A Photovoltaic or PV system is a combination of components that enables us to harness the power of the sun in our own homes or businesses. At the end of this week you will be able to make basic design decisions for you very own PV system.
Here the open circuit voltage of each cell adds up, whereas the current through the series of cells is constant, assuming steady state conditions. Remember what we know, about the basic characteristics of a PV cell, and the various technologies that can be used in such a cell? Typical crystalline silicon PV modules are made from a number of crystalline silicon solar cells. These cells are then connected to form a PV module, which in turn is connected together with other modules to form a PV array. In a grid connected system there are 2 main components, an array of PV modules and a grid connected Inverter. The grid connected topology is especially very common in countries that have supporting solar policies, where excess power generated by the consumer can be fed back to the electricity grid.
But how do we calculate that? Well that’s easy, we now only have to multiply the voltage of one cell, which is still 0.6 Volts, with the number of cells that are connected in series, which is 18. The product of the open circuit voltage and the short circuit current are roughly equal to 108W in both modules.
The grid-connected solar inverters used in the system are also constantly converting the DC output of the solar modules into usable AC power. As we have 2 rows in parallel, we have to multiply the short circuit current by 2 to get the module short circuit current. But how does that look on a module level? Here you can see a module in which all the cells are connected in series. What do we mean by orientation and tilt? Tilt is the degree of freedom that defines the elevation or the pitch of the solar module with respect to the horizontal. Now the voltage across all the cells in parallel is constant, however the current produced by each cell now adds up.
So far we have discussed the basics of a PV system and which role a PV module plays in that.