Solar power generation takes up a good amount of area.
So, one aspect you should consider before deciding to install solar panels on your rooftop is to ensure that you have enough area to install the capacity of solar panels you wish to!
This is the amount of unshaded area (area in which no shade falls during any time of day) required for all the panels and the cablings together, and also includes the space for the inverters and other balance of systems.
The requirement of sizable area is usually not a concern for ground mounted power plants as they are installed in remote areas where land is available in plenty, and is cheap.
The area requirement is a concern more for the rooftop solar power plants, especially for commercial or industrial firms keen on getting a significant portion of power from their rooftop solar panels. Imagine your factory is consuming 3 lakh units of electricity a month. To generate this much electricity, you will require at least a capacity of 2 MW of solar panels. That would need a minimum rooftop space of about 20,000 sq.m, or about 5 acres.
20,000 sq.m of rooftop space? Good luck with that!