How can I tell if my solar system is damaged or underperforming?

How can I tell if my solar system is damaged or underperforming?

If worried about hail damage - As a general rule of thumb, if there's no roof damage than the panels are unlikely to be damaged.  If you suspect there may be some damage or underperformance from your solar, you can either do a self-assessment based on performance or have the system professionally checked by a solar electrician. 

Self-Assessment
If your system suffers from significant shading or has optimisers, then this method may not work.  In this case, you should compare your system's current performance to its performance in the same month in previous years or have a professional check done.

To get an indication of whether your panels are performing well, you can compare your system's electricity generation to a similar system in your area. The goal is to compare your daily generation to someone else's nearby which would have experienced similar weather.   

If you have monitoring, you can check daily generation directly from this. If you don't have monitoring, you will need to get this information from your inverter.  The inverter manual will contain instructions on how to get the daily generation.  You should be able to find a manual online if you google the brand and model name.  

It's a good idea to get daily generation from a full day (use data from yesterday if you're doing this during the day).  You may also want to get data for a few days, particularly if the weather hasn't been sunny, as you want to be sure that if you find performance differences, it is due to damage and not just cloudy weather.

Once you've got the daily generation information, visit the PV output website and enter your postcode in the "Find:" box. 

For example, if you enter 4551 for Caloundra and let it load without pressing anything you should get a bunch of options pop-up like in the screenshot attached.  Click on one of the options and it will open up the data for that system.  If you hover your mouse over the system size, next to the system name above the table, it will give you more details like orientation, tilt and shade.  Have a look through the systems in your postcode (or surrounding postcodes) until you find one that matches well with the orientation of your system and is not shaded.  The overall system size does not need to match. Once you've found a good system to compare to, have a look at the daily data for the relevant days you have data for from your inverter or monitoring.  For each day, multiply the efficiency from the website by the size of your system.

Say your system is 5kW and generated 10kWh on 30/09, and you've found a system to compare to that had an efficiency of 4kWh/kW on 30/09.  That system would have produced 20kWh (5kW x 4kWh/kW) if it was the same size as yours.  This might indicate a problem as you only produced half (10/20) of what we might expect given your neighbours performance.  It's worthwhile doing this over a few sunny days to make sure it's not just clouds over your house, or an anomaly.  

Please note that due to differences in brand, age and other variables, some variation in performance is normal for systems in the same weather conditions, so this method should only be used to guide your decision on whether to pursue further action.  You can contact us if you're unsure whether performance differences are large or not but generally speaking if your system is producing within a few kWh of a similar system nearby, then there is little evidence for any damage and probably no reason to pursue further unless your system is due for a service anyway.  We recommend having your system checked by a professional every 5 years.

Alternatively, we have a document detailing a simplified version of this method here.

Professional Check
You can pay a professional solar electrician to check your solar system.  One of our vetted suppliers, SkyGreen, offers a solar health check service.  The SkyGreen Solar Health check can ensure your system is working efficiently and diagnose any issues that would affect its performance, safety and product warranty.

The following is the scope of the solar health check:
•Inspect and record inverter readings. Make, model and serial number.
•System testing –VOC, ISC, insulation resistance and earth continuity.
•Visual inspection of all system components.
•Remove any buildup of debris from around panels and racking.
•Recommendations and quote for remedial works.
•Health check report provided to the customer.
•Minor service works quoted and completed on the day.
•Where a system is uneconomical to repair, the price of the Health Check can be discounted from the price of a replacement system.

Cost
Up to 6 Panels - $250
7-12 Panels - $299
13-24 Panels - $349
25-36 Panels - $399

You can submit a request for a solar health check here.