ARPAE research marks The University of Tulsa's growth as a solar energy leader

ARPA-E research marks TU’s growth as a solar energy leader

For the past four years, The University of Tulsa’s College of Engineering and Natural Sciences has participated in ARPAE research with support from the Advanced Research Projects Agency-Energy. The agency is housed under the U.S. Department of Energy and promotes the development of advanced energy technologies.

Associate Professor of Mechanical Engineering Todd Otanicar initially received funding in 2014 to design a hybrid solar collector that could produce high temperature thermal energy and electricity simultaneously. Otanicar and Parameswar Hari, associate professor of physics, and Kenneth Roberts, associate professor of chemistry and biochemistry, led a team of graduate researchers, undergraduate students and postdoctoral scholars to perform the task with a nanoparticle based fluid to absorb solar energy not utilized by photovoltaic cells.

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Left to right: Professor Otanicar checks on solar collector fabrication conducted by grad student John Dale and research faculty member Matt Orosz.

“The goal was a collector that could produce energy at costs similar to photovoltaic energy but also have easily storable thermal energy,” Otanicar said.

The group partnered with the research and development firm nanoComposix and the solar energy equipment supplier Cogenra.

“We determined the hybrid system using nanoparticles is an effective collector scheme, but current costs of natural gas are extremely hard to compete with for offsetting usage in industry,” Otanicar said.

The project concluded in February 2017 and developed novel technology related to the collector and nanoparticle stability at high temperature. Total funding amounted to $1.9 million. To date, six journal articles have been generated from the research along with an e-book, and one pending patent application. Also, Kirk Smith (BS ’17) participated in the project as an undergraduate researcher and later received a prestigious Rhodes Scholarship to study solar energy at the University of Oxford.

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One of the hybrid solar collectors at North Campus.

Otanicar received a followup award from ARPA-E worth $922,000 in November 2016 to continue working on the hybrid system. The project is different from the first because it focuses on retrofitting existing concentrating solar power (CSP) plants with a beam splitter that sends a portion of light to a photovoltaic cell. The system boosts a plant’s yearly output by 30 percent but at a lower cost than installing photovoltaic power alone. Funding runs until May 2018 and supports three graduate students and one research scientist.

“We want to build a small on-sun demonstration to prove the concept and hopefully take the next step of performing a field demonstration along a row of collectors at an existing CSP facility,” Otanicar said.

He and his colleagues conducted the ARPA-E research with the help of a solar panel setup at TU’s North Campus research facility. The Cogenra design concentrates sunlight 14 times more than normal.

“Now that the award is expired, it will serve as a testbed for other designs and a system that can be used to demonstrate solar thermal power used for other applications,” Otanicar said.

The team currently is building a second collector at North Campus that will track on two axes and concentrate light up to 100 times that of normal. The devices are significant research tools found at few other universities and national laboratories.

The equipment and research funding have elevated TU’s status as a solar energy specialist, and TU is the only university in Oklahoma to lead an ARPA-E award. Otanicar’s efforts provide an avenue for collaboration with other members of the Oklahoma Photovoltaic Institute (established at TU) and allows for rapid evolution of cost and performance.

In addition to Rhodes Scholar Kirk Smith, other alumni to benefit from the ARPA-E projects include Jordan Hoyt (BS ’16), a recipient of the Christine Mirzayan Science and Technology Policy Fellowship in Washington D.C.