Toosolar, The Renewable Energy Experts

Solar Module Information

A solar module or photovoltaic module converts the sunlight directly into electrical energy. The module consists of solar cells which in turn are manufactured from mineral semiconductor material, mainly silicon. Depending on the type of crystal, we distinguish three types of cells:

 Monocrystalline cells

The manufacture of monocrystalline silicon cells requires high-purity semiconductor material. Single-crystal rods are drawn from molten silicon material and sawn into thin slices afterwards. This manufacturing method ensures a relatively high degree of efficiency.

 Polycrystalline cells

Polycrystalline cells, also called multicrystalline cells are manufactured with the help of a casting process where liquid silicon is cast in blocks which are sawn into slices afterwards. During the ingot solidification, crystal structures with different sizes are generated. Polycrystalline modules mostly have a blueish shimmer, the irregular structure makes them twinkle in the sunlight. They are slightly less efficient than monocrystalline modules.

 Amorphous cells/thin layer

Amorphous silicon does not form a regular crystal structure, but irregular atomic arrangements. It is created in a plasma reactor by chemical gas-phase deposition of gaseous silane. This saves both energy and material in the manufacturing process, which makes these cells very cost effective. Amorphous silicon cells are very temperature resistant and can be easily adjusted to individual requirements in terms of size, design and capacity. They can be connected in series at the same time the cells are formed, making easy to create panels in a variety of voltages. Most flexible solar modules are made of amorphous technology.



Back Contact Silicon Cells

A special type of silicon solar cell is the so called back contact cell. They have both positive and negative metallic contacts on the rear surface. That allows the surface facing the sun to be uniformly black, without the metal electrodes present on most solar cells. The back contact cell structure enables the module to gain more electricity per unit area and leads to a more favourable appearance.

 CIS/CIGS cells

CIS stands for Copper, Indium and Selenium and CIGS stands for Copper Indium Gallium Selenide. The CIS/CIGS technology is normally often used for flexible solar modules. The CIS/CIGS absorber is deposited on a glass or plastic backing, along with electrodes on the front and back to collect current. The semiconductor layer uses the broadest light of all solar technologies. CIS/CIGS cells achieve high conversion efficiencies at low production costs, thanks to the fact that they have the highest spectral response of all photovoltaic technologies. They are suited for application on flexible substrates and can be fabricated on thin polymer foils without any compromise of conversion efficiency


 From the cell to the module

Individual solar cells are interconnected to modules with higher capacity. They are connected in series and in parallel in order to be able to provide voltages or capacities appropriate for the different fields of application. A series cell connection results in a higher voltage, a parallel connection involves a higher current. Solar modules are offered for different applications with different nominal capacities and voltages. The solar module specifications refer to the standard test conditions of 1000 W/m² sun irradiation with 25° cell temperature. Most Off-Grid solar modules are made out of 36, 72 or 142 cells to get a favourable voltage for the battery of 12 VDC, 24 VCD or 48 VDC. Standard modules for grid-connected systems have 60 cells.


The terms „male“ and „female“ refer to the electrical contact inside the plug case, not to its visible appearance.


We have introduced the terms PV Standard3 and PV Standard4 to match the plug systems. These plug systems can be both connected with QuickCab3 and QuickCab4 cable extensions and QuickClip3 or QuickClip4 adapters and can be combined with all commercially available 3 mm and 4 mm PV plug systems. These plug systems usually require crimping pliers to work with. 

There are also tool-free plug systems available which have 2 essentially different characteristics:

  • PV Standard4 can be directly and tool-free connected to a cable with the help of a spring clip and can be combined with all 4 mm plug systems and adapters
  • PV Standard4 can also be cabled without the use of tools, however they are not compatible with commercial 4mm plug systems. This cable joint can be reversed and removed from the cable. 



Waterproofness of the plug case is not guaranteed products of different manufacturers are used.

The durability of the plug system may be reduced if electrical contacts of different manufacturers are incompatible with materials and contact erosion is involved.