# 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.