In the article dedicated toMaintenance of a photovoltaic systemwe have described the interventions and checks to be performed to keep the plant performance under control. On this page we will analyze the most common causes that lead to ayield drop in a photovoltaic system, that is because sometimes, even a few months after installation, thephotovoltaic system produces less energythan it should.
At the time of setting up aphotovoltaic system,installers also offer inspection and maintenance plans on a bimonthly basis. If you are not covered by such a clause, an inspection and maintenance interventionBasicit will cost you around 100 euros. Before contacting a team of experts, however, you would do well to carry out some checks yourself.
Technologyphotovoltaicis solid and reliable, if yoursphotovoltaic system does not produceno energy or anyproduces little, certainly there is something wrong and "luckily" the statistics state that the most common cause of the decline in performance is the accumulation of dirt, so in this case you should do nothing but provide a thorough cleaning of the 'solar system.
Photovoltaic system that produces little
If yours photovoltaic system does not produce enough energy you need to carry out a complete check of the system and all its components: solar field, supports, any solar trackers, wiring and electrical connections, inverters, any accumulators, control units ...
To identify why yourphotovoltaic system produces less energy than it should, you can start by exclusion. Before doing more complex checks (such as instrumental control with thermal imaging camera to check for faults in photovoltaic modules), you can begin to check the most trivial reasons (and also less expensive for repairs!).
The main onescausesof malfunction andreduction of the yield of a solar systemthey can be linked directly to system components (inverters, modules, connections) or to network disturbances. Because the photovoltaic system produces less energy? Here are the most common causes:
- Solar Field Shadings:
shaded areas due to plants, buildings, high voltage pylons, lightning rods, antennas, parabolas or any other system that prevents the modules from capturing the sun's rays.
- Dirt accumulated on the solar field:
bird droppings, resins, leaves, dust and other wind-borne debris are a very common cause of the decrease in the yield of solar panels. In this regard, we invite you to read the in-depth study dedicated tocleaning of solar panels.
most inverters come with 10-year warranties. The inverter is the most delicate component of aphotovoltaic systemand maintenance costs are quite high if you are not covered by a budgeted plan. If thephotovoltaic system has been installed recently and already produces little energythere may have been aincorrect sizing of the inverter. Other problems relate to tuning. Check the correct operation of the inverter directly on the display or on the LED indicators.
- Real power:
if yoursphotovoltaic system produces little, there could be a difference between the real power of the photovoltaic modules compared to the nameplate value. At the time of purchase, it is good to check the actual performance of the panels: check the experiences of other buyers, consult forums or purchase panels distributed by trusted manufacturers.
also disturbances and voltage peaks coming from the electric network can negatively affect the yield of a photovoltaic system.
- Various defects:
there may be defects in the bypass diodes of the modules, defects in the safety and protection devices, wiring defects on the direct current side….
- Other network disturbances:
grid disturbances are among the first among the causes of malfunction and decrease in the electricity production of a solar system. An excessive variation in impedance can also cause a drop in performance as well as excessive deviations in the grid frequency.
- Non-functioning cells:
in this context you should identify the failed modules and replace them. A thermographic analysis could be very useful, especially if the modules are still under warranty, so as to return the cells that are no longer functioning.