Battery Storage Sizing Calculator — 公式
## Sizing Battery Storage for Solar
Battery storage bridges the gap between solar generation and energy use, especially overnight or during cloudy days.
### Formula
**Required Capacity = (Daily Usage x Autonomy Days) / DoD / Round-Trip Efficiency**
Depth of Discharge (DoD) is the fraction of the battery you can actually use without damaging it. Lithium-ion batteries typically allow 80-90% DoD, while lead-acid batteries are limited to 50%.
Battery storage bridges the gap between solar generation and energy use, especially overnight or during cloudy days.
### Formula
**Required Capacity = (Daily Usage x Autonomy Days) / DoD / Round-Trip Efficiency**
Depth of Discharge (DoD) is the fraction of the battery you can actually use without damaging it. Lithium-ion batteries typically allow 80-90% DoD, while lead-acid batteries are limited to 50%.
计算示例
A home uses 30 kWh/day and wants 2 days of autonomy with 80% DoD and 90% efficiency.
- Energy needed = 30 x 2 = 60 kWh
- Account for efficiency = 60 / 0.90 = 66.7 kWh usable
- Account for DoD = 66.7 / 0.80 = 83.3 kWh total capacity