1. What is House Battery Backup Calculation?

The House Battery Backup calculation determines how much battery capacity (in amp-hours) is needed to cover the difference between your solar power production and your home's energy consumption.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• \( Solar\ House\ Consumption \) — Total energy consumed by your house (watt-hours)
• \( Production \) — Total energy produced by your solar panels (watt-hours)
• \( Voltage \) — Voltage of your battery bank (volts)

Explanation: The equation converts the energy difference (in watt-hours) to battery capacity (in amp-hours) by dividing by the system voltage.

3. Importance of Battery Backup Calculation

Details: Accurate battery sizing is crucial for designing solar power systems to ensure you have enough stored energy to cover periods when solar production is insufficient.

4. Using the Calculator

Tips: Enter your total house consumption and solar production in watt-hours, and your battery bank voltage. All values must be positive numbers, with voltage greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between Wh and Ah?
A: Watt-hours (Wh) measure energy, while amp-hours (Ah) measure charge capacity. The conversion depends on system voltage.

Q2: Should I include inverter efficiency?
A: For more accurate results, you might want to multiply consumption by 1.1 (for ~90% inverter efficiency) before calculation.

Q3: What's a typical voltage for home solar systems?
A: Common voltages are 12V, 24V, or 48V. Higher voltages are more efficient for larger systems.

Q4: How do I account for multiple days of autonomy?
A: Multiply the result by the number of days you want your batteries to last without solar production.

Q5: Should I include depth of discharge (DOD)?
A: For lead-acid batteries, divide the result by your desired DOD (typically 0.5 for 50% DOD). Lithium batteries can often use 80-100% DOD.