October 17, 2012
What began in the fall of 2011 as a class project has grown into something much bigger than expected. A group of Arizona State University students launched an experiment that could have far-reaching impacts on renewable energy and a reduction on the reliance of fossil fuels.
The group of seniors, led by Patrick McGarey and Amy Kaczmarowski, planned, designed, and recently launched a wind velocity experiment called the High Altitude Turbine Survey (HATS).
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McGarey, the project lead, graduated from ASU this spring with a degree in Earth & Space Exploration (Systems Design) and decided to stay on to see the project through. McGarey has been with the project since its inception last fall, when he and his team first crafted the project proposal in Professor Srikanth Saripalli’s School of Earth and Space Exploration (SESE) senior design class (SES 410/411).
With an initial plan in mind, the team began working through different ideas. Many different concepts were expressed and “… a lot of wacky ideas,” McGarey quipped.
HATS is studying high altitude wind energy generation by measuring changing performance characteristics of two micro-turbine airfoils (propellers) aboard a NASA high altitude balloon. The balloon is similar to the one carrying Felix Baumgartner, the Red Bull Stratos iconic skydiver, to the edge of space. The study is looking at the feasibility of generating wind energy at high altitudes using specialized turbine airfoils, which would ideally be mounted on a tethered aerostat (stationary airborne platform).
The students’ project looks at wind power generated from turbine airfoils (propellers) at high altitudes. Seven miles into the air, the wind in the jet stream has been measured at more than 100 miles per hour. Harnessing this wind would provide a much more reliable source of wind energy than ground-based or off-shore wind farms currently offer.
Traditional ground-based wind energy has been less reliable due to high variability in wind and weather conditions on the surface. HATS may begin to open the door, making high altitude wind a more reliable renewable energy source.
The students aimed to create an apparatus for testing high altitude micro-turbine airfoils (propellers), to learn how propeller performance characteristics such as thrust and strain varied as the balloon went from sea level to over 24 miles in altitude. Additionally, the students installed sensors to measure varying atmospheric / environmental conditions throughout the flight.
According to McGarey, the system has, “ …sensors including optical encoders, strain gauges, thermocouples, pressure gauges, and a digital weather station, [that]will provide environmental data throughout ascent and descent in order to create a velocity and thrust generation profile corresponding to altitude, pressure, and wind speed.”
The basis for the project began when Kaczmarowski, systems engineering lead, came across an article regarding high altitude energy systems, which inspired her to form the initial concept for the balloon-borne payload that would become HATS. The article illustrated the potential for high altitude wind power to realistically serve as a source for clean energy in the near future.
Beginning in spring of 2012 the team of students, with their faculty lead, professor Srikanth Saripalli, began to design and decide what was practical. They looked at what would work, using off-the-shelf items to develop the project. The team was grateful to receive funding from Saripalli’s ASTRIL field robotics laboratory and ASU/NASA Space Grant.
Later in May, testing began. Shay Cheeseman, another team member majoring in Earth & Space Exploration, programmed the software for the apparatus and refined the machine. The team worked within NASA guidelines and made sure everything met the requirements set forth from the High Altitude Student Platform (HASP), a program offered by Louisiana State University (LSU), NASA Balloon Program Office (BPO), and the Columbia Scientific Balloon Facility (CSBF) that allows 12 student teams from around the country to fly scientific payloads into the upper reaches of the atmosphere.
Over the summer, McGarey traveled to CSBF in Palestine, Texas, and spent a week preparing the payload and getting ready to launch with fellow SESE student Alex Kafka. On September 1, from a different CSBF location in Fort Summer, New Mexico, McGarey attended the HASP balloon launch with the HATS payload attached.
The balloon, filled with over 11 million cubic feet of helium, was monitored as the half ton HASP payload traveled above 25,000 feet in altitude. The payload stayed airborne for over nine hours, traveling more than 500 miles across New Mexico and Arizona, even flying over ASU, before landing just west of Phoenix.
While the collected data will not be fully analyzed until later this year, McGarey and his team are calling the HATS mission a success.
“Anytime you create something that’s never been created before, you’re lucky enough to get functionality out of it,” McGarey explained.
That is precisely what happened. The payload did everything that it was designed to do, and there were no mechanical failures.
McGarey knows this is a field that very few have explored, with the exception of several exciting startup companies, who are currently developing working prototypes to harness airborne wind energy. Geothermal and solar energy are very popular, but harnessing high altitude wind is a field that has yet to be fully tapped.
Written by Heath Harris