Two coal-fired power plants in Colorado will be shut down — not because green groups sued like crazy to make it happen, but because a utility volunteered. Citing concerns about public health and greenhouse-gas emissions, Xcel Energy asked permission of state regulators to close its coal plants, and regulators have approved the plan. Xcel becomes the first utility in the country to shut down power plants on the basis of their greenhouse-gas emissions. Xcel, which is Colorado’s largest utility, will replace its dirty coal power with concentrated solar and wind. “Gov. [Bill] Ritter last year called for a 20 percent reduction in carbon-dioxide emission by 2020,” says an Xcel spokesperson. “These closures will reduce our emissions by 1.4 million tons a year and put us well on the way toward meeting the governor’s goal.” Xcel-lent!