Unit 3 at Xcel Energy’s Sherburne County (Sherco) Generating Station in Becker has returned to service following completion of repairs after a catastrophic failure almost two years ago.
“Restoration following such a significant event on such a large unit was extremely complex,” said Dave Sparby, CEO of Northern States Power Company (Minnesota), a subsidiary of Xcel Energy. “Plant employees, contractors and vendors worked thousands of hours to safely and efficiently return the 884 megawatt unit to service. We implemented repairs that ensure Sherco Unit 3 returned to operation with the highest integrity and reliability.”
The three unit Sherco plant is Xcel Energy’s largest power generator in the Midwest, providing 2400 MW of electricity and serving more than 2 million Minnesota households and businesses.
“Sherco plays an important role in our diverse energy supply, which over the years has provided our customers with safe, reliable energy at a competitive price,” Sparby added.
The failure occurred on 19 November 2011, during turbine testing as Unit 3 was being returned to service following a maintenance outage. The event caused extensive damage to the turbine, generator and associated plant systems.
“We want to again acknowledge the Becker, Big Lake and Monticello first responders for their quick assistance, which limited damage from the incident,” said Sherco Plant Director Ron Brevig.
An investigation by external experts found extensive cracking in one row of turbine blades due to stress corrosion. The problem was a function of the original design and was not related to how the plant has been operated or maintained.
Repair costs are estimated to be in excess of US$ 200 million. It is expected that most of the costs will be reimbursed by insurance proceeds.
Sherco Unit 3 is jointly owned by Xcel Energy and Southern Minnesota Municipal Power Agency.
Adapted from press release by Katie Woodward
Read the article online at: https://www.worldcoal.com/coal/23102013/xcel_energy_coal_unit_returns_to_service_177/