BY BRIAN McGILLIVARY
TRAVERSE CITY — The state's oldest commercial, utility-owned windmill is showing its age.
The wind turbine constructed in 1996 by Traverse City Light & Power on M-72 in Elmwood Township hasn't worked properly for over four months. The turbine initially broke down Aug. 28. It took four months to find and obtain a replacement part at a cost of almost $38,000.
Workers installed the new part on Jan. 4, and two days later it broke down again.
Utility workers had it running on Jan. 8, but the turbine currently only works at about half capacity, said Tim Arends, Light & Power's interim executive director.
"It's nearing the end of its useful life, or it may already be there," Arends said.
The turbine's 160-foot high tower with a blade diameter of 144 feet stands less than half as tall as modern turbines designed to catch Michigan's best winds. Its generator is considered inefficient by today's standards.
It was considered a big deal in 1996, said utility board Chairman Pat McGuire. At that time it was the largest operating wind turbine in the country.
It can produce about 600,000 kilowatt hours of electricity a year, enough power for about 110 homes.
The turbine cost $785,000 to construct, but hasn't paid for itself and likely never will during its useful life, Arends said.
And it appears the turbine doesn't have much of a future, McGuire said.
"This particular wind turbine is obsolete and at some point you have to give up the ghost and let it go," McGuire said. "It's like an old car. At some point you have to make the decision you can no longer afford to make repairs because when you do something else goes wrong."
Arends predicted the turbine would take two years to generate enough income to cover the cost of the latest part replacement if it operated at full output with low maintenance. Now he is waiting for a contractor to determine if the newest problem is due to the new part or if the generator is breaking down.
"If it's the generator, that's a major cost to the unit," he said.
Late last year Arends assigned Light & Power staff to consider options for the wind turbine.
"Does a more modern wind turbine replacement makes sense, or is it better not having one at all," he said.
Utility officials also will try to learn if they can salvage the turbine's towers and blades and try to retrofit a new high-efficiency generator to the tower, as well as explore the cost to tear it all down, Arends said.
The utility doesn't have the expertise to answer those questions in-house, so officials will work with experts in the field to explore alternatives. Arends hopes to have a report to the board by April or May.
Until then, the goal is to keep it operating at the lowest cost possible, he said.