Gov. Dalrymple says if Minnesota energy regulators require utilities to pay more to burn coal it will hamper North Dakota's growing lignite industry, which already provides a large share of Minnesota's electric power. Regulators here imposed higher costs on coal-burners as part of a plan to require utilities to generate a quarter of their energy from renewable sources by 2024.

North Dakota is suing to force the state of Minnesota to drop restrictions on coal-generated electricity, but big utility companies here have already conformed to the rules and say they're not interested.

A consortium of six North Dakota utilities and coal mining companies is chipping in $500,000 to fight Minnesota's ban on energy generated by burning coal. The state's Industrial Commission filed the original lawsuit. The North Dakota legislature is also committing funds for the legal challenge.

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.

Clean-energy supporters are demanding that the Minnesota Public Utilities Commission order Xcel Energy to better plan how it will retire the two oldest and dirtiest coal-fired power plants at its Sherco Generating Station, which produces electricity for the Upper Midwest, the Pioneer Press reports. Renewable advocates packed an all-day hearing Thursday at the commission. They say Xcel has failed to study how wind- and solar-generated energy might replace the Sherco units.