Some good news.

State regulators in Colorado have given the green light to plans by Xcel Energy to shut down two coal-powered energy plants in the state, and build one of the world’s largest utility-scale solar-power facilities.

Following discussions lasting several days, the Colorado Public Utilities Commission (CPUC) backed the power company’s voluntary decision to close the two coal-fired plants at Denver and Grand Junction, making Xcel the first utility in the U.S. to make such a move solely in an effort to reduce emissions.

CPUC also approved Xcel plans to build a new 200 MW solar power plant with energy storage capacity in the state, and granted permission for the company to add 850 MW of intermittent renewable energy, such as wind power.

The move comes in response to Colorado state laws requiring large utilities to generate 20% of their electricity from solar, wind or biomass sources by 2020. Xcel seems to be on track to meet the target with several years to spare. The Cameo plant at Grand Junction is scheduled to close down in December 2010, while the Arapahoe plant in Denver will be shut in 2012. Although Xcel haven’t yet invited bids from contractors to build the solar and wind plants, spokesman Mark Stutz has said, “we look forward to those additions to our system by 2015.”

The Colorado decision follows recent announcements of large-scale renewable energy plans in Florida and Pennsylvania, and is hopefully a sign a of a growing trend throughout the U.S.