Yes, it's possible...however there are important factors that need to be considered to avoid compromising the overall efficiency of the system...
Mixing solar panels of different voltages, wattages or from various manufacturers requires careful consideration of each panel's electrical parameters. It's crucial to understand the implications of connecting panels in series or parallel and the role of MPPT charge controllers in optimising performance.
Series vs. Parallel Connection
Series Connection:
Increases the system's output voltage. The total voltage of the connected panels must not exceed the inverter's maximum input voltage.
In a series connection, the current is determined by the panel with the lowest current rating, which can reduce the overall system performance.
Parallel Connection:
Increases the system's output current. The total current of the connected panels must not exceed the inverter's maximum input current.
In a parallel connection, the voltage is determined by the panel with the lowest voltage rating, which can lead to underperformance.
Optimising the performance of MPPT Charge Controllers
MPPT (Maximum Power Point Tracking) charge controllers are designed to extract the maximum power from the solar panels by adjusting the electrical operating point of the modules.
Using separate MPPT controllers for each string of panels in cases where mixing panels is unavoidable, can help optimise the performance of each set, minimising the impact of mismatches.
Best Practices
1. Using the same panel brand and model:
For Series Connection, to ensure consistent current flow;
For Parallel Connection, to maintain a consistent voltage level.
2. Separate MPPT Controllers:
When mixing panels, using separate MPPT charge controllers for each string is strongly advised to maximise efficiency and performance, without impacting the other PV solar panel strings in the system.
Furthermore, this also enables separate arrays of panels to be placed at different aspects, particularly on fixed solar installations, having the ability to capture optimal sunlight at different times of the day (For example North for the middle of the day and Westerly for later in the day).
Ensure the output voltage of the controller in relation to the battery bank being charged is the same rating (eg. 24v, 48v etc).
Managing multiple MPPT solar controllers
Victron MPPT charge controllers have the ability to communicate with each other, for effective management of the incoming solar energy within a system.
Victron also provides controllers with multiple MPPT inputs within the same unit, for operational flexibility, convenience and value.
Check out the SmartSolar MPPT RS 450/100 with 2 trackers or the range topping SmartSolar MPPT RS 450/200 with 4 trackers for the ultimate in multi-array Solar tracking performance.
Alternatively see our Victron MPPT Solar Charge Controller range HERE.
For more information, Contact Us to help you decide which configuration best suits your needs.