2010 marked the second-straight year the United States did not begin construction on a single new coal-fired power plant, according to a report by the Washington Post. The Post report points to a confluence of events as drivers of the recent downswing in U.S. coal-fired power. Those events include low natural gas prices, shale gas discoveries, the economic slowdown, and litigation by environmental groups.

From 2000 to 2008, construction started on 20 coal-fired power units in 19 plants, according to Edison Electric Institute. Last year, utilities and power-generating companies dropped plans to build 38 coal plants while announcing that they would retire 48 aging, inefficient ones, according to the environmental group Sierra Club.

Although 2010 saw the collapse of climate legislation in the Senate, the Post says the Sierra Club is trumpeting such statistics as a sign that “coal is a fuel of the past.”

However, the Post says the battle over coal plants could sharpen in 2011, as the Environmental Protection Agency deploys regulations to improve the efficiency – and lower the greenhouse gas emissions – of big power plants.

New EPA rules came into effect on Jan. 3, which require plants large enough to emit 75,000 tons of carbon dioxide a year to use the “best available control technology” in order to obtain air permits, needed before construction. Industry argues that such requirements are cost-prohibitive and many Republican lawmakers have spoken out against the new EPA rules.

To read the full Washington Post report on this story, click here.