Solar panel information
Description and details of a solar panel
A typical 36 cell solar panel is designed to have a nominal maximum potential difference of 18 volts. The current flow in amps is calculated by dividing the rated maximum power in watts by the voltage.
All solar cells have a similar voltage
All crystalline solar cells generate a potential difference of just over 0.5 volts regardless of their size. The cell's power output is therefore governed by the surface area of the cell because the current flow depends largely on the quantity of photons (sunlight) absorbed by the cell and more surface area will allow exposure to more sunlight.
Solar cells are like batteries
Just as we can string many battery cells together to produce more volts, so the solar panel manufacturers can produce solar panels of 12 volts, 24 volts, 36 volts or more by connecting the individual cells in strings with the positive side of one cell connected to the negative side of the next. This is called a series connection. The voltage across the string of cells is the sum of the cell voltages. 36 cells connected like this will produce a total of 18 volts. One string of cells might produce 18 volts but will still only produce a current flow of about 0.5 amps, so the ends of several strings of cells are then connected together, positive to positive and negative to negative, this is called a parallel connection, this type of connection will multiply the total amps by the number of strings to increase the total current flow. 10 strings of 36 cells connected together at their ends will still produce 18 volts but now generate a total of 5 amps. Now let's do the same with solar panels.
Solar modules can also be connected together in the same way
Just as solar panel manufacturers connect cells in series and parallel to produce the desired total voltage and amps, so solar panel installers can connect similar solar panels to produce any combination of voltage and amps.