Do you know where your electricity comes from? I was recently wondering this myself. While I was relatively certain that the electricity in Central Illinois comes principally from burning coal, I was curious to what extent Champaign, Illinois relies exclusively on coal and how my region compares to other parts of the nation.
One quick google search later, and I discovered that the EPA maintains a site that divulges which energy sources, and a what proportion, your regional energy company uses. One warning: this data is from 2005, so some sources may have changed in the last six years.
It turns out that the vast majority (83.2%) of electricity consumed in Central Illinois and St. Louis (at least the energy produced by Ameren IP) comes from burning coal. The United States as a whole relies on coal for about 50% of its electricity. Chicago (Commonwealth Edison) is also heavily dependent on coal for electricity, weighing in at 72.8%. Most of the rest of Chicago's electricity comes from nuclear plants. Interestingly, I found that the City of Los Angeles, which generates its own electricity, offers a relatively mixed portfolio of electricity sources including 9.4% from non-hydroelectric renewables and only 11.9% from coal.
I took some time to look up the electricity sources of some of the regions you (yes, you!) might be reading from. They're summarized in handy pie charts below (click to enlarge). Enjoy!