Yesterday, the Obama administration¬†announced a plan to reduce power plant emissions (from 2005 levels)¬†by 30% by 2030. Reuters‘ Valerie Volvoici and Jeff Mason report that 38% of US power comes from coal, and that “states which rely heavily on coal-fired power plants are thought to have the toughest tasks ahead” in complying with the rule.

Here’s what American electricity generation looks like by state and energy source: