Ever wondered where those electrons come from when you plug something into your wall? Well, the Wall Street Journal has a lovely map which shows the main sources of electricity in each of the U.S. states.

In fact, it shows how it's changed since 2001 too—not that you'd notice much difference at a glance. Look closely, though, and more states use natural gas as their main fuel and fewer use coal, and now a full four states use hydroelectricity as their primary source. For a full breakdown, go read the Wall Street Journal post—it's fascinating. [WSJ]