Around the world, there are about 62,500 power plants operating today. That includes everything from coal-fired plants to hydroelectric dams to wind farms.
— This map offers a good way of visualizing where different types power plants are, but it doesn't necessarily show how important each source of electricity is. For instance, the map rightly shows that the German countryside is now blanketed with solar and wind farms. But Germany still gets less electricity from renewable sources (about 25 percent) than it does from coal or even natural gas.
— For a better look at the importance of different energy sources, take a look at this interactive chart from Nature, which shows who consumes what. The data there jibes with some aspects of this map (Brazil really is massively dependent on hydropower). But as the Nature data shows, coal power is still far more important to countries like the United States and China than would appear from the map above.
— Africa really stands out on the map. About 550 million people on the continent still lack access to electricity, and the continent still relies heavily on hydropower and fuel oil plants (many of which were built in a frenzy a decade ago, when crude prices were much lower and they seemed like a good deal). One big question is whether Africa will rely more heavily on coal or seek out renewables as it develops further. For more on that, see this report (pdf).
— By the way, the map comes, randomly enough, from this interesting GE report on "the industrial Internet." The basic argument is that the Internet is poised to boost global productivity in a way that it hasn't done so far by making many industrial processes — including energy — more efficient. You can find a shorter summary of the report from Marco Annunziata here.