Designing an off-grid solar system requires balancing energy production, storage capacity, and backup. This complete guide covers system sizing, component selection, and configuration for residential, cabin, and remote off-grid installations.
KEY STATISTICS
Typical off-grid solar efficiency (overall)65–80% (panels to load)
Battery round-trip efficiency (OPzV)85–90%
Solar panel derating factor0.8 (for real-world output)
Rule of thumb for autonomy3 days without sun = 3× daily consumption
Charge controller efficiency (MPPT)94–98%
Off-Grid System Components
- Solar panels (PV array)
- Charge controller (MPPT recommended)
- Battery bank (OPzV or AGM)
- Inverter (pure sine wave)
- Backup generator (diesel/propane)
- System monitoring
System Design Steps
| Step | Task | Output |
|---|---|---|
| 1 | Calculate daily energy use (Wh) | 2,000–10,000Wh/day |
| 2 | Size battery bank for 3–5 days autonomy | 48V, 300–1500Ah |
| 3 | Calculate solar array: daily Wh × 1.3 ÷ sun hours | 3,000–20,000W |
| 4 | Select MPPT charge controller (string voltage) | 150V or 250V controller |
| 5 | Size inverter (peak load × 1.5 safety) | 5–15kW typical |
| 6 | Plan backup generator capacity | 5–15kW diesel/propane |
CHISEN OPzV Off-Grid Configurations
| System | Daily Load | Battery Bank | Solar Array | Backup |
|---|---|---|---|---|
| Weekend cabin | 2,000Wh | 4×OPzV2-200 (48V 200Ah) | 3kW | None |
| Full-time home | 5,000Wh | 4×OPzV2-300 (48V 300Ah) | 6kW | 5kW generator |
| Small business | 10,000Wh | 4×OPzV2-300×2str (48V 600Ah) | 12kW | 10kW generator |
| Off-grid community | 20,000Wh | 24×OPzV2-1000 (48V 1000Ah) | 25kW | 15kW generator |
Need a Reliable Battery Supplier?
CHISEN Battery — 8 global factories, 70M kVAh/year. OPzV tubular GEL, AGM VRLA, front terminal batteries. Trusted by distributors in 60+ countries.
| Factory | 8 global factories |
| Capacity | 70 million kVAh/year |
| Tel | +86 131 2666 8999 |
| jack@chisen.cn | |
| Web | www.chisen.cn |