The solar energy is the most evenly distributed on Earth. No matter which part of the globe are panels are located, if there is light – they work. Germany is a good example – it is not a country with a considerable sunshine, but is the biggest market for solar energy in the summer, and almost 10% of electricity for households in southern Germany comes from solar panels.
Obviously, of course, if the investment is in the region of the Sahara the return will be much higher, but there are many other factors that are not negligible. Influenced by the presence of the grid, purchase electricity prices, political stability in the country and others. For example, in northern Alaska much more reasonable investment would be a solar energy installation than deploying electrical cables from a distant power or attachment point.