Solar power generation technology is founded upon silicon, a common element that comprises approximately 25% of the earth’s crust by mass. Solar cells are produced from raw silicon materials in a multistage process. Firstly raw quartzite sand is processed into bulk silicon, which is subsequently melted and formed into blocks or ingots. The ingots are cut and sliced to produce wafers which form the basis of a solar cell. In the manufacturing process are added electrodes in the wafer for electrical connectivity. The wafers are then cleaned and treated prior to their introduction into the manufacturing process.
With the appropriate treatment, various layers are created that produce an electric field, which separates positive and negative charges as soon as light falls on the solar cells. The charges remain available for use at the two poles of the solar cell, as in the case of a battery. When light falls on high purity silicon, the PV (photovoltaic) effect causes the release of electrons from the silicon atoms. When silicon is fashioned into a solar cell with collection electrodes, the photovoltaic effect generates an electrical current.
Brief overview of the most important steps in the solar cell manufacturing process:
Texturing and cleaning: The solar cell manufacturing process begins with wafer surface texturing which reduces the solar cell’s reflection of sunlight, followed by surface cleaning of the cells.
Diffusion: Next, through a thermal process, a negatively charged coating is applied to the positively charged raw wafers in a diffusion furnace. At the high furnace temperature, the phosphorous atoms diffuse into the wafer surface. As a result, the wafer now has two separate layers: a negatively charged layer on the surface and a positively charged layer below it.
Isolation: To achieve a clean separation of the negative and positive layers, the edges of the wafers are isolated through etching, a process that removes a very thin layer of silicon around the edges of the solar cell resulting from the diffusion process.
Anti-reflection coating: An anti-reflection coating is then applied to the front surface of the solar cell to enhance its absorption of sunlight.
Printing: In a screen-printing process, silver paste is printed and aluminium is pasted to the front and back surfaces of the solar cell to act as contacts, with the front contact in a grid pattern to allow sunlight to be absorbed.
Co-firing: Subsequently, contacts are connected through an electrode firing process in a conveyor belt furnace at high temperature. The high temperature causes the silver paste to become embedded in the surface of the silicon layer forming a reliable electrical contact. The aluminium paste on the back of the cell serves as a mirror for particles which further enhances the efficiency level.
Testing and sorting: Finally, the Group completes the manufacturing of solar cells by testing and sorting. The finished cells are sorted according to efficiency levels and optical criteria. Each cell is tested and assigned to a performance and quality class depending on the testing results.
The solar modules are then assembled by interconnecting multiple solar cells through taping and stringing into a desired electrical configuration. The interconnected cells are laid out, laminated in a vacuum, cured by heating and then packaged in a protective lightweight anodised aluminium frame. The solar modules are sealed and weatherproofed and are able to withstand high levels of ultraviolet radiation, moisture and extreme temperatures.
OUR ACTIVITIES INCLUDE
» Power engineering
» Preparation of project documentation
» Gathering of required equipment
» Producing of prefabricates
» Delivery of materials and installation
» Programming of control drivers
» Conducting of adjustment
» Mechanical and technological start-up
» Preparation of project documentation
Firma ENAP S.A. uzyskała dofinansowanie z Unii Europejskiej ze środków Europejskiego Funduszu Rozwoju Regionalnego oraz z budżetu państwa na realizację projektu w ramach działania 1.5 RPO WM 2007-2013, pt: „Budowa oraz unowocześnienie zaplecza produkcyjno-usługowego na potrzeby uruchomienia produkcji urządzeń elektroenergetycznych wykorzystujących odnawialne źródła energii oraz usług w zakresie badań certyfikacyjnych”. Informacje źródłowe na temat Regionalnego Programu Operacyjnego Województwa Mazowieckiego 2007-2013 znajdują się na stronie: www.mazowia.eu