Coal-fired Sherco Unit 3 having initial startup problems

Northern States Power d/b/a Xcel Energy (NYSE: XEL) told the Minnesota Public Utilities Commission on Sept. 20 that the restart of the coal-fired Sherburne County (Sherco) Unit 3 ran into a hitch, but the unit should be back up by Oct. 7.

The 884-MW Sherco 3 had been offline since November 2011 due to mechanical failures and a subsequent fire.

The utility said in the Sept. 20 update report that the unit was synchronized to the grid on Sept. 4 following a series of successful initial return-to-service tests. Sherco 3 operated at about a 240 MW level until it was taken off-line on Sept. 7 to address post-restoration items including change-out of the fine-mesh screens that protect the turbine from small particulate damage when the unit initially starts-up.

“At this time we anticipate this short post-restoration outage to end with Sherco 3 returning to service on or around October 7, 2013,” Xcel reported. “Following that return there will be four days of testing at load before the unit is released for full economic dispatch.”

Xcel said it is continuing to work on the release of a root cause analysis report with its insurance provider. Its next update to the commission is expected to be filed in October.

Sherco is a three-unit, 2,400-MW plant that burns low-sulfur Western coal from mines in Montana and Wyoming. The plant normally burns more than 9 million tons of coal a year. Northern States Power, after doing a life-cycle study of Sherco Units 1-2, recently said these units are viable for the long-term future.

U.S. Energy Information Administration data shows that coal suppliers to the plant earlier this year were the Absaloka mine in Montana of Westmoreland Coal and the Black Thunder mine in Wyoming of Arch Coal.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.