Almost too easy:

[S]urrounded by boxes of energy-efficient compact fluorescent light bulbs [Pelosi] wants to install in 12,000 desk lamps, she became conspicuously vague when asked about the pair of towering smokestacks four blocks away.

Congress runs the Capitol Power Plant, which heats and cools buildings on the Hill. Two senators ensure it burns coal, one of the dirtiest fossil fuels.

The Capitol Power Plant, operated by Congress, is the only coal-burning plant in the District and is a major source of sulfur dioxide, carbon monoxide and soot in a city that has repeatedly been found in violation of the Clean Air Act.

Grist thanks its sponsors. Become one.

But any efforts to eliminate coal have been thwarted by two of the most powerful figures in the Senate, who just happen to represent coal-producing states: Robert C. Byrd (D-W.Va.), chairman of the Senate Appropriations Committee, and Minority Leader Mitch McConnell (R-Ky.).