and system efficiency.

Purpose: It helps homeowners and installers determine how many solar thermal panels are required for domestic hot water systems.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• Panels — Number of solar panels needed
• Required Heat — Daily hot water energy requirement (kWh)
• Panel Output — Energy output per panel (kWh/panel)
• Efficiency — System efficiency factor (0-1)

Explanation: The required heat energy is divided by the effective output of each panel (panel output × efficiency) to determine how many panels are needed.

3. Importance of Solar Panel Calculation

Details: Proper sizing ensures adequate hot water supply, maximizes system efficiency, and avoids unnecessary costs from over-sizing.

4. Using the Calculator

Tips: Enter your daily hot water requirement in kWh, the output of each panel (default 0.5 kWh/panel), and system efficiency (default 0.8). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine my required heat?
A: Estimate daily hot water usage in liters and multiply by 0.058 (for 40°C temperature rise) or use an energy monitor.

Q2: What's a typical panel output?
A: Most solar thermal panels produce 0.4-0.6 kWh per panel per day, depending on size and location.

Q3: What affects system efficiency?
A: Factors include panel type, piping losses, heat exchanger efficiency, and storage tank insulation (typically 0.7-0.85).

Q4: Should I round up the panel count?
A: Yes, always round up to the nearest whole panel to ensure adequate capacity.

Q5: Does this account for seasonal variations?
A: No, size for worst-case (winter) conditions or consider a backup heating system.