The Post Bulletin reports Rochester Public Utilities officials could decide to shut down some or all of the generators. Another option is converting the generators from coal to natural gas. RPU just completed a nearly $40 million upgrade to keep its newest generator in compliance with new EPA regulations.

Minnesota's Department of Commerce recommends closing Minnesota Power’s five oldest coal-fired power plants by 2020 to save consumers money. The Duluth News Tribune reports environmental groups have also sent letters urging the Public Utilities Commission to close the plants to reduce emissions.

Minnesota Power says it wants to further study the environmental benefits and economic impacts. The Department of Commerce recommends closing at least three of utility's coal-burning plants by 2016. Each unit is more than 50 years old. Environmental groups have also urged closing the coal power plants, while industrial users want state regulators to disregard the advice.

Therefore, North Dakota officials feel the state should be exempt from a Minnesota law that requires utilities to pay more to burn coal, even those from out-of-state. It's part of Minnesota's Next Generation Energy Act of 2007 that requires new coal power emissions to be offset.

Coal plants in our neighbor state have been violating clean air rules for years with little push back from state or federal regulators, according to a report from the Wisconsin Center for Investigative Journalism and other news organizations. But the nonprofit Sierra Club has campaigned for a decade and applied legal pressure to force energy producers to cut emissions.

Starting Nov. 1, the regional carrier will offer two weekly non-stop flights from the Rochester International Airport to Mesa, Ariz., the Post Bulletin reports. Allegiant Airlines ended its service from Rochester to Las Vegas in 2010 because of a lack of demand. The newspaper notes Mayo Clinic has a campus in a suburb of Phoenix.

The Public Utilities Commission ordered Xcel Energy to study the cost of new pollution control equipment at two of its coal-burning units in Sherburne County and compare that with the cost of replacing them with a cleaner alternative. Environmental groups consider the order a victory, but Xcel says it was planning something similar. The study is due next summer.