How does the performance of series panels compare in winter vs summer?

Series Connection Voltage Loss in Winter

In a series-connected solar panel configuration, voltage loss due to temperature fluctuations is a significant concern. However, in the winter months, the reduced panel temperature means less voltage loss. For example, a 12V, 100W monocrystalline solar panel can lose around 0.1V to 0.15V at 25°C. In a series configuration of 4 panels, this translates to a 0.4V to 0.6V drop. In winter, however, this voltage loss could be reduced by 10% to 15%, resulting in a more stable system voltage.

Impact of Temperature on Series-Connected Panels

As solar panels heat up, their internal resistance increases, resulting in a higher voltage drop across each panel. This can significantly impact the system’s overall efficiency. In a series configuration, a panel with a higher temperature will pull down the entire system voltage. By contrast, in a winter setup, the reduced panel temperature means less voltage loss and a more stable system voltage. This is particularly beneficial for applications that require a high system voltage, such as RV solar systems or remote power generation.

Mitigating Effects of Series Connection Voltage Loss

To mitigate the effects of series connection voltage loss, it’s essential to use a charge controller with a high DC-DC conversion efficiency. Additionally, using a panel with a high open-circuit voltage (Voc) can help minimize voltage loss in series configurations. By selecting the right equipment and configuring the system properly, you can ensure optimal performance and efficiency, even in the face of temperature fluctuations.