In the clouds

Chico State professor discovers vast potential for high-altitude wind energy

WIND MAVEN <br> Cristina Archer is co-author of two global wind surveys. The latest research on jet streams assesses the potential for high-altitude wind power.

Cristina Archer is co-author of two global wind surveys. The latest research on jet streams assesses the potential for high-altitude wind power.

Photo By jasmine roufchaie

On a recent afternoon, Cristina Archer pondered the best location for the desk within her new office in Chico State’s Holt Hall. After analyzing the layout and the angle of the sun through her window, the bubbly professor settled on the back right corner, appearing somewhat unsure about her choice.

Watching her scope out the room, it’s easy to imagine Archer’s ability to collect the data that allowed her to complete not just one, but two first-ever global surveys on wind power.

For years she has studied jet streams, naturally occurring wind currents. She collaborated with Ken Caldeira from the Carnegie Institution for Science’s Department of Global Ecology, and last month the two scientists published a global survey on high-altitude wind power. Their research comprises 28 years of public data from the National Center for Environmental Prediction and the Department of Energy.

Describing jet streams as the driving factor of weather, Archer explained how storms, including hurricanes, attach to parts of these currents. Previously, jet streams were thought to be stationary features, but by analyzing the data she discovered that they actually move—mostly northward.

Sky WindPower Corp. wants to capture energy from the high-altitude wind in the jet streams by using kite-like devices stationed more than six miles in the air, Archer said.

“It’s an incredible amount of energy, and it just makes sense to get some of it down here,” she said. “These people are kite fanatics who have understood that there’s a way of making energy off of the kites.”

High-altitude kites are still under development and likely will not be ready for five to 10 years, but prototypes are available. Archer said the devices would be flown over restricted air space, so that air travel will not be affected.

Archer recently finished her first year teaching in Chico State’s Department of Geological and Environmental Sciences. She earned her doctorate from Stanford University in 2004, while studying the Santa Cruz Eddy, a vortex over Monterey Bay. Her interest in wind was further piqued when one of her professors asked for help with a side project involving wind energy in the United States.

LOOK, UP IN THE AIR <br /> Sky WindPower Corp. is trying to create kite-like devices to capture power from high-altitude jet streams more than six miles in the air.

Image By Ben Shepard

In 2005, Archer and her adviser, Mark Jacobson, a professor in the Civil and Environmental Engineering Department at Stanford, published the first global study pinpointing the exact locations and power of wind energy at 80 meters from the ground. The study led to surprising results with international significance.

While a majority of the 2 terawatts of energy required to power the world is generated by polluting sources such as carbon-emitting coal plants, Archer’s study found that the world’s wind power alone can harness about 72 terawatts of energy. That’s more than 35 times the amount necessary to power the world’s current needs.

“It’s not like the more you use it, the more you run out,” Archer said. “It doesn’t matter how much you use it. It’s still there every day. It’s free energy, continuously guaranteed as long as the Earth is what it is.”

As a part of this survey, Archer created a detailed map showing exactly where the strongest and weakest winds are located. In the United States, the regions with the greatest winds include the Midwest as well as coastal areas. The findings have been used to determine the best areas to construct wind turbines. After the study was published in the Journal of Geophysical Research-Atmosphere, windy regions of Texas and Louisiana were bombarded with calls from developers who wanted to lease the offshore rights to build turbines.

When Archer first made her discovery about the amount of available wind, she started second-guessing herself, double- and triple-checking her calculations due to the enormity of the findings. Last month, Harvard University lent credence to her work by releasing a similar study that employed more observational sources. The results echoed her findings from four years ago, varying by just a few terawatts.

“To me, it was like a confirmation for [us],” she said of the Ivy League university’s research. “They mentioned our study left and right.”

Archer’s research is getting a lot of attention these days because it is still the first objective and scientifically sound assessment of how much wind energy is available on a global scale. It also comes at an opportune time, considering President Obama’s vow to shift the United States to renewable energy.

Last month, in fact, the House of Representatives passed his administration’s energy bill. The legislation is slated to increase America’s total wind-power production to meet about 20 percent of all electrical demands by 2030, according to the New York Times. The American Wind Energy Association estimates that U.S. wind energy currently makes up less than 3 percent of the market.

Despite the enormous potential of this emerging technology, she stressed that she is not an advocate for turning the world solely to wind energy. But one of Archer’s concerns about meeting the world’s energy needs is the idea of switching to nuclear energy, which relies on uranium. Renewable energy, such as wind, is the only sensible, intelligent and sustainable option.

“Do we want to switch to something that will last forever or will just postpone the problem?” she asked.