Basics Maintenance
Maintenance
Shadows
Shadows can kill the output of a module or system, more than you would expect. Depending on the design of the module, shadowing just one cell can drop the output to almost zero. If just half of one cell is shadowed, the output of the whole module can drop to almost half.
Why is this? Sunlight provides the electrons in the cells that allows current to flow through them. No sunlight, no electrons. No electrons, no current. Since the cells are wired in series, this blocks the current from flowing through all the cells. In the same way, one cell shadowed in a module that is connected in series with other modules will kill the output of all the modules. Bypass diodes can allow current to flow around the module with the shadowed cell, but the output still suffers.
Read more about shadows
Maintenance
With the exception of a battery powered systems, solar systems do not require very much maintenance. The main task is to keep the modules clean and to keep shadows off the modules. Usually rain will provide enough cleaning. If you live in a dry, dusty, or polluted environment, you may need to hose off the modules from time to time.