Renewable energy is making quite the noise around us. Especially solar. From educational institutions to residential establishments, people are seriously considering solar solutions, trying to save up on their electricity bills, and doing their part in environment improvement. And with developing countries like India, Africa, Brazil, Indonesia, taking a more courageous stance, showing acceptance towards solar solutions, it is easy to glean that a brighter future awaits us with solar. However, casting our vote without knowing much about what we are choosing is exactly how we ended up with fossil fuels. And by the time we woke up from our trance of industrial progress, we found ourselves on the verge of environmental degradation – Violent, threatening, and consistent.
So, knowing how the clock works, should be on top of our agenda since we are again at the precipice of change. That is exactly what we are doing today. We are taking a trip to a solar module manufacturing facility, to learn how green energy harvesting solar modules are produced.
A trip to a solar manufacturing plant is a treat for even the geekiest of all, since the technology itself promises sustainability through simplicity. Such a process is in itself a miracle of sorts, that reminds the onlookers how we have progressed and finally how we can fully utilize nature’s infinite resources for development. But before getting to automatic machines, we need to understand what a solar module is. A solar module is an assembly of interconnected solar cells, housed in a weatherproof package.
Performance check: The first
Now, get the image of a complete solar module off your mind, and concentrate on the bluish, black cells. Cells are made from wafers, which are sliced into a square or pseudo square shape. The cells go through a close inspection sorting, and are divided in sections depending on their efficiency. The inspection has two stages, involving manual operation as well as instrumental testing under simulated sunlight.
Connecting and bonding
After performance check, the cells go through soldering process that strings multiple cells with metal ribbons together. This offers electrical connection between cells and helps in transference of electricity generated in the cell by sunlight. After interconnecting the cells, they are carefully placed over a tempered glass and a sheet of EVA is placed between the glass and the cells. EVA stands for (Ethylene-vinyl acetate) and it acts as glue, bonding/laminating multiple layers within the solar panel together, providing weatherproofing and durability to the structure. A second layer of EVA is put over the cells and finally a backsheet is put to create a ‘module sandwich’. A laminating machine is used to heat the sandwich and laminate the components. The machine uses elevated temperature, vacuum and atmospheric pressure in a precise manner to complete the cross-linking process.
Completing the circuit and second performance check
After lamination, the module circuit ribbons are connected with output leads through soldering process. This ensures that solar cells can transfer the energy from sunrays through the circuits and output leads to energy storage options or the grid.
Aluminium frames are attached around the laminated module to provide mechanical strength and grounding opportunities. Presence of micro-cracks reduces the performance of solar cells and the module itself. So these are checked by passing through an Electroluminescence (EL) Testing tool. Two stage EL testing (before and after lamination) is performed for ensuring best quality modules.
A junction box (JB) is attached to the backside of the module; JB acts as the collector of electricity that the module generates from sun light. Several QC tests are performed subsequently – like HiPot, to check high potential behavior of modules, Wet leakage test, to check electrical performance in wet conditions. After all these tests the modules are passed through the Sun Simulator to check the final power rating based on which the module is binned.
Finally, after all these tests, the modules are ready to soak up the sun. Sure, the process is multi-layered, but simple in comparison to conventional energy power plants. The process is fume free, radiation free, and free of adding carbon footprint to our environment, which is in stark contrast to our conventional energy generation and usage results.
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