dual

Among
the materials shown about, most famous is Silicon for its availability, found
from the silica sand and purified either in form of monocrystalline or
polycrystalline. Si for its cheapness is mostly used and its pn-junction
behavior as well as it is conducted at mid-range radiation from sun. c-Si solar
cells have efficiency averaging over 15%. Which means they are capable of
converting over 15% of solar energy in electrical. Typically, each solar cell
is made up of a square having an area of approximately 1 cm2 produces
power of about 1.5 W of the voltage 0.6 V, which is too below the least
required to operate for applications. Therefore, they are combined in series to
make a proper standard of voltage. Different sizes and standards are designed
by manufacturers according to the applications. Each photovoltaic system
contains Solar module which is heart of solar PV system.

2.1.4  Solar Photovoltaic System

          Basically, solar system contains,

·       
Photovoltaic cell

·       
Battery backup

·       
Control unit or
solar module

·       
Load

·       
Main supply unit

PV
cell

Battery backup

Load

Control Unit

 

 

 

 

 

Main supply

                                                                             Figure
5.

Typical
Block diagram of solar

                                                                             Photovoltaic
system

          The PV cell is the main component of
the system which converts solar energy into electrical energy, which is usually
a series of solar modules mounted on solar panels for larger output power. It
converts light into direct current, DC power which can be utilized directly for
low power applications and even can be utilized for high power applications by using
inverter and storing the power into the battery for backup.

          Due to the serial connection of
photodiodes, if any of the module is stops conducting in case it is shaded and
other is producing energy, power will start flowing within the shaded solar module
and causing over heat and may damage the solar panel, so for its safety this
problem is prevented by using bypass diodes, even blocking diode is used so
that battery does not drain its power when solar panel is shaded.

          The solar panel is
supported by a mechanical structure or placed such a way that it receives
maximum possible radiations coming onto the surface of earth, or a solar
tracking system is designed.