Photovoltaics is a technology for generating electricity. It involves using solar cells to transform sunlight into electrical energy. Solar energy is a form of renewable energy and an important contributor to a sustainable energy policy.

Solar modules Heterojunction Bifacial Migros Schoenbuehl

Solar panel manufacturing process

Photovoltaic systems consist of solar modules placed on the roofs and facades of buildings for example or erected in open spaces as solar parks. They are made up of many solar cells that transform sunlight into electrical energy.

Three process steps are necessary for the manufacture of solar modules: the wafer, cell and module processes.

Wafer process

In the wafer process, quartz sand is used to produce a mono or multicrystalline ingot. This is then sliced into razor-thin wafers with a diamond wire saw. After cleaning, the resulting silicon wafers pass through an inspection system in which they are checked for faults such as microcracks and material damage, and sorted according to quality.

Cell process

The cell process deals with the surface of the silicon wafer. Surface passivation reduces the energy losses within the cell. Additional coatings prevent excessive reflection of the solar radiation.

The finished silicon solar cell now transforms light into electricity. To allow the electricity to be collected and conducted away, contacts are screen-printed onto the front and back surfaces of the wafer. 
Following this, the solar cell is tested.

Module process

In the module process, SmartWire Connection Technology (SWCTTM) is used to join the individual solar cells together to form a string. A number of strings are then combined and bonded together with a sheet of glass and encapsulant in the lamination process to form a solar module. Finally, each module undergoes testing for performance, hipot and electroluminescence and is classified.