The Bent Tree project site, which features 122 V82-1.65 MW near Albert Lea, Minn., US, is expected to commission its final turbine in early February.
It hasn’t come easy. The site, owned by Alliant Energy, endured 60 weather delays, a summer tornado and one of the worst floods in Minnesota history. And on top of that a December blizzard that collapsed the Metrodome roof in Minneapolis.
“We were joking that Bent Tree became an offshore site,” said Eric Staat, Site Manager. “Alliant, though, has been very complimentary toward us in overcoming these obstacles. First and foremost, we’ve been able to do this safely.”
Availability goals exceeded
The Bent Tree turbines in operation thus far have exceeded availability goals. Availability is the percentage of time a turbine is producing energy. With an availability metric called RUN++, which uses data drawn directly from turbine controller points and is consistent across Vestas’ global operations, Bent Tree reached 98 to 99 percent just five weeks after commissioning. It surpassed its goal of 95 percent availability in the fourth week of operation.
“We were able to conduct the construction work quickly, but we’ve also been able to maintain excellent turbine operation after commissioning,” said Tim Leier, Manager of Performance & Diagnostics.
Leier also said this improves the Lost Production Factor (LPF) statistics.
“LPF is the percentage of possible power of wind production that Vestas has lost the customer,” Leier said. “It’s dollars in and out of our customers’ pockets. In this case, the quick escalation to above 95 percent availability has minimized any lost production down to a world-class level in a very short period of time.”
One-site concept
Bent Tree also employed the one-site concept, which brings service technicians to the site near the beginning of the construction phase.
“Service techs are taking more ownership of the turbines and are feeling more pride behind what they are doing because they were there from day one,” said Søren Bredgaard, Construction Manager. “If they came in at the end, they wouldn’t know what they are taking over.”
Bredgaard, who began at Vestas in 2002 at the Northern Europe SBU, said there has been good cooperation between the Construction and Service teams at Bent Tree.
“We’re here in the same trailer all the time — we are one team,” Staat said. “If you came onto our site and you didn’t know who was a service or project tech, you couldn’t tell the difference from the morning safety meeting to going out to do tasks. The service guys were able to job-shadow and learn some of the construction work, and the project techs were able to work with the service techs on services and troubleshooting and demonstrating TBC (Task Based Certification) tasks. We developed that ownership and learn of any specific peculiarities with the turbine.”
In September, record-breaking floods caused delays in construction.