NORTH OF WILLIAMS – Dozens of wind turbines, their blades swooping rhythmically through the air, punctuate thousands of acres of rolling ranchland north of Williams. For three years, the spinning blades at Perrin Ranch Wind Energy Center have caught northern Arizona’s wind, turning it into power that gets shot across massive power lines onto the region’s electric grid.
Across much of the West and middle America, turbines like these are sprouting up in massive numbers. In a March report, the U.S. Energy Information Administration estimated that wind will account for 9.8 gigawatts of the more than 20 gigawatts of utility-scale generating capacity expected to be added to the power grid this year. That’s more than natural gas and solar combined.
In Arizona, however, the growth of wind power generation isn’t following the same trajectory. A wind and solar status report released this spring by Northern Arizona University anticipated zero new wind power coming online in the state this year.
“While there are thousands of megawatts of wind projects that have been pursued to some degree by developers…wind development is relatively quiet in the state in 2015,” the report said.
Against that backdrop however, wind power generation is going strong at the Perrin Ranch operation. The wind farm, operated by Florida-based NextEra Energy Resources, is generating electricity at an average of 30 percent of its 100-megawatt capacity, which is on par with the generating capacity of similar systems in Arizona, Steve Stengel, spokesman with NextEra Energy Resources, wrote in an email.
The project represents a case study of the opportunities and challenges facing Arizona’s wind industry that are outlined in the NAU report.
One is the checkerboard of state, federal, tribal and private land in Arizona that makes permitting difficult, the NAU report said.
The $2 million Perrin Ranch project is located on a combined 30,000 acres of private ranchland and state trust land. Locating on those lands required obtaining easements for turbines, roads and collection cables as well as coordination with ranchers on access and cattle enclosures, for example.
In another sense however, the fact that ranching still occurs on the Perrin Ranch property represents an advantage of wind, said Karin Wadsack, a project director in clean energy research and education at NAU who contributed to the university report. On open lands or those used for agriculture, wind power can be more appealing because the disturbance is much less than a solar array or a power plant and the original use can continue, she said.
The NAU report also attributed stagnant wind development in the state to the fact that utilities have satisfied the current benchmarks in the state’s renewable energy standard. Those requirements play a big role in how renewable energy companies like NextEra decide on future projects, Stengel said. Arizona’s renewable standard of 15 percent by 2025 pales in comparison to New Mexico’s 20 percent by 2020 standard, Colorado’s 30 percent by 2020 standard and California’s 33 percent by 2020 standard.
Less consistent wind resources have also meant slow wind development in the state, according to the NAU report. Spottier wind conditions mean that a wind turbine built here ends up costing more per kilowatt hour than a place like Wyoming, where the wind is more constant, Wadsack said. That matters because the cost of building utility-scale photovoltaic plants has dropped enough to make them competitive with utility-scale wind farms in Arizona, Stengel said. So solar is not only a stronger resource here, but it also now costs about the same to install.
Benefits of the breeze
At the same time, though, the outlook for wind in Arizona is “hopeful and could be strong,” Wadsack said. Part of that is due to dramatic improvements in wind forecasting that allows utilities to better predict wind generation capacity hours or even days into the future and adjust other power sources accordingly. Thanks to high resolution forecasting, utilities can now calculate how much power will be generated in a certain area down to a 1.8-kilometer area, said Marc Romito, manager of renewable energy at APS.
Another promising sign for large scale renewable projects like wind is the space expected to open up on transmission lines as coal-fired power plants in the Four Corners region reduce generating capacity, Wadsack said. For its part, Perrin Ranch used that strategy, securing space on one of two 500 kilovolt transmission lines installed to connect Navajo Generating Station to population bases farther south.
Another advantage of larger systems like Perrin Ranch is that they are easier for utilities to manage because the developers make the arrangements to secure transmission line capacity, Romito said. Rooftop solar, which is growing at a much faster pace in the state, presents more of a management challenge because it is more random, clustered and harder to predict how those electrons will flow onto the grid, he said.
Distributed solar will likely continue to be the biggest source influx on APS’s grid, though, Romito said. Just between 2013 and 2014, solar power jumped from 4 percent to 9 percent of the utility’s total generation portfolio.
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