As long as you’ve got sun, you’ve got the potential to use solar power in some form. Simple devices like deskfans, lights and information boards can be powered in most places, though more serious applications such as powering a house requires much more in the way of sunlight.
If you’ve got a fairly continuous supply throughout the year and a modern, energy efficient home, it would be possible to power your entire home using solar power - Many people are doing it, though the equipment is still reasonably costly.
As far as I’m aware solar power is now faesible - that is, you will save more money in the long run than you will spend initially to purchase the panels and other related equipment.