The PV plant shows high levels of soiling caused by pollution, bird droppings and hard water, and significant module damages caused by bad handling. The modules are also affected by product defects. The mounting structure is in very bad shape and will likely not last for the whole project lifetime. It is recommended to (i) increase the cleaning frequency to at least 3 times per month (ii) replace the modules exceeding the manufacturer’s guaranteed performance drop and (iii) reinforce immediately the structural integrity of the mounting structure. The estimated production boost caused by the retrofitting actions lies between 5% and 7%.
Heavy soiling has been detected on site. The use of hard water for cleaning increases the accumulation if soil on the module surface. This leads to soiling induced hotspots.
Based on the crack distribution and types detected with electroluminescense, is it likely that the modules perform 2-4% less. Furthermore, these types of crack could eventually lead to inactive areas and higher power losses in the midterm.
Modules with inactive cell strings underperform 33% to 66% depending on the amount of affected strings. The extrapolation of the inspected sample to the whole system leads to a loss of 3% at system level.
Total Estimated Energy Loss
The mounting structure should be retrofitted immediately.
Defective and loose connectors should be replaced and the connectors should be homogenized.
The irradiation sensor should be properly installed in order to ensure accurate performance ratio calculations.
All modules with inactive cell strings shall be replaced according to the warranty terms. A similar exercise shall be conducted with all modules showing product defects.