Nine of 11 stalled wind turbines from California are spinning in Minnesota now, but questions of efficacy swirl.
When 11 wind turbines stood idle about a month ago, some in the Minnesota wind industry worried that the machines were generating something other than power -- bad publicity.
At a time when wind power is getting federal energy grants, the fear was that people might question taxpayer subsidies and how effective wind energy is in Minnesota, which is one of top five wind energy producing states in the nation.
The stalled machines were giving Minnesota wind energy "a black eye," said Todd McNurlin, of Private Energy Systems, of Oakdale.
The 20-year-old windmills were made in Denmark, and had operated on a wind farm in California before being bought by the Minnesota Municipal Power Agency (MMPA), a consortium of five metro and six outstate cities, with $5 million in federal renewable-energy bonds. Last year, they went up in MMPA member cities -- Anoka, Buffalo, Chaska, North St. Paul, Shakopee and six outstate cities -- but weren't fully operating as of early February.
Now, after some upgrades, nine of the 11 are spinning, and the other two should be running by the end of this month, says Avant Energy, the machines' operator.
Avant president Derick Dahlen said that low temperatures that thickened fluids could have been a factor in their troubled start, but he also pointed to the contractor hired to erect the turbines, Henkels & McCoy of Blue Bell, Pa. "Our people are doing work that should have been done by the contractor," he said. Henkels, in turn, stands by its work, saying it completed the installation it was hired to do.
Avant brought in enXco, the California firm that had refurbished the windmills. EnXco performed upgrades, including new control systems with heaters, Avant said.
When the machines languished, critics said the problem could be that they're too short and too old: 80 feet high (115 if you include the blade) with a 160-kilowatt capacity, compared with 2-megawatt models over 300 feet tall on southern Minnesota wind farms.
Dan Juhl, president of Juhlwind, which builds wind farms in southwest Minnesota, said he worked on Danish-made turbines like the 11 in Minnesota back in the mid-1980s, when they were installed in the Palm Springs, Calif., area.
Juhl, who has worked with wind power in Minnesota for 30 years, said Henkels asked him early last year to help erect the 11 turbines, but he declined after being told that their 20-year-old control systems hadn't been replaced.
He and McNurlin said the turbines' relative shortness also could make them less effective, especially in the metro area, which has relatively low wind speeds and high turbulence because of tall buildings, trees and homes.
McNurlin said publicity about the stalled windmills, including stories in the Star Tribune and the New York Times, might lead people to think wind power doesn't work well in Minnesota. "It has the potential to give the public the feeling that we are throwing all this money and stimulus out there from the public pocket," McNurlin said.
"They want to know they are getting good value for that and doing good things with that money." They are, with properly sized and located turbines, he said.
Green power payoff?
A University of Minnesota official involved in wind energy said he doesn't think the stalled windmills will hurt the industry, although they may cause agencies to be more careful about where they acquire turbines. "I think wind energy is riding a crest," said Rod Larkins, associate director of Initiative for Renewable Energy and the Environment.
Meanwhile, Juhl said the newly installed control systems will give the 11 windmills a chance to run. "But if you put 80-foot towers in town, you will have a hard time getting enough wind, and you'll need a lot of wind to pay off a $417,000 turbine," he added.
Dahlen said Avant used historic weather data for computer wind modeling to select sites for the windmills. He said he expects the turbines to generate enough power to pay off their $5 million cost by the time the bonds mature in 15 years. "We did an economic analysis on these pieces of equipment and we are satisfied it makes sense," he said. "I think they will be good and reliable units ... and will produce electricity for many years."
Buffalo's windmill started spinning in February. City utilities director Joe Steffel, who watched the start-up, is optimistic.
"I realize there are some challenges with any of this technology," he said. "But standing beneath it was a great moment. It tells us there are things we can do about our energy use."
Jim Adams • 612-673-7658