Soaring over solar?

In Arizona, power generated by the sun is the darling of many renewable-energy advocates, solar-power based companies and the governor. There is, however, another less cost-intensive player trying to gain a foothold in the renewable power game: wind.

Wind power technology is cheaper than solar in many cases, yet some serious limitations have kept wind from becoming a major contributor to Arizona’s power grid. To be efficient, wind turbines must be placed near existing transmission lines and in a reliably windy location — and in Arizona, the wind is less dependable than the sun.

“Utilities in Arizona are looking at renewable energy resources available in the state, and wind power is certainly one of them,” says Joe Salkowski, spokesman for Tucson Electric Power. “But it pales behind solar energy.”

Gusting wind and free-rotating turbines have been producing power, of sorts, for more than 1,000 years, and the basic mechanics of wind power haven’t changed since windmills were first used in the 9th century to grind grain. The historical strengths of wind power remain today as the turbines require no fuel and emit no pollutants, and new technology has made electricity generation more efficient.

Corporation Commissioner Paul Newman says wind power has been used throughout modern history, and is now ripe for easing society’s reliance on other fuels.

“Wind has come of age in the U.S.,” he says. “Last year, Iowa got 14 percent of its electricity from wind, and in the past 20 years, the cost of wind power is down 80 percent.”

While the cost of developing wind technology measures up well when compared against renewable technology such as solar, it loses ground when stacked up against traditional power sources.

“Wind power is more expensive than coal fired technology and natural gas, but it’s generally cheaper than solar technology,” Salkowski says.

Now, Arizona’s largest utility companies are moving to purchase and produce more wind power as part of a larger effort to comply with a state requirement to generate at least 15 percent of Arizona’s energy through renewable sources by 2025.

Tucson Electric Power’s parent company, UniSource Energy Corporation, announced plans late last year to buy power from a facility near Kingman that produces power through a combination of solar panels and wind turbines.

“We’ll be tapping two of Mohave County’s most abundant resources — the sun and the wind — to help us provide clean, renewable power to our customers,” Paul Bonavia, chairman and CEO of UniSource Energy Services, said when the project was announced.

Tucson Electric Power also has announced plans to purchase energy from a wind farm in New Mexico, where wind-generated electricity is considered to be fairly reliable. And it’s near existing power lines, which lowers the cost of connecting power-generating technology with the electricity grid.

In eastern Arizona, Salt River Project (SRP) is banking energy through a large wind power generator near Snowflake. The Dry Lake Wind Power Project, which began operations last year in Navajo County, generates about 63 megawatts of power, enough to fuel about 10,000 Arizona homes, through the use of 30 wind turbines built by Iberdrola Renewables, a Spanish firm with American offices based in Portland, Ore.

The Navajo County Board of Supervisors on June 8 approved construction of the second phase of the Dry Lake operation, which will double the number of turbines at a price of $110 million. SRP has committed to buying energy from the expansion project, which is expected to begin producing power by spring 2011.

“We wanted to do something to jumpstart the wind technology industry here,” says John Coggins, manager of resource planning and development with SRP. “There are some key benefits.”

Proximity to existing power transmission lines, Coggins says, is vital in the economic feasibility of a wind farm, as running additional lines can cost more than $1 million per mile.

“That’s something that made the Dry Lake Project unique, that we could tie into existing transmission lines,” Coggins says. “That, combined with the low cost of the resource generally, makes sense when compared with other renewable options.”

Approximately 20,000 homes will be served by the combined resources of when phases one and two of the Dry Lake Wind Project are producing power simultaneously, says SRP spokesman Scott Harelson.

Despite the upsides, huge wind turbines are not without environmental concerns. Besides marring the view of the landscape, the turbines can create dangers for local wildlife.

Sandy Bahr, director of the Sierra Club’s Grand Canyon Chapter, says the organization is generally supportive of wind power in Arizona, and has provided input on about half a dozen projects so far. “We have not come out against any projects to date, but we have asked for adjustments on some,” Bahr says. “We generally try to provide comments encouraging them to minimize environmental impacts.”

Bahr says a variety of animals, such as birds, bats and tortoises are potentially at risk when a wind farm emerges. Some solutions to mitigate wind farms’ impact on native species include altering the way fan blades rotate to save birds and digging escape trenches on excavated land for burrowing animals.

“Siting away from major flyways is important,” she says. “Fortunately, a lot of companies do a fair amount of research up front, but there is the potential for great conflict.”

She also adds that wind projects can be a mystery as they develop because they do not undergo the same type of scrutiny as other natural resource developments, including solar plants.

“In Arizona, it is not the same process as for solar thermal plants, which go through power plant and line-siting committees,” Bahr says. “Because of that, people often don’t find out about these projects until they are fairly far along.”

As Arizona companies look to the future of providing reliable power to a growing state, cost, proximity to existing transmission lines and a desire to reduce reliance on fossil fuels all dictate the growth rate of the wind-power industry.

Arizona Public Service (APS), which generates 190 megawatts of power through contracts with New Mexico wind farms, is examining potential sites for wind farms in northern Arizona. But prime locations are limited, and the logistical challenges are daunting, according to Eran Mahrer, director of renewable energy with APS.

“In technical terms, it is challenging,” says Mahrer. “The single largest constraint on the wind market is that it’s not necessarily windy where the transmission lines are.”

Kristin Mayes, chairman of the Arizona Corporation Commission, says companies like SRP and APS understand the risks of continued reliance on energy from fossil fuels. Overcoming the difficulties of transitioning to renewable energy will pay off in the long run, she says.

“The reason that these utilities are so interested in these sorts of projects is that they see what’s coming on the horizon,” she says. “We know the price of fossil fuels is going up. But the price of wind is level over time. And the fuel itself is free. I’ll take free over the cost of coal any day.”