Here is the good news: Solar panels have no moving parts and are maintenance free. A good rain shower will clean them. They are impervious to most natural conditions other than major hail storms which can wreak havoc with the glass panels that house the silicon wafers.
Most important, all major solar manufacturers provide warranties on performance of 20-25 years (sometimes the warranty for workmanship may be less, say, 10 years). But since most homeowners are more concerned about overall performance – i.e., total electrical output — they can take the risk that some panels may degrade.
Unlike appliances, cars and other big purchases you make, solar panels are old and proven technology.
Inverters are different story. Solar panels produce direct current – the kind of current used by most motors such as a lawnmower. But US utilities, since the days of Edison, transmit alternating current, the current that is used by most appliances, lighting fixtures, and the like. Inverters convert the direct current or DC produced by solar panels into alternating current or AC.
Traditionally one or two inverters are sufficient to convert all of the electricity produced by a long series (or “string”) of solar panels. Since 2012 a number of panel manufacturers have introduced so-called micro-inverters that are attached to each panel. These micro-inverters have some advantages in home-based installations but they can cause problems for large commercial installations as a single failure at the panel level can interfere with the production from a whole string of panels.
Unlike panels, inverters often do not carry 20-25 year warranties but rather only 10 year warranties. Accordingly, solar hosts must be prepared to replace the inverters at some point in the life of their system. The cost of inverters has been steadily declining but can amount to as much as 10% of the cost of a small system.
In the case of ground mounts, other maintenance challenges may present themselves including mowing, dust removal, treatment of land subsidence and impact of erosion from inadequate or poor drainage around the ground mounted piers.
We recommend that our clients alert their insurance companies to the potential maintenance requirements of solar panels. While nominal in cost the insurance will be useful in the event of an unexpected event such as a hailstorm or fire.