With growing solar demand (expected to grow 15% by 2021) year after year, the world is leaning towards high efficiency modules to increase generation efficiency and make green energy much more reliable. This growing demand can be taken as an unequivocal proof that solar is going to be the future of energy. As the high efficiency modules are focusing towards more energy generation, solar technological evolution is also making sure to reduce shading loss.

What is Shading Loss?

Solar plants generate electricity from the sunrays. In many cases shadow over the Photovoltaic panels obstruct the sunlight from reaching the panels, thus reducing energy generation level. This is called shading loss. Shading loss can happen from Self-shading, which casts shadow from other PV panel rows, Horizon shading from the terrain surrounding the installation site and various other factors such as panel orientation, soiling etc. It is important to note that the power output of a solar panel system declines proportionally to the amount of shading.

How Shading can Cause Power Loss?

It is easy to understand the impact of shading on solar system. Solar cells in a solar panel convert sunlight into energy and this energy is passed on from one solar panel to the other in a solar plant. Now, if a portion of a solar panel is covered under shadow energy flow from one cell to the next and one panel to the other is restricted. Thus, reducing the energy generation.

Although, there are several solutions to this problem such as-

Arranging arrays in parallel strings, using Bypass Diodes to allow the current to “skip over” shaded regions of the string, introducing a higher creepage distance to reduce less soil accumulation on the last row of the cell, and even use of MLPE devices include micro inverters and DC power optimizers can help in monitoring solar plant’s energy generation and solve the shading challenge to an extent.

High Hopes from New Solar Technology

With the advancement in solar technology, new and efficient solar panels that offer better performance in low light and shaded conditions.

For example, Vikram Solar’s new M6 cell powered Series 6 PV modules come in Mono & Bifacial variants titled Somera Series 6 and Prexos Series 6 respectively with Mono PERC technology and Multi Bus Bar features.

This new M6 series from Vikram Solar modules offer-

• Module configuration: Solar module’s behavior under partial shading condition is improved and its energy characteristics are raised by using half cut-cell technology, changing the module configuration and design. Since the configuration has two blocks of series connected cells, so if one is shaded the other will keep on working.
• Performance guaranteed in partial shadow– Bypass diodes and Innovative Series Parallel connection to ensure shadow optimisation in portrait mode.
• Reduction in hotspot temperatures– With half- cell, one cell generates half of the current than the standard. This declines the heat production further minimizing the chances of hot spot when one cell of the module is shaded. Lower heat production positively affects module longevity.
• Triple JB in Half cut module: Triple JBs are more reliable and cause less power loss due to shorter cable length. Also if one JB gets burnt then the other two JB’s will keep working and prevent the module from hotspot.

Therefore, it is easy to comprehend that although shading can be a threat to solar module performance, now with higher efficiency solar modules circumventing the challenges is possible.