Solar Panel Shading - the problem and what you can do about it.

Solar panels shaded by tree Solar panel shading will cause your panels to produce significantly less power. It’s therefore really important to ensure your solar panels are located in full sun for as long as possible. If foliage is shading your solar panels it’s definitely best to prune it back. Any shading on those panels is costing you money!

If it’s not possible to have the panels in full sun all day then to maximise the power output of your system you really want to make sure that they are in full sun at least between 10 am and 2 pm. This time during the middle of the day is when your solar power system will be producing the most power as the sun is at the best angle to the panels.

Problems from solar panel shading

A thermal image of solar panel shading from a cable tv dish. Note the temperature the shaded cell is operating at. This shading will affect the system performance and will eventually burn out the solar cell altogether.

Most solar power systems have the panels installed in what’s called “series strings”, which is usually great. A problem can arise however with systems being wired in series when a small amount of the system is in shade. The panels experiencing shading can pull down the power production of all the other panels that they are connected in series to. There is also the potential of “hot spots” forming on the solar panels. These hot spots happen when shading on a small portion of a panel causes the cells to heat up and in time burn out. That’s not what you want!

I can’t avoid solar panel shading. What can I do?

If your roof area is shaded all day long you may as well just forget solar as an option. The performance of a solar power system that’s consistently in the shade will be woeful. If, however, your shading issue just affects a few panels for a portion of the day then there are some clever solutions available. To mitigate the shading losses there are two solutions – power optimisers and micro inverters.

Mitigate your losses with Power Optimisers or Micro Inverters

Power optimisers and micro inverters help with shading by optimising the power production of each panel individually. By doing this any shade on one solar panel doesn’t affect the rest of the system. This ensures that your solar yield will be as high as possible.

Power Optimisers: At Gold Coast Solar Power Solutions we highly recommend using power optimisers from SolarEdge to mitigate any shading losses. SolarEdge power optimisers are installed underneath each solar panel and optimiser the panels performance on the DC side of the system.

Mirco Inverters: These units sit underneath each panel just like a power optimiser. However, instead of just optimising the DC, they also convert the DC power from the solar panel into usable AC power. In our opinion the best micro inverter products on the market are from Enphase.