Very little. Solar panels are passive and so faults are very rare, however, they can collect dust, bird poo and other particles that will build up over time. Luckily the rain will typically wash off all of this debris. If there is a period of many months without rain, by all means safely wash your solar panels by spraying them with a hose (whilst standing safely on the ground), but we don’t recommend that you go up onto your roof and wash them by hand. It is not worth your time and of course, it can be dangerous. If you get up onto your roof to clean the gutters then spraying your panels could be a good idea if you are able to do it safely.
Over 80% of our systems are now installed with Enphase Micro Inverters or SolarEdge DC optimisers. These systems are connected to the internet and allow for panel-level back to base monitoring. If anyone panel or micro inverter is underperforming, the Solaray Technical Team will receive an alert notifying us that a service check may be required, providing you with an additional level of support.
We have heard of solar installer charging yearly service fees to maintain your system, but our general advice is why pay for something you don’t need? Especially now that Enphase and SolarEdge systems provide back to base monitoring.