How solar panels are connected
How are the panels connected to have more performance? How is it better to connect the panels, in series or in parallel? ” In reality, the way of connecting the panels is indifferent for the total output power, which will be the same. What must be taken into account is to respect the voltages allowed by the regulators to which we connect the panels and based on that, make series, parallel or a combination of both .
How solar panels are connected
The result of the multiplication will be the same if we connect 2 panels in series or in parallel, for example. In series the voltage will be the sum of 2 panels and the intensity that of a single panel, while in parallel the voltage will be that of a single panel and the intensity will be the sum of the 2. In both cases the result of the multiplication, the total power will be the same.
Practical example with a panel
325W and 24V solar panel with the following characteristics:
– Maximum power (Pmax) : 325W
– Open circuit voltage (Voc) : 45.7V
– Maximum power voltage (Vmpp) : 37.4V
– Short circuit current (ISC) 9.22A
– Maximum power current (Impp) : 8.7A
If we apply the previous formula: Vmpp x Impp = Pmax 37.4V x 8.7A = 325.38W, which is the maximum power of the panel.
Let’s suppose that we use 4 panels, the total power would be 1300W and with the two examples of series or parallel or a series-parallel combination we will see that the result does not vary in terms of total power.
Serial connection
We connect the positive pole of one panel with the negative of the next. In this case the voltage is added and the current remains constant:
– Vmpp: 37.4 x 4 = 149.6V
– Impp: 8.7A
– Total in series: Vmpp x Impp = Pmax 149.6V x 8.7A = 1301.52W
parallel connection
We connect together the positives of the panels on one side and on the other side together the negatives. In this case the current intensity is added and the voltage remains constant:
– Vmpp: 37.4V
– Impp: 8.7A x 4 = 34.8A
– Total in series: Vmpp x Impp = Pmax 37.4V x 34.8A = 1301.52W
Serial-parallel connection
As a minimum we will make pairs of panels in series, and later we will make parallels of those pairs. In this case the current intensity is doubled and also the voltage:
– Vmpp: 37.4V x 2 = 74.8V
– Impp: 8.7A x 2 = 17.4A
– Total in series: Vmpp x Impp = Pmax 74.8V x 17.4A = 1301.52W
conclusion
Although the total power result is always the same, in terms of efficiency due to energy losses, it is always better to go to a higher voltage than to a higher current and it allows us to work with smaller sections of wiring. However, we cannot always connect the solar panels as we want, that depends on the type of regulator of our installation.
