Energy project gets its day in the sun

A broad consortium led by UD could receive nearly $53 million in funding—with the bulk of the money coming from the Defense Advanced Research Projects Agency (DARPA)—to more than double the efficiency of terrestrial solar cells within the next 50 months.

The University’s Consortium for Very High Efficiency Solar Cells, which consists of 15 universities, corporations and laboratories, could receive up to $33.6 million from DARPA, if all options are awarded, and another $19.3 million from UD and corporate team members. Those corporate members may include DuPont, BP Solar, Corning Inc., LightSpin Technologies and Blue Square Energy.

The consortium is being led by Allen Barnett, principal investigator and research professor in the Department of Electrical and Computer Engineering, and Christiana Honsberg, co-principal investigator and associate professor of electrical and computer engineering.

The award is the largest in the history of solar energy research, according to Rhone Resch, president of the Washington, D.C.-based Solar Energy Industries Association. “I applaud DARPA for recognizing the tremendous potential of solar energy to provide reliable electricity to our troops in the field and to improve our energy security here at home,” Resch says.

“The University of Delaware is very excited by the support provided by DARPA and our corporate partners for this important research,” UD President David P. Roselle says. “We look forward to taking a lead role in this project, which is one we believe will provide for a wholesale advance in the efficiency of solar cells.”

Provost Dan Rich notes that solar energy research has a long history at the University and called the newest project “significant.”

“This project is of vital importance, given the need for alternative sources of energy,” Rich says.

The DARPA program calls upon the consortium to develop and produce 1,000 Very High Efficiency Solar Cell (VHESC) prototypes that are affordable and that operate at efficiencies of at least 50 percent. Currently, high-end solar cells operate at a peak efficiency of 24.7 percent, and solar cells off the production line operate at 15-20 percent efficiency.

The consortium’s goal is to create solar cells that operate at about 54 percent efficiency in the laboratory and 50 percent in production, Barnett says. The VHESC would have immediate application in the high-technology military, which increasingly relies upon a variety of electronics for individual soldiers and the equipment that supports them. It also is expected that the solar cells will have a large number of commercial applications.

“When successfully completed, the Very High Efficiency Solar Cell technology will be a breakthrough in providing portable power to the soldier in the field,” Douglas Kirkpatrick, program manager for DARPA, says.

“Solar-generated electricity is a high value energy source,” Barnett says. “This award provides another critical step as solar electric power moves into the commercial mainstream.”

“The creation of affordable, high-efficiency solar cells is a challenge in that it presents not a single problem but a complex set of interrelated problems,” Honsberg says. “We believe that with the support provided by DARPA, and with the large pool of knowledge and creativity within the consortium, we will be able to achieve that goal.”

To achieve high efficiency in less than five years at low cost, Barnett and Honsberg have proposed using a new, very high performance crystalline silicon solar cell platform and then adding multiple innovations. They had been working on very high efficiency solar cells long before learning of the DARPA program. An important new feature is based on novel approaches to the integration of the optical, interconnect and solar cell design to provide for affordability and also flexibility in the choice of materials and the integration of new technologies as they are developed.

“By integrating the optical design with the solar cell design, we have entered previously unoccupied design space that leads to a new paradigm about how to make solar cells and how to use solar cells, and about what they can do,” Barnett says.

A key part of the project is not just developing high efficiency solar cells but making the transition from the laboratory to production and the marketplace. Barnett says he believes the consortium will be successful because of the participation of corporations already involved in manufacturing in the field and because he and several other team members have experience in bringing high-technology products to market.

Honsberg says the scientific research teams will take an interdisciplinary approach, considering developments in a number of areas, including materials engineering, bio-inspired materials and self-assembly at the nanoscale.

“This project requires the consortium to invent, develop and transfer to production this breakthrough solar cell. One rarely gets an opportunity such as that,” Barnett says. “Engineering is the use of science to develop products for the benefit of mankind, and this is a classic case. Furthermore, it will lead to extraordinary student experiences at all levels.”

In addition to UD and the corporate members, the consortium includes the National Renewable Energy Laboratory; Purdue, Harvard, Yale and Carnegie Mellon universities; the universities of Rochester, California Santa Barbara and New South Wales; and the Georgia and Massachusetts institutes of technology, all subject to successful negotiation of subcontracts.

UD offers one of the nation’s broadest research programs in photovoltaics, and it is developing one of the nation’s most complete courses of study for solar power systems. It is home to the Institute of Energy Conversion, a multidisciplinary laboratory devoted to the research and development of thin film photovoltaic solar cells, and the High Efficiency Solar Cell Program in the Department of Electrical and Computer Engineering.

Barnett earned a doctorate in electrical engineering from Carnegie Mellon University and is a fellow of the Institute of Electrical and Electronic Engineers, which awarded him its William R. Cherry Award for outstanding contributions to the advancement of photovoltaic science and technology. He also won UD’s Karl W. Böer Solar Energy Medal of Merit in 2001 for “pioneering high-performance, thin-crystalline silicon solar cells, founding and leading a world-class enterprise for the commercialization of solar electric products and outstanding continuing service to the solar electric power community.”

Honsberg earned a bachelor’s degree in electrical engineering in 1986, a master’s degree in 1989 and a doctorate in electrical and computer engineering in 1992, all from UD. She was an associate professor in the Centre for Photovoltaic Engineering at the University of New South Wales from 1993-2000 and an associate professor of electrical and computer engineering at Georgia Institute of Technology before joining the UD faculty in 2004.

—Neil Thomas, AS ’76