Senior Team Wins Conference Award

SOCORRO, N.M. June 10, 2013 – A New Mexico Tech team of mechanical engineering students won third place for their presentation at a design conference in April.

The “Reduced-Cost Heliostat” team presented their technical paper at the IEEE Green Tech Energy Conference.

Team leader Tim Rushenberg gave the 20-minute presentation. His co-authors included current and former students Nicholas Alvarez, Andrew Smith, David Patterson, Niall Norton-Cormier and Harry Hupman and faculty member Dr. David Grow.

“They won against professionals,” department chair and team advisor Dr. Warren Ostergren said. “This wasn’t a student award. And their feedback was about how well they presented their material among this large group of experienced engineers and scientists.”

Tech students have been working on this project for more than five years and are currently finishing their second prototype. A heliostat is a mirror that focuses sunlight on a central point. Normally, an array - or field of heliostats - track the sun throughout the day, focusing light on a single point atop a tower in the center of the array. The tower collects the solar energy, then powers a turbine to generate electricity or utilizes the heat in other capacities. Globally, heliostats are in their early stages of implementation. One full-scale heliostat array was put into operation in Spain and another test facility in France.

heliostat-team-june-2013-IMG 0356Among the disadvantages of heliostats to date is the cost. Building and installing the central collector and the array of heliostats represents a large cost. The Tech project has focused on reducing the cost of the heliostats by creating an alternative method to have each mirror track the sun.

“The long-term outlook is good,” Rushenberg said. “Cost is the issue.”

CAPTION: The 2012-2013 heliostat team is (from left) Ethan Hays, Nick Alvarez, Tim Rushenberg, Aaron Krueger and James Anderson.

Since its inception, the Tech project has employed a water ballast system to move the mirror and activate braking. The students are currently improving the control system to use off-the-shelf circuit boards, instead of custom-designed units.

Ostergren said, “The water ballast system is part of the invention that New Mexico Tech came up with. If you can control it precisely by moving liquid ballast, you don’t require an expensive gear system. The key question is can it be moved reliably and with extreme accuracy?”

The Tech team has applied for a Department of Energy research grant and is partnering with Sandia National Laboratories, which has been their project sponsor. Sandia has a strong research background in concentrating solar power and has the facilities and expertise to test how accurately a prototype performs.

heliostat-in-californiaAn earlier rendition of the Heliostat Team published their results and Rushenberg said he hopes to publish results of the second prototype testing. The 2013-2014 team will spend the fall semester on completing fabrication and initiating testing.

Rushenberg graduated this year, but Ostergren said he has great confidence in the rising seniors to take over leadership.

CAPTION: An array of heliostats (at right) surrounds a central tower at a trial installation in California.

“Ethan Hayes has dived into the control systems and is working very closely with Dr. Grow, who is advising students in this critical area. Aaron Krueger and James Anderson have performed considerable SolidWorks analytical modeling of the current heliostat which can also be used to help identify future improvements,” Ostergren said. “Nick Alvarez has been a great contributor and will be back for the fall too and we’ll be getting new team members from the junior class.”

– NMT –

By Thomas Guengerich/New Mexico Tech