Hey guys Harrison here from Florance Electrical and today i’m looking at a 30 kW solar installation that is not generating the power that it should be.
There could be a few reasons as to why this is happening and today we will go through our thoughts and findings from this premises.
A good first place to inspect is always the cleanliness of the solar panels. Having dirty panels can result in a 5% – 10% performance drop depending on the severity of the dirtiness. And for such an easily identifiable and quick task to perform it is well worth the benefit.
We always recommend the use of a harness when working on a roof as it is dangerous and respect and care should be given when working on a roof whether it be a ground level home or single storey.
When cleaning solar panels, always ensure to clean the panels when the ambient temperature is reasonably cool such as early in the morning or later in the afternoon. As the top layer of a solar panel is glass, a sudden fast change in temperature on the surface can cause the glass to shatter.
Use a soft bristled indoor broom and cool soapy water (car wash is fine) to gently scrub the panels down and then hose off all residue. Typically, cleaning the panels is reasonably fast and does not require much effort unless they have not been maintained and have heavy build up of dirt, mould, poo and grime. Always ensure to regularly check and clean the panels as required.
Today Harrison is going to show the performance of a single panel before and after cleaning. Now, we would not normally do this but this system is severely lacking in performance so we are performing some tests at the same time to verify existing faults from a competitor’s solar installation.
The before voltage open circuit of the dirty panel is measured at 32VOC and 8.2Amps under load.
Unfortunately, the after video of this clean panel is not usable as the microphone ran out of battery but the data was 33VOC and 8.93Amps. As you can see, this is a huge change in performance simply by cleaning an individual solar panel.
Whilst testing this system it became apparent very quickly that the panels were not the issue and that the cabling installed by the competitor was connected poorly. We identified multiple MC4 (weatherproof connectors) that were installed on the cabling ran for this system that were connected so loosely that the DC cabling was falling out of the plugs.
This is a timely reminder to always take care on a roof when there is a solar system present as there are high levels of DC or AC voltage on the roof top. If it is installed correctly, in normal operating conditions this is completely safe but as you can see, not all solar installations in Darwin are installed to the same high standard that we would install a system to.
After checking over all of the connections and replacing many, many MC4 plugs and cleaning all of the panels which were very dirty we were able to get this system back to peak performance conditions so that that the client can enjoy a great return on investment moving forward.
Initially, we suspected that there were several faulty solar panels on this roof as the voltages measured on each string were much lower than expected. As it turns out, all of the panels were fine and rather it was the installed wiring which could have led to a dangerous situation, not just poor performance.
Even if your system is performing well, it is strongly advised that you have it inspected by an electrician (preferably with CEC Accreditation) as over time many parts of a solar system deteriorate. Solar installations are not something that you can install and forget about or become complacent. They must be maintained for safety and performance by a qualified individual.
Suspect that your solar system is not operating correctly? Don’t risk having a dangerous or poorly performing solar system on your Darwin roof, have it inspected for safety and performance today as you may be wasting lots of money or have a potential fire hazard on your roof.