Series vs parallel
| Series | Parallel | |
|---|---|---|
| Voltage | Adds up | Stays the same |
| Current | Stays the same | Adds up |
| Cable size | Thinner cable | Thicker cable |
| Shading | One shaded panel pulls down the string | Each panel works more independently |
| Controller | Needs MPPT with enough voltage headroom | Works with PWM or MPPT |
Which should you choose?
- Series suits long cable runs and unshaded locations, like a cabin roof or ground mount, with an MPPT controller.
- Parallel suits van and boat roofs where shading moves around, and low-voltage PWM setups.
- Series-parallel combines both for larger arrays.
Always check the cold string voltage against your controller with the MPPT string voltage calculator.
Frequently asked questions
Is it better to wire solar panels in series or parallel?
Series is better for efficiency and cable cost when panels are unshaded. Parallel is better when panels may be partly shaded, like on a van or boat.
Can I mix different solar panels?
Only panels with similar Imp should go in series, and only panels with similar Vmp should go in parallel. Mismatched panels waste output.