Voltage versus current tradeoffs in solar wiring — what should I prioritize?

Voltage Maximization

When designing a solar panel system, prioritizing voltage allows you to take full advantage of the available sunlight. In a series configuration, multiple panels are connected end-to-end, increasing the overall voltage output of the system while maintaining the same current. This approach simplifies system sizing, reduces wire size requirements, and decreases overall system costs.

Series-Parallel Configuration

For larger systems or those requiring higher current outputs, a series-parallel configuration is often employed. In this setup, multiple panels are connected in series to achieve the desired voltage, and then multiple series strings are connected in parallel to achieve the desired current. By prioritizing voltage in the series configuration, you can maintain a high system voltage while minimizing wire size requirements. For example, a 48V system with 10 panels in series, each producing 5V, can achieve a total system voltage of 50V while reducing wire size requirements.

Wire Sizing Considerations

When wiring a solar panel system, it’s essential to consider the wire size and type to ensure efficient energy transfer and prevent overheating. By prioritizing voltage, you can reduce wire size requirements, which decreases material costs and simplifies installation. For example, a 20A current through a 10-gauge wire (AWG) is acceptable for a 48V system, but the same current would require a 6-gauge wire (AWG) at 12V. By maintaining a higher system voltage, you can reduce wire size requirements and minimize system costs.