Oct 21 - McClatchy-Tribune Regional News - Duane Schrag The Salina Journal, Kan.

The cheapest way for Westar Electric to add new generating capacity is with wind, a corporate executive on Monday told members of the Salina Noon Rotary.

"Wind does have a place in anybody's portfolio," said Greg Greenwood. "If customers' demand for electricity continues to grow, we're going to need new resources."

During the debates earlier this year over the proposal for two new coal-fired power plants in Holcomb, the claim was frequently made that Kansas needs new, inexpensive coal-generated power.

In fact, Kansas has an electricity surplus: in 2007, Kansas power plants generated 20 percent more electricity than the state's residents used; the surplus was used by retail customers outside the state.

Greenwood said Monday that Westar's cost to produce electricity -- most of its generation is from coal, with a sizable chunk coming from the Wolf Creek nuclear power plant -- is about 3.5 cents a kilowatt hour. The cost a kilowatt hour of power from a new coal-fired power plant would be more than 5 cents.

Westar has a 20-year contract to buy wind energy for 4.1 cents a kilowatt hour.

Greenwood reminded the audience that wind does have other issues.

"Wind energy is only available when the wind blows," he said.

However, experience has shown that the cost associated with that variability is quite low. Xcel Energy, which is based in Minnesota but has customers in eight Midwest states, is the country's largest retailer of wind energy. It estimates that the cost of using wind to supply 25 percent of a utility's energy adds about 0.5 cents a kilowatt hour.

In Kansas last year, 73 percent of the electricity came from coal-fired plants, and another 21 percent came from Wolf Creek. Wind farms generated only 2.3 percent of the state's power.

200 mph turbine blades

Greenwood said that Westar will get its wind energy from three farms. The Meridian Way farm near Concordia is expected to start delivering its first electricity this week. The other two sites are Central Plains Wind Farm in Scott County and Flat Ridge Wind Farm near Medicine Lodge. Those farms are expected to start generating before the end of the year.

The wind turbines are immense. The turbine diameter -- from blade tip to blade tip -- is about 300 feet, the length of a football field. And although the blades seem to be turning lazily -- about three seconds a rotation -- the tips are traveling at 200 mph.

They're sophisticated, too. Computers change the pitch of the blades, not merely for prevailing winds but for the changing wind each blade encounters during each revolution (typically, the wind is stronger at the top).

Most turbines have a massive gearbox that transfers the blades' kinetic energy to a generator. If the gearbox fails, the turbine is out of service until a (very expensive) crane can be brought onto the site and the gearbox replaced.

But Greenwood said some turbines are built with four gearboxes. If one fails it merely reduces the turbine's output. Even more importantly, it has a built-in winch that allows the transmission to be replaced without a crane, he said.

Reporter Duane Schrag can be reached at 822-1422 or by e-mail at dschrag@salina.com.

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