On a windy night, when some of us might worry about things going bump in the dark, Dan Rottler ’92 frets over 20-ton boxes of gears turning more than 200 feet above the ground. The gearboxes are like outsized automobile transmissions, capable of cranking the energy of the slowly turning 16-rpm blade of a wind turbine up to 1,800 rpm.
As plant manager of Puget Sound Energy’s Wild Horse Wind and Solar Facility, Rottler has 149 of these beasts to lose sleep over. Not to mention wildfires, lightning strikes, microbursts of changing weather, blizzards, ice-covered power lines, and even more unexpected things, like the time the Kittitas emergency dispatcher said homeowners were calling “about the mountain flashing.” A switch in a power substation had malfunctioned, creating a blindingly bright three-foot arc.
“So I came up in the middle of the night and I felt like Frodo going to Mount Doom,” he says. “There was smoke everywhere and this flashing light in the center of it… I called the load office and said, ‘Shut it down!’ Not good.”
Oddly, Rottler tends to thrive on moments when things don’t go quite right. Sure, he would much prefer things go smoothly, and understands that a plant manager needs “to have a little more paranoia than other people.” But when things do go wrong, they also get interesting.
“My job has always been to minimize how many things go wrong,” he says, “but it’s also to troubleshoot and correct anything that does.
Wild Horse is one of Washington’s largest wind-power facilities, as well as one of the most visible, with 262-foot rotors mesmerizing drivers on I-90 between Ellensburg and the Columbia River. At full capacity, it can power 80,000 homes, or nearly all the households in Spokane.
But while Rottler keeps a weather eye on the electricity produced by the facility, he was trained as a mechanical engineer, and the mechanical side of the operation is daunting. It’s hard to overemphasize: The wind turbines are huge. Even from the top of a nacelle, the bus-sized unit holding the blades, transformer, gearbox, and generator, a blade may look to be, say, 40 feet long. But it’s actually 129 feet long. It weighs seven tons. That slow-looking blade tip can be moving 150 mph.
The towers weigh more than 100 tons. When they were being erected, contractors built a concrete plant and quarried rock on the site for the tower foundations. The foundation bolts alone can be 28 feet long and weigh 150 pounds.
The towers had to be put up in sections with a massive crane. Their interior ladders were installed while they were still on the ground. To avoid stressing the structure, they’re attached by magnets.
A gearbox is the most expensive part to replace in the nacelle, and installation requires a crane. That’s why Rottler is working with Vestas, their Danish manufacturer, to install a finer oil filter to catch more of the impurities that can wear down the gearing.
Rottler was introduced to engineering by his father Don Rottler ’63, who managed the acoustics division at the Naval Undersea Warfare Center at Bangor. His dad also introduced him to WSU, bringing him to Pullman on trips to recruit students.
“He had electrical as well as mechanical engineers working with him,” says Rottler, “so I started off at WSU as an electrical engineer and switched over to mechanical, because I liked having things a little more visual. Electrical is a little more abstract.”
Once out of school he held a variety of jobs, including an internship at the Puget Sound Naval Shipyard, a year at Seattle City Light, then steam, hydroelectric, and diesel generation at Tacoma Power.
If he’s learned anything, it’s that things can go wrong at most any type of power project.
He saw landslides at Tacoma’s Cushman hydro project, flooding at its Nisqually River project, and a diesel generator catch fire.
“The Nisqually Earthquake happened while I was there,” he says. “We ended up shutting down at the request of the load office there, but we ended up fine.”
At Wild Horse, the work is quieter—Rottler didn’t leave his office without hearing protection at the diesel facility—but by its very nature, the facility gets tested by the elements. Between maintenance outages, spells of no wind, and moments of too much wind, the facility on average produces one-third its rated output.
Yes, there can be too little wind. The turbines need a nine-mile-per-hour wind to produce power.
There can also be too much wind. The turbines hit peak production around 30 and shut down at 56 mph. Recently, a microburst came through with top speeds of 61 mph.
“The challenge of it is the wind is coming down and it’s going both directions at the same time,” Rottler says. “And the wind turbines are used to the wind coming only one direction. It’s kind of awkward to have one of those come in behind them when they’re actually generating with the wind coming from the opposite direction.”
Rottler likes to fly a Cougar flag outside his office downhill from the towers, but carefully. If it gets too windy, the flag gets torn up.
If a blade gets damaged—two so far have been struck by lightning—technicians from Rope Partner Inc. will descend from the nacelle and make fiberglass repairs. Regular maintenance is carried out by Vestas teams who climb the towers on a rotating schedule. Rottler himself checks out a turbine about once a month.
A climb inside one of the towers is a study in safety systems. Prior to a climb, Rottler gives an extensive safety briefing, including a warning to avoid the 34 kilovolt line inside the nacelle.
“We’ve never had any problems with it,” he says. But “please don’t touch it.”
Guests—the general public is not allowed in the towers—wear safety harnesses and are required to have hardhats on when they get out of the car. The harnesses have not one but two lifelines, both of which have to be secured to rails on top of the nacelle.
Outside the nacelle, Rottler is cautious but relaxed, taking pictures of a guest and pointing past the rows of towers to smoke from a wildfire that threatened the facility just days earlier. He may have a lot of concerns, but a fear of heights is not one of them. Speaking with The Seattle Times earlier this year, he said his only phobia is losing to the Huskies in the Apple Cup.
Gallery: Wild Horse Wind and Solar Facility
Images by Robert Hubner of the Wild Horse Wind and Solar Facility in central Washington.