Elements of photovoltaic panel construction

A single photovoltaic cell does not produce much voltage and the current output is limited by its size. To augment either the voltage or the current output, solar cells can be connected in either series or parallel. Although it is not always the case, usually the sun-facing surface of the solar cell is negative and the back side is positive. 

When cells are connected in series to increase voltage, the negative terminal on the face of one cell is connected with tab ribbon to the positive terminal of the next cell s back. This type of connection adds the voltage of each cell. For instance, for five cells that put out. 5 volts apiece and are connected in series, the leads at the top and bottom will give a reading on a voltmeter of 2.5 volts. 

For parallel, the faces of the cells are connected to each other and the backs of the cells are connected to each other. With this arrangement, the current output of each cell is added, but the voltage remains the same as the output of one cell. Five cells connected in parallel would give a reading of. 5 volts at 20 amperes of current if the cells are 4 amps output. 

Connecting two or more cells to each other creates a string. A string is a row of cells connected to each other in either series or parallel. Multiple strings are then connected to each other in series or parallel to form the whole of the solar panel or module. 

Two or more solar panels connected together form an array. Arrays can be connected in series, parallel or in series-parallel. 

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