What are the maintenance costs of solar systems?
The general Comment
For various types and sizes of PV installations, one statement is general and true: Acquisition or upfront costs are much higher than routine maintenance costs of solar systems. Various rules of thumb are available in the literature. All are rules of thumb, and no better. Further, they would apply to particular situations. One rule attributed to an old document of US Department of Energy hints at $30 per megawatt-hour (MWh).
• Batteries if installed
• Panel Cleaning
• Routine inspection
• Positioning mechanism, if any
In a grid-tied system batteries are not required. But an off-grid PV installation will need batteries. Normal lead acid batteries need maintenance in terms of monitoring and top up of water level, cleaning, and occasional flushing. Further, they will need replacement every so often, and that is a big cost.
Sealed lead acid batteries, have a longer life, have no maintenance cost, but have high cost of acquisition, and replacement. Overall, maintenance free batteries are preferable.
Inverters are complex electronics equipment having a lot of switching at high voltages. Semiconductors used are the weakest link, and hence, inverter repair or replacement will be a major part of the running cost.
The panels must be kept clean of dust, snow, and grit. A simple spray with a hose or automatic sprinklers can be sufficient. The washing should be performed in the morning or evening, else, hot panels may crack.
Inspection and cleaning does not require a highly trained manpower. Most systems will be monitored automatically and warning alarms sounded. However, there is no replacement for the human eye. For large systems, a regular technical hand will have to be employed, while for smaller systems occasional inspection can be arranged by a contractor.
Positioning mechanism or the tracker system is an electromechanical system. It will need inspection, cleaning, and lubrication of mechanical rotating parts. This is not much of a cost if one does it oneself. For large systems, normally trackers are not used.
Unforeseen Failures, Accidents etc.
There will always be a possibility of unforeseen events, e.g., hurricane damage to panels and the structure, effect of a lightening stroke, etc. These costs cannot be estimated.
Other Non-maintenance Costs
Additional costs will occur due to insurance, any interest on loans, rents of space, and local taxes.