It will be months before a Golden Valley Electric Association coal fired power plant comes back online. The plant, one of two Golden Valley operates in Healy, has been down since a coal dust explosion March 3. The incident is similar to two others that occurred during initial testing of the recently re-started power plant.
Golden Valley Electric Association vice president of power supply Lynn Thompson said the utility is still in the early stages of reviewing the March 3 explosion at the Healy 2 coal fired power plant.
“We believe that it’s gonna be a combination of events from probably equipment failure and instrument failure that led to this,” said Thompson.
The explosion happened within the plant’s coal pulverization and transport facility, and Thompson said at least one major component needs to be replaced.
“The mill exhaustion fan,” Thompson said. “That will be about fourteen weeks for … delivery to Healy.”
Thompson said a repair cost estimate is not yet available. The $300 million Healy 2 power plant was built with state and federal support to test new coal burning technology, but it failed start up testing in 1999, and sat dormant during a prolonged legal dispute, until Golden Valley purchased it from the state in 2013 for $44 million. The plant has since undergone major renovation. Thompson said the $190 million project includes work on the coal pulverization and transport facility.
“We’ve added additional safeguard equipment to see that these events don’t happen,” said Thompson. “It sounds like they’re going to have to resolve this coal feeder problem.”
Brian Litmans is an attorney with Trustees for Alaska, which successfully pushed for updated emissions controls at both of GVEA’s Healy coal power plants. Litmans said the explosion inspired him to review similar past problems at the Healy 2 plant.
“Back in 1999, GVEA did not want the facility,” Litmans said. “They were very concerned given all of the problems in the 90-day testing period including two major explosions in the coal feeder zone.”
GVEA purchased Healy 2 to help stabilize electric rates by relying more on low cost coal from the Usibelli Coal Mine in Healy. Litmans said the recurring coal pulverization and transport system problem raises concerns about cost-savings potential.
“At what point do you stop sinking good money after bad?” asked Litmans. “Those are important questions for GVEA and the repairer should know what it’s going to take to keep this facility online.”
Golden Valley will attempt to answer those questions, according to the utility’s Thompson.
“We have a forensic engineering team coming in to look at the problems that we experienced this time and so we will do a very thorough evaluation of the equipment and if we need to change procedures or add additional equipment to that system,” said Thompson.
Meanwhile, Thompson said a three-month shutdown scheduled for this summer for installation of new emissions controls has been moved up.
”To try to take advantage of this time we’ll be offline,” Thompson clarified.
GVEA’s other Healy coal plant continues to operate. Thompson said lost power output from Healy 2 represents about 30 percent of the GVEA load and is being compensated for with electricity purchased over the intertie, and generated at a Golden Valley oil-fired plant in North Pole.