PHOTOVOLTAIC SYSTEMS Miro Zeman Delft University of Technology

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PHOTOVOLTAIC SYSTEMS
Miro Zeman
Delft University of Technology

Components  of  a  PV  system
The solar energy conversion into electricity takes place in a semiconductor device that
is called a solar cell. A solar cell is a unit that delivers only a certain amount of electrical
power. In order to use solar electricity for practical devices, which require a particular voltage
or current for their operation, a number of solar cells have to be connected together to form a
solar panel, also called a PV module. For large-scale generation of solar electricity the solar
panels are connected together into a solar array.
The solar panels are only a part of a complete PV solar system. Solar modules are the
heart of the system and are usually called the power generators. One must have also
mounting structures to which PV modules are fixed and directed towards the sun. For PV
systems that have to operate at night or during the period of bad weather the storage of energy
is required, the batteries for electricity storage are needed. The output of a PV module
depends on sunlight intensity and cell temperature; therefore components that condition the
DC (direct current) output and deliver it to batteries, grid, and/or load are required for a
smooth operation of the PV system. These components are referred to as charge regulators.
For applications requiring AC (alternating current) the DC/AC inverters are implemented in
PV systems. These additional components form that part of a PV system that is called balance
of system (BOS). Finally, the household appliances, such as radio or TV set, lights and
equipment being powered by the PV solar system are called electrical load. The elements of a
PV system are schematically presented in Figure 9.1.        more ........