Q&A for How to Maintain a Solar Panel

Not really! If you notice a thick layer of dust, pollen, dander, or ashes on your panels, you should probably spray that off with a hose. Other than that, most solar panels come with a guaranteed 25 years of performance. There aren't moving parts in solar panels, so it's hard for them to break.

Yes, most solar inverter manufacturers have a system which will allow you to monitor the performance. If not, then you can retrofit proprietary systems from 3rd parties which can offer many of the same features.

Yes, they should be cleaned at least annually to keep them performing optimally. Every three months is preferred, especially in dusty areas.

It depends on what kind of solar system and what kind of water heating you have. If your solar panel meter is blank, this would (in the UK, at least) indicate that the solar panel inverters (assuming you have a solar electric system with PV panels) are not connected to the power grid. First place to check this is at the fuse board to make sure no protective devices had turned off automatically. If this is the case, then you should ask someone skilled to check why they have tripped, as the system may have reached a dangerous condition.

Evaluate the power company semi-annual adjustment where they buy back surplus power credits at low value, and the customer then has to buy power back during times of peak usage. The timing is heavily weighted in favor of the utility company. Also, evaluate the property tax status of the unit. Some are the responsibility of the service provider while others are paid by the property owner. Discuss maintenance and repair costs, especially if it is a leased system.

No. Rainwater can wash off some dirt and dust, but it won't completely clean the panels. For most efficient performance, clean them regularly with dish soap and water, then gently wipe and dry.