For Longmont, renewable energy is a breeze — literally

July 22, 2012 by  
Filed under Green Energy News

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CHEYENNE, Wyo. — The hot Wyoming air lay still. Silent. Unmoving.

Not, perhaps, the best time to be showing off a wind farm.

“The summer months are our low times here,” John Valerius of Duke Energy acknowledged as he showed off the Silver Sage wind farm to a group from Longmont.

“First time I’ve ever been to Wyoming when there’s not a breath of wind,” teased Mayor Dennis Coombs.

But when the wind blows, Longmont notices. In 2011, all of Longmont Power and Communications’ “renewable mix” came from wind farms like Silver Sage. That’s about 3.1 percent of all the energy in the system — small, perhaps, but not insignificant.

“I think it’s really important to Longmont,” said LPC director Tom Roiniotis.

“I think giving people a choice, especially to purchase renewable energy, is a big deal.”

Standing tall

The Silver Sage turbines themselves tower roughly 260 feet over the hilly Wyoming landscape like giant three-bladed pinwheels. Just one of those blades weighs nine tons; at their highest speed, the tip of one can reach 157 mph.

For the newer farms like this one, the placement of the “fans” can seem a little random, scattered here and there across the landscape. Older sites used to line them up neatly, Valerius said, but found the turbine at the front of the line would steal the breeze from all the others. “If you get a wind, the first one in the line is running good and the rest of them don’t have so

much,” he said.

Being the first one in line for a new utility can be challenging, too. It was around 20 years ago that wind first got the attention of the Platte River Power Authority, the power co-op that Longmont belongs to. The PRPA decided to get involved with a project near Arlington, Wyo., division manager John Bleem said — but the developer went bankrupt.

It would be 1998 when the co-op finally started catching the breeze, this time through a site at Medicine Bow, Wyo. Retail customers could buy wind power and know they were getting emission-free electricity, so long as they were willing to pay a little extra. These days, it comes to an extra 2.38 cents per kilowatt-hour if someone wants to go all-renewable. (For an

average Northern Colorado home at 700 kwh per month, that would run to an additional $16.66 a month.)

Why the premium? Again, because the wind doesn’t always blow. Sites like Medicine Bow or Silver Safe work at full power about one third of the time, which doesn’t mean they get built at one-third of the cost. Lately, that cost runs to about $2 million a megawatt.

“Wind’s a good deal — when you can get it,” Roiniotis said.

On the upside, once you’re ready to build a wind turbine, it goes up fast.

“They can actually stick one out in a day,” Valerius said.

The fan with the power

At full tilt, those whipping blades can generate 42 megawatts of power. Take away the calm days, the sub-zero days, and the days when the wind is too fast to be used safely (50 mph or higher) and it still adds up fast. In a typical year, the 30 percent share that belongs to the Platte River Power Authority adds up to 39,000 megawatt hours.

What does that mean in plain English? That’s enough to light up around 4,700 homes. And that’s one site. Add in a second wind farm at Medicine Bow and other producers in Colorado, Kansas and Oklahoma, and the total amount of power is enough to plug in 15,300 Northern Colorado households.

Or take it down to Longmont’s level. In 2011, Silver Sage provided the city with 9,743 megawatt-hours — enough for around 1,160 homes.

“I think more and more people are becoming aware of the environmental impact,” Roiniotis said. “That’s one of the nice things about being a public utility … if people start demanding a new energy source, we’re going to look into getting that for them.”

Just don’t say it’s for the birds. Despite the large moving blades, Silver Sage hasn’t downed many birds or bats, plant administrator Jill Grund said. 2010 was a high year for bat deaths — six of them all together.

“It was during their migration and for a whole week, it was foggy,” Grund said. It wasn’t even the blades that did it, she said — they got caught in the nacelle, the housing for the generator and other machinery, and their lungs couldn’t take it.

“Pennsylvania’s had more of an issue,” she said. “They’ve had to put up sound systems to scare them away.”

Details on LPC’s renewable energy program can be found online at ci.longmont.co.us/lpc/gen/wind_esub_form.htm. Blocks are sold at $2.38 a month for each 100 kwh for homes, $11.90 a month per 500 kwh for businesses, or 2.38 cents per kwh if all the energy bought is renewable.

Scott Rochat can be reached at 303-684-5220 or srochat@times-call.com.

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