Like all plant and equipment, sooner or later problems arise with solar modules, requiring them to be repaired or replaced. When you consider that some of our solar PV plants in central Italy were commissioned in 2011, it’s not unexpected that they might require some upgrading to maintain productivity. We have always espoused a proactive asset management strategy at Solar 21. That same strategy saw us complete an overhaul of underperforming inverters in our solar plants last year, resulting in a 10% increase in productivity.
This time it was the modules (or solar panels) that demanded our attention. The latest performance study we conducted revealed that some modules were affected by hotspot problems. This is a very common issue. It occurs when some of the power generated is dissipated in a localised area, resulting in lower power output and a speeding up of the deterioration of the module.We found that around 10% of the modules installed were affected by hotspot issues resulting in a production loss of approximately 10% in each of the two plants that were affected.As you can imagine, we were keen to restore power output to its original value and we commissioned BFP Group, our O&M, to carry out the work. In roughly three months, they replaced 900 modules across two plants.Of course it was not that simple; the replacement of defective modules required the reconfiguration of the affected strings (a string is a series-connected configuration of solar modules). We had to reposition good modules in strings of good modules and substitute defective modules with new ones.We were delighted with the results. By replacing even a small number of modules, it was possible to return to full operating capacity at both affected plants. Each plant in question is now able to produce up to 1,450 MWh per annum, equivalent to the annual consumption of around 400 homes.This article was written by Silvia Raineri, Energy Engineer with Solar 21.