More on this extensive topic later in a separate post.
Here I will just mention that I have installed solar electricity to my back porch, two sheds and the outdoor shower.
My primary reasons for doing so were twofold. None of these locations had a mains electricity supply, and I believed that solar was cheaper than the considerable costs involved in having mains power connected. Secondly, in the event of a power outage the porch provides a comfortable backup location to continue reading, use a laptop and listen to music – all powered via the sun. I also have an inverter to enable the use of small 240 volt appliances.
Originally the security lights around the perimeter of the house were all mains powered. Each held two 150 watt incandescent spotlights. As these were frequently turned on by passing animals and trees blowing in the wind, over time the energy consumption was considerable. I now run 15 watt LED security lights, each powered by small photo-voltaic panels supplying self-contained batteries inside the units.