Is there any maintenance?

A system that has no batteries needs virtually no maintenance. Solar panels have no moving parts so there is very little to break. The inverter, the electronic device that converts the DC electricity from the panels to the AC for the house, also has very little to break. The warranties on the panels are 20 to 25 years depending on manufacturer. Nobody really knows how long they will last because the ones made back in the 1970s are still working. So probably a lot longer than the warranty. Inverters are generally warrantied by the manufacturer for 10 years. Not having seen one fail catastrophically yet we can not say how long they might last. We have had to do minor repairs which usually means replacing the circuit board. When this happens, which is rare, it happens early on in the life of the inverter. The problems we have come across have occurred in the first few weeks of operation and have been easily repaired in the field. We think of an inverter like a TV. It can last for years unless somebody hits it with a car or a lawnmower. Both pretty unlikely events.