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What is the right way connect to solar cell

mrel

Jul 2, 2008
115
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Jul 2, 2008
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115
Hello
I would like to hear from people who have try this setup of solar cells.
I have many different kind of solar cell make from different materials, can i connect in series for high voltage and in parallel for high currents.
How can I connect all different solar cell materials to get high voltage and high currents.
If can be done ,how do i hookup the different cell and what do I need ,diodes ,resistors capacitor for the hookup?
Thank for the help
mrel
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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In general, if you connect the cells in series, the voltage will be the sum of the cell's voltages and the current equal to lowest of the currents that any individual cell can supply.

For example if you have 0.5V 1A, a 0.55V 500mA and a 0.55V 100mA cells:

If you place them in series you will get a max voltage of around 1.6V (0.5+0.55+0.55) and a max current of 100mA (that of the lowest current cell)

If you connect them in parallel, the voltage will be that of the lowest voltage cell, and the current the sum of the currents.

So for the same cells, the max voltage would be 0.5V and the max current 1.6A.

For highest power, if you are connecting cells in series, ensure that they have very similar current ratings. For connections in parallel, ensure that the voltage ratings are similar.

In practice, you will probably connect a number of cells in series, then connect these strings in parallel. With arrays of cells like this, it is important that you do not allow individual cells to be shaded as it will drastically reduce your power output and cause the cells to heat up.

You may decide to connect a series diode with each string of cells, but beware that normal silicon diodes can have a voltage drop in the region of 1.2V (almost 3 cells) at high currents. Shottky diodes have a lower forward voltage drop but may have a PIV ratings that are too low if a string of cells are completely shaded.

Note also that cells are typically rated for max (i.e open circuit) voltage and max (i.e short circuit) current. You won't get both at once. a module designed to give an output of 12V typically has an open circuit voltage of around 18V (i.e. 36 cells in series).

You will notice that many solar panels have some multiple of 18 cells in them -- it's not an accident ;-)
 
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