Although these numbers only go through 2014, they are the most up-to-date available. (These numbers tell us who is generating the most raw energy from solar, not who is providing the most electricity.
The surprising thing about this list is that very small countries are on it. Germany, Japan, Italy – all of them rank higher than the US, even though our land area is much greater.
For now, solar power requires a great deal of space, so the fact that small countries are leading the way in overall capacity is impressive. It also shows how much space there is to install solar in places like the USA that have lots of open land.