solar-panels-working-scheme

When researching the topic of “how does a solar panel work”, one will find mixed information concerning how the energy is produced through the panels and cells themselves. A number of solar cells should be connected in series to achieve a usable voltage to work with an electrical device or storage.

The electricity produced by the panel is a direct current (DC) that is usually identified by its negative and positive terminals. Just like the battery which also has a positive and negative terminals, the cells work in a similar sense.

In a series connection, two cells, which have 4 terminals (2 positives and 2 negatives), can become one bigger cell when you simply connect 1 of the negatives to 1 of the positive terminals (Positive to Negative and Vice Versa). What’s left would be just 1 negative and 1 positive but the voltage of both panels were added (0.5V + 0.5V = 1V). Two cells became one bigger cell. In the same manner, when you have 12 cells, you can connect them in series by simply connecting all the positives with the negatives and you will end up no matter what you do with just 1 negative and 1 positive on both ends.

In a parallel connection, the same two cells, which have 4 terminals (2 positives and 2 negatives), are connected differently. 1 positive terminal is connected to 1 positive terminal and 1 negative to 1 negative terminal (Positive to Positive or Negative to Negative). These two cells did not become one big solar cell instead they started working together to amplify the current which is measured in ampere (A). Here we can probably say that two wires became one big wire, in this case two positives became one bigger positive wire and the same goes with the negative wires. Parallel connections are only used when you have reached your target voltage on a series connected solar cells. A series of 36 cells can generate around 18V (36 x 0.5 = 18V) and this 18V is the ideal voltage to charge a 12V battery. If you want to charge the battery quickly, you’d have to add more solar cells but has to maintain the same voltage (18V), and in order to achieve that, you need to connect the next group of solar cells in a parallel connection (Positive to Positive and Negative to Negative).

If you connected three groups of “series” connected solar cells, it is called a connection of 3 strings of solar cells and all 3 strings is called a module or the solar module. It becomes a solar panel when all the other components such as the frame, the back-sheet, the cover glass, and the junction box have been integrated.

A solar panel in turn can be connected to another solar panel also in series or parallel depending on the design of the photovoltaic system. Multiple solar panels connected in a series, let’s say 12 panels, is also considered a string when connected in parallel to another string or multiple other strings. Multiple strings of solar panels are then called an array or solar array.

It is important to note that in a series connection, the voltage (V) adds up while in a parallel connection, the ampere (A) increases. Voltage multiplied by Ampere results in determining Watts (VxA=W)

At this point, you should be able to understand the relationship of small solar cells to its bigger counterpart, the solar array. If you can build a solar panel, then in principle, you can also build a large solar array equivalent to a solar power plant.

It is up to you which solar cells to purchase but make sure to order the right amount of cells based on the solar panel you plan to make which is something that this article will cover in the later how-to sections. Be also aware of the electrical ratings of the solar cell which is important in achieving the amount of electricity you need to attain. Typically a solar cell has a DC voltage of 0.5V and its nominal power is around 4Wp. Hopefully, this information helps you in your search for “how does a solar panel work”.